TWI593695B - Organic electroluminescent device and method of manufacturing the same - Google Patents

Description

Organic electroluminescent device and method of manufacturing same

The present invention relates to an organic electroluminescent device and a method of fabricating the same. More specifically, the present invention relates to an organic electroluminescence device that can be used as a display device such as a display portion of an electronic device, an illumination device, and the like, and a method of manufacturing the same.

As a novel light-emitting element that can be applied to a display device or illumination, an organic electroluminescence element (organic EL element) is expected in the industry.

The organic electroluminescent device is characterized in that it has a thinner, softer, and flexible feature, and when used as a display device, has a liquid crystal display device or a plasma display device that is currently in the mainstream. It is possible to realize high-brightness and high-definition display, and has a superior viewing angle as compared with a liquid crystal display device. Therefore, it is expected to be expanded as a display of a television or a mobile phone or the like as an illumination device.

The organic EL device has a structure in which one or a plurality of layers including a light-emitting layer containing a light-emitting organic compound are sandwiched between an anode and a cathode, and is recombined with electrons injected from the cathode by a hole injected from the anode. The energy of time to excite the luminescent organic compound to obtain luminescence. The organic EL element is a current-driven element, and in order to utilize the current flowing more efficiently, the industry is making various improvements in the structure of the element, and various materials for the layers constituting the element are also being studied.

The organic electroluminescence element has a structure in which a plurality of layers such as an electron transport layer, a light-emitting layer, and a hole transport layer are laminated between a cathode and an anode, and thus the industry is suitable for forming each layer. Materials are researched and developed. For example, a luminescent material containing a compound having a specific structure containing a boron atom is disclosed (refer to Patent Document 1). Further, a compound having a specific structure containing a boron atom is suitably used as a hole blocking layer of an organic electroluminescent device (see Patent Document 2).

Moreover, for the re-junction of electrons injected from the anode and the electrons injected from the cathode In the case of an organic electroluminescence device that emits a light-emitting organic compound and emits light, it is important that the hole injection from the anode and the electron injection from the cathode are smoothly performed, so that a smoother hole is required. Injection, electron injection, and various materials for the hole injection layer and the electron injection layer have been studied. Recently, a compound modified with polyethyleneimine or polyethyleneimine has been reported as a coatable electron. An organic electroluminescence device having a smooth structure of a material of the injection layer (see Non-Patent Documents 1 to 3).

And said that the layer between the cathode and the anode is formed entirely of organic compounds. Electromechanical excitation of optical elements is likely to be degraded by oxygen or water, and in order to prevent such intrusion, strict sealing is indispensable. The above-described situation is a cause of complicating the manufacturing steps of the organic electroluminescent device. In this regard, an organic-inorganic hybrid electroluminescent device (HOILED device) in which a partial layer between a cathode and an anode is formed of an inorganic oxide has been proposed (see Patent Document 3). In this device, by changing the hole transport layer and the electron transport layer to an inorganic oxide, FTO or ITO as a conductive oxide electrode can be used as a cathode, and gold can be used as an anode. From the point of view of component driving, the above situation means that the restriction on the electrode is eliminated. As a result, it becomes unnecessary to use a metal having a small work function such as an alkali metal or an alkali metal compound, and it is possible to emit light without a strict seal. Further, the HOILED element is characterized in that the cathode is located directly above the substrate and has a reverse structure in which the upper electrode is an anode. With the development of oxide TFTs, in the course of research on the application of large-scale organic EL displays, the reverse-structured organic EL has been attracting attention due to its characteristics as an n-type oxide TFT. The HOILED element is expected to be developed as a candidate for an inverse structure organic EL element.

As a prior organic-inorganic hybrid type organic electroluminescent device, it is disclosed that An anode and a cathode, an organic compound layer of one or more layers sandwiched between the anode and the cathode, and at least one or more between the anode and the organic compound layer and between the cathode and the organic compound layer An organic thin film light-emitting device of a metal oxide thin film (see Patent Document 4). Further, an organic compound layer having one or a plurality of layers sandwiched between an anode, a cathode, an anode, and a cathode, and at least one metal or more between the anode and the organic compound layer or between the cathode and the organic compound layer are disclosed. An organic thin film electroluminescent device having an oxide film and a self-assembled monomolecular film in which the main carrier is an energy barrier between the respective layers, and the opposite carrier does not become an energy barrier (see Patent Document 5). Furthermore, an organic-inorganic hybrid organic electroluminescent device having a structure in which a ruthenium compound is added as a dopant to a metal oxide layer in a polyvinyl carbazole polymer is disclosed (see Non-Patent Document 4). Or an organic-inorganic hybrid organic electroluminescent device in which a ruthenium compound is added to a poly(9,9-dioctylfluorenyl-2,7-diyl group) as a light-emitting layer (see Non-Patent Document 5).

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-184430

Patent Document 2: International Publication No. 2005/062676

Patent Document 3: Japanese Patent Laid-Open Publication No. 2009-70954

Patent Document 4: Japanese Laid-Open Patent Publication No. 2007-53286

Patent Document 5: Japanese Laid-Open Patent Publication No. 2012-4492

Non-Patent Document 1: Tao Xiong and three others, "Applied Physics Letters", Volume 93, 2008, pp123310-1

Non-Patent Document 2: Yinhua Zhou and 21 others, "Science" No. 336, 2012, pp327

Non-Patent Document 3: Jianshan Chen and 6 others, Journal of Materials Chemistry, 2012, volume 22, pp5164

Non-Patent Document 4: Henk J. Bolink and three others, "Advanced Materials", 2010, Vol. 22, p2198-2201

Non-Patent Document 5: Henk J. Bolink and 2 others, "Chemistry of Materials", 2009, Vol. 21, p439-441

As described above, all the layers constituting the organic electroluminescent device are composed of organic substances. The organic electroluminescence device and the organic-inorganic hybrid organic electroluminescence device are constructed and developed.

It is considered that the organic-inorganic hybrid organic electroluminescent device can have both the flexibility and the formability of the organic component, the strength and durability of the inorganic component, and the organic electroluminescence of each layer composed only of the organic compound. Since the resistance to oxygen or water is higher than that of the element, the necessity of tightly sealing the layers inside the element is reduced, and the number of steps in the production is also small, and it is expected to be put into practical use. On the other hand, the organic-inorganic hybrid organic electroluminescent device has a room for improvement in various characteristics such as light-emitting characteristics as compared with an organic electroluminescent device in which all layers constituting the organic electroluminescent device are made of an organic material. An organic-inorganic hybrid organic electroluminescent device having improved characteristics such as luminescent characteristics has been developed.

In general, an organic electroluminescence device in which all of the layers constituting the organic electroluminescence device are made of an organic material is known as a method of laminating a plurality of kinds of low molecular compound layers by vacuum deposition or the like, or doping in a host molecule. A method of a guest molecule or the like to obtain an element having a high luminescent property. On the other hand, the mainstream of the organic-inorganic hybrid organic electroluminescent device which has been studied in the past has been coated with a film-forming polymer compound as a light-emitting layer. In order to improve the light-emitting characteristics of the organic-inorganic hybrid organic electroluminescent device, the present inventors have used a low-molecular compound as a material for forming a light-emitting layer or a hole transport layer, and deposited a plurality of layers by vacuum evaporation or the like. The morphology of a low molecular compound layer or the morphology of a guest molecule in a host molecule Various studies are conducted. Thus, it has been found that when the oxide layer formed on the cathode is brought into contact with the low molecular compound layer, there is a new problem that the low molecular compound layer which is in contact with the oxide layer is crystallized. As a result, the leakage current increases and the current efficiency decreases, and in the case of a significant decrease, uniform surface luminescence cannot be obtained due to crystallization. Although the above-mentioned case is not observed, it is considered that the element having the coated polymer organic layer has an adverse effect, and it is considered that solving this problem is important for extending the life of the organic-inorganic hybrid organic electroluminescent device.

Further, in the organic-inorganic hybrid organic electroluminescent device, there is a problem in that electrons injected from the cathode are smaller than holes injected from the anode, and the holes injected from the anode cannot be sufficiently effectively utilized for light emission. In addition, the long-term good physical electrical contact between the original inorganic layer and the organic layer is difficult, which leads to a short life of the device and is a major problem.

In the case of an organic electroluminescence device that is expected to be expanded to a display device or a illuminating device, it is also an important factor for easy production. Therefore, there is a high expectation for an organic-inorganic hybrid organic electroluminescent device that does not require strict sealing. A method for further improving the luminous efficiency and life of an organic-inorganic hybrid organic electroluminescent device. In addition, in display applications, HOILED elements with inverse construction are useful on circuits and are expected to evolve.

The present invention has been made in view of the above circumstances, and its object is to: (1) provide one When a low molecular compound layer is used as a layer constituting the organic electroluminescent device, the crystallization of the low molecular compound is also suppressed, and the organic-inorganic hybrid organic electroluminescent device having excellent luminescent properties; (2) providing a luminescent property An organic-inorganic hybrid organic electroluminescent device that is superior to the prior organic-inorganic hybrid organic electroluminescent device; and (3) provides an organic electroluminescent device that is easy to manufacture and has excellent luminous efficiency and lifetime.

The inventors have found that by having metal oxygen between the first electrode and the second electrode The organic-inorganic hybrid organic electroluminescent device of the chemical layer has a buffer layer formed of an organic compound on the metal oxide layer, and the above problem can be solved. The buffer layer referred to herein is a junction of an organic layer such as a light-emitting layer that solves the above-described problem of the organic-inorganic hybrid organic electroluminescent device. A layer of crystallization, lower electron injecting ability, and physical chemical long-term stability of the interface. Specifically, in order to prevent crystallization caused by irregularities or the like existing on the surface of the oxide, an organic substance having a higher molecular weight is preferable, and in order to improve the electron injecting ability, it is preferable to form the energy level up to the light-emitting layer. In order to smoothly perform the pumping of energy (gradually increasing the energy level (uphill)), which is a problem unique to the reverse structure, it is preferable to do it by doping or the like. Method to increase the number of carriers. In order to improve the electron injecting ability, there is also a method of generating an interface dipole by disposing a large amount of nitrogen elements on the surface, which is also preferable. Further, in order to stably exist such long-term, it is preferable to prepare a chemical bond which prevents the existence of a local electric field or can withstand the existence of a local electric field. The former is formed by a wide range of energy level changes caused by an increase in the number of carriers by doping or the like, and a good energy balance with a stepped shape. The latter is a chemical bond between the organic layer of the buffer layer and the metal element on the surface of the oxide. Specific examples are described below.

The present inventors have studied a solution to a new problem of crystallization of a low molecular compound layer which has been found in various processes for improving the luminescent properties of an organic-inorganic hybrid organic electroluminescent device, and as a result, found that A buffer layer having a specific film thickness formed by coating an organic compound is disposed between the oxide layer formed on the cathode and the low molecular compound layer such as the light-emitting layer, and a low molecular layer such as a light-emitting layer is laminated on the buffer layer. In the case of the compound layer, the crystallization of the low molecular compound in the low molecular compound layer is suppressed, and when the organic-inorganic hybrid organic electroluminescent device has a layer formed of a low molecular compound as a light-emitting layer or the like, Suppression of leakage current and uniform surface illumination are obtained.

Further, the inventors have found that when a boron-containing compound having a specific structure or a boron-containing polymer is used as the organic compound forming the buffer layer, the buffer layer formed of the organic compound also exhibits an excellent function as an electron transport layer.

Further, the present inventors conducted various studies on a method for improving the light-emitting characteristics of an organic-inorganic hybrid organic electroluminescent device, and as a result, it has been found that the first electrode and the second electrode are formed between the first electrode and the second electrode. a metal oxide layer having an organic electroluminescence element having a buffer layer formed of an organic compound on the metal oxide layer, and a reducing agent contained in a buffer layer of the organic electroluminescence element; The electron n-type dopant functions as an organic electroluminescence device having excellent light-emitting characteristics as compared with the conventional organic-inorganic hybrid organic electroluminescence device. Further, it has been found that the first metal oxide layer, the buffer layer, and the low molecular compound layer including the light emitting layer laminated on the buffer layer are preferably formed between the first electrode and the second electrode. An organic electroluminescence device having a structure in which a metal oxide layer is composed of a metal oxide layer and a buffer layer of the organic electroluminescence device contains a reducing agent.

Further, the present inventors conducted various studies on a method of further improving the luminous efficiency and lifetime of an organic-inorganic hybrid type organic electroluminescent device which does not require strict sealing, and as a result, found that it is present on the metal oxide layer between the anode and the cathode. When a nitrogen-containing film having a specific thickness is formed, electron injection characteristics are improved and the life of the device is prolonged. Among them, it has been found that a nitrogen-containing film formed by a method of forming a nitrogen-containing film having a high ratio of nitrogen atoms in atoms constituting the nitrogen-containing film or a method of decomposing a nitrogen-containing compound is further found. Further, it is preferably one which is formed by decomposition of a nitrogen-containing compound and which has a higher ratio of nitrogen atoms in atoms constituting the nitrogen-containing film. The present inventors have found that when such a nitrogen-containing film is used as a layer constituting an organic-inorganic hybrid organic electroluminescent device, it is an organic electroluminescence device which is excellent not only in luminous efficiency but also has high driving stability and long driving life. The present invention has been completed in view of solving the above problems perfectly.

That is, the present invention is an organic electroluminescent device having a laminate In the layer structure, the organic electroluminescent device has a metal oxide layer between the first electrode and the second electrode, and has a buffer layer made of an organic compound on the metal oxide layer.

Further, the organic electroluminescence device is a first preferred embodiment of the organic electroluminescence device of the present invention, and the organic electroluminescence device has a structure in which a plurality of layers are laminated, and the organic electroluminescence device is characterized in that the organic electroluminescence device First metal oxidation between the first electrode and the second electrode a material layer, a buffer layer, a low molecular compound layer comprising a light emitting layer laminated on the buffer layer, and a second metal oxide layer, wherein the buffer layer is formed by applying a solution containing an organic compound to have an average thickness of 5 ~50nm layer.

Further, the organic electroluminescence device is a second preferred embodiment of the organic electroluminescence device of the present invention, and the organic electroluminescence device has a structure in which a plurality of layers are laminated, and the organic electroluminescence device is characterized in that the organic electroluminescence device is The first metal oxide layer, the buffer layer, the low molecular compound layer including the light emitting layer and the second metal oxide layer laminated on the buffer layer, and the buffer layer are sequentially provided between the first electrode and the second electrode. Contains a reducing agent.

Further, the organic electroluminescence device is a third preferred embodiment of the organic electroluminescence device of the present invention, and the organic electroluminescence device has a structure in which a plurality of layers are laminated between an anode and a cathode formed on a substrate. The organic electroluminescent device has a metal oxide layer between the anode and the cathode, and has a layer composed of a nitrogen-containing film and having an average thickness of 3 to 150 nm on the metal oxide layer.

The invention is described in detail below.

Further, a combination of two or more preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

The organic electroluminescent device of the present invention has a structure in which a plurality of layers are laminated. The organic electroluminescent device has a metal oxide layer between the first electrode and the second electrode, and has a buffer layer formed of an organic compound on the metal oxide layer.

The first electrode is a cathode formed on a substrate, and has a metal oxide layer and a buffer layer formed of an organic compound in sequence with the anode as the second electrode, which is the organic electroluminescent device of the present invention. Good form.

Further, the buffer layer is a layer having an average thickness of 3 nm or more formed by applying a solution containing an organic compound, and the buffer layer is formed adjacent to the metal oxide layer, which is also preferable for the organic electroluminescent device of the present invention. form.

The organic electroluminescent device of the present invention has three preferred embodiments in which the layer structure or the buffer layer of the device is different. Hereinafter, the three preferred embodiments will be described in order. Further, two or more forms conforming to the three preferred embodiments are also preferred embodiments of the organic electroluminescent device of the present invention.

[Organic Electroluminescent Device of the First Preferred Embodiment of the Present Invention]

The organic electroluminescent device of the first preferred embodiment of the present invention (hereinafter also referred to as the first organic electroluminescent device of the present invention) has a first metal oxide layer between the first electrode and the second electrode. The buffer layer, the low molecular compound layer including the light emitting layer and the second metal oxide layer laminated on the buffer layer, and the buffer layer has an average thickness of 3 nm. Further, the average thickness of the buffer layer is preferably 5 to 50 nm. Further, it is preferable that the buffer layer has an electron energy level in which the order of the electron levels from the electrodes formed on the substrate to the layers of the light-emitting layer is the order of the layers of the layers.

When the first organic electroluminescent device of the present invention has such a configuration, when the layer constituting the organic electroluminescent device such as the light-emitting layer is a low molecular compound layer, the crystallization of the low molecular compound layer can be suppressed. It can suppress leakage current and obtain uniform surface illumination.

The reason why the low molecular compound layer is crystallized in the organic-inorganic hybrid organic electroluminescent device can be considered as follows.

In the organic-inorganic hybrid organic electroluminescence device, the first electrode and the first metal oxide layer are disposed on a substrate such as glass, and a low molecular compound layer containing the light-emitting layer is formed thereon. Here, according to the conventional method, the first metal oxide layer is formed by a method such as a spray pyrolysis method, a sol-gel method, or a sputtering method, and the surface is not smooth and has irregularities. When a low molecular compound layer containing a light-emitting layer is formed on the first metal oxide layer by a method such as vacuum deposition, the unevenness on the surface of the first metal oxide layer serves as a crystal nucleus and promotes contact with the first metal. Crystallization of the low molecular compound layer of the oxide layer. Therefore, even if the organic electroluminescence element is completed, a large leakage current flows, and the light-emitting surface becomes uneven, and a component that can withstand practical use cannot be obtained.

On the other hand, in the organic electroluminescence device of the so-called normal structure in which the first metal oxide layer is not provided on the first electrode, the surface of the first electrode can be obtained to be sufficiently smooth, even on the surface of the first electrode. The formation of a low molecular compound layer containing a light-emitting layer also causes a problem of crystallization. Therefore, the first organic electroluminescence device of the present invention has the above-described configuration, and the organic-inorganic hybrid organic battery can be solved by the above-described organic-inorganic hybrid organic electroluminescent device. A problem specific to the excitation light element.

The first organic electroluminescent device of the present invention is the above-mentioned preferred constructor In the case of a shape, a first metal oxide layer is sequentially provided between the first electrode and the second electrode, a buffer layer having an average thickness of 5 to 50 nm formed of an organic compound, and a light-emitting layer laminated on the buffer layer. The low molecular compound layer and the second metal oxide layer may have other layers than those described above.

Further, in the present invention, the term "low molecular compound" means a compound which is not a polymer compound (polymer), and does not necessarily mean a compound having a relatively low molecular weight.

The above-mentioned "low molecular compound layer containing a light-emitting layer" means low molecular combination One layer formed of the substance or a plurality of layers formed of a low molecular compound and one of which is a layer of the light-emitting layer. In other words, the low molecular compound layer including the light-emitting layer means any one of a light-emitting layer formed of a low molecular compound or a light-emitting layer formed of a low molecular compound and another laminated layer formed of a low molecular compound. . The other layer formed of the low molecular compound may be one layer or two or more layers. Further, the order of lamination of the light-emitting layer and the other layers is not particularly limited.

The other layer formed of the low molecular compound is preferably a hole transport layer or electricity. Sub transport layer. That is, in the case where the low molecular compound layer is composed of a plurality of layers, it is preferred to have a hole transport layer and/or an electron transport layer as a layer other than the light emitting layer. As described above, the organic electroluminescence device has a hole transport layer and/or an electron transport layer as a separate layer from the light-emitting layer, and is one of preferred embodiments of the first organic electroluminescence device of the present invention.

The first organic electroluminescent device of the present invention has a hole transport layer as an independent layer In the case of a shape, it is preferred to have a hole transport layer between the light-emitting layer and the second metal oxide layer. In the case where the first organic electroluminescent device of the present invention has an electron transport layer as an independent layer, it is preferred to have an electron transport layer between the buffer layer formed of the organic compound and the light-emitting layer.

When the first organic electroluminescent device of the present invention does not have a hole transport layer or an electron transport layer as an independent layer, any one of the layers of the first organic electroluminescent device of the present invention has a necessary structure. Both have the functions of these layers.

One of the preferred embodiments of the first organic electroluminescent device of the present invention is organic electricity. The excitation light element is composed only of the first electrode, the first metal oxide layer, the buffer layer formed of the organic compound, the light-emitting layer, the hole transport layer, the second metal oxide layer, and the second electrode, and the layers are One has the function of the function of the electron transport layer.

Further, the organic electroluminescence device is composed only of the first electrode, the first metal oxide layer, the buffer layer formed of the organic compound, the light-emitting layer, the second metal oxide layer, and the second electrode, and any of the layers The form of the function of the hole transport layer and the electron transport layer is also one of the preferred embodiments of the first organic electroluminescence device of the present invention.

In the first organic electroluminescence device of the present invention, the first electrode is a cathode, and the second electrode is an anode. In the organic electroluminescent device of the present invention, a known conductive material can be suitably used as the anode and the cathode. However, at least one of the light extraction is preferably transparent. Examples of the known transparent conductive material include ITO (tin-doped indium oxide), ATO (indium-doped indium oxide), IZO (indium-doped zinc oxide), AZO (aluminized zinc oxide-doped), and FTO (fluorine-doped oxidation). _{indium), In 3 O 3, SnO} 2, Sb-containing of SnO _2, or ZnO containing Al of oxides. Examples of the opaque conductive material include calcium, magnesium, aluminum, tin, indium, copper, silver, gold, platinum, or the like.

As the cathode, among them, ITO, IZO, and FTO are preferable.

Examples of the anode include Au, Pt, Ag, Cu, Al, and alloys containing the same. Among these, Au, Ag, and Al are preferable.

As described above, since the metal generally used for the anode can be used for the cathode and the anode, it can be easily realized in the case where it is assumed that light is extracted from the upper electrode (in the case of a top emission structure), and various types can be selected. The above electrodes are used for the respective electrodes. For example, the lower electrode is Al, and the upper electrode is ITO or the like.

The average thickness of the first electrode is not particularly limited, and is preferably 10 to 500. Nm. More preferably, it is 100 to 200 nm. The average thickness of the first electrode can be measured by a stylus type step meter and a spectroscopic ellipsometer.

The average thickness of the second electrode is not particularly limited, but is preferably 10 to 1000 nm. More preferably 30 to 150 nm. Further, when a non-transmissive material is used, for example, it can be used as an anode of a top emission type and a transparent type by making the average thickness into about 10 to 30 nm.

The average thickness of the second electrode can be measured by a crystal oscillation film thickness gauge at the time of film formation.

The first metal oxide layer is used as an electron injection layer or an electrode (cathode) The functional layer is a layer in which the second metal oxide layer functions as a hole injection layer.

The first metal oxide layer is a layer composed of one layer of a single metal oxide film, or a layer of a semiconductor or an insulating volume layer film which is a layer formed by laminating and/or mixing a simple substance or two or more metal oxides. The metal elements constituting the metal oxide are free of magnesium, calcium, barium, strontium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, indium, gallium, iron, cobalt, nickel, copper, zinc. Choose from a group consisting of cadmium, aluminum, antimony and tin. Among these, it is preferable that at least one metal element constituting the laminated or mixed metal oxide layer is composed of magnesium, aluminum, calcium, zirconium, hafnium, tantalum, titanium, zinc, tin, and if it is a simple metal The oxide preferably contains a metal oxide selected from the group consisting of magnesium oxide, tungsten oxide, cerium oxide, iron oxide, aluminum oxide, zirconium oxide, cerium oxide, cerium oxide, titanium oxide, zinc oxide, and tin oxide. Things.

Examples of the layer formed by laminating and/or mixing a single or two or more metal oxides include laminated and/or mixed titanium oxide/zinc oxide, titanium oxide/magnesium oxide, titanium oxide/zirconia, and titanium oxide. /alumina, titanium oxide / cerium oxide, titanium oxide / cerium oxide, zinc oxide / magnesium oxide, zinc oxide / zirconium oxide, zinc oxide / cerium oxide, zinc oxide / cerium oxide, calcium oxide / alumina and other metal oxides Combination, or laminated and / or mixed titanium oxide / zinc oxide / magnesium oxide, titanium oxide / zinc oxide / zirconia, titanium oxide / zinc oxide / aluminum oxide, titanium oxide / zinc oxide / cerium oxide, titanium oxide / A combination of three kinds of metal oxides such as zinc oxide/yttria, indium oxide/gallium oxide/zinc oxide. These include IGZO as an oxide semiconductor or 12CaO as an electret which exhibits good characteristics as a special composition. 7Al ₂ O ₃ .

Further, in the present invention, those having a sheet resistance of less than 100 Ω/□ are classified as electric conductors, and those having sheet resistances higher than 100 Ω/□ are classified as semiconductors or insulators. Therefore, thin films of ITO (tin-doped indium oxide), ATO (indium-doped indium oxide), IZO (indium-doped zinc oxide), AZO (aluminum-doped zinc oxide), FTO (fluorine-doped indium oxide), etc., which are known as transparent electrodes, are known. The conductivity is high and is not included in the range of the semiconductor or the insulator, so it does not conform to one of the layers of the first metal oxide layer constituting the present invention.

The second metal oxide layer is not particularly limited, and one type of vanadium oxide (V ₂ O ₅ ), molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), ruthenium oxide (RuO ₂ ), or the like may be used. More than 2 types. Among these, it is preferred to use vanadium oxide or molybdenum oxide as a main component. When the second metal oxide layer is composed of vanadium oxide or molybdenum oxide as a main component, the second metal oxide layer is injected into the hole from the second electrode and transmitted to the light-emitting layer or the hole transport layer as a hole injection. The function of the layer is more excellent. Further, since vanadium oxide or molybdenum oxide has high hole transportability itself, it has an advantage that the injection efficiency of the hole from the second electrode to the light-emitting layer or the hole transport layer can be preferably prevented from being lowered. More preferably, it is composed of vanadium oxide and/or molybdenum oxide.

The average thickness of the first metal oxide layer may be allowed to be 1 nm to several μm. The left and right sides are not particularly limited, but from the viewpoint of forming an organic electroluminescence device that can be driven at a low voltage, it is preferably 1 to 1000 nm. More preferably 2 to 100 nm.

The average thickness of the second metal oxide layer is not particularly limited, but is preferably 1 to 1000 nm. More preferably 5 to 50 nm.

The average thickness of the first metal oxide layer can be measured by a stylus type step meter or a spectroscopic ellipsometer.

The average thickness of the second metal oxide layer can be measured by a crystal oscillation film thickness gauge at the time of film formation.

As the material of the light-emitting layer, any of materials which are generally used as the light-emitting layer can be used. A low molecular compound may also be used in combination.

As a low molecular group, a tricoordinate ruthenium complex having a 2,2'-bipyridyl-4,4'-dicarboxylic acid as a ligand, a surface tris(2-phenylpyridine) can be cited.铱(Ir(ppy) ₃ ), 8-hydroxyquinoline aluminum (Alq ₃ ), tris(4-methyl-8-hydroxyquinoline)aluminum (III) (Almq ₃ ), 8-hydroxyquinoline zinc (Znq) ₂ ), (1,10-morpholine)-tris-(4,4,4-trifluoro-1-(2-thienyl)-butane-1,3-diacid) ruthenium (III) (Eu ( TTA) ₃ (phen)), 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphine platinum (II) and other metal complexes; stilbene a benzene compound such as benzene (DSB) or diaminostilbene benzene (DADSB), a naphthalene compound, a phenanthrene compound, a compound, an anthraquinone compound, an anthraquinone compound, an anthraquinone compound, an anthraquinone compound, a pyran compound, an acridine compound, an anthraquinone compound, an oxazole compound, a thiophene compound, a benzo compound An azole compound, a benzimidazole compound, a benzothiazole compound, a butadiene compound, a naphthyl imine compound, a coumarin compound, a purple ketone compound, Diazole compound, aldehyde nitrogen compound, cyclopentadiene compound, quinacridone compound, pyridine compound, 2,2',7,7'-tetraphenyl-9,9'-spiro A spiro compound such as a ruthenium, a metal or a non-metallic phthalocyanine compound, and the Japanese Patent Publication No. 2009-155325, Japanese Patent Application No. 2010-28273, Japanese Patent Application No. 2010-230995, and Japanese Patent Application No. 2011-6458 One or two or more kinds of these may be used as the boron compound material or the like.

The above light-emitting layer may also contain a dopant. As a dopant, it can be used generally available As a compound of any of the dopants. Examples of the compound which can be used as a dopant include an anthracene compound; 4,4'-bis(9-ethyl-3-carbazolevinyl)-1,1'-biphenyl (BCzVBi), etc. One type or two or more types may be used for the low molecular organic compound or the like.

In the case where the above light-emitting layer contains a dopant, the content of the dopant is relative to the shape The material of the light-emitting layer is 100% by mass, preferably 0.5 to 20% by mass. If it is such a content, the luminescent property can be made more favorable. More preferably, it is 0.5 to 10% by mass, and further preferably 1 to 6% by mass.

The average thickness of the light-emitting layer is not particularly limited, but is preferably 10 to 150 nm. More preferably 20 to 100 nm. Further preferably, it is 40 to 100 nm.

The average thickness of the light-emitting layer can be measured by a crystal oscillator film thickness meter in the case of a low molecular compound, and can be measured by a contact type step meter in the case of a polymer compound.

As the material of the above hole transport layer, it can be used as a hole transport layer. Any of the low molecular compounds of the materials may be used in combination.

Examples of the low molecular compound include an arylcycloalkane compound, an arylamine compound, a phenylenediamine compound, an oxazole compound, an anthraquinone compound, and An azole compound, a triphenylmethane compound, a pyrazoline compound, a petroleum ether (cyclohexadiene) compound, a triazole compound, an imidazole compound, A bisazole compound, an anthraquinone compound, an anthrone compound, an aniline compound, a decane compound, a pyrrole compound, an anthraquinone compound, a porphyrin compound, a quinacridone compound, a metal or a non-metal phthalocyanine system One type or two or more types of the compound, the metal or the non-metal naphthol phthalocyanine compound, the benzidine compound, and the like can be used.

Among these, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD) is preferred. An arylamine compound such as TPTE.

The first organic electroluminescent device of the present invention has a hole transport layer as a single In the case of the standing layer, the average thickness of the hole transport layer is not particularly limited, and is preferably 10 to 150 nm. More preferably, it is 20 to 100 nm, and further preferably 40 to 100 nm.

The average thickness of the hole transport layer can be measured by a crystal oscillation film thickness gauge at the time of film formation.

As a material of the above electron transport layer, it can be used as an electron transport layer. Any of the low molecular compounds of the materials may be used in combination.

Examples of the low molecular compound which can be used as the material of the electron transporting layer include a pyridine derivative, a quinoline derivative, a pyrimidine derivative, and a pyrene, in addition to the boron-containing compound represented by the formula (1) to be described later. Derivative, phenanthroline derivative, three Derivatives, triazole derivatives, Azole derivatives, An oxadiazole derivative, an imidazole derivative, an aromatic cyclic tetracarboxylic anhydride, bis[2-(2-hydroxyphenyl)benzothiazolyl]zinc (Zn(BTZ) ₂ ), tris(8-hydroxyquinoline)aluminum One or two or more kinds of these may be used, and various metal complexes represented by (Alq ₃ ) and the like, and an organic decane derivative represented by a pyrene derivative.

Among these, a metal complex such as Alq ₃ or a pyridine derivative such as tris-1,3,5-(3'-(pyridine-3"-yl)phenyl)benzene (TmPyPhB) is preferred. Things.

The first organic electroluminescent device of the present invention has an electron transport layer as a single In the case of the standing layer, the average thickness of the electron transport layer is not particularly limited, and is preferably 10 to 150 nm. More preferably, it is 20 to 100 nm, and further preferably 40 to 100 nm.

The average thickness of the electron transport layer can be measured by a crystal oscillation film thickness gauge at the time of film formation.

In the first organic electroluminescence device of the present invention, the first and second metal oxygen are formed The method of the chemical layer, the second electrode, the light-emitting layer, the hole transport layer, and the electron transport layer is not particularly limited, and a chemical vapor deposition method such as plasma CVD, thermal CVD, or laser CVD which is a vapor phase film formation method can be used ( CVD), dry plating such as vacuum deposition, sputtering, ion plating, spray coating, wet plating such as electrolytic plating, immersion plating, electroless plating, or the like as a liquid phase film formation method, sol - Gel method, MOD method, spray pyrolysis method, doctor blade method using fine particle dispersion, spin coating method, inkjet method, screen printing method, printing technology, atomic layer deposition (ALD) method, etc. The appropriate method corresponding to the material.

The buffer layer contained in the first organic electroluminescent device of the present invention is coated by coating A layer formed by a solution containing an organic compound. By forming a buffer layer having a specific thickness by coating, crystallization of a low molecular compound formed on the buffer layer can be effectively suppressed.

The method of applying the solution containing the organic compound described above is not particularly limited, and spin coating can be used. Cloth method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, slit coating method, dip coating method, spray coating method, Various coating methods such as screen printing, flexographic printing, lithography, and inkjet printing. Among them, a spin coating method is preferred.

By coating the film formation buffer layer, the unevenness on the surface of the first metal oxide layer is smooth, and thus the crystallization of the low molecular compound formed on the buffer layer is suppressed.

As a solvent for preparing the above solution containing an organic compound, as long as it is The organic compound is not particularly limited, and examples thereof include inorganic solvents such as nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, and ethylene carbonate, or ketone solvents and alcohol solvents. , an ether solvent, a serosol solvent, an aliphatic hydrocarbon solvent such as hexane, pentane, heptane or cyclohexane; an aromatic hydrocarbon solvent such as toluene, xylene or benzene; and an aromatic heterocyclic compound solvent; Various organic solvents such as a guanamine-based solvent, a halogen compound-based solvent, an ester-based solvent, a sulfur compound-based solvent, a nitrile-based solvent, and an organic acid-based solvent, or a mixed solvent thereof. Among these, THF, toluene, and chloroform are preferable.

The above organic compound-containing solution is preferably an organic compound in a solvent The concentration is 0.05 to 10% by mass. If it is such a concentration, uneven coating or unevenness at the time of coating can be suppressed. The concentration of the organic compound in the solvent is more preferably 0.1 to 5% by mass, still more preferably 0.1 to 3% by mass.

Preferably, the buffer layer has an electrode formed on the substrate until it is emitted The order of the electron energy levels of the layers of the optical layer becomes the electron energy level of the stacking order of the layers. The height of the electron energy level from the electrode (cathode) formed on the substrate to the layers of the light-emitting layer is the same as the order of the layer, and the height of the electron energy level is gradually increased from the electrode (cathode) to the light-emitting layer. The electron migration from the electrode (cathode) up to the luminescent layer can be performed relatively smoothly even during the ascending process.

The buffer layer preferably has an average thickness of 5 to 50 nm. By making the average thickness For this range, the effect of suppressing the crystallization of the low molecular compound layer containing the light-emitting layer can be sufficiently exhibited. When the average thickness of the buffer layer is less than 5 nm, the unevenness of the surface of the first metal oxide is not sufficiently smoothed, and the leakage current is increased, so that the effect of the present invention cannot be sufficiently exhibited. Further, when the average thickness of the buffer layer is thicker than 50 nm, the driving voltage rises and it is practically unsatisfactory. Further, when a compound having a preferred structure in the present invention described later is used as the organic compound, the buffer layer can sufficiently exhibit the function as an electron transport layer. The average thickness of the above buffer layer is preferably 10 to 30 nm.

The average thickness of the buffer layer can be measured by a stylus type step meter and a spectroscopic ellipsometer.

Further, it is disclosed in Japanese Laid-Open Patent Publication No. 2012-4492 (Patent Document 5). An organic compound layer having one or a plurality of layers sandwiched between an anode, a cathode, an anode and a cathode, and at least one metal oxide between the anode and the organic compound layer or between the cathode and the organic compound layer A film, and an organic thin film electroluminescent device having a single layer or a plurality of layers between the layers and the like, and the main carrier is an energy barrier, and the opposite carrier does not become an energy barrier of the self-assembled monomolecular film. This patent document relates to an organic-inorganic hybrid electroluminescent device which is formed by forming a self-assembled monomolecular film having a specific energy level on an oxide substrate (by a film forming method including coating). The element configuration in which the carrier having the opposite main carrier is subjected to carrier injection by tunneling is described. Further, it is described that when a film having a tunneling carrier is injected into a film having a self-assembled monomolecular film of 2 nm or less, it is preferably functional (the average thickness of the organic compound layer is estimated to be 2 nm or less according to Patent Document 5) . On the other hand, as described in the examples below, in order to obtain a sufficient effect on the problem to be solved by the present invention, it is necessary to make the organic compound layer have an average thickness of 5 nm or more.

As described above, the problem to be solved and the means for solving the problem of the present invention are substantially different from the invention disclosed in Patent Document 5, and should be clearly distinguished.

The first organic electroluminescent device of the present invention may also be laminated on a substrate. The layers of the organic electroluminescent element are formed. When it is a case where layers are stacked on a substrate, It is preferable that each layer is formed on the first electrode formed on the substrate. In this case, the first organic electroluminescent device of the present invention may be a top emission type that extracts light on the side opposite to the side having the substrate, or may be a bottom emission that extracts light on the side having the substrate. ) type.

Examples of the material of the substrate include polyethylene terephthalate and polynaphthalene. a resin material such as ethylene diformate, polypropylene, cycloolefin polymer, polyamine, polyether oxime, polymethyl methacrylate, polycarbonate, polyarylate, or quartz glass, soda glass or the like One or two or more of these may be used.

Further, in the case of the top emission type, an opaque substrate may be used. For example, a substrate made of a ceramic material such as alumina or an oxide film (insulating film) formed on the surface of a metal substrate such as stainless steel may be used. A substrate made of a resin material or the like.

The average thickness of the substrate is preferably 0.1 to 30 mm. More preferably 0.1~10 Mm.

The average thickness of the substrate can be measured by a digital multimeter and a vernier caliper.

The first organic electroluminescent device of the present invention has a coating containing an organic compound The solution is formed into a buffer layer, and a low molecular compound layer such as a light-emitting layer is laminated thereon, whereby the problem of the organic-inorganic hybrid organic electroluminescent device in which the low molecular compound is crystallized can be solved. The method for producing an organic electroluminescence device according to the first preferred embodiment of the present invention is also one of the inventions, and the method of production is the organic-inorganic hybrid organic electroluminescent device according to the first preferred embodiment of the present invention. A manufacturing method, that is, a method of manufacturing an organic electroluminescence device having a structure in which a plurality of layers are laminated, characterized in that the manufacturing method includes the step of causing an organic electroluminescence device to be a first electrode and a second electrode The first metal oxide layer, the buffer layer, the low molecular compound layer including the light emitting layer laminated on the buffer layer, and the second metal oxide layer are sequentially laminated to form each layer of the organic electroluminescent device. The step of laminating includes the step of applying a solution containing an organic compound to form a buffer layer having an average thickness of 3 nm or more.

In the method for producing an organic electroluminescent device of the present invention, the step of applying a solution containing an organic compound to form a buffer layer is preferably a step of forming a buffer layer having an average thickness of 5 to 50 nm.

The manufacturer of the organic electroluminescent device of the first preferred embodiment of the present invention The method may include other steps as long as the above steps are included, and may include a step of forming a layer other than the first and second metal oxide layers, the buffer layer, and the low molecular compound layer including the light emitting layer. Further, a material for forming each layer of the organic electroluminescence element, a method for forming the organic compound, a solvent for preparing a solution containing the organic compound, and a thickness of each layer are the same as those of the first organic electroluminescence device of the present invention, preferably The same is true.

In the first organic electroluminescent device of the present invention, an organic compound of a buffer layer is formed The material is not particularly limited as long as it can form a layer of an organic compound by coating. Examples of the organic compound include trans-polyacetylene, cis-polyacetylene, and poly(diphenylacetylene) (PDPA). a polyacetylene compound such as poly(alkyl/phenylacetylene) (PAPA); a polyparaphenylene acetylene compound; a polythiophene compound; a polyfluorene compound; a polyparaphenylene compound; a polycarbazole compound; a boron-containing compound, a polyethyleneimine (PEI), or a boron-containing compound represented by the following formula (1), and a boron-containing compound obtained by polymerizing a monomer component containing a boron-containing compound represented by the following formula (2) A boron-containing compound such as a polymer, or a boron-containing electron transporting material such as 3TPYMB: tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane. These may be used alone or in combination of two or more.

In the first organic electroluminescent device of the present invention, an organic compound of a buffer layer is formed The substance is preferably an organic compound having a boron atom. More preferably, the organic compound having a boron atom is a compound represented by the following formula (1), or a boron-containing polymerization obtained by polymerizing a monomer component containing a boron-containing compound represented by the following formula (2). Things.

In the first organic electroluminescent device of the present invention, the organic compound having a boron atom forming the buffer layer is preferably a boron-containing compound represented by the following formula (1) or containing the following formula (2). The boron-containing polymer obtained by polymerizing the monomer component of the boron-containing compound represented:

(wherein, the arc of the dotted line indicates a ring structure together with the skeleton portion indicated by the solid line; the broken line portion of the skeleton portion indicated by the solid line indicates that one pair of atoms connected by a broken line may also be double-bonded; from the nitrogen atom The arrow pointing to the boron atom indicates that the nitrogen atom coordinates the boron atom; Q ¹ and Q ^{2 are the} same or different, and the linking group in the skeleton portion indicated by the solid line forms at least a part of the ring structure with the circular arc portion of the broken line. It may have a substituent; X ¹ , X ² , X ³ and X ^{4 may be the} same or different, and represent a hydrogen atom or a monovalent substituent which is a substituent of a ring structure, and may also form a ring structure of a circular arc portion of a broken line. The upper key is plural; n ¹ represents an integer of 2-10; Y ¹ is a direct bond or a n ¹ valent link, indicating that the structure other than the n ¹ Y ¹ existing is independently formed by the circle of the dotted line Ring structure of the arc portion, bonding of any of Q ¹ , Q ² , X ¹ , X ² , X ³ , X ⁴ )

(wherein, the circular arc of the dotted line indicates a ring structure together with a portion of the skeleton portion linking the boron atom and the nitrogen atom; and the broken line portion in the skeleton portion connecting the boron atom and the nitrogen atom indicates that at least one pair of atoms are linked by a double bond, The double bond may also be conjugated to the ring structure; the arrow from the nitrogen atom to the boron atom indicates that the nitrogen atom coordinates the boron atom; and X ⁵ and X ^{6 are the} same or different, indicating a hydrogen atom or a valence of a substituent which becomes a ring structure. The substituent may also be bonded to a plurality of ring structures forming a circular arc portion of a broken line; R ¹ and R ^{2 are the} same or different and represent a hydrogen atom or a monovalent substituent; X ⁵ , X ⁶ , R ¹ and R ² At least one of them is a substituent having a reactive group).

It is known that in the organic-inorganic hybrid electroluminescent device, the hole injection from the anode is more The electron injection from the cathode proceeds more efficiently, and the light-emitting position exists in the vicinity of the interface of the cathode-side oxide (corresponding to the first metal oxide in the present invention). In order to avoid luminescence from the buffer layer of the first metal oxide layer, as the organic compound forming the buffer layer, it is preferred to select a HOMO level having a HOMO level deeper than the luminescent compound contained in the luminescent layer. Compound. Further, in order to prevent the energy of the excitons generated in the light-emitting layer from being transferred to the compound of the buffer layer to emit light, it is more preferable to select the HOMO-LUMO energy having a HOMO-LUMO energy gap which is wider than the light-emitting compound contained in the light-emitting layer. The compound of the gap. The boron-containing compound represented by the above formula (1) or the boron-containing polymer obtained by polymerizing the monomer component containing the boron-containing compound represented by the formula (2) has both a very deep HOMO and a wider HOMO-LUMO energy. The gap is a coatable compound and thus can effectively function for various light-emitting layers.

Further, when the organic compound having a boron atom is a compound having such a structure, the buffer layer formed of the organic compound is excellent in function as an electron transport layer, and it is not necessary to provide an electron transport layer in addition to the buffer layer.

In the following, first, the boron-containing compound represented by the above formula (1) will be described, and then the boron-containing polymer obtained by polymerizing the monomer component containing the boron-containing compound represented by the above formula (2) will be described.

The boron-containing compound represented by the above formula (1) has (i) a thermal stability compound The material (i) has a low energy level of HOMO and LUMO, and (iii) can produce various properties such as a good coating film, and can be preferably used as a material of the first organic electroluminescent device of the present invention.

In the above formula (1), the arc of the broken line indicates a part of the skeleton portion indicated by the solid line, that is, a part of the skeleton portion to which the boron atom, Q ¹ , and the nitrogen atom is bonded, or a part of the skeleton portion to which the boron atom and the Q ^{2 are} bonded. Form a ring structure. It is shown that the compound represented by the above formula (1) has at least four ring structures in the structure, and the above formula (1) contains a skeleton moiety linking a boron atom, Q ¹ , and a nitrogen atom, and a boron atom and a Q ² bond. The skeleton portion serves as a part of the ring structure. Further, the ring structure to which X ¹ is bonded is a structure in which the ring structure skeleton does not contain an atom other than a carbon atom and is composed of carbon atoms.

In the above formula (1), the skeleton portion indicated by the solid line, that is, the skeleton portion linking the boron atom, Q ¹ , and the nitrogen atom, and the dotted line portion in the skeleton portion connecting the boron atom and Q ² are represented in the respective skeleton portions. A pair of atoms linked by a broken line may also be linked by a double bond.

In the above formula (1), an arrow pointing from a nitrogen atom to a boron atom indicates a pair of nitrogen atoms The boron atom is coordinated. Here, the term "coordination" means that a nitrogen atom acts on the boron atom in the same manner as a ligand to cause a chemical influence, and a coordinate bond (covalent bond) may be formed or a coordinate bond may not be formed. Preferably, a coordinate bond is formed.

In the above formula (1), Q ¹ and Q ^{2 are the} same or different, and are a linking group in a skeleton portion represented by a solid line, and at least a part thereof forms a ring structure together with a circular arc portion of a broken line, and may have a substituent. It is meant that Q ¹ and Q ² are incorporated as part of the ring structure, respectively.

In the above formula (1), X ¹ , X ² , X ³ and X ^{4 are the} same or different and each represents a hydrogen atom or a monovalent substituent which is a substituent of the ring structure, and may also form a ring of a circular arc portion of a broken line. There are a plurality of structural bonds. In other words, when X ¹ , X ² , X ³ and X ⁴ are a hydrogen atom, it means that the structure of the compound represented by the above formula (1) has 4 of X ¹ , X ² , X ³ and X ⁴ . The ring structure does not have a substituent, and when any one or all of X ¹ , X ² , X ³ and X ⁴ is a monovalent substituent, any one or all of the four ring structures have a substituent. In this case, the number of substituents in one ring structure may be one or two or more.

In addition, in the present specification, the term "substituent" means including a carbon-containing organic group, and a halogen atom. A group having no carbon group such as a hydroxyl group or a hydroxyl group.

In the above formula (1), n ¹ represents an integer of 2 to 10, and Y ¹ is a direct bond or a n ¹ valent linkage. That is, in the compound represented by the above formula (1), Y ¹ is a direct bond, and the two structural portions other than Y ¹ are independently formed independently of the ring structure forming the circular arc portion of the broken line, Q ¹ , Q ² Any one of X ¹ , X ² , X ³ , and X ⁴ is bonded, or Y ¹ is a n ¹ valent linking group, and a plurality of structural portions other than Y ¹ in the above formula (1) are present, etc. Bonded via Y ¹ as a linking group.

In the above formula (1), when Y ¹ is a direct bond, the above formula (1) represents a ring structure of a circular arc portion forming a dotted line of one of the two structural portions other than Y ¹ present, Q ¹ a ring structure of a circular arc portion forming a dotted line with any one of Q ² , X ¹ , X ² , X ³ , and X ⁴ , Q ¹ , Q ² , X ¹ , X ² , X ³ , Any part of X ⁴ is directly bonded. The bonding position is not particularly limited, but preferably ^one of the structural portions other than Y ¹ has a ring of X ¹ or a ring with X ² bonded to the other with a ring of X ¹ Or the key is directly bonded to the ring of X ² . More preferably, ^one of the structural parts other than Y ¹ has a bond of X ² and a bond of the other with a direct bond of X ² .

In this case, the structures of the structural parts other than the two Y ¹ existing may be the same or different.

In the above formula (1), when Y ¹ is a linking group of n ¹ valence, a plurality of structural portions other than Y ¹ in the above formula (1) are plural, and when they are bonded via Y ¹ as a linking group, The structure in which a plurality of structural portions other than Y ¹ in the above formula (1) are bonded via Y ¹ as a linking group is directly bonded to a structure in which a structure other than Y ¹ is directly bonded. It is more resistant to oxidation and has improved film formability, which is better in this respect.

Furthermore, in the case where Y ¹ is a n ¹ valent linking group, Y ¹ and the existing n ¹ Y ¹ structural portions are independently independent of the ring structure forming the circular arc portion of the dotted line, Q ¹ , Q ^2. Any one of X ¹ , X ² , X ³ , and X ⁴ is bonded, and represents a ring structure other than Y ¹ in a ring structure forming a circular arc portion of a broken line, Q ¹ , Q ² , X ¹ , X ^2, X ^3, X ⁴ in any of a portion bonded to the Y ^1, Y ¹ on the structure of the portion other than the bonding portion of Y ^1, the n moieties are present other than the ^Y-11 are each independently All may be the same part, and some may be the same part, or all of them may be different parts. The bonding position is not particularly limited, and it is preferred that all of the structural portions other than n ¹ Y ¹ present are bonded to Y ¹ on the ring to which X ¹ is bonded or the ring to which X ² is bonded. More preferably, all of the structural moieties other than n ¹ Y ¹ are bonded to Y ¹ on the ring to which X ² is bonded.

Further, the structures of the structural portions other than the n ¹ Y ¹ may be all the same, and may be partially the same or all different.

When in (1) in the case where Y in the above Formula ¹ is a divalent linking group of n ^1, the Examples of the linking group, examples thereof include: chain may have a substituent group, the hydrocarbon group of the branched-chain or cyclic, may have a substituent The hetero atom-containing group, the aryl group which may have a substituent, and the heterocyclic group which may have a substituent. Among these, a group having an aromatic ring such as an aryl group which may have a substituent and a heterocyclic group which may have a substituent is preferable. That is, Y ¹ in the above formula (1) is a group having an aromatic ring and is also one of preferred embodiments of the present invention.

Further, Y ¹ may be a linking group having a structure in which a plurality of the above-mentioned linking groups are combined.

The chain, branched or cyclic hydrocarbon group is preferably a group represented by any one of the following formulae (3-1) to (3-8). Among these, the following formulas (3-1) and (3-7) are more preferable.

The group containing a hetero atom is preferably a group represented by any one of the following formulas (3-9) to (3-13). Among these, the following formulas (3-12) and (3-13) are more preferable.

The aryl group is preferably a group represented by any one of the following formulas (3-14) to (3-20). Among these, the following formulas (3-14) and (3-20) are more preferable.

The heterocyclic group is preferably a group represented by any one of the following formulas (3-21) to (3-27). Among these, the following formulas (3-23) and (3-24) are more preferable.

As the above-mentioned chain, branched or cyclic hydrocarbon group, a group containing a hetero atom, Examples of the substituent of the heterocyclic group include a halogen atom; a haloalkyl group; a linear or branched alkyl group having 1 to 20 carbon atoms; a cyclic alkyl group having 5 to 7 carbon atoms; Straight chain or branch of 1~20 Alkoxy; nitro; cyano; dialkylamino group having an alkyl group having 1 to 10 carbon atoms; diarylamino group such as diphenylamino group or carbazolyl; fluorenyl group; carbon number 2~ An alkenyl group of 30; an alkynyl group having 2 to 30 carbon atoms; an aryl group which may be substituted by a halogen atom or an alkyl group, an alkoxy group, an alkenyl group, an alkynyl group or the like; may be a halogen atom or an alkyl group, an alkoxy group or an alkene group; Alkynyl-substituted heterocyclic group; N,N-dialkylaminecarbamyl; dioxaborolanyl, stannyl, fluorenyl, ester, mercapto, thioether Base, epoxy group, isocyanate group, and the like. Further, the groups may be substituted by a halogen atom or a hetero atom, an alkyl group, an aromatic ring or the like.

Among these, the chain group, the branched chain or the cyclic hydrocarbon group in Y ¹ contains a substituent of a hetero atom, a aryl group or a heterocyclic group, and preferably has a halogen atom and a carbon number of 1 to a linear or branched alkyl group of 20, a linear or branched alkoxy group having 1 to 20 carbon atoms, an aryl group, a heterocyclic group or a diarylamino group. More preferably, it is an alkyl group, an aryl group, an alkoxy group, or a diarylamine group.

In the case where the chain, branched or cyclic hydrocarbon group in the above Y ¹ contains a hetero atom group, an aryl group or a heterocyclic group has a substituent, the position or number of the substituent bond is not particularly limited. .

n ¹ in the above formula (1) represents an integer of 2 to 10, preferably 2 to 6. More preferably, it is an integer of 2 to 5, and further preferably an integer of 2 to 4, and particularly preferably 2 or 3 from the viewpoint of solubility of the solvent. The best is 2. That is, the boron-containing compound represented by the above formula (1) is preferably a dimer.

Examples of Q ¹ and Q ² in the above formula (1) include the structures represented by the following formulas (4-1) to (4-8):

Further, the above formula (4-2) is a structure in which two hydrogen atoms are bonded to a carbon atom, and three atoms are bonded, and three atoms other than the hydrogen atom bonded to the carbon atom are hydrogen atoms. The atom. Among the above formulae (4-1) to (4-8), any of (4-1), (4-7), and (4-8) is preferable. More preferably (4-1). That is, Q ¹ and Q ^{2 are the} same or different, and the form of the linking group having a carbon number of 1 is also one of the preferred embodiments of the present invention.

In the above formula (1), the ring structure formed by a portion of the skeleton portion indicated by the arc of the broken line and the solid line is composed of carbon atoms as long as the skeleton of the ring structure to which X ¹ is bonded is a ring structure. There are no special restrictions.

In the above formula (1), when Y ¹ is a direct bond and n ¹ is 2, examples of the ring to which X ¹ is bonded include a benzene ring, a naphthalene ring, an anthracene ring, a thick tetraphenyl ring, and a thick one. Pentabenzene ring, triazine ring, anthracene ring, anthracene ring, anthracene ring, thiophene ring, furan ring, pyrrole ring, benzothiophene ring, benzofuran ring, anthracene ring, dibenzothiophene ring, diphenyl And furan ring, carbazole ring, thiazole ring, benzothiazole ring, Oxazole ring, benzo Oxazole ring, imidazole ring, pyrazole ring, benzimidazole ring, pyridine ring, pyrimidine ring, pyridyl Ring, 嗒 Ring, quinoline ring, isoquinoline ring, quin A phenyl ring, a benzothiadiazole ring.

Among these, it is preferred that the ring structure skeleton is composed only of carbon atoms, and is preferably a benzene ring, a naphthalene ring, an anthracene ring, a condensed tetraphenyl ring, a fused pentacene ring, a ternary benzene ring, an anthracene ring or an anthracene. Ring, ring. More preferably, it is a benzene ring, a naphthalene ring, an anthracene ring, and further preferably a benzene ring.

In the above formula (1), when Y ¹ is a direct bond and n ¹ is 2, the ring to which X ² is bonded is, for example, represented by the following formulas (5-1) to (5-17). Ring. Further, the symbol * in the following formulae (5-1) to (5-17) represents a ring constituting X ¹ and constitutes a boron atom, a Q ¹ , and a nitrogen atom in the above formula (1). The carbon atom of the backbone moiety is bonded to any carbon atom to which the symbol * is attached. Further, it may be condensed with other ring structures at a position other than the carbon atom to which the mark * is attached. Among these, a pyridine ring, a pyrimidine ring, a quinoline ring, and a pyridine ring are preferable. More preferably, it is a pyridine ring, a pyrimidine ring, and a quinoline ring. Further, a pyridine ring is preferred.

Further, in the above formula (1), when Y ¹ is a direct bond and n ¹ is 2, the ring to which X ³ is bonded and the ring to which X ⁴ is bonded may be a direct bond with Y ¹ described above. And when n ¹ is 2, the ring to which X ¹ is bonded is the same ring. Among these, a benzene ring, a naphthalene ring, and a benzothiophene ring are preferable. More preferably, it is a benzene ring.

In the above formula (1), X ¹ , X ² , X ³ and X ^{4 are the} same or different and each represents a hydrogen atom or a monovalent substituent which is a substituent of the ring structure. The monovalent substituent is not particularly limited, and examples of X ¹ , X ² , X ³ and X ⁴ include a hydrogen atom, an aryl group which may have a substituent, a heterocyclic group, an alkyl group, and an alkenyl group. Alkynyl, alkoxy, aryloxy, arylalkoxy, fluorenyl, hydroxy, amine, halogen atom, carboxyl, thiol, epoxy, fluorenyl, oligoaryl group which may have a substituent a monovalent oligo heterocyclic group, an alkylthio group, an arylthio group, an arylalkyl group, an arylalkoxy group, an arylalkylthio group, an azo group, a tin alkyl group, a phosphino group, a decyloxy group, An aryloxycarbonyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an amine carbenyl group which may have a substituent, an arylcarbonyl group which may have a substituent, an alkylcarbonyl group which may have a substituent, may have An arylsulfonyl group of a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfinylene group which may have a substituent, an alkylsulfinyl group which may have a substituent, a mercapto group, a cyano group , nitro, arylsulfonyloxy, alkylsulfonyloxy; alkylsulfonate group such as mesylate group, ethanesulfonate group, triflate group; benzenesulfonate An aryl sulfonate group such as a p-toluenesulfonate group; an aralkyl sulfonate group such as a benzyl sulfonate group; a boryl group, a fluorenylmethyl group, a fluorenylmethyl group, a phosphonate methyl group, and a sulfonic acid aryl group; Ester group, aldehyde group, acetonitrile group and the like.

Examples of the substituent in the above X ¹ , X ² , X ³ and X ⁴ include a halogen atom; a haloalkyl group; a linear or branched alkyl group having 1 to 20 carbon atoms; and a carbon number of 5 to 7. a cyclic alkyl group; a linear or branched alkoxy group having 1 to 20 carbon atoms; a hydroxyl group; a thiol group; a nitro group; a cyano group; an amine group; an azo group; and an alkyl group having 1 to 40 carbon atoms Mono or dialkylamino group; amine group such as diphenylamino group or carbazolyl; fluorenyl group; alkenyl group having 2 to 20 carbon atoms; alkynyl group having 2 to 20 carbon atoms; alkenyloxy group; An aryloxy group such as a phenoxy group, a naphthyloxy group, a biphenyloxy group or a decyloxy group; a perfluoro group and further a long-chain perfluoro group; a boron alkyl group; a carbonyl group; a carbonyloxy group; an alkoxycarbonyl group; Sulfhydryl; alkylsulfonyloxy; arylsulfonyloxy; phosphino; fluorenyl; decyloxy; tin alkyl; phenyl substituted by halogen atom or alkyl, alkoxy, etc. 2,6-xylyl, 2,4,6-trimethylphenyl, fluorenyl, biphenyl, terphenyl, naphthyl, anthracenyl, fluorenyl, tolylmethyl, anisyl, fluorobenzene An aryl group such as a diphenylaminophenyl group, a dimethylaminophenyl group, a diethylaminophenyl group or a phenanthryl group; a thienyl group; Furanyl, silicon heterocyclyl pentadienyl, Azolyl, Diazolyl, thiazolyl, thiadiazolyl, acridinyl, quinolinyl, quin Boryl, morpholinyl, benzothienyl, benzothiazolyl, indolyl, oxazolyl, pyridyl, pyrrolyl, benzo a heterocyclic group such as an azolyl group, a pyrimidinyl group or an imidazolyl group; a carboxyl group; a carboxylate; an epoxy group; an isocyano group; a cyanate group; an isocyanate group; a thiocyanate group; an isothiocyanate group; Sulfhydryl; N,N-dialkylaminecarbamyl; indolyl; nitroso; methyloxy. Further, the groups may be substituted by a halogen atom, an alkyl group, an aryl group or the like, and further, the groups may be bonded to each other at any position to form a ring.

Among these, as X ¹ , X ² , X ³ and X ⁴ , a hydrogen atom is preferred; a halogen atom, a carboxyl group, a hydroxyl group, a thiol group, an epoxy group, an amine group, an azo group, a decyl group, an alkene group. Propyl, nitro, alkoxycarbonyl, decyl, cyano, decyl, tin alkyl, boralkyl, phosphino, decyloxy, arylsulfonyloxy, alkylsulfonyloxy a reactive group; a linear or branched alkyl group having 1 to 20 carbon atoms; a linear or branched alkyl group having 1 to 8 carbon atoms; and a linear or branched chain having 1 to 8 carbon atoms; Alkoxy group, aryl group, alkenyl group having 2 to 8 carbon atoms, alkynyl group having 2 to 8 carbon atoms or linear or branched alkyl group having 1 to 20 carbon atoms substituted by the reactive group; carbon number a linear or branched alkoxy group of 1 to 20; a linear or branched alkyl group having 1 to 8 carbon atoms; a linear or branched alkoxy group having 1 to 8 carbon atoms; , an alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 2 to 8 carbon atoms, or a linear or branched alkoxy group having 1 to 20 carbon atoms substituted by the reactive group; an aryl group; a carbon number of 1~ a linear or branched alkyl group of 8 , a linear or branched alkoxy group having 1 to 8 carbon atoms, an aryl group, an alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 2 to 8 carbon atoms or Reactivity a substituted aryl group; an oligoaryl group; a linear or branched alkyl group having 1 to 8 carbon atoms; a linear or branched alkoxy group having 1 to 8 carbon atoms; an aryl group; Alkenyl group of ~8, alkynyl group having 2 to 8 carbon atoms or oligomeric aryl group substituted by the reactive group; monovalent heterocyclic group; linear or branched alkyl group having 1 to 8 carbon atoms, carbon a linear or branched alkoxy group of 1 to 8, an aryl group, an alkenyl group having 2 to 8 carbon atoms, an alkynyl group having 2 to 8 carbon atoms or a monovalent heterocyclic group substituted with the reactive group; a monovalent oligo heterocyclic group; a linear or branched alkyl group having 1 to 8 carbon atoms; a linear or branched alkoxy group having 1 to 8 carbon atoms; an aryl group; and a carbon number of 2 to 8 An alkenyl group, an alkynyl group having 2 to 8 carbon atoms or a monovalent oligomeric heterocyclic group substituted with the reactive group; an alkylthio group; an aryloxy group; an arylthio group; an arylalkyl group; an arylalkoxy group; Arylalkylthio; alkenyl; linear or branched alkyl having 1 to 8 carbon atoms; linear or branched alkoxy having 1 to 8 carbon atoms; aryl group, carbon number 2 to 8 Alkenyl group, alkynyl group having 2 to 8 carbon atoms or alkenyl group substituted with the reactive group; alkynyl group; linear or branched alkyl group having 1 to 8 carbon atoms; linear chain having 1 to 8 carbon atoms Or branched alkoxy, aryl, carbon An alkenyl group of 2 to 8 or an alkynyl group having 2 to 8 carbon atoms or an alkynyl group substituted by the reactive group.

More preferably, it is a hydrogen atom, a bromine atom, an iodine atom, an amine group, a boryl group, an alkynyl group, an alkenyl group, a decyl group, a decyl group, a tin alkyl group, a phosphino group, an aryl group substituted with the reactive group, The reactive group-substituted oligoaryl group, monovalent heterocyclic group or a monovalent heterocyclic group substituted with the reactive group, a monovalent oligo heterocyclic group substituted with the reactive group, an alkenyl group or the like A reactive group-substituted alkenyl group, alkynyl group or an alkynyl group substituted with the reactive group. Among them, X ¹ and X ^{2 are more} preferably a functional group which is resistant to reduction such as a hydrogen atom, an alkyl group, an aryl group, a nitrogen-containing heteroaromatic group, an alkenyl group, an alkoxy group, an aryloxy group or a fluorenyl group. More preferably, it is a hydrogen atom, an aryl group, or a nitrogen-containing heteroaromatic group. Further, X ³ and X ^{4 are more} preferably an oxidation-resistant functional group such as a hydrogen atom, a carbazolyl group, a triphenylamine group, a thienyl group, a furyl group, an alkyl group, an aryl group or a fluorenyl group. More preferably, it is a hydrogen atom, a carbazolyl group, a triphenylamino group, and a thienyl group. As described above, when the functional group having a reduction-resistant functional group is used as X ¹ and X ² and the functional group having oxidation resistance is used as X ³ and X ⁴ , the boron-containing compound as a whole is further resistant to reduction and oxidation.

Further, in the above formula (1), when X ¹ , X ² , X ³ and X ⁴ are a monovalent substituent, X ¹ , X ² , X ³ and X ⁴ are bonded to the ring structure or The number of key combinations is not particularly limited.

When in the above formula (1), in Y ¹ is n ¹ price of the linking group and n ¹ is the case of 2 to 10 of, X ¹ are bonded Ring above formula (1), Y ¹ is a direct bond and n ¹ In the case of 2, the ring to which X ¹ is bonded is the same. Among the isocyclic rings, a benzene ring, a naphthalene ring, and a benzothiophene ring are preferred. More preferably, it is a benzene ring.

In the above formula (1), when Y ¹ is a linking group of n ¹ valence and n ¹ is 2 to 10, a ring bonded by X ² , a ring bonded by X ³ , and a bond of X ⁴ The ring is respectively a ring in which Y ¹ is a direct bond and n ¹ is 2 in the above formula (1), as a ring to which X ² is bonded, a ring to which X ³ is bonded, and a ring to which X ⁴ is bonded. The rings are the same and the preferred structure is the same.

That is, in the case where Y ¹ in the above formula (1) is a direct bond and n ¹ is 2, and Y ¹ is a linking group of n ¹ valence and n ¹ is 2 to 10, the above formula (1) The boron-containing compound represented by the following formula (6) is also one of the preferred embodiments of the present invention:

(In the formula, the arrow from the nitrogen atom to the boron atom, X ¹ , X ² , X ³ , X ⁴ , n ¹ and Y ^{1 are the} same as in the formula (1)).

The boron-containing compound represented by the above formula (1) can be reversed by using Suzuki coupling It should be synthesized in accordance with various reactions which are usually applied. Further, it can also be synthesized by the method described in Journal of the American Chemical Society, 2009, Vol. 131, No. 40, pp. 14549-14559.

An example of the synthesis scheme of the boron-containing compound represented by the above formula (1) is shown in the following reaction formula. The reaction represented by the following formula (I) of the boron-containing compound represented by the above formula (1), Y ¹ is a direct bond, N1 is an example of the process of synthesis of Compound 2, the reaction represented by the following formula (II) above formula (1) In the boron-containing compound, an example of a synthesis scheme in which Y ¹ is a linking group of n ¹ valence and n ¹ is a compound of 2 to 10. However, the method for producing the boron-containing compound represented by the above formula (1) is not limited thereto.

Further, in the following scheme, the compound (a) which is a raw material can be, for example, a method described in Journal of Organic Chemistry, 2010, Vol. 75, No. 24, No. 8709-8712. And synthesis. Further, the compound of (b) which becomes a raw material can be combined with (a) The product was synthesized by a boronation reaction represented by the following reaction formula (III).

Next, the monomer containing the boron-containing compound represented by the above formula (2) is formed. The boron-containing polymer obtained by partial polymerization is described.

In the above formula (2), an arc of a broken line indicates a ring structure together with a portion of a skeleton portion to which a boron atom and a nitrogen atom are bonded. That is, the boron-containing compound represented by the above formula (2) has at least two ring structures in the structure, and the above formula (2) contains a skeleton portion linking a boron atom and a nitrogen atom as a part of the ring structure.

In the above formula (2), the dotted line in the skeleton portion connecting the boron atom and the nitrogen atom indicates that at least one pair of atoms is linked by a double bond, and the double bond may be conjugated to the ring structure. In the compound represented by the formula (1), the double bond and the ring structure are conjugated, and examples thereof include those of the following formulae (7-1) to (7-4).

In the above formula (2), an arrow pointing from a nitrogen atom to a boron atom indicates a pair of nitrogen atoms The boron atom is coordinated. The term "coordination" means the same meaning as the coordination of the nitrogen atom in the above formula (1) with respect to the boron atom.

In the above formula (2), X ⁵ and X ^{6 are the} same or different and each represents a hydrogen atom or a monovalent substituent which is a substituent of the ring structure, and may be bonded to a plurality of ring structures forming a circular arc portion of a broken line. In other words, when X ⁵ and X ⁶ are a hydrogen atom, the structure of the boron-containing compound represented by the formula (2) has two ring structures of X ⁵ and X ⁶ having no substituent, and X ⁵ and In the case where X ⁶ is a monovalent substituent, any one or all of the two ring structures have a substituent. In this case, the number of substituents in one ring structure may be one or two.

In the above formula (2), R ¹ and R ^{2 are the} same or different and each represents a hydrogen atom or a monovalent substituent. The R ¹ and R ² may be the same or different, and are preferably the same. The R ¹ and R ^{2 are} not particularly limited, and examples thereof include a hydrogen atom, an aryl group which may have a substituent, a heterocyclic group, an alkyl group, an alkoxy group, an arylalkoxy group, a decyl group, and a hydroxyl group. Oxyboronic acid, amine group, halogen atom, 2,2'-biphenyl group in which R ¹ and R ^{2 are} bonded, oligoaryl group which may have a substituent, monovalent oligomeric heterocyclic group, alkyl sulfide , arylthio, arylalkyl, arylalkoxy, arylalkylthio, azo, stanny, phosphino, decyloxy, arylsulfonyloxy, alkylsulfonyl An oxyalkyl group; an aryl sulfonate group; an arylalkyl sulfonate group; a boroalkyl group represented by the following formulas (8-1) to (8-4); The methyl group represented by the formula (8-5) to (8-6); the methyl group represented by the following formula (8-7); the methyl group represented by the following formula (8-8); Phosphonic acid methyl group; aryl sulfonate group; aldehyde group; acetonitrile group; magnesium halide represented by the following formula (8-9).

Further, in the formula, Me represents a methyl group. Et represents an ethyl group. X represents a halogen atom. R' represents an alkyl group, an aryl group or an arylalkyl group.

Examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, and a tetrahydronaphthyl group. Mercapto, dihydroindenyl and the like. Among these, a phenyl group, a biphenyl group, and a naphthyl group are preferable.

Examples of the heterocyclic group include a pyrrolyl group, a pyridyl group, a quinolyl group, a piperidinyl group, an N-hexahydropyridyl group (piperidino), a furyl group, and a thienyl group. Among these, a pyridyl group and a thienyl group are preferable.

The halogen atom may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and among these, a bromine atom or an iodine atom is preferred.

The alkyl group may, for example, be a linear or branched hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 30 carbon atoms. In the first organic electroluminescent device of the present invention, the buffer layer is formed of a boron-containing polymer obtained by polymerizing a monomer component containing the boron-containing compound represented by the above formula (2), and is represented by the formula (2). In the boron-containing compound, R ¹ and R ^{2 are the} same or different, and a form of a linear or branched hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 30 carbon atoms is also a form of the present invention. One of the preferred embodiments.

Among the above alkyl groups, among these, a methyl group, an ethyl group, an isopropyl group, an isobutyl group, and an octyl group are preferable. More preferably, it is a methyl group, an ethyl group, an isobutyl group, or an octyl group.

Examples of the substituent in R ¹ and R ² include the same substituents as those in X ¹ to X ⁴ of the above formula (1).

Among these, the substituent which the monovalent substituent in the above R ¹ and R ² has is preferably a halogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and a carbon number of 1~. a linear or branched alkoxy group, an aryl group or a haloalkyl group of 8. More preferred are ethyl, isopropyl, octyl, fluorine atom, bromine atom, vinyl group, ethynyl group, diphenylamino group, diphenylaminophenyl group, trifluoromethyl group.

The above R ¹ and R ² are more preferably a hydrogen atom, a bromine atom, a methyl group, an ethyl group, an isopropyl group, an isobutyl group, an n-octyl group, a phenyl group or a 4-methoxyphenyl group. 4-trifluoromethylphenyl, pentafluorophenyl, 4-bromophenyl, 2,2'-biphenyl, styryl, diphenylaminophenyl. Further preferred are a bromine atom, methyl, ethyl, isopropyl, isobutyl, n-octyl, phenyl, 4-methoxyphenyl, 4-trifluoromethylphenyl, pentafluorophenyl, 4-bromophenyl, 2,2'-biphenyl, styryl, diphenylaminophenyl, especially bromine, isopropyl, isobutyl, n-octyl, phenyl, 4- Trifluoromethylphenyl, pentafluorophenyl, 4-bromophenyl, 2,2'-biphenyl, styryl, diphenylaminophenyl.

In the above formula (2), X ⁵ and X ^{6 are the} same or different and each represents a hydrogen atom or a monovalent substituent which is a substituent of the ring structure. The monovalent substituent is not particularly limited, and examples thereof are the same as those of R ¹ and R ² described above.

Among these, X ⁵ and X ^{6 are} preferably a hydrogen atom; a halogen atom, a carboxyl group, a hydroxyl group, a thiol group, an epoxy group, an isocyanate group, an amine group, an azo group, a decyl group, an allyl group, Reactivity such as nitro, alkoxycarbonyl, decyl, cyano, decyl, tin alkyl, boralkyl, phosphino, decyloxy, arylsulfonyloxy, alkylsulfonyloxy a linear or branched alkyl group having 1 to 4 carbon atoms or a linear or branched alkyl group having 1 to 4 carbon atoms substituted with the reactive group; a linear chain having 1 to 8 carbon atoms; Or a branched alkoxy group or a linear or branched alkoxy group having 1 to 8 carbon atoms substituted with the reactive group; an aryl group or an aryl group substituted with the reactive group; an oligomeric aryl group or An oligomeric aryl group substituted with the reactive group; a monovalent heterocyclic group or a monovalent heterocyclic group substituted with the reactive group; a monovalent oligo heterocyclic group or a monovalent oligomeric group substituted with the reactive group Heterocyclyl; alkylthio; aryloxy; arylthio; arylalkyl; arylalkoxy; arylalkylthio; alkenyl or alkenyl substituted by the reactive group; The alkynyl group substituted with the reactive group. More preferably, it is a hydrogen atom, a bromine atom, an iodine atom, a boryl group, an alkynyl group, an alkenyl group, a decyl group, a tin alkyl group, a phosphino group, an aryl group or an aryl group substituted with the reactive group, and the reactivity a monovalent heterocyclic group such as an oligoaryl group or a diphenylamino group, a monovalent heterocyclic group such as a group represented by the following formula (8-10), or a monovalent heterocyclic group substituted with the reactive group; The reactive group-substituted monovalent oligo heterocyclic group, alkenyl group or an alkenyl group substituted with the reactive group, an alkynyl group or an alkynyl group substituted with the reactive group.

At least one of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) is a substituent having a reactive group. The substituent having a reactive group is preferably a halogen atom, a carboxyl group, a hydroxyl group, a thiol group, an epoxy group, an isocyanate group, an amine group, an azo group, a decyl group, an allyl group, a nitro group or an alkoxy group. a reactive group such as a carbonyl group, a decyl group, a cyano group, a decyl group, a tin alkyl group, a boryl group, a phosphino group, a decyloxy group, an arylsulfonyloxy group or an alkylsulfonyloxy group; a linear or branched alkyl group having 1 to 4 carbon atoms; a linear or branched alkoxy group having 1 to 8 carbon atoms substituted by the reactive group; substituted by the reactive group An aryl group; an oligomeric aryl group substituted with the reactive group; a monovalent heterocyclic group substituted with the reactive group; a monovalent oligo heterocyclic group substituted with the reactive group; an alkenyl group or the reactivity a substituted alkenyl group; an alkynyl group or an alkynyl group substituted with the reactive group. More preferably, it is a bromine atom, an iodine atom, a boryl group, a decyl group, a tin alkyl group, a phosphino group, an aryl group substituted with the reactive group, an oligomeric aryl group substituted with the reactive group, and the reactivity a monovalent heterocyclic group substituted with a monovalent group, a monovalent oligo heterocyclic group substituted with the reactive group, an alkenyl group or an alkenyl group substituted with the reactive group, an alkynyl group or an alkynyl group substituted with the reactive group. Further preferred are a bromine atom, a boryl group, a decyl group, a tin alkyl group, a phosphino group, an aryl group substituted with the reactive group, an oligomeric aryl group substituted with the reactive group, and substituted with the reactive group. a monovalent heterocyclic group, a monovalent oligo heterocyclic group substituted with the reactive group, an alkenyl group or an alkenyl group substituted with the reactive group, an alkynyl group or an alkynyl group substituted with the reactive group.

In the case where both of X ⁵ , X ⁶ , R ¹ and R ² are a substituent having a reactive group, the reactive groups of the two substituents are different, and one type is used. The boron-containing compound may be a combination of a reactive group which is condensed by a single polymerization, or a boron-containing compound represented by the formula (2), or a reactive group which has such a boron-containing compound to be copolymerized, or may have A combination of one or more boron-containing compounds represented by the formula (2) and a reactive group copolymerizable with another compound having at least one reactive group, whereby it can be preferably used as a raw material of the polymer .

In the above formula (2), examples of the ring to which X ⁵ is bonded include a benzene ring, a thiophene ring, a benzothiophene ring, and a thiazole ring. Oxazole ring, naphthalene ring, anthracene ring, fused tetraphenyl ring, fused pentabenzene ring, imidazole ring, pyrazole ring, pyridine ring, hydrazine Ring, pyr The ring, the pyrimidine ring, the quinoline ring, and the isoquinoline ring are represented by the following formulas (9-1) to (9-17), respectively. Among these, a benzene ring, a naphthalene ring, and a benzothiophene ring are preferable.

Further, in the above formula (2), examples of the ring to which X ⁶ is bonded include a pyrrole ring, a pyrazole ring, an imidazole ring, a pyridine ring, and an anthracene. Ring, pyr Ring, pyrimidine ring, anthracene ring, isoindole ring, quinoline ring, isoquinoline ring, pyridine ring, thiazole ring, Oxazole ring. These are represented by the following formulas (10-1) to (10-14), respectively. Among these, a pyridine ring, a pyrimidine ring, a quinoline ring, and a pyridine ring are preferable. More preferably, it is a pyridine ring, a pyrimidine ring, and a quinoline ring.

In the boron-containing compound represented by the above formula (2), when X ⁵ and/or X ⁶ is a monovalent substituent, the bonding position or the number of bonding of the ring structure of X ⁵ and/or X ⁶ is There are no special restrictions.

Further, at least two monovalent substituents are bonded to the ring structure as X ⁵ , and one of the monovalent substituents is a boryl group which may have a substituent, and the other of the monovalent substituents may be The pyridyl group having a substituent, and the nitrogen atom of the pyridyl group is coordinated to the boron atom of the boron alkyl group is also one of preferred embodiments of the present invention. That is, the form in which the boron-containing compound represented by the above formula (2) has a portion in which two or more nitrogen atoms are coordinated to a boron atom in the structure is also one of preferred embodiments of the present invention.

In the above formula (2), at least one of X ⁵ and X ⁶ has a structure in which two atoms are bonded to each other at a terminal portion by a double bond, and one of the two atoms forms a dotted line. The form of the substituent of the structure of the ring structure of the arc portion is also one of the preferred embodiments of the present invention. That is, the organic compound having a boron atom forming the buffer layer of the organic electroluminescent device is a boron-containing polymer, and the boron-containing compound contained in the monomer component of the raw material of the boron-containing polymer has a boron atom and a double bond. a boron-containing compound, wherein the boron-containing compound is represented by the following formula (2), and at least one of the above-mentioned X ⁵ and X ⁶ has a structure in which two atoms are bonded at a terminal portion by a double bond, and The form of the boron-containing compound in which one of the two atoms is bonded to the ring structure forming the arc portion of the dotted line is also one of the preferred embodiments of the present invention:

(wherein, the circular arc of the dotted line indicates a ring structure together with a portion of the skeleton portion linking the boron atom and the nitrogen atom; and the broken line portion in the skeleton portion connecting the boron atom and the nitrogen atom indicates that at least one pair of atoms are linked by a double bond, The double bond may also be conjugated to the ring structure; the arrow from the nitrogen atom to the boron atom indicates that the nitrogen atom coordinates the boron atom; and X ⁵ and X ^{6 are the} same or different, indicating a hydrogen atom or a valence of a substituent which becomes a ring structure. The substituent may be bonded to a plurality of ring structures forming a circular arc portion of a broken line; R ¹ and R ^{2 are the} same or different and represent a hydrogen atom or a monovalent substituent).

The above-mentioned structure in which two atoms are connected by a double bond at the terminal portion, and a structure in which one of the two atoms is bonded to a ring structure forming a circular arc portion of a broken line means that X ⁵ and/or In the atomic group of X ⁶ , at least two end portions of each structure are present, and the end portion of the end portion which is bonded to the ring structure forming the arc portion of the broken line in the above formula (2) has a circular arc portion which forms a broken line. A structure in which an atom of a ring structure is bonded to a neighboring atom of the atom by a double bond. Examples of such a substituent include the structures represented by the following formulas (11-1) to (11-2).

Further, in the formulae (11-1) to (11-2), * represents an atom bonded to a ring structure forming a circular arc portion of a broken line in the formula (2). r ¹ , r ² , r ³ and r ^{4 are the} same or different and each represents an atom which can form a double bond between r ¹ and r ^{2 and} between r ³ and r ⁴ . In the formula (11-1), q ¹ represents a hydrogen atom or a monovalent organic group, and it is also indicated that a plurality of bonds may be bonded to r ² depending on the valence of r ² . In the formula (11-2), the circular arc of the broken line indicates that a ring structure is formed together with the double bond portion formed by r ³ and r ⁴ . Further, q ² represents a hydrogen atom or a monovalent substituent which is a substituent of the ring structure, and it is also indicated that a plurality of ring structures which form a circular arc portion of a broken line in the formula (11-2) can be bonded.

In the above formulae (11-1) to (11-2), r ¹ , r ² , r ³ and r ^{4 are the} same or different, and represent between r ¹ and r ^{2 and} between r ³ and r ⁴ respectively. The atom forming a double bond is preferably a carbon atom, a nitrogen atom, a phosphorus atom or a sulfur atom. More preferably, it is a carbon atom or a nitrogen atom.

In the above formula (11-1), q ¹ represents a hydrogen atom or a monovalent organic group, and it is also indicated that a plurality of bonds may be bonded to r ² depending on the valence of r ² , which means, for example, that r ² is a nitrogen atom. At the time, one q ¹ bond is bonded to r ² , and when r ² is a carbon atom, two q ¹ bonds are bonded to r ² . In the case where a plurality of q ¹ bonds are attached to r ² , q ¹ may be all the same or different. The monovalent organic group is not particularly limited, and examples thereof are the same as those of R ¹ and R ² in the above formula (2).

Among these, as q ¹ , a hydrogen atom is preferred; a halogen atom, a carboxyl group, a hydroxyl group, a thiol group, an epoxy group, an isocyanate group, an amine group, an azo group, a decyl group, an allyl group, a nitro group, a reactive group such as an alkoxycarbonyl group, a decyl group, a cyano group, a decyl group, a tin alkyl group, a boryl group, a phosphino group, a decyloxy group, an arylsulfonyloxy group or an alkylsulfonyloxy group; a linear or branched alkyl group of 1 to 4 or a linear or branched alkyl group having 1 to 4 carbon atoms substituted by the reactive group; a linear or branched chain having 1 to 8 carbon atoms; Alkoxy or a linear or branched alkoxy group having 1 to 8 carbon atoms substituted with the reactive group; an aryl group or an aryl group substituted with the reactive group; an oligomeric aryl group or a reaction thereof a aryl group-substituted oligoaryl group; a monovalent heterocyclic group or a monovalent heterocyclic group substituted with the reactive group; a monovalent oligo heterocyclic group or a monovalent oligo heterocyclic group substituted with the reactive group ; alkylthio; aryloxy; arylthio; arylalkyl; arylalkoxy; arylalkylthio; alkenyl or alkenyl substituted by the reactive group; alkynyl or via the reactivity a substituted alkynyl group. More preferably, it is a hydrogen atom, a bromine atom, an iodine atom, a boryl group, an alkynyl group, an alkenyl group, a decyl group, a tin alkyl group, a phosphino group, an aryl group or an aryl group substituted with the reactive group, and the reactivity a substituted oligoaryl group, a monovalent heterocyclic group substituted with the reactive group, a monovalent oligo heterocyclic group substituted with the reactive group, an alkenyl group or an alkenyl group or alkyne substituted with the reactive group Or an alkynyl group substituted with the reactive group.

In the above formula (11-2), q ² represents a hydrogen atom or a monovalent substituent which is a substituent of the ring structure, and represents a ring structure which can also form a circular arc portion of a broken line in the formula (11-2). Combine several.

That is, when q ² is a hydrogen atom, it means that the ring structure having q ^{2 in} the structure represented by the formula (11-2) does not have a substituent, and when q ² is a monovalent substituent, the ring structure Has a substituent. In this case, the number of substituents in the ring structure may be one or two or more.

The above-mentioned monovalent substituent may be the same as X ⁵ and X ⁶ in the above formula (2), and among these, a group represented by the above formula (8-10), a naphthyl group or a phenyl group is particularly preferable. .

In the present invention, X ⁵ and X ⁶ in the above formula (2) each have a structure in which two atoms are bonded to each other at a terminal portion, and one of the two atoms forms a circle with a dotted line. The form of the substituent of the structure in which the ring structure of the arc portion is bonded is also one of the preferred embodiments of the present invention. That is, the organic compound having a boron atom forming the buffer layer of the organic electroluminescent device is a boron-containing polymer, and the boron-containing compound contained in the monomer component of the raw material of the boron-containing polymer has a boron atom and a double bond. a boron-containing compound, wherein the boron-containing compound is characterized by the following formula (2), and each of X ⁵ and X ⁶ has a structure in which two atoms are bonded at a terminal portion by a double bond, and in the two atoms The form of the boron-containing compound in which one atom is bonded to the ring structure forming the circular arc portion of the broken line is also one of the preferred embodiments of the present invention:

(wherein, the circular arc of the dotted line indicates a ring structure together with a portion of the skeleton portion linking the boron atom and the nitrogen atom; and the broken line portion in the skeleton portion connecting the boron atom and the nitrogen atom indicates that at least one pair of atoms are linked by a double bond, The double bond may also be conjugated to the ring structure; the arrow from the nitrogen atom to the boron atom indicates that the nitrogen atom coordinates the boron atom; and X ⁵ and X ^{6 are the} same or different, indicating a monovalent substituent which becomes a substituent of the ring structure, A plurality of ring structures may be bonded to the ring structure forming the arc portion of the broken line; R ¹ and R ^{2 are the} same or different and represent a hydrogen atom or a monovalent substituent).

In the above formula (2), both of X ⁵ and X ⁶ have a structure in which two atoms are bonded at a terminal portion by a double bond, and one of the two atoms is bonded to a ring structure forming a circular arc portion of a broken line. In general, a boron-containing compound having a structure in which the double bond portion which is bonded to a ring structure forming a circular arc portion of a broken line in the above formula (2) does not constitute a ring structure, and a constituent ring Specific examples of the form of the structure include the following formulas (2'-1) to (2'-4).

Further, in the formulas (2'-1) to (2'-4), a dotted line in a skeleton portion connecting a boron atom and a nitrogen atom, an arrow pointing from a nitrogen atom to a boron atom, and R ¹ and R ² and a formula (1) Same. In the formula (2'-1), the arc of the broken line is the same as the formula (2). In the formulae (2'-2) to (2'-4), the arc of a broken line connecting a part of the skeleton portion connecting the boron atom and the nitrogen atom is the same as the formula (2), and the boron atom and the nitrogen atom are bonded. One of the skeleton portions forms a ring structure together, and a circular arc of a dotted line formed by the double bond portion formed by r ⁵ and r ⁶ and/or the double bond portion formed by r ⁷ and r ⁸ represents the double bond The parts together form a ring structure. r ⁵ to r ^{8 are the} same or different and are the same as r ¹ to r ⁴ in the above formulas (11-1) to (11-2). q ³ and q ^{4 are the} same or different and are the same as q ¹ in the above formula (11-1). q ⁵ and q ^{6 are the} same or different and are the same as q ² in the above formula (11-2). In the case where the boron-containing compound is in the form of the formula (2'-4), at least one of q ⁵ and q ⁶ is a substituent having a reactive group.

Among these forms, it is preferable to form a circular arc portion with a broken line in the above formula (2). The double bond portion composed of the atoms bonded by the ring structure does not constitute the form of the ring structure or any form of the form of a part of the ring structure. That is, it is preferably in the form of the above formulas (2'-1) and (2'-4).

The organic compound having a boron atom in the buffer layer forming the organic electroluminescent device is a boron-containing compound represented by the above formula (2'-1) or boron-containing represented by the above formula (2'-4) The form of the boron-containing polymer obtained by polymerizing the monomer component of the compound is also preferred in the present invention. One of the embodiments.

In the above formula (2'-1), the circular arc of the broken line shows a ring structure together with a part of the skeleton portion connecting the boron atom and the nitrogen atom, similarly to the formula (1), and in the above formula (2'-1), The ring structure formed by the arc of the dotted line and the portion of the skeleton portion connecting the boron atom and the nitrogen atom is not particularly limited as long as it has a cyclic structure, and is bonded as a group having q ^{3 in} the formula (2'-1). The ring may be the same as the ring to which X ⁵ in the formula (2) is bonded. Further, examples of the ring to which the group having q ^{4 in} the formula (2'-1) is bonded are the same as those ringed by X ⁶ in the formula (2).

In the above formulas (2'-2) to (2'-4), an arc of a broken line connecting a part of a skeleton portion connecting a boron atom and a nitrogen atom is similar to the formula (2), and a boron atom and a nitrogen atom are bonded. One of the skeleton portions of the atom forms a ring structure together, and a double-bonded portion formed by r ⁵ and r ⁶ and/or a double-bonded portion formed by r ⁷ and r ⁸ represents a double arc The key portions together form a ring structure. That is, the boron-containing compound represented by the above formulas (2'-2) to (2'-3) has at least three ring structures in the structure, and contains a skeleton portion and a double bond connecting a boron atom and a nitrogen atom. Part of it is part of the ring structure. Further, the boron-containing compound represented by the above formula (2'-4) has at least four ring structures in the structure, and contains a skeleton portion linking a boron atom and a nitrogen atom and two double bond portions as a part of the ring structure. .

In the above formula (2'-2) to (2'-4), an arc of a broken line connected to a portion of a skeleton portion linking a boron atom and a nitrogen atom, and a portion of a skeleton portion connecting a boron atom and a nitrogen atom The ring structure to be formed is not particularly limited as long as it has a cyclic structure, and the ring to which the group including the double bond portion formed by r ⁵ and r ⁶ is bonded may be exemplified by the bond of X ⁵ in the formula (2). The ring is the same. Further, examples of the ring to which the group including the double bond portion formed by r ⁷ and r ⁸ are bonded may be the same as the ring to which X ⁶ is bonded in the formula (2).

Further, in the above formulas (2'-2) to (2'-4), the double bond portion formed by r ⁵ and r ⁶ and/or the double bond portion formed by r ⁷ and r ⁸ are connected. The ring structure formed by the circular arc of the dotted line and the double bond portion may be, for example, the same as the ring bonded by X ^{5 in} the formula (2) and the ring bonded by X ⁶ in the formula (2). Further, in the above formula (2'-4), an arc of a dotted line connected to a double bond portion formed by r ⁵ and r ⁶ and a double bond portion formed by r ⁷ and r ⁸ and the double bond portion There are at least two ring structures formed, and the like may be the same or different.

The method for producing the boron-containing compound represented by the above formula (2) is not particularly limited. For example, it can be produced by the method described in JP-A-2011-184430.

The boron-containing polymer obtained by polymerizing the monomer component containing the boron-containing compound represented by the above formula (2) has at least two groups of X ⁵ , X ⁶ , R ¹ and R ^{2 in} the formula (2) A repeating unit formed by condensation or polymerization of at least one group. That is, it is a boron-containing polymer having a structure of a repeating unit represented by the following formula (12):

(wherein, the arc of the dotted line, the dotted line in the skeleton portion connecting the boron atom and the nitrogen atom, and the arrow pointing from the nitrogen atom to the boron atom are the same as in the formula (2); X ^{5 '} , X ^{6 '} , R ^{1 '} and R ^{2 'is the} same group as the X ⁵ , X ⁶ , R ¹ and R ^{2 of the} formula (2), a divalent group, a trivalent group or a direct bond, respectively. The above formula (12) represents that any one of X ^{5 '} , X ^{6 '} , R ^{1 '} and R ^{2 '} is a part of the main chain of the polymer to form a bond. When at least two of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) are polycondensed to form a boron-containing polymer, X ^{5 '} and X ⁶ in the above formula (12) At least two of ^' , R ^{1 '} and R ^2' are a divalent group or a direct bond. When at least one of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) is polymerized alone to form a boron-containing polymer, X ^{5 '} and X ⁶ in the above formula (12) At least one of ^' , R ^{1 '} and R ^2' is a trivalent group or a direct bond.

The boron-containing polymer having the repeating unit represented by the above formula (12) may be the above formula (12) The one of the structures shown may be one or more of the structures including the above formula (12). When two or more types of structures represented by the above formula (12) are included, the two or more types of structures may be a random polymer, a block polymer, or a graft polymer. Further, it may be a case where a branch is present in the polymer main chain and three or more terminal portions are present or a dendrimer.

Boron-containing polymer having structural repeating units represented by the above formula (12), preferably in the above formula (12) R ^{1 'and} R ^2' are of the formula R (2) and R ¹ in the ^{2 the} same base. Further, it is preferable that R ^{1 '} and R ^{2 '} in the above formula (12) are a linear or branched hydrocarbon group having 1 to 30 carbon atoms and an alicyclic hydrocarbon group having 3 to 30 carbon atoms.

That is, the organic compound having a boron atom forming the buffer layer of the organic electroluminescent device is a boron-containing polymer obtained by polymerizing a monomer component containing the boron-containing compound represented by the formula (2), and is in the formula (2) R ¹ and R ^{2 are the} same or different, and the form of a linear or branched hydrocarbon group having 1 to 30 carbon atoms or an alicyclic hydrocarbon group having 3 to 30 carbon atoms is also a preferred embodiment of the present invention. One.

In the specific example of the structure of the repeating unit represented by the above formula (12), the structure obtained by the polycondensation is, for example, a structure of the following formulas (13-1) to (13-6). Among these, the structures of (13-1) and (13-6) are preferable. More preferably, the structure of (13-1). That is, the boron-containing polymer obtained from the boron-containing compound having the structure represented by the formula (2) and wherein X ⁵ and X ⁶ in the formula (2) are substituents having a reactive group is also one of the inventions.

As a combination of the above reactive groups capable of undergoing polycondensation, as long as it is capable of being polymerized The combination is not particularly limited, and examples thereof include a carboxyl group and a hydroxyl group, a carboxyl group and a thiol group, a carboxyl group and an amine group, a carboxylate group and an amine group, a carboxyl group and an epoxy group, a hydroxyl group and an epoxy group, and a thiol group. And epoxy groups, amine groups and epoxy groups, isocyanate groups and hydroxyl groups, isocyanate groups and thiol groups, isocyanate groups and amine groups, hydroxyl groups and halogen atoms, thiol groups and halogen atoms, borane groups and halogen atoms, Tin alkyl and halogen atoms, aldehyde and methyl, vinyl and halogen atoms, aldehyde and phosphonate methyl, haloalkyl and haloalkyl, fluorenylmethyl and fluorenylmethyl, aldehyde and acetonitrile An aldehyde group and an aldehyde group, a halogen atom and a boron alkyl group, a halogen atom and a magnesium halide, a halogen atom and a halogen atom, and the like.

Among these, a combination of a halogen atom and a borane group, and a combination of a halogen atom and a halogen atom are preferred.

When at least two of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) are polycondensed to form a boron-containing polymer, X ^{5 '} and X in the above formula (12) At least two of ^6' , R ^{1 '} and R ^2' represent a divalent group or a direct bond, and the divalent group represents a residue which is not desorbed by a polycondensation reaction between substituents having a reactive group. . In the case where a substituent having a reactive group which is a combination of the above-mentioned reactive groups capable of undergoing polycondensation is subjected to a polycondensation reaction, there are cases in which residues remain in the polymer and remain in the case of the former. When at least one of X ^{5 '} , X ^{6 '} , R ^{1 '} and R ^{2 '} represents a residue which is not desorbed by a polycondensation reaction between substituents having a reactive group, in the latter case, At least one of X ^{5 '} , X ^{6 '} , R ^{1 '} and R ^{2 '} represents a direct bond.

Further, when two or more repeating units represented by the above formula (12) are continuous, X ^{5 '} , X ^{6 '} , and R are formed between two repeating units such as, for example, -X ^5' -X ^{6 '} Two consecutive keys of ^1' and R ^2' , in which case either of the two is a direct key.

Specific examples of the case where a substituent having a reactive group which is a combination of the above-mentioned reactive group capable of undergoing polycondensation is subjected to a polycondensation reaction and a residue remains in the polymer include a substituent having a carboxyl group and a hydroxyl group. A combination of substituents. For example, when a -CH ₂ COOH group is subjected to a polycondensation reaction with a -CH ₂ CH ₂ OH group, the residue remaining in the polymer becomes a -CH ₂ (CO)-O-CH ₂ CH ₂ - group. Further, for example, when a substituent having a reactive group is composed only of a reactive group as in the reaction of a -COOH group and an -OH group, the residue remaining in the polymer becomes a -(CO)-O- group. .

Further, specific examples of the case where the combination of the reactive groups capable of undergoing polycondensation is subjected to a polycondensation reaction and the residue does not remain in the polymer include a combination of a boryl group and a halogen atom, a halogen atom and a halogen atom. .

In a specific example of the structure of the repeating unit represented by the above formula (12), a structure obtained by polymerizing at least one of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2), for example, is, for example, The structure obtained by the polymerization of X ⁶ is a structure of the following formula (14). Thus, when X ⁶ in the formula (2) is a substituent having a reactive group obtained by polymerization alone in the structure, a repeating unit having a structure in which X ^{6 '} is a trivalent group or a direct bond is obtained. Similarly, in the case where any of X ⁵ , X ⁶ , R ¹ and R ² in the formula (2) is a substituent having a reactive group obtained by polymerization alone in the structure, it becomes X ⁵ respectively. ^' , X ^6' , R ^{1 '} and R ^{2 '} are repeating units of a structure of a trivalent group or a direct bond.

Examples of the reactive group which can be polymerized alone include 3,5-dibromophenyl group. An alkenyl group, an alkynyl group, an epoxy group, a halogen atom or the like. The boron-containing compound of the above formula (2) can be polymerized by allowing the boron-containing compound of the above formula (2) to have at least one of these groups. Among these, an alkenyl group, an epoxy group, and a 3,5-dibromophenyl group are preferable.

In the X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2), the group to be subjected to polycondensation may be a substituent having a reactive group capable of undergoing polycondensation in the structure. Similarly, the group to be polymerized alone may be a substituent having the above-mentioned separately polymerizable reactive group in the structure. Examples of such a substituent include a linear or branched alkyl group having 1 to 4 carbon atoms, a cyclic alkyl group having 3 to 7 carbon atoms, and a linear or branched alkyl group having 1 to 8 carbon atoms. The hydrogen atom of any of the oxygen group, the aryl group or the heterocyclic group may be substituted with the above-mentioned reactive group capable of undergoing polycondensation or a reactive group which may be polymerized alone. Among these, a styryl group and a 3,5-dibromophenyl group are preferable.

The boron-containing polymer of the present invention is contained as long as it is represented by the above formula (2). If the monomer component of the boron compound is obtained, other monomer may be included in the monomer component.

That is, the boron-containing polymer formed by polymerizing the boron-containing compound represented by the formula (2) and another monomer represented by the following formula (15) is also included in the boron-containing polymer of the present invention: X ⁷ -AX ⁸ (15)

(In the formula, A represents a divalent group; and X ⁷ and X ^{8 are the} same or different and each represents a hydrogen atom or a monovalent substituent, and at least one of X ⁷ and X ⁸ is a substituent having a reactive group).

The A in the above formula (15) is not particularly limited as long as it is a divalent group, and examples thereof include benzene, naphthalene, anthracene, phenanthrene, and the like. , ruthenium, anthracene, anthracene, anthracene, anthracene, adamantane, anthracene, anthrone, dibenzofuran, oxazole, dibenzothiophene, furan, pyrrole, pyrroline, pyrrolidine, thiophene, dioxane Dioxolane, pyrazole, pyrazoline, pyrazolidine, imidazole, Oxazole, thiazole, Diazole, triazole, thiadiazole, pyran, pyridine, piperidine, two alkyl, Porphyrin Pyrimidine, pyridyl Piper ,three , trithiane, norbornene, benzofuran, anthracene, benzothiophene, benzimidazole, benzo Azole, benzothiazole, benzothiadiazole, benzo Diazole, hydrazine, quinoline, isoquinoline, coumarin, Porphyrin a metal complex such as a porphyrin, an acridine, a phenanthroline, a phenothiazine, a flavonoid, a triphenylamine, an acetoacetone, a benzhydrazine, a picolinic acid, a pyrene, a porphyrin or a hydrazine, or the like a derivative, a polymer or oligomer containing a structure of a derivative thereof, and the like.

Further, as the above substituent, the same substituent as in the above R ¹ and R ² can be used.

As the above-mentioned A, in addition to the above, for example, the structures of the following formulas (16-1) to (16-4) may be mentioned.

(wherein, Ar1, Ar2, and Ar3 are the same or different and each represents an extended aryl group, a divalent heterocyclic group or a divalent group having a metal complex structure; and Z1 represents -C≡C-, -N(Q3)-, -(SiQ4Q5)b-, or a direct bond; Z2 represents -CQ1=CQ2-, -C≡C-, -N(Q3)-, -(SiQ4Q5)b-, or a direct bond; Q1 and Q2 are the same or different, Represents a hydrogen atom, an alkyl group, an aryl group, a monovalent heterocyclic group, a carboxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylalkoxycarbonyl group, a heteroaryloxycarbonyl group, or a cyano group; Q3, Q4, and Q5 The same or different, representing a hydrogen atom, an alkyl group, an aryl group, a monovalent heterocyclic group, or an arylalkyl group; a represents an integer of 0 to 1; b represents an integer of 1 to 12)

The above-mentioned "aryl group" means an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon, and the carbon number of the ring is usually from about 6 to 60, preferably from 6 to 20. The aromatic hydrocarbon also includes a condensed ring, a benzene ring or a condensed ring in which two or more direct bonds are bonded, or a group such as a vinyl group is bonded.

Examples of the above-mentioned extended aryl group include a group represented by the following formulas (17-1) to (17-23). Among these, a phenyl group, a biphenyl group, a fluorene-diyl group, and a fluorenyl-diyl group are preferred.

Further, in the formulae (17-1) to (17-23), R is the same or different and represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, or an arylthio group. , arylalkyl, arylalkoxy, arylalkylthio, decyl, decyloxy, decylamino, quinone imine, imine residue, amine, substituted amine, substituted Mercapto group, substituted decyloxy group, substituted decane Thio group, substituted mercaptoamine group, monovalent heterocyclic group, heteroaryloxy group, heteroarylthio group, arylalkenyl group, arylethynyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, aromatic Alkoxycarbonyl, heteroaryloxycarbonyl or cyano.

In the formula (17-1), a line intersecting the ring structure as indicated by x-y and a line attached indicates that the ring structure is directly bonded to an atom in the bonded portion. That is, it means that it is directly bonded to any carbon atom of the ring of the line represented by x-y in the formula (17-1), and the bonding position in the ring structure is not limited. In the formula (17-10), as indicated by the line z-, the line marked on the apex of the ring structure indicates that the ring structure is directly bonded to the atom in the bonded portion at this position. Further, the line marked with R attached to the ring structure indicates that R can be bonded to the ring structure, and a plurality of bonds can be bonded, and the bonding position is not limited.

Further, in the formulae (17-1) to (17-10) and (17-15) to (17-20), a carbon atom may be substituted with a nitrogen atom, an oxygen atom or a sulfur atom, and a hydrogen atom may be substituted. A fluorine atom.

The above-mentioned divalent heterocyclic group means that two hydrogen atoms are removed from the heterocyclic compound. The residual atomic group obtained usually has a carbon number of about 3 to 60. As the heterocyclic compound, the organic compound having a cyclic structure also includes not only a carbon atom but also a hetero atom such as oxygen, sulfur, nitrogen, phosphorus, boron or arsenic in the ring.

Examples of the above-mentioned divalent heterocyclic group include a heterocyclic group represented by the following formulas (18-1) to (18-38).

Further, in the formulae (18-1) to (18-38), R is the same as R of the above-mentioned extended aryl group. Y represents O, S, SO, SO ₂ , Se, or Te. Regarding the line attached to the ring structure, the line marked on the apex of the ring structure, the line marked on the R attached to the ring structure, and the formula (17-1)~(17-23 )the same.

Further, in the formulae (18-1) to (18-38), a carbon atom may be substituted with a nitrogen atom, an oxygen atom or a sulfur atom, and a hydrogen atom may be substituted with a fluorine atom.

The above-mentioned divalent group having a metal complex structure means a residual divalent group obtained by removing two hydrogen atoms from an organic ligand of a metal complex having an organic ligand. The carbon number of the organic ligand is usually about 4 to 60, and examples thereof include 8-hydroxyquinoline and derivatives thereof, benzoquinolinol and derivatives thereof, 2-phenyl-pyridine and derivatives thereof, 2-phenyl-benzothiazole and its derivatives, 2-phenyl-benzo Oxazole and its derivatives, porphyrins and their derivatives.

Examples of the center metal of the above metal complex include aluminum, zinc, and antimony. Examples of the metal complex having an organic ligand include ruthenium, platinum, gold, rhodium, iridium, etc., and a low molecular fluorescent material. Examples of the phosphorescent material include a known metal complex and triplet luminescence. Compounds, etc.

As the above-mentioned divalent group having a metal complex structure, specifically, for example, The groups represented by the following formulas (19-1) to (19-7) are listed.

Further, in the formulae (19-1) to (19-7), R is the same as R of the above-mentioned extended aryl group. The line attached to the apex of the ring structure indicates direct bonding as in the equations (17-1) to (17-23).

Further, in the formulae (19-1) to (19-7), a carbon atom may be substituted with a nitrogen atom, an oxygen atom or a sulfur atom, and a hydrogen atom may be substituted with a fluorine atom.

Further, as the structure of A, a structure of the following formula (16-5) can also be mentioned.

(wherein Ar4, Ar5, Ar6 and Ar7 are the same or different and represent an aryl group or a divalent heterocyclic group; Ar8, Ar9 and Ar10 are the same or different and represent an aryl group or a monovalent heterocyclic group; o and p are the same or different and represent 0 or 1, and 0≦o+p≦1)

Specific examples of the structure represented by the above formula (16-5) include the structures represented by the following formulas (20-1) to (20-8).

Furthermore, in the formulae (20-1) to (20-8), R and the above-mentioned extended aryl group have The same R. The line attached to the apex of the ring structure indicates direct bonding as in the equations (17-1) to (17-23). In the above formulae (20-1) to (20-8), one structural formula has a plurality of R's, and the like may be the same or different bases. In order to improve the solubility in a solvent, it is preferable to have a group other than one or more hydrogen atoms, and it is preferable that the shape of the structure including the substituent has a small symmetry. Further, in the above formulae (20-1) to (20-8), when R contains an aryl group or a heterocyclic group in a part thereof, the one or more substituents may further have one or more substituents. Further, in the substituent in which R includes an alkyl chain, the substituent may be any of a straight chain, a branch or a ring, or a combination thereof, and examples of the case of a non-linear chain include, for example, isopentyl group, and Ethylhexyl, 3,7-dimethyloctyl, cyclohexyl, 4-C1-C12 alkylcyclohexyl, and the like. In order to improve the solubility of the boron-containing copolymer of the present invention in a solvent, it is preferred that one or more alkyl chains having a cyclic or branched group are contained.

Further, a plurality of Rs may be joined to form a ring. Further, in the case where R is a group containing an alkyl chain In the form, the alkyl chain may also be interrupted via a group containing a hetero atom. Examples of the hetero atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

As the structure of the above A, among the above, the formula (16-5), the formula (17-9), the formula (18-16), and the formula (18-28) are preferable.

The boron-containing polymer is formed by polymerizing at least one group of X ⁵ , X ⁶ , R ¹ and R ^{2 in} the formula (2) with at least one group of X ⁷ and X ⁸ in the formula (15). Repeat unit. That is, a boron-containing polymer having a structure of a repeating unit represented by the following formula (21) is further contained in the boron-containing polymer of the present invention:

(wherein, the arc of the dotted line, the dotted line in the skeleton portion connecting the boron atom and the nitrogen atom, and the arrow pointing from the nitrogen atom to the boron atom are the same as in the formula (2); X ^{5 '} , X ^{6 '} , R ^{1 '} and R ^{2 'is the} same as formula (12); A is the same or different and represents a divalent group; X ^{7 '} and X ^{8 '} respectively represent the same group as X ⁷ and X ^{8 of} formula (15), a divalent group, and a trivalent group. Base, or direct key).

The above formula (21) represents any one of X ^{5 '} , X ^{6 '} , R ^{1 '} and R ^{2 '} and any one of X ^{7 '} and X ^{8 '} is a part of the main chain of the polymer. Form a bond.

In the boron-containing polymer having the repeating unit represented by the above formula (21), the repeating unit derived from the above formula (2) and the repeating unit derived from the above formula (15) may be a random polymer and may be a block. The polymer may also be a graft polymer. Further, it may be a case where a branch is present in the polymer main chain and three or more terminal portions are present or a dendrimer. Further, a polymer obtained by polycondensing a boron-containing compound represented by the above formula (2) and a compound represented by the above formula (15) may be used.

Further, the boron-containing polymer having the repeating unit represented by the above formula (21) may be one containing one repeating unit derived from the above formula (2) and the repeating unit derived from the above formula (15), or may be Contains 2 or more types. In the case where two or more types of repeating units are contained, the two or more kinds of structures may be a random polymer, may be a block polymer, or may be a graft polymer. Further, it may be a case where a branch is present in the polymer main chain and three or more terminal portions are present or a dendrimer.

The boron-containing polymer represented by the above formula (21) has (i) any one of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) and X in the above formula (15). ⁷ and X ^{8 are formed} as a part of a main chain of the polymer; (i) any one of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) and the above formula (15) The case where any one of X ⁷ and X ⁸ forms a bond as a part of the main chain of the polymer. Specific examples of the configuration of the repeating unit in such a case include the following formulas (22) and (23).

(i) either of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) and X ⁷ and X ⁸ in the above formula (15) form a bond as a part of the main chain of the polymer In the case of random addition of the repeating unit derived from the above formula (2) and the repeating unit derived from the above formula (15), it may be a block addition or a Any one of X ⁵ , X ⁶ , R ¹ and R ^{2 in} the above formula (2) is polycondensed with X ⁷ and/or X ⁸ in the above formula (15), among which In the above formula (2), the polymer of any one of X ⁵ , X ⁶ , R ¹ and R ² is polycondensed with X ⁷ and/or X ⁸ in the above formula (15). In the formula (2), X ⁵ and X ⁶ are polycondensed with X ⁷ and X ⁸ in the above formula (15), and the polymer represented by the following formula (24) is a repeating unit.

In the case of the structure of the above (i), the repetition represented by the above formula (21) In the unit, as a specific example of the structural part derived from the above formula (2), there are structures of the above formulas (13-1) to (13-6). Among these, the structures of (13-1) and (13-6) are preferable. More preferably, the structure of (13-1).

A reactive group in the case where any one of X ⁵ , X ⁶ , R ¹ and R ^{2 in} the above formula (2) is polycondensed with any one of X ⁷ and X ^{8 in} the above formula (15) The combination of the above may be the same as the above. That is, in the case where any one of X ⁵ , X ⁶ , R ¹ and R ² in the above formula (2) is polycondensed with any of X ⁷ and X ^{8 in} the above formula (15), In X ⁷ and X ⁸ in the formula (15), as the group of the polycondensation, any substituent having the above-mentioned reactive group capable of undergoing polycondensation is preferably contained in the structure.

Further, in the case where any of X ⁷ and X ⁸ in the above formula (15) is a substituent having a reactive group which can be polymerized alone in the structure, the substituent preferably has the above-mentioned separately polymerizable structure. Any substituent of the reactive group.

The group to be bonded at both ends of the boron-containing polymer of the present invention is not particularly limited System, again, can be the same or different. Examples of the group bonded to the both terminals include a hydrogen atom, a halogen atom, an aryl group which may have a substituent, an oligoaryl group, a monovalent heterocyclic group, a monovalent oligomeric heterocyclic group, and an alkyl group. , alkoxy, alkylthio, aryloxy, arylthio, arylalkyl, arylalkoxy, arylalkylthio, alkenyl, alkynyl, allyl, amine, azo ,carboxy, fluorenyl, alkoxycarbonyl, decyl, nitro, cyano, decyl, tin alkyl, boralkyl, phosphino, decyloxy, arylsulfonyloxy, alkyl sulfonate Alkoxy groups, etc.

The weight average molecular weight of the boron-containing polymer in the present invention is preferably from 10 ³ to 10 ⁸ . When the weight average molecular weight is in such a range, it can be favorably thinned. More preferably, it is 10 ³ to 10 ⁷ , and further preferably 10 ⁴ to 10 ⁶ .

The weight average molecular weight can be measured by a gel permeation chromatography (GPC apparatus, developing solvent: chloroform) in the following apparatus and measurement conditions in terms of polystyrene.

High-speed GPC device: HLC-8220GPC (manufactured by Tosoh Corporation)

Developing solvent chloroform

Column TSK-gel GMHXL×2

Dissolution flow rate 1ml/min

Column temperature 40 ° C

The boron-containing polymer in the present invention is produced by polymerizing a monomer component containing the boron-containing compound represented by the above formula (2). The monomer component may contain another monomer as long as it contains the boron-containing compound represented by the above formula (2), and preferably contains a boron-containing compound represented by the above formula (2) with respect to 100% by mass of the entire monomer component. 0.1 to 99.9 mass%. More preferably, it is 10 to 90% by mass.

Further, in the polymerization reaction, the solid content concentration of the monomer component can be dissolved at 0.01% by mass. If it is too thin, the efficiency of the reaction may be deteriorated. If it is too thick, it may be difficult to control the reaction. Therefore, it is preferably 0.1 to 20% by mass.

As the other monomer, it is preferred to have the structure represented by the above formula (15) By. In the above-mentioned monomer component, the boron-containing compound represented by the above formula (2) and the compound represented by the formula (15) may be contained alone or in combination of two or more.

As the other monomer, the structure represented by the above formula (15) is contained In the case of the compound, it is preferred to contain the boron-containing compound 1 mol represented by the above formula (2) contained in the monomer component, and the ratio represented by the above formula (15) is contained in a ratio of 0.3 to 3 mol. a compound of structure. More preferably, it is a ratio of 0.2 to 2 moles with respect to the boron-containing compound 1 represented by the above formula (2).

In the compound represented by the above formula (15), X ⁷ and X ⁸ may be the same as those having a reactive group in the above X ⁵ and X ⁶ .

In the case of forming a boron-containing polymer in the present invention by a polycondensation reaction The method for producing the boron-containing polymer is not particularly limited, and can be produced, for example, by the production method described in JP-A-2011-184430.

The boron-containing compound represented by the above formula (1) or the above formula (2) The boron-containing polymer obtained by polymerizing the monomer component of the boron-containing compound can achieve uniform film formation by coating, and has a lower HOMO, LUMO energy level, and thus can be preferably used as the first aspect of the present invention. 1 material of organic electroluminescent element.

[Organic Electroluminescent Device of Second Preferred Embodiment of the Present Invention]

The organic electroluminescent device of the second preferred embodiment of the present invention (hereinafter also referred to as the second organic electroluminescent device of the present invention) is a buffer layer containing a reducing agent. In the organic electroluminescent device of the present invention, as described below, the first electrode is a cathode, the second electrode is an anode, and the buffer layer is a layer that functions as an electron transport layer depending on the material for forming the buffer layer.

In the organic electroluminescent device, a hole is supplied from the anode, and electrons are supplied from the cathode, which is equal to The light layer is recombined to cause light emission, and a part of the hole from the anode supply reaches the cathode through the second metal oxide layer, the light-emitting layer, the buffer layer, and the first metal oxide layer, and is considered to be an organic electroluminescence light. One reason for the reduced efficiency of components. By providing a buffer layer of a specific thickness, it is possible to suppress the hole from reaching the cathode, thereby improving the efficiency of the element. On the other hand, if the thickness of the buffer layer is thickened, the migration of electrons from the cathode to the light-emitting layer is hindered, and the light-emitting layer is reached in a portion other than the edge portion and the edge portion where the thickness of the buffer layer is relatively less affected. There is a difference in the proportion of the electrons, and a phenomenon in which only the edge portion emits light is generated. On the other hand, when the buffer layer contains a reducing agent having a function of supplying electrons, sufficient electrons can be supplied to the light-emitting layer, and re-engagement of electrons and holes can be efficiently performed, and the driving voltage necessary for light emission also changes. low. Thereby, an organic electroluminescence device having extremely excellent luminous efficiency can be obtained.

The second organic electroluminescent device of the present invention is preferably the first electrode and the second electrode. The electrodes have a first metal oxide layer, a buffer layer, a low molecular compound layer containing a light emitting layer laminated on the buffer layer, and a second metal oxide layer, and the buffer layer contains a reducing agent.

In the second organic electroluminescent device of the present invention, the first metal oxide layer, the buffer layer, and the low molecular compound layer containing the light emitting layer laminated on the buffer layer are sequentially provided between the first electrode and the second electrode. Further, the second metal oxide layer may have other layers than those described above. The meaning of the low molecular compound in the present invention is as described above.

In the second organic electroluminescent device of the present invention, the buffer layer is preferably coated by coating A layer having an average thickness of 5 to 100 nm formed by a solution containing an organic compound.

In the case where the second organic electroluminescent device of the present invention has a configuration in which a low molecular compound layer containing a light-emitting layer is laminated on the first metal oxide layer, there is a problem that the metal oxide layer is contacted. Since the low molecular compound layer is crystallized, the leakage current increases and the current efficiency decreases, and in a remarkable case, uniform surface light emission cannot be obtained due to crystallization. In the organic-inorganic hybrid organic electroluminescent device, the reason why the low molecular compound layer is crystallized is as described above. Such a crystallization is a problem unique to an organic-inorganic hybrid organic electroluminescence device. A new problem in the case of using a low molecular compound as a main component of the light-emitting layer.

In order to solve this problem, when a buffer layer having an average thickness of 5 to 100 nm formed by coating a solution containing an organic compound is provided between the first metal oxide layer and the low molecular compound layer containing the light-emitting layer, the low molecular compound When the crystallization of the low-molecular compound in the layer is suppressed, even when the organic-inorganic hybrid organic electroluminescent device has a layer formed of a low molecular compound as a light-emitting layer or the like, leakage current can be suppressed, and It suppresses uneven surface luminescence caused by leakage current.

As described above, when the thickness of the buffer layer is thickened, it is observed that only the edge portion of the light-emitting layer emits light more strongly than other portions, whereas the buffer layer contains a reducing agent, thereby suppressing This kind of illumination only at the edge portion achieves uniform surface illumination. Therefore, according to the present invention, even if the buffer layer has an average thickness of 5 to 100 nm, good element characteristics can be obtained.

The second organic electroluminescent device of the present invention is formed by coating to form a buffer layer capable of functioning as an electron transport layer, and the buffer layer contains a reducing agent as an n-type dopant. With such a configuration, the light-emitting layer can be formed of a low molecular compound, and the light-emitting efficiency is also excellent.

The method or material for forming the buffer layer, the preferred thickness, and the like are as follows.

The reducing agent contained in the buffer layer is not a compound for electron-donating, and there is no Particularly limited, a hydride reducing agent capable of performing hydride reduction is preferred.

As the hydride reducing agent, a 2,3-dihydrobenzo[d]imidazole compound; a 2,3-dihydrobenzo[d]thiazole compound; 2,3-dihydrobenzo[d] can be used. One or two or more kinds of the azole compound, the triphenylmethane compound, and the dihydropyridine compound.

Thus, the hydride reducing agent is selected from the group consisting of 2,3-dihydrobenzo[d]imidazole compounds, 2,3-dihydrobenzo[d]thiazole compounds, 2,3-dihydrobenzo[d] The form of at least one of the group consisting of the azole compound, the triphenylmethane compound, and the dihydropyridine compound is one of the preferred embodiments of the present invention.

As the hydride reducing agent, a 2,3-dihydrobenzo[d]imidazole compound or a dihydropyridine compound is preferred among them. More preferably (4-(1,3-dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)phenyl)dimethylamine (N-DMBI), or 2,6- Dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid diethyl ester (Hantzsch ester).

The amount of the reducing agent contained in the buffer layer is relative to the organication forming the buffer layer The compound is 100% by mass, preferably 0.1 to 15% by mass. When the reducing agent is contained in such a ratio, the luminous efficiency of the organic electroluminescent device can be made sufficiently high. More preferably, it is 0.5 to 10% by mass, and more preferably 1 to 5% by mass based on 100% by mass of the organic compound forming the buffer layer.

The second organic electroluminescent device of the present invention comprises a package laminated on a buffer layer The low molecular compound layer containing the light emitting layer, the low molecular compound layer containing the light emitting layer means one layer formed of a low molecular compound or a plurality of laminated layers formed of a low molecular compound and one of which is a light emitting layer. By. In other words, the low molecular compound layer including the light-emitting layer means any one of a light-emitting layer formed of a low molecular compound or a light-emitting layer formed of a low molecular compound and another laminated layer formed of a low molecular compound. . The other layer formed of the low molecular compound may be one layer or two or more layers. Further, the order of lamination of the light-emitting layer and the other layers is not particularly limited.

The other layer formed of the low molecular compound is preferably a hole transport layer or electricity. Sub transport layer. That is, in the case where the low molecular compound layer is composed of a plurality of layers, it is preferred to have a hole transport layer and/or an electron transport layer as a layer other than the light emitting layer. As described above, the organic electroluminescence device has one of a preferred embodiment of the second organic electroluminescence device of the present invention in that the hole transport layer and/or the electron transport layer are separate layers from the light-emitting layer.

In the case where the second organic electroluminescent device of the present invention has a hole transport layer as an independent layer, it is preferable to have a hole transport layer between the light-emitting layer and the second metal oxide layer. In the case where the second organic electroluminescent device of the present invention has an electron transport layer as an independent layer, it is preferred to have an electron transport layer between the buffer layer and the light-emitting layer.

When the second organic electroluminescent device of the present invention does not have a hole transport layer or an electron transport layer as an independent layer, any one of the layers of the second organic electroluminescent device of the present invention has a necessary structure. Both have the functions of these layers.

One of the preferred embodiments of the second organic electroluminescent device of the present invention is organic electricity. The excitation light element is composed only of the first electrode, the first metal oxide layer, the buffer layer, the light-emitting layer, the hole transport layer, the second metal oxide layer, and the second electrode, and any of the layers has both electrons The form of the function of the transport layer.

Further, the organic electroluminescence device is composed only of the first electrode, the first metal oxide layer, the buffer layer, the light-emitting layer, the second metal oxide layer, and the second electrode, and any of the layers has a hole The form of the function of the transport layer and the electron transport layer is also one of the preferred embodiments of the second organic electroluminescent device of the present invention.

In the second organic electroluminescence device of the present invention, the first electrode is a cathode, and the second The electrode is an anode. The compound which can be used as the first electrode and the second electrode and the like thereof are the same as those of the first organic electroluminescent device of the present invention described above.

Further, preferred values of the average thickness of the first electrode and the second electrode are also the same as those of the first organic electroluminescent device of the present invention.

The first metal oxide layer is a layer that functions as an electron injection layer, and the second metal oxide layer functions as a hole injection layer.

Specific examples of the compound forming the first metal oxide layer and the second metal oxide layer and preferred ones thereof are the same as those of the first organic electroluminescence device of the present invention described above.

The average thickness of the first metal oxide layer is not particularly limited, but is preferably 1 to 1000 nm. More preferably 2 to 100 nm.

The average thickness of the second metal oxide layer is not particularly limited, but is preferably 1 to 1000 nm. More preferably 5 to 50 nm.

The average thickness of the first metal oxide layer can be obtained by a stylus type step meter and a spectroscopic ellipsometer Determination.

The average thickness of the second metal oxide layer can be measured by a crystal oscillation film thickness gauge at the time of film formation.

As the material of the light-emitting layer, any of materials which are generally used as the light-emitting layer can be used. A low molecular compound may also be used in combination.

As the low molecular weight, the same as the low molecular weight of the first organic electroluminescence device of the present invention described above can be used.

The above light-emitting layer may also contain a dopant. As a dopant, it can be used with the above In the case where the dopant in the first organic electroluminescence device of the invention is the same, the preferable range of the content of the dopant in the case where the light-emitting layer contains a dopant is also the same as that of the first organic electroluminescent device of the present invention. The situation is the same.

Regarding the light-emitting layer of the second organic electroluminescence device of the present invention, among the above Jia is a person who contains phosphorescent materials. By including the phosphorescent material in the light-emitting layer, the organic electroluminescent device is more excellent in luminous efficiency.

In the case where the light-emitting layer contains a phosphorescent material, it is preferred to form the light-emitting layer from a material containing a phosphorescent material as a guest material (dopant) in the host material. In the case where the light-emitting layer is formed of such a material, the content of the phosphorescent material relative to the material forming the light-emitting layer is preferably such that the dopant in the case where the light-emitting layer contains a dopant is opposite to the light-emitting layer. The content of the materials is the same.

As the phosphorescent material, the following formulas (25) and (26) can be preferably used. A compound represented by either.

(In the formula (25), a circular arc of a broken line indicates a ring structure together with a part of a skeleton portion composed of an oxygen atom and three carbon atoms, and a ring structure formed by containing a nitrogen atom is a heterocyclic structure; X', X" The same or different, a monovalent substituent representing a hydrogen atom or a substituent which becomes a ring structure may be bonded to a ring structure forming a circular arc portion of a broken line; X', X" may also be bonded and One of the two ring structures represented by the arc of the dotted line together forms a new ring structure; and in the case where n ² is 2 or more, a plurality of X's or X" may be bonded to each other to form a substitution. A dotted line in a skeleton portion composed of a nitrogen atom and three carbon atoms indicates that two atoms linked by a broken line are bonded by a single bond or a double bond; M' represents a metal atom; an arrow pointing from the nitrogen atom to M' represents nitrogen The atom coordinates the M'atom; n ² represents the valence of the metal atom M')

(In the formula (26), a circular arc of a broken line indicates a ring structure together with a part of a skeleton portion composed of an oxygen atom and three carbon atoms, and a ring structure formed by containing a nitrogen atom is a heterocyclic structure; X', X" The same or different, a monovalent substituent representing a hydrogen atom or a substituent which becomes a ring structure may be bonded to a ring structure forming a circular arc portion of a broken line; X', X" may also be bonded and A part of the two ring structures represented by the arc of the dotted line together form a new ring structure. The dotted line in the skeleton portion composed of a nitrogen atom and three carbon atoms represents two atoms linked by a broken line as a single bond or a double bond. M' represents a metal atom; the arrow from the nitrogen atom pointing to M' indicates that the nitrogen atom coordinates the M'atom; n ² represents the valence of the metal atom M'; the arc connecting the solid line of X ^a and X ^b It is indicated that X ^a and X ^{b are} bonded by at least one other atom, and X ^a and X ^b together form a ring structure; X ^a and X ^{b are the} same or different, and represent any of an oxygen atom, a nitrogen atom and a carbon atom. The arrow from X ^b to M' indicates that X ^b coordinates to the M'atom;m' is the number from 1 to 3)

Examples of the ring structure represented by the circular arc of the dotted line in the above formulas (25) and (26) include an aromatic ring or a heterocyclic ring having 2 to 20 carbon atoms, and examples thereof include a benzene ring, a naphthalene ring, and an anthracene ring. Hydrocarbon ring; pyridine ring, pyrimidine ring, pyridyl Ring, three Ring, benzothiazole ring, benzothiol ring, benzo Oxazole ring, benzoxetylene ring, benzimidazole ring, quinoline ring, isoquinoline ring, quin a sulfonate ring, and a heterocyclic ring such as a pyridine ring, a thiophene ring, a furan ring, a benzothiophene ring, or a benzofuran ring.

In the above formula (25) and (26), examples of the substituent of the ring structure represented by X' and X" include a halogen atom, a carbon number of 1 to 20, preferably a carbon number of 1 to 10. An alkyl group having 1 to 20 carbon atoms, preferably an aralkyl group having 1 to 10 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and 1 to 20 carbon atoms, preferably carbon. 1 to 10 aryl, arylamine, cyano, amine, fluorenyl, alkoxycarbonyl having 1 to 20 carbon atoms, preferably 1 to 10 carbon, carboxyl group, carbon number 1 to 20, Preferably, it is an alkoxy group having 1 to 10 carbon atoms, a carbon number of 1 to 20, preferably an alkylamino group having 1 to 10 carbon atoms, a carbon number of 1 to 20, preferably a dialkyl group having 1 to 10 carbon atoms. Amino group, arylalkylamino group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, haloalkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, hydroxyl group, aryloxy group, hydrazine Azolyl and the like.

In the case where the substituent represented by X' and X" has an aryl group or an arylamine group, the aromatic ring contained in the aryl group or the arylamine group may further have a substituent. The substituent in this case is the same as the specific example of the substituent represented by the above X' and X".

In the above formulas (25) and (26), represented by X' and X" When the substituents are bonded to each other and form a new ring structure together with one of the two ring structures represented by the arc of the broken line, the two ring structures represented by the arcs of the merged dashed line and the ring of the new ring structure The structure is, for example, the following structures (27-1) and (27-2).

In the above formula (25) and formula (26), examples of the metal atom represented by M' include ruthenium, rhodium, palladium, silver, rhodium, iridium, iridium, platinum, and gold.

Examples of the structure represented by the above formula (26) include the structures of the following formulas (28-1) and (28-2).

(In the formulae (28-1) and (28-2), R ³ to R ^{5 are the} same or different and each represents a hydrogen atom or a monovalent substituent; and in the formula (28-2), R ³ to R ⁵ are monovalent. In the case of a substituent, the ring structure may have a plurality of monovalent substituents; an arrow pointing from the nitrogen atom to M' and an arrow pointing from the oxygen atom to M' indicate that the nitrogen atom and the oxygen atom coordinate the M'atom; The circular arc, the dotted line in the skeleton portion composed of a nitrogen atom and three carbon atoms, X', X", M', n ² , m' is the same as in the formula (26)

Examples of the monovalent substituent of R ³ to R ⁵ include the same substituents as those of the ring structure represented by X' and X" in the above formulas (25) and (26).

Specific examples of the compound represented by the above formula (25) or (26) include compounds represented by the following formulas (29-1) to (29-30).

As the phosphorescent material of the present invention, one type or two or more types of the above may be used, and among these, tris(2-phenylpyridine)anthracene (Ir) represented by the above formula (29-1) is preferable. (ppy) ₃ ), tris(1-phenylisoquinoline)indole (Ir(piq) ₃ ) represented by the above formula (29-19), and bis(2-A represented by the above formula (29-27) Dibenzo-[f,h]quina (i(MDQ) ₂ (acac)), three [3-methyl-2-phenylpyridine] oxime (Ir(mpy) ₃ ) represented by the above formula (29-28) Wait.

As the host material, a metal error represented by the following formula (30) is exemplified. The metal complex represented by the following formula (31) and the metal complex represented by the following formula (32) may be used alone or in combination of two or more.

(In the formula (30), the circular arc of the broken line indicates a ring structure together with a portion of the skeleton portion connecting the oxygen atom and the nitrogen atom, and the ring structure including Z ¹ and the nitrogen atom is a heterocyclic structure; X', X" The same or different, a monovalent substituent representing a hydrogen atom or a substituent which becomes a ring structure may be bonded to a ring structure forming a circular arc portion of a broken line; X', X" may also be bonded and One of the two ring structures represented by the arc of the dotted line together forms a new ring structure; the dotted line in the skeleton portion connecting the oxygen atom and the nitrogen atom indicates that two atoms linked by a broken line are bonded by a single bond or a double bond; Represents a metal atom; Z ¹ represents a carbon atom or a nitrogen atom; an arrow pointing from the nitrogen atom to M indicates that the nitrogen atom coordinates the M atom; R ⁰ represents a monovalent substituent or a divalent linking group; m represents the number of R ⁰ , is 0 or 1; n ³ represents the valence of the metal atom M; r is the number of 1 or 2)

(wherein X' and X" are the same or different and each represents a hydrogen atom or a monovalent substituent which becomes a substituent of a quinoline ring structure, and may also be bonded to a plurality of quinoline ring structures; M represents a metal atom; The arrow from the nitrogen atom to M indicates that the nitrogen atom coordinates the M atom; R ⁰ represents a monovalent substituent or a divalent linking group; m represents the number of R ⁰ , which is a number of 0 or 1; n ³ represents a metal atom The price of M; r is the number of 1 or 2)

(wherein, the circular arc of the dotted line indicates a ring structure together with a portion of the skeleton portion connecting the oxygen atom and the nitrogen atom, and the ring structure formed by including Z ¹ and the nitrogen atom is a heterocyclic structure; X', X" are the same or different , a hydrogen atom, or a monovalent substituent which becomes a substituent of a ring structure, may also be bonded to a ring structure forming a circular arc portion of a broken line; X', X" may also be bonded to a circle of a dotted line One of the two ring structures represented by the arc forms a new ring structure together; the dotted line in the skeleton portion connecting the oxygen atom and the nitrogen atom indicates that two atoms linked by a broken line are bonded by a single bond or a double bond; M represents a metal atom. Z ¹ represents a carbon atom or a nitrogen atom; an arrow pointing from the nitrogen atom to M indicates that the nitrogen atom coordinates the M atom; n ³ represents the valence of the metal atom M; an arc representing the solid line connecting X ^a and X ^b X ^a and X ^{b are} bonded by at least one other atom, and X ^a and X ^b together form a ring structure; and, in addition, at least one other atom may also contain ^a bond between X ^a and X ^b . bond; X ^a, X ^b are the same or different, represent any one of an oxygen atom, a nitrogen atom, a carbon atom of one Arrow pointing from X ^b X ^b M represents the atom is coordinated to M; m 'is a number of 1 to 3)

In the case of the above formula (30), when r is 1, it is a metal complex represented by the following formula (33-1) having one M atom in the structure, and when r is 2, it becomes a structure. A metal complex represented by the following formula (33-2) having two M atoms.

In the above formulas (30) and (32), the ring structure represented by the circular arc of the broken line may be a ring structure composed of one ring or a ring structure composed of two or more rings. Examples of the ring structure include an aromatic ring or a heterocyclic ring having 2 to 20 carbon atoms, and examples thereof include an aromatic ring such as a benzene ring, a naphthalene ring or an anthracene ring; a diazole ring, a thiazole ring, and an isothiazole ring. Oxazole ring, different Oxazole ring, thiadiazole ring, Diazole ring, triazole ring, imidazole ring, imidazoline ring, pyridine ring, pyridyl Ring, 嗒 Ring, pyrimidine ring, two Ring, three Ring, benzimidazole ring, benzothiazole ring, benzo A heterocyclic ring such as an azole ring or a benzotriazole ring.

Among these, a benzene ring, a thiazole ring, an isothiazole ring, Oxazole ring, different Oxazole ring, thiadiazole ring, Diazole ring, triazole ring, imidazole ring, imidazoline ring, pyridine ring, hydrazine Ring, pyrimidine ring, benzimidazole ring, benzothiazole ring, benzo Oxazole ring, benzotriazole ring.

In the above formulae (30) to (32), examples of the substituent of the ring structure represented by X' and X" include those represented by X' and X" in the above formulas (25) and (26). The ring structure has the same substituents.

In the above formulas (30) and (32), the substituents of the ring structure represented by X' and X" are bonded to each other and form a new one together with one of the two ring structures represented by the arc of the broken line. In the case of the ring structure, as the ring structure of the two ring structures and the new ring structure represented by the arc of the merging line, for example, the structures of the above (27-1) and (27-2) can be cited.

In the above formulae (30) to (32), the metal atom represented by M is preferably a metal atom of Groups 1 to 3, Group 9, Group 10, Group 12 or Group 13 of the periodic table, preferably zinc. Any of aluminum, gallium, platinum, rhodium, ruthenium, osmium, and magnesium.

In the above formula (30) and formula (31), when R ⁰ is a monovalent substituent, the monovalent substituent is preferably any one of the following formulas (34-1) to (34-3).

(wherein, Ar ¹ to Ar ⁵ represent a structure in which an aromatic ring, a hetero ring, or two or more aromatic rings or heterocyclic rings which may have a substituent may be directly bonded, and Ar ³ to Ar ⁵ may have the same structure or different structures. ;Q ⁰ represents a helium atom or a helium atom)

Specific examples of the aromatic ring or the hetero ring of Ar ¹ to Ar ⁵ include the same as the specific examples of the aromatic ring or the hetero ring of the ring structure represented by the arc of the broken line in the above formula (30), and two or more examples thereof. The structure in which the aromatic ring or the hetero ring is directly bonded may be a structure in which two or more ring structures exemplified as specific examples of the aromatic ring or the hetero ring are directly bonded. Further, in this case, two or more aromatic rings or heterocyclic rings directly bonded may have the same ring structure or different ring structures.

Specific examples of the substituent of the aromatic ring or the hetero ring include the same as the specific examples of the substituent of the aromatic ring or the hetero ring represented by the ring structure represented by the circular arc in the above formula (30).

In the above formulas (30) and (31), when R ⁰ is a divalent linking group, R ^{0 is} preferably any of -O- and -CO-.

The above-described formula (32), the structure is formed by an arc of a solid line X ^a, X ^b and X ^a and X ^b connected to it or may comprise a plurality of ring structures. The ring structure may be formed by including X ^a and X ^{b ,} and the ring structure in this case may be the same as the ring structure represented by the arc of the broken line in the above formulas (30) and (32) or the pyrazole ring. A structure comprising X ^a and X ^b to form a pyrazole ring is preferred.

In the above formula (32), the arc of the solid line connecting X ^a and X ^b may be composed only of carbon atoms, and may contain other atoms. Examples of the other atom include a boron atom, a nitrogen atom, and a sulfur atom.

Further, the circular arc connecting the solid lines of X ^a and X ^b may include one or two or more ring structures other than the ring structure formed by X ^a and X ^{b ,} and the ring structure in this case may be exemplified above. The ring structure represented by the arc of the broken line in the formula (30) or the formula (32) is the same or the pyrazole ring.

The structure represented by the above formula (32) includes the structure of the following formula (35).

(In the formula (35), R ³ to R ^{5 are the} same or different and each represents a hydrogen atom or a monovalent substituent; an arrow pointing from the nitrogen atom to M and an arrow pointing from the oxygen atom to M indicate that a nitrogen atom or an oxygen atom is used for the M atom. Coordination; the arc of the dotted line, the dotted line in the skeleton portion connecting the oxygen atom and the nitrogen atom, X', X", M, Z ¹ , n ³ , m' are the same as in the formula (32)

Examples of the monovalent substituent of R ³ to R ^{5 in} the formula (35) include the same substituents as those of the ring structure represented by X' and X" in the above formulas (25) and (26).

Specific examples of the compound represented by the above formula (30) include the following formula a compound of the structure represented by (36-1) to (36-40).

Specific examples of the compound represented by the above formula (31) include compounds represented by the following formulas (37-1) to (37-3).

Specific examples of the compound represented by the above formula (32) include compounds represented by the following formulas (38-1) to (38-8).

One or two or more of the above may be used as the host material in the present invention, and among these, bis[2-(2-benzothiazolyl) represented by the above formula (36-11) is preferred. Phenol]zinc, bis(10-hydroxybenzo[h]quinoline)indole (Bebq ₂ ) represented by the above formula (36-34), and bis [2-(2-) represented by the above formula (36-35) Hydroxyphenyl)-pyridine]indole (Bepp ₂ ).

The average thickness of the light-emitting layer is not particularly limited, but is preferably 10 to 150 nm. More preferably 20 to 100 nm.

The average thickness of the light-emitting layer can be measured by a crystal oscillation film thickness gauge at the time of film formation.

As the material of the hole transport layer, the same material as that of the hole transport layer in the first organic electroluminescence device of the present invention can be used.

Further, the preferable value of the average thickness of the hole transport layer is also the same as that of the above-described first organic electroluminescent device of the present invention.

As the material of the electron transport layer, the same material as that of the electron transport layer in the first organic electroluminescence device of the present invention can be used.

Further, the preferable value of the average thickness of the electron transporting layer is also the same as that of the above-described first organic electroluminescent device of the present invention.

In the organic electroluminescent device of the present invention, the method of forming the first and second metal oxide layers, the second electrode, the light-emitting layer, the hole transport layer, and the electron transport layer is also in combination with the first organic charge of the present invention. The formation of the layers in the optical element is the same.

As described above, the buffer layer contained in the organic electroluminescent device of the present invention is preferably a layer formed by coating a solution containing an organic compound. By forming a buffer layer having a specific thickness by coating, crystallization of a low molecular compound formed on the buffer layer can be effectively suppressed.

The method of applying the solution containing the organic compound, the solvent for preparing the solution containing the organic compound, and the concentration of the organic compound in the solvent are also coated with the organic compound in the first organic electroluminescent device of the present invention. The method of forming a buffer layer by the solution, the solvent, and the same concentration. By coating the film formation buffer layer, the unevenness on the surface of the first metal oxide layer is smooth, and thus the crystallization of the low molecular compound formed on the buffer layer is suppressed.

The difference between the buffer layer and the invention disclosed in Japanese Laid-Open Patent Publication No. 2012-4492 (Patent Document 5) is as described above.

The buffer layer preferably has an average thickness of 5 to 100 nm. By making the average thickness For this range, the effect of suppressing the crystallization of the low molecular compound layer containing the light-emitting layer can be sufficiently exhibited. When the average thickness of the buffer layer is less than 5 nm, the unevenness of the unevenness on the surface of the first metal oxide cannot be sufficiently smoothed, and the leakage current is increased, so that the effect of forming the buffer layer cannot be sufficiently exhibited. Further, when the average thickness of the buffer layer is thicker than 100 nm, the driving voltage rises and it is practically unsatisfactory. Further, when a compound having a preferred structure in the present invention described later is used as the organic compound, the buffer layer can sufficiently exhibit the function as an electron transport layer. The average thickness of the above buffer layer is preferably from 10 to 60 nm.

The average thickness of the buffer layer can be measured by a stylus type step meter and a spectroscopic ellipsometer.

The second organic electroluminescent device of the present invention may also be laminated on a substrate. The layers of the organic electroluminescent element are formed. In the case where each layer is laminated on the substrate, it is preferable that each layer is formed on the first electrode formed on the substrate. In this case, the organic electroluminescent device of the present invention may be a top emission type that extracts light on the side opposite to the side having the substrate, or may be a bottom emission type that extracts light on the side having the substrate.

The material of the substrate, the average thickness of the substrate, and the first organic of the present invention described above The material of the substrate in the electroluminescent device and the average thickness of the substrate are the same.

In the second organic electroluminescence device of the present invention, as an organic layer forming a buffer layer Examples of the compound include the same as the organic compound forming the buffer layer in the first organic electroluminescent device of the present invention.

Further, in the second organic electroluminescent device of the present invention, the organic compound forming the buffer layer is preferably an organic compound having a boron atom, and more preferably a boron-containing compound represented by the above formula (1). The reason why the boron-containing compound of such a structure is preferable is as described above.

Further, a preferred structure of the boron-containing compound represented by the formula (1) is also the same as in the case of the first organic electroluminescent device of the present invention.

The boron-containing compound represented by the above formula (1) can achieve uniform formation by coating Since the film has a low HOMO and LUMO energy level, it can be preferably used as a material of the second organic electroluminescent device of the present invention.

The second organic electroluminescent device of the present invention is the organic electroluminescent light of the present invention In the element, the buffer layer contains a reducing agent, whereby the organic electroluminescent device can be made excellent in light-emitting characteristics. In the second organic electroluminescent device of the present invention, it is preferable that the first metal oxide layer, the buffer layer, and the layered on the buffer layer are sequentially provided between the first electrode and the second electrode. The layer of the low molecular compound layer and the second metal oxide layer, and the buffer layer contains a reducing agent.

The method for producing an organic electroluminescence device according to a second preferred embodiment of the present invention is also one of the inventions, which is the manufacture of the organic-inorganic hybrid organic electroluminescent device according to the second preferred embodiment of the present invention. A method of manufacturing an organic electroluminescent device having a structure in which a plurality of layers are laminated, characterized in that the manufacturing method includes the step of causing an organic electroluminescent device to be between the first electrode and the second electrode The organic electroluminescence light is laminated to form a first metal oxide layer, a buffer layer containing a reducing agent, a low molecular compound layer including a light emitting layer laminated on the buffer layer, and a second metal oxide layer. The layers of the component.

The method for producing an organic electroluminescence device according to a second preferred embodiment of the present invention preferably comprises the step of applying a solution containing an organic compound to form a buffer layer having an average thickness of 5 to 100 nm.

The manufacturer of the organic electroluminescent device of the second preferred embodiment of the present invention The method may include other steps as long as the above steps are included, and may include a step of forming a layer other than the first and second metal oxide layers, the buffer layer, and the low molecular compound layer including the light emitting layer. Further, a material for forming each layer of the organic electroluminescence element, a method for forming the organic compound, a solvent for preparing a solution containing the organic compound, and a thickness of each layer are the same as those of the second organic electroluminescence device of the present invention, preferably The same is true.

[Organic Electroluminescent Device of the Third Preferred Embodiment of the Present Invention]

An organic light-emitting device according to a third preferred embodiment of the present invention (hereinafter also referred to as a third aspect of the present invention) Electromechanical Excitation Element) The buffer layer of the organic light-emitting device of the present invention is a layer composed of a nitrogen-containing film and having an average thickness of 3 to 150 nm.

In other words, the third organic electroluminescent device of the present invention has an organic electroluminescent device having a structure in which a plurality of layers are laminated between an anode and a cathode formed on a substrate, and the organic electroluminescent device is applied to the anode and the cathode. There is a metal oxide layer interposed therebetween, and the metal oxide layer has a layer composed of a nitrogen-containing film and having an average thickness of 3 to 150 nm.

The nitrogen-containing film is preferably one which does not have electron transport properties. Further, the term "no electron transport property" as used herein means that the electron mobility is extremely low. Specifically, it refers to any case where the electron mobility is less than about 10 ^-6 cm ² /Vs or the conductivity is less than 10 ^-6 S/m.

The third organic electroluminescent device of the present invention is formed to have an anode and a a reverse-structured organic electroluminescent device having a plurality of layers formed between the cathodes on the substrate, and having a metal oxide layer between the anode and the cathode, and having a nitrogen-containing film on the metal oxide layer The layer having an average thickness of 3 to 150 nm is not particularly limited as to the number of layers of the other layers, the material constituting the other layers, or the order of lamination. Preferably, the metal oxide layer and the nitrogen-containing compound layer are located between the cathode and the light-emitting layer. The nitrogen-containing compound is excellent in electron injection characteristics, and the organic electroluminescence device having such a layer structure has high electron injection characteristics and is an element excellent in luminous efficiency.

The nitrogen-containing film used in the third organic electroluminescence device of the present invention is as There are four kinds in total: (1) a nitrogen-containing film formed of a nitrogen-containing compound on a metal oxide layer, (2) a high-nitrogen-containing film formed of a nitrogen-containing compound on a metal oxide layer, and (3) a metal a nitrogen-containing film formed by decomposing a nitrogen-containing compound on the oxide layer, and (4) a high-nitrogen-containing film formed by decomposing the nitrogen-containing compound on the metal oxide layer.

The reason for improving the performance of the organic electroluminescent device by forming such a film is presumed as follows.

First, when the first is in the case of a nitrogen atom, there is a tendency for its lone pair to form a bond with a metal atom in the substrate. The polarization between the metal-nitrogen bonds exhibits strong electron injection characteristics. All of the nitrogen-containing films of the above (1) to (4) satisfy the above conditions. More preferably, the above-mentioned (2) has a higher nitrogen atom ratio of a lone electron pair.

In the above (3) and (4), it is expected that a film having a high density of nitrogen atoms on the substrate is formed by a decomposition phenomenon related to film formation, and as a result, a colorful metal-nitrogen bond is expected to occur. Moreover, it can be considered that there is also a stronger metal-nitrogen bond than before. Further, depending on the state of decomposition, there is a case where other components such as carbon which are not required are eliminated, whereby the nitrogen atomic ratio is relatively increased, and as a result, a better environment is achieved (4). Since the origin of the main nitrogen in the nitrogen-containing films is a metal-nitrogen bond, it is expected that the nitrogen atoms are concentrated at a higher density than the physical adsorption of the usual molecules. Based on these factors, it is considered that the organic electroluminescence device has excellent light-emitting efficiency and excellent device drive stability and device life by having such a nitrogen-containing film. In fact, the phenomenon caused by the decomposition of the above nitrogen-containing compound can be confirmed by X-ray photoelectron spectroscopy which is one of the surface analysis methods. The specific results are shown in the examples, but by using a compound containing nitrogen and carbon as a constituent element as a nitrogen-containing compound, a treatment for decomposing the compound is carried out, and it is observed that the carbon:nitrogen ratio (CN ratio) is changed from 2:1. It is a high nitrogen ratio of 1:1. At the same time, by the above treatment, an increase in the half-height width of the spectrum of nitrogen is observed, which shows an enlargement of the chemical environment and implies a stronger metal-nitrogen bond.

Therefore, it is considered that the case where the base of the layer composed of the nitrogen-containing film is a film containing a metal element contributes greatly to the performance of the third organic electroluminescent device of the present invention as described above.

The nitrogen-containing film of the above (1) and (2) is a nitrogen-containing film formed on the metal oxide layer. A film composed of a compound, that is, a film formed without decomposing a nitrogen-containing compound. The nitrogen-containing film of the above (2) is formed by using a nitrogen-containing compound as a ratio of the number of nitrogen atoms to the total number of atoms constituting the nitrogen-containing compound.

The method for forming the nitrogen-containing film of the above (1) and (2) is not particularly limited, and a method of volatilizing a solvent after applying a solution containing a nitrogen-containing compound onto a metal oxide layer can be preferably used.

The nitrogen-containing film of the above (3) and (4) is formed by nitriding on the metal oxide layer. The film formed by decomposition of the compound may also remain undecomposed in one of the nitrogen-containing compounds. Preferably, all of the nitrogen-containing compound is decomposed.

The method for forming the nitrogen-containing film of the above (3) and (4) is not particularly limited, and a method of forming a solution containing a nitrogen-containing compound on a metal oxide layer and decomposing the nitrogen-containing compound can be preferably used. .

Preferably, the nitrogen-containing film is coated on the metal oxide layer by containing Formed by the method of the step of the solution of the nitrogen compound. By forming a nitrogen-containing film by a method including such a step, the organic electroluminescent device having the metal oxide layer can suppress leakage current and uniform surface light emission.

The reason and the first organic light-emitting device of the present invention described above have the same reason for suppressing leakage current and uniform surface light emission by having a buffer layer formed by applying a solution containing an organic compound.

The above nitrogen-containing film preferably contains nitrogen and carbon as elements constituting the film. The ratio of the existence of the nitrogen atom and the carbon atom constituting the film satisfies

Number of nitrogen atoms / (number of nitrogen atoms + number of carbon atoms) > 1/8

Relationship.

As described above, when the ratio of the number of nitrogen atoms in the nitrogen-containing film is high, the total number of metal-nitrogen bonds increases, and as a result, the electron injection characteristics are higher by the stronger polarization. The number of nitrogen atoms in the nitrogen-containing film / (number of nitrogen atoms + number of carbon atoms) is more preferably more than 1/5.

The ratio of the presence of nitrogen and carbon in the nitrogen-containing film can be determined by photoelectron spectroscopy (XPS).

The nitrogen-containing film of the above (3) and (4) is only required to be contained on the metal oxide layer. When the nitrogen compound is decomposed and formed, the method of decomposing the nitrogen-containing compound is not particularly limited, and it is preferably formed by decomposing the nitrogen-containing compound by heating.

When the nitrogen-containing compound is decomposed by heating, the bonding between the metal atom and the nitrogen atom in the metal oxide layer can be strengthened, whereby the organic electroluminescent device can exhibit a higher driving stability for a longer period of time.

Therefore, the above nitrogen-containing film is preferably utilized by coating a metal oxide layer. When a solution containing a nitrogen-containing compound is formed by a method in which a nitrogen-containing compound is decomposed by heating, by the formation of such a method, the following effects can be obtained: suppression of leakage current and effect of uniform surface light emission, Further, the organic electroluminescence device is effective in that it exhibits high driving stability for a longer period of time.

The method for producing an organic electroluminescence element according to the present invention is also a method for producing the above HOILED element, that is, an organic electroluminescence light having a structure in which a plurality of layers are laminated between an anode and a cathode formed on a substrate. A method for producing a device, comprising the steps of: applying a solution containing a nitrogen-containing compound to a metal oxide layer, and heat-treating at a temperature at which the nitrogen-containing compound is decomposed to produce a nitrogen-containing film of the present invention. The steps of the layer.

The heat treatment for decomposing the above nitrogen-containing compound is preferably carried out under the atmosphere Row. By performing in the atmosphere, the decomposition of the nitrogen-containing compound can be sufficiently promoted, and the organic electroluminescent device can exhibit a higher driving stability for a long period of time.

The heat treatment for decomposing the nitrogen-containing compound is preferably 80 to 200 ° C, and the time is preferably 1 to 30 minutes.

The temperature or time of the heat treatment may be appropriately set depending on the type of the nitrogen-containing compound within the above range. For example, when a polymer having a polyalkyleneimine structure on a main chain skeleton is used as a nitrogen-containing compound, the molecular weight of the polymer is higher as the decomposition temperature is higher, so that the molecular weight of the polymer can be considered, which will be described later. The heat treatment conditions in the examples are reference, and the temperature and time of the heat treatment are appropriately set.

Whether or not the nitrogen-containing compound is decomposed can be confirmed by X-ray photoelectron spectroscopy (XPS).

The above nitrogen-containing film may also be a nitrogen-containing compound on the metal oxide layer. After the decomposition step, a step of washing the surface of the film with an organic solvent such as ethanol or methoxyethanol is carried out.

Examples of the nitrogen-containing compound include pyrrolidone such as polyvinylpyrrolidone, aniline such as polypyrrole or polyaniline, or pyridine such as polyvinylpyridine. Also, the pyrrolidines, imidazoles, piperidines, pyrimidines, and the like A compound having a nitrogen-containing hetero ring or an amine compound. Among them, a compound having a high nitrogen content is preferable, and a polyamine or a tri-containing compound is preferred. a compound of the ring.

Since the ratio of the number of nitrogen atoms to the total number of atoms of the constituent compound is high, the polyamine has a high electron injecting property and driving stability, and is preferable in this respect.

The polyamine is preferably a layer which can be formed by coating, and may be a low molecular compound or a polymer compound. As the low molecular compound, a polyalkylene polyamine such as diethylenetriamine can be preferably used. Among the polymer compounds, a polymer having a polyalkyleneimine structure can be preferably used. Especially preferred is polyethyleneimine.

Further, the term "low molecular compound" as used herein means a compound of a non-polymer compound (polymer), and does not necessarily mean a compound having a relatively low molecular weight.

In the above polyamines, a straight chain alkylimine structure is used on the backbone of the main chain. The form of the polymer of the chain structure is one of the preferred embodiments of the present invention.

Among the polyamines, by using a polymer having such a structure, component driving stability and element life are more excellent. It is presumed that the reason is that the polymer having a polyalkyleneimine structure on the main chain skeleton has a linear structure and thus is solid, thereby being stably present in the apparatus.

The nitrogen-containing film formed on the metal oxide layer by the polymer having a linear structure of a polyalkyleneimine structure on the main chain skeleton is the nitrogen-containing film of the above (1).

Further, the polymer having a linear structure having a polyalkylene structure on the main chain skeleton may be a linear one of a polyalkylenimine structure forming a main chain skeleton, and can For those who have a branch structure in one part. Preferably, 80% or more of the polyalkylene imine structure forming the main chain skeleton is bonded to a linear chain, more preferably 90% or more is bonded to a linear chain, and more preferably 95% or more is bonded to a linear chain. Preferably, it is preferably 100% of the polyalkylene structure forming the backbone skeleton to be linearly linked.

Polyalkylene imine structure of the above polymer having a polyalkyleneimine structure It is preferably a structure formed of an alkyleneimine having 2 to 4 carbon atoms. More preferably, it is a structure formed of a stretched alkylimine having 2 or 3 carbon atoms.

The above polymer having a polyalkyleneimine structure is only required to have a main chain skeleton It may be a polyalkyleneimine structure or a copolymer having a structure other than the polyalkyleneimine structure.

The above polymer having a polyalkyleneimine structure has a polyalkyleneimine In the case of a structure other than the structure, examples of the monomer which is a raw material for the structure other than the polyalkylene imine structure include ethylene, propylene, butylene, acetylene, acrylic acid, styrene, or vinyl carbazole. One or two or more of these may be used. Further, it is also preferred to use a structure in which a hydrogen atom bonded to a carbon atom of the monomer is substituted with another organic group. Examples of the other organic group to be substituted with a hydrogen atom include a hydrocarbon group having 1 to 10 carbon atoms and at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom and a sulfur atom.

The above polymer having a polyalkyleneimine structure is formed in the main chain of the polymer In 100% by mass of the monomer component of the skeleton, the monomer forming the polyalkyleneimine structure is preferably 50% by mass or more. More preferably, it is 66% by mass or more, and further preferably 80% by mass or more. The polymer which is preferably a monomer having a polyalkyleneimine structure is 100% by mass, that is, a polymer having a polyalkyleneimine structure is a homopolymer of a polyalkyleneimine.

The above polymer having a polyalkyleneimine structure is preferably a weight average molecule The amount is 100,000 or less. When such a weight average molecular weight is used, a layer is formed by heat treatment at a temperature at which the polymer is decomposed, whereby the organic electroluminescent device can be made to have better driving stability. Different. More preferably, it is 10,000 or less, and further preferably 100 to 1000. Further, in the case where the polymer having a polyalkyleneimine structure is a polymer having a linear structure, the weight average molecular weight of the polymer is more preferably 250,000 or less, still more preferably 10,000 to 50,000.

The weight average molecular weight can be determined by GPC (gel permeation chromatography) measurement under the following conditions.

Measuring machine: Waters Alliance (2695) (trade name, manufactured by Waters Corporation)

Molecular weight column: TSKguard column (protective column) α, TSKgel α-3000, TSKgel α-4000, TSKgel α-5000 (both manufactured by Tosoh Corporation) are connected in series.

Eluent: a solution of 96 g of a 50 mM aqueous sodium hydroxide solution and 3,600 g of acetonitrile in 14304 g of a 100 mM aqueous boric acid solution.

Standard material for calibration curve: polyethylene glycol (manufactured by Tosoh Corporation)

In the measurement method, the object to be measured is dissolved in the eluate so that the solid content is about 0.2% by mass, and the molecular weight is measured by using the filter as a sample.

As the above three The compound of the ring is preferably melamine or decylamine because it is a nitrogen-containing cyclic compound, and the ratio of the number of nitrogen atoms to the total number of atoms of the constituent compound is high and rigidity. When a film made of melamine or decylamine is formed on the metal oxide layer, it is a film containing the high nitrogen of the above (2).

As the above three a compound of a ring, other than melamine or benzoguanamine/acetamidine In addition to the guanamine, one or more compounds having a melamine/melamine skeleton such as melamine or melamine, a melamine resin/melamine resin, or the like may be used. The melamine is preferred in that the proportion of the nitrogen atoms in all the atoms constituting the compound is high.

Further, as the above compound having a nitrogen-containing hetero ring or an amine compound, it is also preferred A polymer having a repeating unit of the structure represented by the following formulas (39) to (47), a triethylamine of the formula (48), and an ethylenediamine of the formula (49) are used.

Further, when the nitrogen-containing compound is decomposed on the metal oxide layer, the nitrogen-containing film of the above (3) or the high-nitrogen-containing film of (4) is obtained. Can be considered by using, for example, polyamines or As the nitrogen-containing compound, a compound having a high nitrogen content such as a ring compound can cause the decomposition product of the nitrogen-containing compound to be more densely deposited on the metal oxide layer. The nitrogen-containing film on such a metal oxide is also one of the inventions of this patent. The nitrogen-containing film is further described below.

The nitrogen-containing film of the present invention has an average thickness of 3 to 150 nm. If the nitrogen film is used for this purpose The average thickness is excellent in that the effect of having the above nitrogen-containing film can be exhibited. The average thickness of the nitrogen-containing film is preferably from 5 to 100 nm. More preferably 5 to 50 nm. In particular, in the case of a nitrogen-containing film in which a nitrogen-containing compound is decomposed, it is preferably 5 to 100 nm, more preferably 5 to 50 nm.

The average thickness of the nitrogen-containing film can be measured by a contact step meter at the time of film formation. The contact type step meter largely depends on the measurement environment in the measurement of the polar film, and the variation in the measured value becomes large. Therefore, the determination of the average thickness in this patent is determined by the average of a number of measurements.

The third organic electroluminescent device of the present invention preferably has an anode and a cathode, And an organic compound layer of one or more layers sandwiched between the anode and the cathode, having a metal oxide layer between the cathode and the organic compound layer, and further between the metal oxide layer and the organic compound layer There is a layer composed of the nitrogen-containing film of the present invention. Here, the organic compound layer is a layer including a light-emitting layer and, if necessary, an electron transport layer or a hole transport layer.

Preferably, the third organic electroluminescent device of the present invention is an organic-inorganic hybrid organic electroluminescent device having a metal oxide layer between the anode and the cathode, and having a light-emitting layer and an anode. An electron injection layer and an electron transport layer as needed between the cathode and the light-emitting layer, and an element having a hole transport layer and/or a hole injection layer between the anode and the light-emitting layer. The third organic electroluminescent device of the present invention may have other layers between the layers, but is preferably an element composed only of the layers. That is, it is preferably an element in which the laminated cathode, the electron injecting layer, the optional electron transporting layer, the light emitting layer, the hole transporting layer, and/or the hole injecting layer and the anode are sequentially adjacent to each other. Further, each of the layers may be composed of one layer, or may be composed of two or more layers.

As described above, since the nitrogen-containing film is excellent in electron injection characteristics, it is preferably used for the electron injection side, that is, the cathode side. Further, as described below, the metal oxide layer is preferably laminated as a part of the cathode or a layer of the electron injecting layer and/or a part of the anode or a layer of the hole injecting layer.

In the organic electro-active element having the above configuration, when the element does not have an electron-transporting layer, the electron injecting layer is adjacent to the light-emitting layer. Further, when the element has only one of a hole transport layer and a hole injection layer, the layer of the one layer is laminated adjacent to the light-emitting layer and the anode, and the element has a hole transport layer and a hole injection layer. In the case of both, the layers are adjacent to each other in the order of the light-emitting layer, the hole transport layer, the hole injection layer, and the anode.

In the third organic electroluminescence device of the present invention, as a material for forming a light-emitting layer For the material, any compound which is generally used as a material for the light-emitting layer may be used, and it may be a low molecular compound or a high molecular compound, or may be used in combination.

Further, the term "low molecular material" as used in the present invention means a material of a non-polymer material (polymer), and does not necessarily mean an organic compound having a relatively low molecular weight.

Examples of the polymer material forming the light-emitting layer include the above-mentioned present invention. In the first organic light-emitting device of the first embodiment, the compound described in the example of the organic compound forming the buffer layer is a compound other than the polyethyleneimine (PEI), or the Japanese Patent Application No. 2010-230995, Japanese Patent Application No. 2011- The boron compound described in No. 6457 is a polymer material or the like.

As the low molecular material forming the above light-emitting layer, for example, the above-mentioned hair can be used The low molecular compound which can be used as the material of the light-emitting layer in the first organic light-emitting element of the same is the same.

The average thickness of the light-emitting layer is not particularly limited, and is preferably the same as the above invention. The average thickness of the light-emitting layer of the first organic light-emitting element is the same.

In the case where the third organic electroluminescent device of the present invention has an electron transport layer In the case of the material, any of the compounds which are generally used as the material of the electron transport layer may be used, or these may be used in combination.

Examples of the compound which can be used as the material of the electron transporting layer include the same compounds as the low molecular weight compound which can be used as the material of the electron transporting layer in the first organic light emitting device of the present invention, and preferred compounds are also the same.

In the case where the third organic electroluminescent device of the present invention has a hole transport layer In the case of the hole transporting organic material used as the hole transporting layer, various p-type polymer materials or various p-type low molecular materials may be used singly or in combination.

Examples of the p-type polymer material (organic polymer) include a polyarylamine, a fluorene-arylamine copolymer, a fluorene-biphenylene copolymer, a poly(N-vinylcarbazole), and a polyvinyl group. Anthracene, polyvinyl hydrazine, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylacetylene), polythienylenevinylene, hydrazine formaldehyde resin, ethyl carbazole formaldehyde resin or derivatives thereof.

Further, the compounds can also be used in the form of a mixture with other compounds. As an example, poly(3,4-ethylenedioxythiophene/styrenesulfonic acid) (PEDOT/PSS) which is a mixture containing polythiophene, etc. are mentioned.

As the p-type low molecular material, the first aspect of the present invention can be cited. The same compound as the low molecular compound used as the material of the hole transport layer in the organic light-emitting element.

The third organic electroluminescent device of the present invention has an electron transport layer or a hole In the case of the transport layer, the average thickness of the layers is not particularly limited, and is preferably the same as the average thickness of the electron transport layer or the hole transport layer in the first organic light-emitting device of the present invention.

The average thickness of the electron transport layer or the hole transport layer can be measured by a crystal oscillator film thickness meter in the case of a low molecular compound, and can be measured by a contact type step meter in the case of a polymer compound.

The third organic electroluminescent device of the present invention has a metal oxide layer between the cathode and the light-emitting layer and between the anode and the light-emitting layer, preferably between the cathode and the light-emitting layer and the light-emitting layer. There are metal oxide layers at two places between the anodes. When the metal oxide layer between the cathode and the light-emitting layer is the first metal oxide layer, and the metal oxide layer between the anode and the light-emitting layer is the second metal oxide layer, the third aspect of the present invention is shown. An example of a preferred element configuration of the electromechanical excitation device is a layer in which a cathode, a first metal oxide layer, a layer composed of a nitrogen-containing film, a light-emitting layer, a hole transport layer, and a second metal oxide layer are sequentially laminated. The composition of the anode. Further, an electron transport layer may be provided between the layer composed of the nitrogen-containing film and the light-emitting layer as needed. Regarding the importance of the metal oxide layer, the first metal oxide layer is of high importance, and the second metal oxide layer can also be replaced by an organic material having a minimum unoccupied molecular orbital depth, such as HATCN, F ₄ TCNQ, or the like. .

The material or layer structure of the first metal oxide layer and the second metal oxide layer The average thickness of the layer and the layer is the same as that of the first organic light-emitting device of the present invention.

In the third organic light-emitting device of the present invention, the material of the anode and the cathode or the average thickness The degree is the same as that of the first organic light-emitting device of the present invention described above.

The third organic electroluminescent device of the present invention is the organic electroluminescent light of the present invention In the element, the buffer layer is a layer composed of a nitrogen-containing film and having an average thickness of 3 to 150 nm, whereby the organic electroluminescence device can be excellent in luminous efficiency and life.

The method for producing an organic electroluminescence device according to a third preferred embodiment of the present invention is also one of the inventions, and the method for producing the organic-inorganic hybrid organic electroluminescent device according to the third preferred embodiment of the present invention A manufacturing method, that is, a method of manufacturing an organic electroluminescence device having a structure in which a plurality of layers are laminated, characterized in that the manufacturing method includes the step of causing an organic electroluminescence device to be a first electrode and a second electrode Each of the layers of the organic electroluminescent device is laminated in a manner that has a metal oxide layer and a layer of a nitrogen-containing film laminated on the metal oxide layer, and the layering step includes forming an average thickness of 3 to 150 nm. The step of the nitrogen-containing film.

The manufacturer of the organic electroluminescent device of the third preferred embodiment of the present invention The method may include other steps as long as it includes the above steps, and may also include a step of forming a metal oxide layer and a layer other than the layer composed of the nitrogen-containing film. Further, a material for forming each layer of the organic electroluminescence element, a method for forming the organic compound, a solvent for preparing a solution containing the organic compound, and a thickness of each layer are the same as those of the third organic electroluminescence device of the present invention, preferably The same is true.

In the organic electroluminescent device of the present invention, a layer formed of an organic compound The film method is not particularly limited, and various methods can be appropriately used depending on the characteristics of the material. When the solution can be applied as a solution, the first organic light-emitting device of the present invention can be used to form a buffer. A film is formed by various coating methods at the time of layer. Among them, in terms of easier control of the film thickness, a spin coating method or a slit coating method is preferred. In the case where coating is impossible or the solvent solubility is low, a vacuum vapor deposition method or an ESDUS (Evaporative Spray Deposition from Ultra-dilute Solution) method is preferably used.

When the organic compound solution is applied to form a layer formed of the above organic compound, as a solvent for dissolving the organic compound, a solution for preparing an organic compound-containing compound in the first organic light-emitting device of the present invention described above can be used. Among the solvents, the solvent is preferably a nonpolar solvent, and examples thereof include aromatics such as xylene, toluene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, and tetramethylbenzene. Hydrocarbon solvent, pyridine, pyr A solvent such as an aromatic heterocyclic compound such as furan, pyrrole, thiophene or methylpyrrolidone; an aliphatic hydrocarbon solvent such as hexane, pentane, heptane or cyclohexane; these may be used singly or in combination.

When polyamines are used as the above nitrogen-containing compound, water or low can be used. The alcohol is used as a solvent for a solution containing a nitrogen-containing compound. As the lower alcohol, it is preferred to use an alcohol having 1 to 4 carbon atoms, and methanol, ethanol, propanol, ethoxyethanol, methoxyethanol or the like may be used singly or in combination.

The cathode, the anode, and the oxide layer may be excited by the first organic electricity described above The method of forming the first and second metal oxide layers, the second electrode, the light-emitting layer, the hole transport layer, and the electron transport layer in the optical element is formed by the same method. When the anode and the cathode are formed, the joining of the metal foil can also be used. Preferably, the methods are selected based on the properties of the materials of the layers, and the method of fabrication may vary from layer to layer. Among the second metal oxide layers, these are more preferably formed by a vapor phase film formation method. According to the vapor phase film formation method, it is possible to clean and form a good contact with the anode without damaging the surface of the organic compound layer, and as a result, the effect obtained by using the second metal oxide layer as described above becomes More significant.

In order to further improve the characteristics of the third organic electroluminescent device of the present invention, etc. For reasons, it is also possible to have, for example, a hole blocking layer, an electronic component layer, and the like. Can be used usually The materials forming the layers are used as the material for forming the layers, and the layers are formed by a method generally used to form the layers.

The third organic electroluminescent device of the present invention is composed of all layers of the constituent elements Compared to an organic electroluminescent device composed of an organic compound, a strict seal is not required, but sealing may be performed as needed. As the sealing step, a usual method can be suitably used. For example, a method of sealing a container in an inert gas or a method of directly forming a sealing film on an organic EL element can be mentioned. In addition to these methods, a method of enclosing a moisture absorbing material may be used in combination.

The third organic electroluminescent device of the present invention is formed on the substrate adjacent to the cathode The counter-structured organic electroluminescent element. The third organic electroluminescence device of the present invention may be a top emission type that extracts light on the side opposite to the side having the substrate, or may be a bottom emission type that extracts light on the side having the substrate.

The material and the average thickness of the substrate are the same as those of the first organic electroluminescence device.

The organic electroluminescent device of the present invention is as described above on the metal oxide layer The layer which consists of a nitrogen-containing film improves the electron injection characteristics, is excellent in luminous efficiency, and is excellent in the drive stability of the element and the lifetime of the element.

The effect of improving such electron injection characteristics is not limited to organic electroluminescence devices, and is also beneficial to other optoelectronic devices such as solar cells and organic semiconductors. The following nitrogen-containing film is also one of the inventions, and the film is a nitrogen-containing film which contributes to the improvement of the performance of the optoelectronic device, that is,

a film containing nitrogen, characterized in that the film is formed on a substrate containing a metal, formed of a solid nitrogen-containing compound, or contains a nitrogen element and a carbon element as elements constituting the film, and constitutes a nitrogen atom and a carbon atom of the film. The ratio of existence satisfies the number of nitrogen atoms / (number of nitrogen atoms + number of carbon atoms) > 1/8

Relationship. The preferred embodiment or production method of the nitrogen-containing film of the present invention is the same as the layer composed of the nitrogen-containing film in the above-described organic electroluminescent device of the present invention.

The electroluminescent device of the present invention can emit light by applying a voltage (usually 15 volts or less) between the anode and the cathode. A DC voltage is usually applied, but an AC component can also be included.

The organic electroluminescence device of the present invention is an organic-inorganic hybrid device, but the crystallization of a low-molecular compound peculiar to the organic-inorganic hybrid device is suppressed, and leakage current suppression and uniform surface luminescence can be achieved. Goodly used as a material for a display device or a lighting device. In the organic electroluminescent device of the present invention, the luminescent color can be changed by appropriately selecting the material of the organic compound layer, and a color filter or the like can be used in combination to obtain a desired luminescent color. Therefore, it can be preferably used as a light-emitting portion or a lighting device of a display device. In particular, in view of the characteristics of the reverse structure, a display device in combination with an oxide TFT is preferable.

Such a display device formed using the organic electroluminescent device of the present invention is also one of the inventions. Further, an illumination device formed by using the organic electroluminescent device of the present invention is also one of the inventions.

The first organic electroluminescent device of the present invention is constituted by the above-described configuration, and can suppress leakage current and uniform surface light emission.

Further, the second organic electroluminescence device of the present invention has a buffer layer, and has a longer luminescence lifetime than the conventional organic-inorganic hybrid organic electroluminescence device, and the buffer layer contains a reducing agent. The luminous efficiency is excellent. The organic-inorganic hybrid organic electroluminescent device has the advantages of manufacturing, such as an organic electroluminescent device in which all of the layers of the organic electroluminescent device are made of an organic material, and the necessity of tightly sealing the layers, and has the above advantages and advantages. Luminescence characteristics such as luminescence lifetime and luminescence efficiency.

Further, the third organic electroluminescent device of the present invention is composed of the above-described configuration, and does not require a strict sealing organic-inorganic hybrid type organic electroluminescence device having an inverse structure, and has excellent luminous efficiency and repeatability of luminescence. Excellent uniformity with luminescence, high driving stability, and long life of components.

The organic electroluminescent device of the present invention has the above-described excellent characteristics and can be suitably used for a material of a display device or a lighting device.

1‧‧‧Substrate

2‧‧‧ cathode

3‧‧‧1st metal oxide layer

4‧‧‧ layer of nitrogen-containing film

5‧‧‧Organic compound layer

6‧‧‧2nd metal oxide layer

7‧‧‧Anode

Fig. 1 is a SEM photograph of a solution obtained by dissolving a boron-containing compound 1 in THF on a transparent glass substrate with ITO.

2 is a graph showing voltage-current efficiency characteristics of the organic electroluminescent device produced in Example 1 and Comparative Example 1.

3 is a graph showing voltage-current efficiency characteristics of the organic electroluminescence devices produced in Examples 2 to 4 and Comparative Example 2.

4 is a graph showing voltage-current efficiency characteristics of the organic electroluminescent device produced in Example 5 and Comparative Example 2.

Fig. 5 is a graph showing voltage-current efficiency characteristics of the organic electroluminescent device produced in Example 6 and Comparative Example 3.

Fig. 6 is a graph showing voltage-luminance characteristics of the organic electroluminescent device produced in Example 7 and Comparative Example 4.

Fig. 7 is a graph showing current density-current efficiency characteristics of the organic electroluminescent device produced in Example 7 and Comparative Example 4.

Fig. 8 is a graph showing voltage-luminance characteristics of the organic electroluminescent device produced in Example 8 and Comparative Example 5.

Fig. 9 is a graph showing current density-current efficiency characteristics of the organic electroluminescent device produced in Example 8 and Comparative Example 5.

Fig. 10 is a graph showing the voltage-luminance characteristics of the organic electroluminescent elements produced in Examples 9 and 10 and Comparative Example 6.

Fig. 11 is a graph showing current density-current efficiency characteristics of the organic electroluminescent devices produced in Examples 9 and 10 and Comparative Example 6.

Fig. 12 is a graph showing voltage-luminance characteristics of the organic electroluminescent device produced in Example 11 and Comparative Example 7.

Fig. 13 is a graph showing current density-current efficiency characteristics of the organic electroluminescent device produced in Example 11 and Comparative Example 7.

Fig. 14 is a graph showing voltage-luminance characteristics of the organic electroluminescent device produced in Example 12 and Comparative Example 8.

Fig. 15 is a graph showing current density-current efficiency characteristics of the organic electroluminescent device produced in Examples 12 and 13 and Comparative Example 8.

Fig. 16 is a schematic view showing an example of a laminated structure of a third organic electroluminescence device shown in the present invention.

Fig. 17-1 is a graph showing the results of measurement of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 14.

17-2 shows the continuous driving characteristics (c-2) constant current density at (c-1) constant current density (corresponding to 100 cd/m ² ) of the organic electroluminescent device fabricated in Example 14. A graph showing the measurement results of the continuous driving characteristics (corresponding to 1000 cd/m ² ).

18 is a view showing measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Comparative Example 9.

Fig. 19-1 is a graph showing the measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 15.

Fig. 19-2 is a graph showing the measurement results of the continuous driving characteristics at (c-2) constant current density (corresponding to 1000 cd/m ² ) of the organic electroluminescent device produced in Example 15.

Fig. 20-1 is a graph showing the measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 16.

Fig. 20-2 is a graph showing the measurement results of the continuous driving characteristics at (c-2) constant current density (corresponding to 1000 cd/m ² ) of the organic electroluminescent device produced in Example 16.

Figure 21 is a graph showing (a) voltage-current density/luminance characteristics of the organic electroluminescent device produced in Example 17, and continuous driving characteristics at (c-1) constant current density (corresponding to 100 cd/m ² ). A graph of the measurement results.

Fig. 22-1 is a graph showing the results of measurement of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 18.

Fig. 22-2 is a graph showing the measurement results of the continuous driving characteristics at a constant current density (corresponding to 100 cd/m ² ) of the organic electroluminescent device (c-1) produced in Example 18.

23-1 is a graph showing measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 19.

Fig. 23-2 is a graph showing the measurement results of the continuous driving characteristics at (c-1) constant current density (corresponding to 100 cd/m ² ) of the organic electroluminescent device produced in Example 19.

Fig. 24-1 is a graph showing the measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 20.

Fig. 24-2 is a graph showing the measurement results of the continuous driving characteristics at (c-2) constant current density (corresponding to 1000 cd/m ² ) of the organic electroluminescent device produced in Example 20.

Fig. 25-1 is a graph showing the results of measurement of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 21.

Fig. 25-2 is a graph showing the measurement results of the continuous driving characteristics at (c-2) constant current density (corresponding to 1000 cd/m ² ) of the organic electroluminescent device produced in Example 21.

Fig. 26-1 is a graph showing the measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 22.

Fig. 26-2 is a graph showing the measurement results of the continuous driving characteristics at (c-1) constant current density (corresponding to 100 cd/m ² ) of the organic electroluminescent device produced in Example 22.

27-1 is a graph showing measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 23.

Fig. 27-2 is a graph showing the measurement results of the continuous driving characteristics at (c-2) constant current density (corresponding to 1000 cd/m ² ) of the organic electroluminescent device produced in Example 23.

Fig. 28 is a view showing the results of photoelectron spectroscopy measurement of the nitrogen-containing film produced in Production Example 1.

Fig. 29 is a view showing the results of photoelectron spectroscopy measurement of the nitrogen-containing film produced in Production Example 2.

Fig. 30 is a view showing the results of photoelectron spectroscopy measurement of the nitrogen-containing film produced in Production Example 3.

Fig. 31 is a view showing the results of photoelectron spectroscopy measurement of the nitrogen-containing film produced in Production Example 4.

Fig. 32 is a graph showing the results of measurement of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 24-1.

Fig. 33 is a graph showing the measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 24-2.

Fig. 34 is a graph showing the measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Example 25.

35 is a view showing measurement results of (a) voltage-current density/luminance characteristics and (b) current density-current efficiency characteristics of the organic electroluminescent device produced in Comparative Example 10.

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited to the examples. In addition, unless otherwise indicated, "part" means "parts by weight", and "%" means "mass%".

In the following examples, various physical properties were determined by the following methods.

< ¹ H-NMR>

The obtained boron-containing compound was made into a solution of deuterated chloroform, and the measurement was performed using a high-resolution nuclear magnetic resonance apparatus (product name "Gemini 2000": 300 MHz, manufactured by Varian, Inc.). The chemical shift was recorded on a low magnetic field side of 1 part per million (ppm: δ scale) from tetramethyl decane, and the hydrogen nucleus (δ 0.00) of tetramethyl decane was used as a reference.

< ¹³ C-NMR>

The obtained boron-containing compound was made into a solution of deuterated chloroform, and the measurement was performed using a high-resolution nuclear magnetic resonance apparatus (product name "Gemini 2000": 75 MHz, manufactured by Varian, Inc.). The chemical shift is recorded as 1 part per million (ppm: δ scale) from tetramethyl decane on the low magnetic field side, with carbon nuclei in NMR solvent (CDCl ₃ : δ = 77.0, CD ₂ Cl ₂ : δ = 53.1, CD ₃ CN: δ = 1.32, DMSO-d ₆ : δ = 39.52) as a reference.

< ¹¹ B-NMR>

The obtained boron-containing compound was made into a solution of deuterated chloroform, and the measurement was performed using a high-resolution nuclear magnetic resonance apparatus (product name "Mercury-400": 128 MHz, manufactured by Varian, Inc.). The chemical shift was recorded by using a boron nucleus (δ = 0.00) of a boron trifluoride-diethyl ether complex as a reference of 1 part per million (ppm: δ scale).

<High-resolution mass spectrometry analysis spectrum>

Using a high-resolution mass spectrometer (product name "JMS-SX101A", "JMS-MS700", "JMS-BU250", manufactured by JEOL), by electron ionization (EI) or high-speed atomic impact method ( FAB, fast atom bombardment).

<weight average molecular weight>

The weight average molecular weight was measured by a gel permeation chromatography (GPC apparatus, developing solvent: chloroform) in the following apparatus and measurement conditions in terms of polystyrene.

High-speed GPC device: HLC-8220GPC (manufactured by Tosoh Corporation)

Determination conditions: developing solvent chloroform

Column TSK-gel GMHXL×2

Dissolution flow rate 1ml/min

Column temperature 40 ° C

<First organic electroluminescent device of the present invention>

(Synthesis Example 1)

Synthesis of (2,7-bis(3-dibenzoboronocyclopentadienyl-4-pyridylphenyl)-9,9'-spiro)

Add 2-(dibenzoborohedylphenyl)-5-bromopyridine (2.6 g, 6.5 mmol), 2,7-bis (4,4,5, in a 100 mL two-neck round bottom flask. 5- tetramethyl-1,3,2-dioxaborolan-pentyl) -9,9' fluorene (1.5g, 2.7mmol), Pd ( PtBu 3) 2 (170mg, 0.32mmol). The inside of the flask was placed under a nitrogen atmosphere, and THF (65 mL) was added and stirred.

2M aqueous solution of tribasic phosphate (11 mL, 22 mmol) was added thereto, and the mixture was heated and stirred while refluxing at 70 °C. After 12 hours, it was cooled to room temperature, and the reaction solution was transferred to a separatory funnel, and water was added, and extracted with ethyl acetate. The organic layer was washed with 3N hydrochloric acid, water, and brine, and dried over magnesium sulfate. The filtrate obtained by filtration was concentrated, and the obtained solid was washed with methanol to obtain 2,7-bis(3-dibenzoborofyl-4-pyridylphenyl) in a yield of 47%. 9,9'-spiropyrene (boron-containing compound 1) (1.2 g, 1.3 mmol).

The physical property values are as follows.

¹ H-NMR (CDCl ₃ ): δ 6.67 (d, J = 7.6 Hz, 2H), 6.75 (d, J = 1.2 Hz, 2H), 6.82 (d, J = 7.2 Hz, 4H), 6.97 (dt, J=7.2, 1.2 Hz, 4H), 7.09 (dt, J=7.2, 0.8 Hz, 2H), 7.24-7.40 (m, 14H), 7.74-7.77 (m, 6H), 7.84-7.95 (m, 10H)

Further, the reaction of Synthesis Example 1 is shown by the following reaction formula.

The elemental properties shown below were evaluated for the boron-containing compound 1 synthesized in Synthesis Example 1.

<Coating film formation property>

When a solution obtained by dissolving the boron-containing compound 1 in THF is applied onto a transparent glass substrate with ITO, a smooth film can be obtained. The SEM (Scanning Electron Microscope) photograph (magnification: 10000 times) is shown in Fig. 1 . From this result, it was confirmed that the boron-containing compound 1 is a low molecule and is a compound which can form a film formed by coating of a solution.

(Synthesis Example 2)

Ethyldiisopropylamine (39 mg, 0.30) was added to a dichloromethane solution (0.3 ml) containing 5-bromo-2-(4-bromophenyl)pyridine (94 mg, 0.30 mmol). After mmol), boron tribromide (1.0 M, 0.9 ml, 0.9 mmol) was added at 0 ° C and stirred at room temperature for 9 hr. After cooling the reaction solution to 0 ° C, a saturated aqueous solution of potassium carbonate was added and extracted with chloroform. The organic layer was washed with saturated brine, dried over magnesium sulfate and filtered. After the filtrate was concentrated by a rotary evaporator, the obtained white solid was filtered, washed with hexane, and the boron-containing compound 2 (40 mg, 0.082 mmol) represented by the following formula (50) was obtained in a yield of 28%. .

The physical property values are as follows.

¹ H-NMR (CDCl ₃ ): 7.57-7.59 (m, 2H), 7.80 (dd, J = 8.4, 0.6 Hz, 1H), 7.99 (s, 1H), 8.27 (dd, J = 8.4, 2.1 Hz, 1H), 9.01 (d, J = 1.5 Hz, 1H);

(Synthesis Example 3)

The solution of pentafluorophenylmagnesium bromide in diethyl ether (1M, 61.2 ml, 70.4 mmol) was cooled to 0 ° C under a nitrogen atmosphere, and a solution of diethyl ether (1 M, 17 ml) was added dropwise thereto. 17mmol). After the completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour. A toluene solution (80 ml) containing 5-bromo-2-(4-bromo-2-dibromoborylphenyl)pyridine (3.8 g, 8 mmol) represented by the above formula (26) was added thereto at 80 ° C. The mixture was heated and stirred for 15 hours. After cooling to room temperature, the reaction solution was added to ice water and extracted with chloroform. The organic layer was washed with brine and dried over sodium sulfate and filtered. After the filtrate was concentrated by a rotary evaporator, purification was carried out by silica gel chromatography (hexane: dichloromethane = 1:1), whereby a boron-containing compound represented by the following formula (51) was obtained in a yield of 58%. (2.2g, 4.61mmol), .

The physical property values are as follows.

¹ H-NMR (CDCl ₃ ): δ 7.16-7.26 (m, 10H), 7.45-7.48 (m, 1H), 7.69-7.71 (m, 1H), 7.81 (d, J = 2.0 Hz, 1H), 7.90 (d, J = 8.0 Hz, 1H), 8.15-8.18 (m, 1H), 8.56 (d, J = 2.0 Hz, 1H)

(Synthesis Example 4)

The BC6F5 dibromide (boron-containing compound 3) represented by the above formula (51) (337 mg, 0.51 mmol) and the F8 boric acid diester (292 mg, 0.52 mmol) represented by the following formula (52) were dissolved in toluene (3 ml). With THF (3 ml), the mixture was stirred at room temperature for 10 minutes under an argon atmosphere. A mixed aqueous solution of Aliquat 336 (21 mg), a 25% by mass aqueous solution of Et ₄ NOH (0.86 ml) and distilled water (0.75 ml) was added thereto, and further stirred under an argon atmosphere at room temperature for 20 minutes to complete degassing. After adding tetrakis(triphenylphosphine)palladium (8.9 mg, 0.007 mmol) thereto, the mixture was heated and stirred while refluxing at 115 ° C for 48 hours. To carry out blocking, bromobenzene (105 mg, 0.67 mmol) was added and stirred for 5 hours, and phenylboric acid (294 mg, 2.41 mmol) was further added and stirred for 5 hours. The mixture was cooled to room temperature, and the reaction solution diluted with toluene was washed once with hydrochloric acid, and washed twice with a pure water solution to concentrate the organic layer to a few ml. The concentrated liquid was added to 300 ml of methanol, stirred directly for 10 minutes, and the obtained precipitate was collected by filtration. The same purification process was repeated three times in total, and the solid was dried under reduced pressure to obtain a boron-containing polymer F8BC6F5 represented by the following formula (53). The weight average molecular weight of the boron-containing polymer F8BC6F5 was 126,000.

(Production of organic electroluminescent elements)

In the following examples, the average thickness of the buffer layer was measured using a stylus type step meter (product name "Alpha Step IQ", manufactured by KLA Tencor Co., Ltd.).

(Example 1)

[1] A commercially available transparent glass substrate with an ITO electrode layer having an average thickness of 0.7 mm was prepared. this At the time, the ITO electrode (first electrode) of the substrate was patterned to have a width of 2 mm. The substrate was ultrasonicated for 10 minutes in acetone and isopropanol, and then boiled in isopropyl alcohol for 5 minutes. The substrate was taken out from isopropyl alcohol, dried by a nitrogen blowing method, and washed by UV ozone for 20 minutes.

[2] The substrate was fixed on a substrate holder of a Mirror Tron sputtering apparatus having a zinc metal target. After depressurization to about 1 × 10 ^-4 Pa, sputtering was carried out while introducing argon gas and oxygen gas to form a zinc oxide layer having a film thickness of about 2 nm. At this time, a portion of the ITO electrode was not formed into a film of zinc oxide by a metal mask to take out the electrode.

[3] A mixed solution of 1% water-ethanol (1:3 by volume) of magnesium acetate was prepared. The substrate prepared in the step [2] was washed again in the same manner as in the step [1]. The washed substrate with the zinc oxide film was placed on a spin coater. A magnesium acetate solution was added dropwise to the substrate and rotated at 1300 rpm for 60 seconds. This was baked in a hot plate set at 400 ° C for 2 hours in the atmosphere to form a zinc oxide/magnesium oxide layer (first metal oxide layer).

[4] A solution of a boron-containing compound 1 in 0.2% tetrahydrofuran was prepared. The substrate prepared in the step [3] with the zinc oxide/magnesia film was placed on a spin coater. A solution containing a boron compound 1 was dropped on the substrate and rotated at 2000 rpm for 30 seconds to form a buffer layer composed of a boron-containing organic compound. The buffer layer has an average thickness of 5 nm.

[5] A substrate formed to a layer containing a boron-containing organic compound is fixed on a substrate holder of a vacuum evaporation apparatus. 4,4'-bis[9-dicarbazolyl]-2,2'-biphenyl (CBP), tris(1-phenylisoquinoline)indole (Ir(piq) ₃ ), N,N'-Di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD) was added to alumina crucible and set to evaporate source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-5 Pa, and CBP was mainly used, and Ir(piq) _{3 was} used as a dopant, and 35 nm was vapor-deposited to form a light-emitting layer. At this time, the doping concentration was such that Ir(piq) ₃ became 6 wt% with respect to the entire light-emitting layer. Then, α-NPD was vapor-deposited at 60 nm to form a hole transport layer. Then, after performing a nitrogen purge once, molybdenum trioxide and gold were added to the alumina crucible to provide a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-5 Pa, and molybdenum trioxide (second metal oxide layer) was vapor-deposited so as to have a film thickness of 10 nm. Then, gold (second electrode) was vapor-deposited so as to have a film thickness of 50 nm to fabricate an organic electroluminescence device 1-1. In the vapor deposition of the second electrode, a vapor deposition mask made of stainless steel was used to form the vapor deposition surface in a strip shape having a width of 2 mm. That is, the light-emitting area of the produced organic electroluminescent device was set to 4 mm ² .

(Comparative Example 1)

The organic electroluminescent device 1-2 was produced in the same manner as in Example 1 except that the step [4] was omitted.

(Example 2)

[1] A commercially available transparent glass substrate with an ITO electrode layer having an average thickness of 0.7 mm was prepared. At this time, the ITO electrode (first electrode) of the substrate was patterned to have a width of 2 mm. The substrate was ultrasonicated for 10 minutes in acetone and isopropanol, and then boiled in isopropyl alcohol for 5 minutes. The substrate was taken out from isopropyl alcohol, dried by a nitrogen blowing method, and washed by UV ozone for 20 minutes.

[2] The substrate was fixed on a substrate holder of a Mirror Tron sputtering apparatus having a zinc metal target. After the pressure was reduced to about 1 × 10 ^-4 Pa, sputtering was carried out while introducing argon gas and oxygen gas to form a zinc oxide layer (first metal oxide layer) having a film thickness of about 2 nm. At this time, a portion of the ITO electrode was not formed into a film of zinc oxide by a metal mask to take out the electrode.

[3] A 0.2% tetrahydrofuran solution of a boron-containing polymer F8BC6F5 was prepared. The substrate with the zinc oxide film prepared in the step [2] was placed on a spin coater. A boron-containing polymer F8BC6F5 solution was dropped on the substrate and rotated at 2000 rpm for 30 seconds to form a buffer layer composed of a boron-containing organic compound. The buffer layer has an average thickness of 10 nm.

[4] A substrate formed to a layer containing a boron-containing organic compound is fixed on a substrate holder of a vacuum evaporation apparatus. Tris(8-hydroxyquinoline)aluminum (Alq ₃ ), N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'- Diamine (α-NPD) was added to the alumina crucible and set as a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-4 Pa, and Alq ₃ was vapor-deposited to 65 nm to form a light-emitting layer. Then, α-NPD was vapor-deposited at 60 nm to form a hole transport layer. Then, after performing a nitrogen purge once, molybdenum trioxide and gold were added to the alumina crucible to provide a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-4 Pa, and molybdenum trioxide (second metal oxide layer) was vapor-deposited so as to have a film thickness of 10 nm. Then, gold (second electrode) was vapor-deposited so as to have a film thickness of 30 nm to fabricate an organic electroluminescence element 1-3. In the vapor deposition of the second electrode, a vapor deposition mask made of stainless steel was used to form the vapor deposition surface in a strip shape having a width of 2 mm. That is, the light-emitting area of the produced organic electroluminescent device was set to 4 mm ² .

(Example 3)

The 0.2% tetrahydrofuran solution of the boron-containing polymer F8BC6F5 used in the step [3] in Example 2 was changed to 0.2% of a commercially available poly(dioctylfluorene-alternate-benzothiadiazole) (F8BT). An organic electroluminescence element 1-4 was produced in the same manner except for the xylene solution. The buffer layer has an average thickness of 10 nm.

(Example 4)

The 0.2% tetrahydrofuran solution of the boron-containing polymer F8BC6F5 used in the step [3] in Example 2 was changed to a commercially available poly(dioctylfluorene) (PFO) 0.2% xylene solution, and The organic electroluminescent device 1-5 was produced in the same manner. The buffer layer has an average thickness of 10 nm.

(Comparative Example 2)

The organic electroluminescent device 1-6 was produced in the same manner as in Example 2 except that the step [3] was omitted.

(Example 5)

The 0.2% tetrahydrofuran solution of the boron-containing polymer F8BC6F5 used in the step [3] in Example 2 was changed to a 1% ethanol solution of polyethylenimine SP-200 manufactured by Nippon Shokubai Co., Ltd., and The organic electroluminescent elements 1-7 were produced in the same manner. The buffer layer has an average thickness of 10 nm.

(Example 6)

[1] A commercially available transparent glass substrate with an ITO electrode layer having an average thickness of 0.7 mm was prepared. At this time, the ITO electrode (first electrode) of the substrate was patterned to have a width of 2 mm. The substrate was ultrasonicated for 10 minutes in acetone and isopropanol, and then boiled in isopropyl alcohol for 5 minutes. The substrate was taken out from isopropyl alcohol, dried by a nitrogen blowing method, and washed by UV ozone for 20 minutes.

[2] The substrate was fixed on a substrate holder of a Mirror Tron sputtering apparatus having a titanium metal target. After the pressure was reduced to about 1 × 10 ^-4 Pa, sputtering was carried out while introducing argon gas and oxygen gas to form a titanium oxide layer (first metal oxide layer) having a film thickness of about 2 nm. At this time, a portion of the ITO electrode was not formed into a film with a metal mask to take out the electrode.

[3] A 0.2% tetrahydrofuran solution of a boron-containing polymer F8BC6F5 was prepared. The substrate with the titanium oxide film prepared in the step [2] was placed on a spin coater. A boron-containing polymer F8BC6F5 solution was dropped on the substrate and rotated at 2000 rpm for 30 seconds to form a buffer layer composed of a boron-containing organic compound. The buffer layer has an average thickness of 10 nm.

[4] A substrate formed to a layer containing a boron-containing organic compound is fixed on a substrate holder of a vacuum evaporation apparatus. Tris(8-hydroxyquinoline)aluminum (Alq ₃ ), N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'- Diamine (α-NPD) was added to the alumina crucible and set as a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-4 Pa, and Alq ₃ was vapor-deposited to 65 nm to form a light-emitting layer. Then, α-NPD was vapor-deposited at 60 nm to form a hole transport layer. Then, after performing a nitrogen purge once, molybdenum trioxide and gold were added to the alumina crucible to provide a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-4 Pa, and molybdenum trioxide (second metal oxide layer) was vapor-deposited so as to have a film thickness of 10 nm. Then, gold (second electrode) was vapor-deposited so as to have a film thickness of 30 nm, and the organic electroluminescent device 1-8 was produced. In the vapor deposition of the second electrode, a vapor deposition mask made of stainless steel was used to form the vapor deposition surface in a strip shape having a width of 2 mm. That is, the light-emitting area of the produced organic electroluminescent device was set to 4 mm ² .

(Comparative Example 3)

The organic electroluminescent device 1-9 was produced in the same manner as in Example 6 except that the step [3b] was carried out instead of the step [3].

[3b] A solution prepared by diluting the self-assembled monomolecular film material F8TES described in paragraphs [0064] to [0066] of JP-A-2012-4492 (Patent Document 5) to 1% by using ethanol . The substrate with the titanium oxide film prepared in the step [2] was placed on a spin coater. A F8TES solution of a self-assembled monomolecular film was dropped on the substrate and rotated at 2000 rpm for 30 seconds. Immediately thereafter, it was washed with ethanol, and further washed with ultrasonic waves for 10 minutes. After rinsing, the plate was fixed by heating at 90 ° C for 10 minutes to form a self-assembled monomolecular film layer. The buffer layer has an average thickness of 2 nm. F8TES is a compound of the following formula (54).

(Measurement of Luminescence Characteristics of Organic Electroluminescence Element)

The voltage application and current measurement of the device were performed by a "2400 type power meter (SourceMeter)" manufactured by Keithley. The luminance of the light was measured by "LS-100" manufactured by Konica Minolta. Moreover, the uniformity of the light-emitting surface was confirmed by visual observation.

The voltage-current efficiency characteristics when the organic electroluminescence device produced in Example 1 and Comparative Example 1 was applied with a DC voltage of 4 V to 10 V under an argon atmosphere are shown in Fig. 2 . It can be seen that the element fabricated in Comparative Example 1 has a low current efficiency and a large leakage current. On the other hand, it was found that the current efficiency of the element fabricated in Example 1 was high, and the leakage current was suppressed. Further, it was confirmed by visual observation that the element produced in Example 1 was able to emit light with a very uniform light.

The organic electroluminescent elements produced in Examples 2 to 4 and Comparative Example 2 were subjected to an argon atmosphere. The voltage-current efficiency characteristics when a DC voltage of 4V to 15V is applied downward is shown in Fig. 3. Further, the voltage-current efficiency characteristics when the organic electroluminescence device produced in Example 5 and Comparative Example 2 was applied with a DC voltage of 4 V to 15 V under an argon atmosphere are shown in Fig. 4 . The leakage current of the element fabricated in Comparative Example 2 was very large and did not emit light at all. On the other hand, it is understood that the current efficiency of the elements fabricated in Examples 2 to 5 is high, and the leakage current is suppressed. Further, it was confirmed by visual observation that the elements produced in Examples 2 to 5 showed very uniform light emission.

The voltage-current efficiency characteristics when the organic electroluminescence device produced in Example 6 and Comparative Example 3 was applied with a DC voltage of 4 V to 15 V under an argon atmosphere are shown in Fig. 5 . The leakage current of the element fabricated in Comparative Example 3 was very large, and it did not emit light at all immediately after the light was emitted. On the other hand, it was found that the current efficiency of the element fabricated in Example 6 was high, and the leakage current was suppressed. Further, it was confirmed by visual observation that the element produced in Example 6 was able to emit light with a very uniform light.

From the above, it has been confirmed that in the organic-inorganic hybrid organic electroluminescent device, by laminating an organic compound into a film, leakage current suppression and uniform surface light emission can be achieved.

<The second organic electroluminescent device of the present invention>

In the following examples, the average thickness of each layer constituting the organic electroluminescent device was measured using a stylus type step meter (product name "Alpha Step IQ", manufactured by KLA Tencor Co., Ltd.).

(Production of organic electroluminescent elements)

(Example 7)

[1] A commercially available transparent glass substrate with an ITO electrode layer having an average thickness of 0.7 mm was prepared. At this time, the ITO electrode (first electrode) of the substrate was patterned to have a width of 2 mm. The substrate was ultrasonicated for 10 minutes in acetone and isopropanol, and then boiled in isopropyl alcohol for 5 minutes. The substrate was taken out from isopropyl alcohol, dried by a nitrogen blowing method, and washed by UV ozone for 20 minutes.

[2] The substrate was fixed on a substrate holder of a Mirror Tron sputtering apparatus having a zinc metal target. After depressurization to about 1 × 10 ^-4 Pa, sputtering was carried out while introducing argon gas and oxygen gas to form a zinc oxide layer having a film thickness of about 2 nm. At this time, a portion of the ITO electrode was not formed into a film of zinc oxide by a metal mask to take out the electrode. This was baked in a hot plate set at 400 ° C for 1 hour in the atmosphere to form a zinc oxide layer (first metal oxide layer).

[3] 0.2% of the boron-containing compound 1 synthesized in the above Synthesis Example 1, (4-(1,3-dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)) A mixed solution of 0.002% of 1,2-dichloroethane of phenyl)dimethylamine (N-DMBI). The substrate with the zinc oxide film prepared in the step [2] was placed on a spin coater. A mixed solution of a boron-containing compound 1 and an N-DMBI was dropped on the substrate, and the mixture was rotated at 2000 rpm for 30 seconds to form a buffer layer containing a boron-containing organic compound. Further, this was subjected to an annealing treatment for 1 hour on a hot plate set to 100 ° C in a nitrogen atmosphere. The buffer layer has an average thickness of 10 nm.

[4] A substrate formed to a layer containing a boron-containing organic compound is fixed on a substrate holder of a vacuum evaporation apparatus. Bis(10-hydroxybenzo[h]quinoline)indole (Bebq ₂ ), tris(1-phenylisoquinoline)indole (Ir(piq) ₃ ), N,N'-di(1-naphthyl) -N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD) was added to the alumina crucible and set as a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-5 Pa, and Bebq _{2 was} used as a main component, and 1r (piq) _{3 was} used as a dopant, and 35 nm was vapor-deposited to form a light-emitting layer. At this time, the doping concentration was such that Ir(piq) ₃ became 6 wt% with respect to the entire light-emitting layer. Then, α-NPD was vapor-deposited at 60 nm to form a hole transport layer.

[5] Next, after performing a nitrogen purge, molybdenum trioxide and gold were added to the alumina crucible to provide a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-5 Pa, and molybdenum trioxide (second metal oxide layer) was vapor-deposited so as to have a film thickness of 10 nm. Then, gold (second electrode) was vapor-deposited so as to have a film thickness of 50 nm to fabricate an organic electroluminescence device 2-1. In the vapor deposition of the second electrode, a vapor deposition mask made of stainless steel was used to form the vapor deposition surface in a strip shape having a width of 2 mm. That is, the light-emitting area of the produced organic electroluminescent device was set to 4 mm ² .

(Comparative Example 4)

In step [3], a boron-containing compound 1 of 0.2% 1,2-dichloroethane is used instead of boron. An organic electroluminescent device 2-2 was produced in the same manner as in Example 7 except that a mixed solution of 0.2% of the compound 1 and 0.002% of N-DMBI was used.

(Example 8)

In the step [3], a mixed solution of 1% of a boron-containing compound 1 and 0.01% of N-DMBI is used in place of 0.2% of the boron-containing compound 1 and 0.002% of the N-DMBI. An organic electroluminescent device 2-3 was produced in the same manner as in Example 7 except that a mixed solution of 2-dichloroethane was used. The buffer layer has an average thickness of 60 nm.

(Comparative Example 5)

In the step [3], a 1% solution of a boron compound 1 is used in place of 1% of a boron-containing compound 1 and a 0.01% mixture of 1,2-dichloroethane of N-DMBI. An organic electroluminescent device 2-4 was produced in the same manner as in Example 8 except for the solution.

(Example 9)

The organic electroluminescent device 2-5 was produced in the same manner as in Example 8 except that the step [4b] was carried out instead of the step [4].

[4b] The substrate formed to the layer containing the boron-containing organic compound is fixed on the substrate holder of the vacuum evaporation apparatus. Tris(8-hydroxyquinoline)aluminum (Alq ₃ ), N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'- Diamine (α-NPD) was added to the alumina crucible and set as a vapor deposition source. The pressure in the vacuum vapor deposition apparatus was reduced to about 1 × 10 ^-4 Pa, and Alq _{3 was} vapor-deposited to 35 nm to form a light-emitting layer. Then, α-NPD was vapor-deposited at 60 nm to form a hole transport layer.

(Embodiment 10)

In the step [3], a mixed solution of 1% of a boron-containing compound 1 and 0.05% of N-DMBI is used in place of 1% of the boron-containing compound 1 and 0.01% of the N-DMBI. An organic electroluminescent device 2-6 was produced in the same manner as in Example 7 except that a mixed solution of 2-dichloroethane was used. The buffer layer has an average thickness of 60 nm.

(Comparative Example 6)

The organic electroluminescent device 2-7 was produced in the same manner as in Comparative Example 5 except that the step [4b] was carried out instead of the step [4].

(Example 11)

In the step [3], a commercially available poly(dioctylfluorene-alternate-benzothiadiazole) (F8BT) 1%, N-DMBI 0.01% tetrahydrofuran mixed solution is used instead of the boron-containing compound 1 The organic electroluminescent device 2-8 was produced in the same manner as in Example 9 except that a mixed solution of 0.01% of 1,2-dichloroethane of 0.01% of N-DMBI was used.

(Comparative Example 7)

An organic electroluminescent device was produced in the same manner as in Example 10 except that a 1% tetrahydrofuran solution of F8BT was used in place of a 1% solution of F8BT and a 0.01% tetrahydrofuran mixed solution of N-DMBI in the step [3]. 2-9.

(Embodiment 12)

The organic electroluminescent device 2-10 was produced in the same manner as in Example 9 except that the step [3b] was carried out instead of the step [3].

[3b] A 1,2-dichloroethane mixed solution containing 1% of a boron-containing compound 1 and 0.01% of a leuco crystal violet was prepared. The substrate with the zinc oxide film prepared in the step [2] was placed on a spin coater. A boron-containing compound 1 and a leuco crystal violet mixed solution were dropped on the substrate, and rotated at 2000 rpm for 30 seconds to form a buffer layer containing a boron-containing organic compound. Further, this was subjected to an annealing treatment for 1 hour on a hot plate set at 200 ° C in a nitrogen atmosphere. The buffer layer has an average thickness of 60 nm.

(Comparative Example 8)

In the step [3b], a 1% solution of a boron-containing compound 1 is used in place of 1% of the boron-containing compound 1, and 0.01% of the leuco crystal violet is 1,2-dichloroethane. An organic electroluminescent device 2-11 was produced in the same manner as in Example 11 except that the solution was mixed.

(Example 13)

In the step [3b], Hans ester (=2,6-dimethyl-1,4-dihydropyridine-3,5-di) is used. The organic electroluminescent device 2-12 was produced in the same manner as in Example 12 except that diethyl carboxylic acid was used instead of the leuco crystal violet.

The summary of the organic electroluminescent elements produced in Examples 7 to 13 and Comparative Examples 4 to 8 is shown in Table 1. The wt% of the reducing agent is a ratio relative to the amount of the organic compound used in the buffer layer.

(Measurement of Luminescence Characteristics of Organic Electroluminescence Element)

The voltage application and current measurement of the components are performed by the "2400-type power supply meter" manufactured by Keithley. The luminance of the light was measured by "LS-100" manufactured by Konica Minolta.

The voltage-luminance characteristics and current density-current efficiency characteristics when the organic electroluminescent elements produced in Examples 7 to 13 and Comparative Examples 4 to 8 were applied with a DC voltage under an argon atmosphere are shown in Figs. 6 to 15 . It can be seen that in either case, the doped element produced in the examples has higher luminance and current efficiency than the undoped element produced in the comparative example, and is excellent in characteristics.

<The third organic electroluminescent device of the present invention>

(Production of organic electroluminescent elements)

(Example 14)

[1] A commercially available transparent glass substrate 1 with an ITO electrode layer having an average thickness of 0.7 mm was prepared. At this time, the ITO electrode 2 of the substrate was patterned to have a width of 2 mm. The substrate was ultrasonicated for 10 minutes in acetone and isopropanol, and then boiled in isopropyl alcohol for 5 minutes. The substrate was taken out from isopropyl alcohol, dried by a nitrogen blowing method, and washed by UV ozone for 20 minutes.

[2] The substrate was again fixed on a substrate holder of a Mirror Tron sputtering apparatus having a zinc metal target. After the pressure was reduced to about 1 × 10 ^-4 Pa, sputtering was carried out while introducing argon gas and oxygen gas to form a zinc oxide layer having a film thickness of about 2 nm as the first metal oxide layer 3. At this time, a portion of the ITO electrode was not formed into a film of zinc oxide by a metal mask to take out the electrode.

[3] The substrate was again subjected to the washing step of [1] (supersonic washing in acetone and isopropanol for 10 minutes, followed by boiling in isopropanol for 5 minutes, followed by nitrogen blowing) After drying, it was subjected to UV ozone washing for 20 minutes), and then annealed on a hot plate at 400 ° C for 1 hour.

[4] Next, in order to form the layer 4 containing the nitrogen-containing film, spin coating was performed at 2000 rpm for 30 seconds to dilute the polyethyleneimine (registered trademark: EPOMIN) manufactured by Nippon Shokubai Co., Ltd. to 0.5% by weight with ethanol. Founder.

The EPOMIN used herein is sp003 having a molecular weight of 300.

[5] The film (substrate) produced in [4] was annealed at 150 ° C for 5 minutes in the air under a hot plate. The average thickness of the layer of the nitrogen-containing film measured after annealing was 5 nm.

[6] Next, the substrate subjected to the treatment of [5] was introduced into a vacuum apparatus, and the pressure was reduced to 1 × 10 ^-4 Pa or less. As the organic compound layer 5, 32.5 nm of an Alq ₃ layer was used as a light-emitting layer by a vacuum deposition method, and 60 nm of an α-NPD layer was used as a hole transport layer.

[7] Next, the second metal oxide layer 6 is formed on the organic compound layer 5. Here, 10 nm of molybdenum oxide was formed by a vacuum vapor deposition method as a vapor phase film formation method.

[8] Next, as a final step, the anode 7 is formed on the second metal oxide layer 6. Here, a film of aluminum was 150 nm by a vacuum evaporation method.

[9] The characteristics of the organic electroluminescent device (voltage-current density/luminance characteristic, current density) are measured by the following (measurement of the luminescence characteristics of the organic electroluminescence device) and (the measurement of the lifetime characteristics of the organic electroluminescence device). Current efficiency characteristics, continuous drive characteristics at a constant current density (corresponding to 100 cd/m ² , equivalent to 1000 cd/m ² ). The measurement results are shown in (a), (b), (c-1), and (c-2) of Figs. 17-1 and 17-2, respectively.

(Measurement of Luminescence Characteristics of Organic Electroluminescence Element)

The voltage application and current measurement of the device were performed by a "2400-type power supply meter" manufactured by Keithley. The luminance of the light was measured by "BM-7" manufactured by TOPCON Corporation. The measurement was carried out under an argon atmosphere.

(Measurement of life characteristics of organic electroluminescent elements)

The voltage application to the device and the relative luminance were measured by an "organic EL life measuring device" manufactured by System Technology Co., Ltd. In this apparatus, the relative luminance measurement by the photodiode is performed while automatically adjusting the voltage so that a fixed current flows through the element. The current value was set for each element so that the luminance at the start of the measurement was 100 cd/m ² and 1000 cd/m ² . The results of the above are shown in (c-1) and (c-2) of the respective examples and comparative examples.

In addition, the descriptions such as "t _1/2 =200h@1000cd/m ² " outside the columns of (c-1) and (c-2) indicate the half life, and in the above case, the continuous supply is performed at a constant current. The luminance half life of the current density equivalent to 1000 cd/m ² was 200 hours.

(Comparative Example 9)

The organic electroluminescent device was fabricated in the same manner except that the steps [4] and [5] of Example 14 were omitted, and the voltage-current density/brightness of the organic electroluminescent device was measured in the same manner as in Example 14. Characteristics, and current density - current efficiency characteristics. The results of these are shown in Figures 18(a) and (b), respectively.

(Example 15)

The organic electroluminescent device was produced in the same manner as in Example 14 except that the step of the step [4] of the example 14 was changed to the following [4-2], and the organic electroluminescent device was measured in the same manner as in the example 14. Voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous drive characteristics at a constant current density (corresponding to 1000 cd/m ² ). The results of these are shown in (a), (b) and (c-2) of Figures 19-1 and 19-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 6 nm.

[4-2] Next, in order to form the layer 4 containing the nitrogen-containing film, spin coating was performed at 2000 rpm for 30 seconds to dilute the polyethyleneimine (registered trademark: EPOMIN) manufactured by Nippon Shokubai Co., Ltd. to 0.5 using ethanol. % by weight. The EPOMIN used herein is P1000 having a molecular weight of 70,000.

(Embodiment 16)

The steps of steps [4] and [5] of the fourteenth embodiment were changed to the following [4-3] and [5-3], and an organic electroluminescent device was produced in the same manner as in the example. In the same manner, the voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous driving characteristics at a constant current density (corresponding to 1000 cd/m ² ) of the organic electroluminescent device were measured in the same manner. The results of these are shown in (a), (b) and (c-2) of Figs. 20-1 and 20-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 5 nm.

[4-3] Next, in order to form the layer 4 of the nitrogen-containing film, it is rotated at 2000 rpm for 30 seconds. The transfer coating was carried out by diluting diethylenetriamine to 1.0% by weight with ethanol.

The film (substrate) produced in [5-3] and [4-3] was annealed in a hot plate at 100 ° C for 2 minutes.

(Example 17)

The organic electroluminescent device was fabricated in the same manner except that the step [5] of Example 14 was omitted, and the voltage-current density/luminance characteristics and constant of the organic electroluminescent device were measured in the same manner as in Example 14. Continuous drive characteristics at current density (equivalent to 100 cd/m ² ). The results of these are shown in Figures 21(a) and (c-1), respectively. Further, since the film thickness of the layer containing the nitrogen film is not annealed, the film is not cured and cannot be measured, but the film thickness of the layer of the nitrogen-containing film after annealing in Example 14 is known and the atmosphere is used. The film thickness of the next annealing is reduced, and it is estimated to be about 10 nm.

(Embodiment 18)

The procedure of the step [4] of the fourteenth embodiment is changed to the above [4-2], and the step of [5] is changed to the following [5-5], and otherwise, the organic electroluminescent element is produced in the same manner. The voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous driving characteristics at a constant current density (corresponding to 100 cd/m ² ) of the organic electroluminescent device were measured in the same manner as in Example 14. The results of these are shown in (a), (b) and (c-1) of Figs. 22-1 and 22-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 8 nm.

The film (substrate) produced in [5-5] and [4-2] was annealed in a hot plate at 100 ° C for 10 minutes.

(Embodiment 19)

The procedure of the step [4] of the fourteenth embodiment is changed to the above [4-2], and the step of [5] is changed to the following [5-6], except that the organic electroluminescent element is produced in the same manner. The voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous driving characteristics at a constant current density (corresponding to 100 cd/m ² ) of the organic electroluminescent device were measured in the same manner as in Example 14. The results of these are shown in (a), (b) and (c-1) of Figures 23-1 and 23-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 7 nm.

The film (substrate) prepared in [5-6] and [4-2] was annealed at 150 ° C for 10 minutes in the air under a hot plate.

(Embodiment 20)

The procedure of the step [4] of the fourteenth embodiment is changed to the above [4-2], and the step of [5] is changed to the following [5-7], and otherwise, the organic electroluminescent element is produced in the same manner. The voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous driving characteristics at a constant current density (corresponding to 1000 cd/m ² ) of the organic electroluminescent device were measured in the same manner as in Example 14. The results of these are shown in (a), (b) and (c-2) of Figures 24-1 and 24-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 5 nm.

The film (substrate) prepared in [5-7] and [4-2] was annealed in the atmosphere at 150 ° C for 30 minutes on a hot plate.

(Example 21)

The organic electroluminescent device was produced in the same manner as in Example 14 except that the procedure of the step [5] of the Example 14 was changed to the following [5-8], and the organic electroluminescent device was measured in the same manner as in Example 14. Voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous drive characteristics at a constant current density (corresponding to 1000 cd/m ² ). The results of these are shown in (a), (b) and (c-2) of Figures 25-1 and 25-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 5 nm.

[5-8] The film (substrate) produced in [4] was annealed at 100 ° C for 30 minutes in the air under a hot plate.

(Example 22)

The procedure of the step [4] of the fourteenth embodiment is changed to the above [4-2], and the step of [5] is changed to the following [5-9], and otherwise, the organic electroluminescent element is produced in the same manner. The voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous driving characteristics at a constant current density (corresponding to 100 cd/m ² ) of the organic electroluminescent device were measured in the same manner as in Example 14. The results of these are shown in (a), (b) and (c-1) of Figures 26-1 and 26-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 8 nm.

[5-9] The film (substrate) produced in [4-2] was annealed on a hot plate at 150 ° C for 10 minutes under nitrogen.

(Example 23)

The organic electroluminescent device was produced in the same manner as in Example 14 except that the procedure of the step [5] of the example 14 was changed to the following [5-11], and the organic electroluminescent device was measured in the same manner as in the example 14. Voltage-current density/luminance characteristics, current density-current efficiency characteristics, and continuous drive characteristics at a constant current density (corresponding to 1000 cd/m ² ). The results of these are shown in (a), (b) and (c-2) of Figures 27-1 and 27-2, respectively. Further, the average film thickness of the layer containing the nitrogen film was 5 nm.

[5-11] The film (substrate) produced in [4] was annealed at 150 ° C for 5 minutes in the air under a hot plate. Thereafter, it was washed with ethanol.

(Manufacturing Example 1)

The following photoelectron spectroscopy was carried out on the nitrogen-containing film obtained by the operation of [1] to [5] of Example 14.

Quantitative analysis was performed by simultaneously measuring the carbon 1S orbital and the nitrogen 1S orbital domain.

These are shown in Figs. 28(d) and (e).

(Measurement by X-ray photoelectron spectroscopy)

The measurement was carried out under the following conditions using a photoelectron spectroscopy apparatus manufactured by JEOL Ltd. (JPS-9000MX).

X-ray source: MgK α

Beam output (acceleration voltage - current amount): 10kV-10mA

Pass Energy: 10eV

Step: 0.1eV

(Manufacturing Example 2)

The above photoelectron spectroscopy was carried out on the nitrogen-containing film obtained by the operation of [1] to [4] of Example 14.

Quantitative analysis was performed by simultaneously measuring the carbon 1S orbital and the nitrogen 1S orbital domain.

These are shown in Figs. 29(d) and (e).

(Manufacturing Example 3)

The photoelectron spectroscopy was carried out on the nitrogen-containing film produced by the steps [1] to [3] of Example 14 and the following steps [4-12] and [5-12]. Further, the average film thickness of the layer containing the nitrogen film was 10 nm.

[4-12] Next, in order to form the layer 4 containing the nitrogen-containing film, ethoxylated polyethyleneimine (molecular weight: 70,000) manufactured by Aldrich using ethoxyethanol was spin-coated at 5000 rpm for 60 seconds. Diluted to 0.4% by weight.

[5-12] The film (substrate) produced in [4-12] was annealed at 100 ° C for 10 minutes in the air under a hot plate.

Quantitative analysis was performed by simultaneously measuring the carbon 1S orbital and the nitrogen 1S orbital domain.

These are shown in Figs. 30(d) and (e).

(Manufacturing Example 4)

The operation of [1] to [3] of Example 14, and the following [4-13] and [5] of Example 14 were carried out, and the obtained photo-electron spectroscopy was performed on the obtained nitrogen-containing film. Further, the film thickness of the layer containing the nitrogen film is a film thickness at which the average film thickness cannot be estimated even by a plurality of measurements. This is presumed to be less than 3 nm.

[4-13] Next, in order to form the layer 4 containing the nitrogen-containing film, spin coating was performed at 2000 rpm for 30 seconds to dilute the polyethyleneimine (registered trademark: EPOMIN) manufactured by Nippon Shokubai Co., Ltd. using ethanol. Released into 0.125% by weight. The EPOMIN used herein is P1000 having a molecular weight of 70,000.

Quantitative analysis was performed by simultaneously measuring the carbon 1S orbital and the nitrogen 1S orbital domain.

These are shown in Figs. 31(d) and (e).

(Example 24-1)

The organic electroluminescent device was produced in the same manner except that the steps [4] and [5] of the fourteenth embodiment were changed to the following [4-18] and [5-18]. The voltage-current density/luminance characteristics, current density-current efficiency characteristics of the organic electroluminescent device were measured in the same manner. The results of these are shown in Figures 32(a) and (b), respectively. Further, the average film thickness of the layer containing the nitrogen film was 10 nm.

[4-18] Next, in order to form the layer 4 containing the nitrogen-containing film, spin-coating was carried out at 2000 rpm for 30 seconds to dilute the linear polyethyleneimine (purchased from Polysciences, molecular weight: 25,000) to 0.1 using ethanol. % by weight.

[5-18] The film (substrate) produced in [4-18] was annealed at 150 ° C for 5 minutes in the air under a hot plate.

(Example 24-2)

The organic electroluminescent device was fabricated in the same manner except that the steps [5-18] of Example 24-1 were omitted, and the voltage-current density of the organic electroluminescent device was measured in the same manner as in Example 14. Brightness characteristics, current density - current efficiency characteristics. The results of these are shown in Figures 33(a) and (b), respectively. Further, the average film thickness of the layer containing the nitrogen film was 12 nm.

(Embodiment 25)

The organic electroluminescent device was fabricated in the same manner except that the steps [4] and [5] of the fourteenth embodiment were changed to the following [4-20] and [5-20], and the examples were The voltage-current density/luminance characteristics, current density-current efficiency characteristics of the organic electroluminescent device were measured in the same manner. The results of these are shown in Figures 34(a) and (b), respectively. Further, the average film thickness of the layer containing the nitrogen film was 10 nm.

[4-20] Next, in order to apply the melamine resin as the nitrogen-containing compound for forming the layer 4 of the nitrogen-containing film, spin coating was performed at 2000 rpm for 30 seconds to mix melamine and formaldehyde with 1:3 and to 0.1 weight. % is dissolved in a mixed solvent of methanol: water = 1:1.

[5-20] The film (substrate) prepared in [4-20] was annealed at 80 ° C for 60 minutes in the air under a hot plate.

(Comparative Example 10)

The organic electroluminescent device was fabricated in the same manner except that the steps [4] and [5] of the fourteenth embodiment were changed to the following [4-21] and [5-21], and the examples were The voltage-current density/luminance characteristics, current density-current efficiency characteristics of the organic electroluminescent device were measured in the same manner. The results of these are shown in Figures 35(a) and (b), respectively.

[4-21] Next, a polystyrene film (10 nm) as a nitrogen-free organic film was used instead of the layer 4 containing a nitrogen-containing film, and a film was formed by spin coating using toluene.

[5-21] The film (substrate) produced in [4-21] was annealed at 150 ° C for 5 minutes in the air under a hot plate.

17 to 27 and 32 to 35, (a) to (c) respectively show the following.

(a) is a voltage-current density (black dot) / brightness (white dot) characteristic. The first -, the higher the brightness is better. Second, it is better to exhibit higher brightness at lower voltages.

(b) is the current density-current efficiency (black diamond shape) characteristic. First, it is better to have higher current efficiency (hereinafter referred to as "efficiency"). Second, it is better to fix the current efficiency. In particular, the high current density region (high luminance region) is high and fixed.

(c) is a change in voltage over time at a constant current (here, a current value of 1000 cd/m ² which is an initial luminance) and a change in relative luminance with time. First, it is preferable that the change in relative luminance with time is small (the initial luminance can be maintained for a long period of time) (hereinafter referred to as "long life"). Second, it is preferable to have a smaller voltage rise in the process as a content related thereto.

The three elements of brightness, efficiency, and longevity are all important, but among them, life expectancy should be the first priority.

Based on the above, the results of FIGS. 17 to 27 and 32 to 34 will be described.

Fig. 17: luminescence started from a low voltage (about 2 V), and reached a high luminance of 3000 cd/m ² at 6V. Overall, the efficiency is also higher than 4 cd/A. Moreover, with respect to long-term changes, it is also possible to achieve high reliability of about 200 hours from brightness to half-life. At an initial luminance of 100cd / m under the driving condition of the other ^two, with the estimated half lifetime of several thousand hours, thereby clearly also high reproducibility.

Fig. 18: Fig. 18 shows the measurement results of an element having no layer between the metal oxide layer and the light-emitting layer. It can be seen that the brightness and efficiency are both 1/10 or less of FIG. The measurement results below in Fig. 19 are necessarily superior to the values of Fig. 18, thereby showing an effect when a layer having a nitrogen-containing film is used.

Fig. 19: The efficiency is superior to that of Fig. 17 (the element of the embodiment 14), but the decrease in the luminance in the initial few hours is imminent, and in terms of the life, the result is superior to Fig. 17. From the results, it is estimated that the stability of the film under the redox reaction is excellent in the element of Example 14.

Figure 20: Brightness and efficiency are comparable to those of Figure 17 (component of Example 14). The life is also about 10 hours from the initial stage, which is equivalent to FIG. However, the result subsequently caused rapid deterioration.

According to the results of Figs. 19 and 20, even if polyethyleneimine having a different molecular weight is used, there is no significant difference in initial characteristics, and it is excellent as compared with those having no nitrogen-containing film. However, with regard to long-term stability, the results vary.

In FIGS. 21 to 27 (Examples 17 to 23), the influence of the process (annealing conditions (temperature, time, environment) and rinsing) on the device characteristics (process dependency) after coating with a nitrogen-containing compound was confirmed. In addition, it indicates the molecular weight dependence of them.

Fig. 21 is a measurement result of the element characteristics in the case where liquid branched polyethyleneimine (low molecular weight) is used without annealing. Almost no luminescence is observed, and it is not as high as the characteristic.

Fig. 22 and Fig. 23 are the results of measuring the characteristics of the element obtained by using the liquid branched polyethyleneimine (high molecular weight) and changing the annealing temperature. A result of obtaining a higher temperature in terms of brightness and efficiency. The effect of obtaining the annealing temperature is slightly remarkable on the life, and the result of the annealing at a high temperature of 2 times or more in terms of the half life is good. It can be considered that the difference is caused by a small decrease in luminance at the initial stage of the annealing at a high temperature. Including the case of Fig. 21, the above case implies that annealing has an effect on the life extension, that is, the long-term stability of redox. Although not described here, in the case of annealing at 200 ° C, since the discoloration was brown, the element measurement was not performed. From this, it is estimated that there is an optimum value with respect to the annealing temperature.

Fig. 24 is a view showing the results of producing a nitrogen-containing film by changing the annealing time at 150 ° C which is the optimum value of the annealing temperature obtained in the results of Examples 17 to 19 (Figs. 21 to 23) in Example 20. The brightness and efficiency were slightly lower than those of Fig. 23 (Example 19). Further, regarding the life curve, it is also known that the initial deterioration starts to be slightly stronger. It is speculated from these cases that there is also an optimum value for the annealing time.

Figure 26: Results of the last study under the above optimal conditions for the environment in which annealing was performed. When the production of the nitrogen-containing film under the conditions of Fig. 23 (Example 19) was carried out under nitrogen, no significant difference was observed between the initial characteristics (brightness and efficiency) and Fig. 23. From this, it is presumed that the effect of having a nitrogen-containing film here is an electron attraction effect utilizing the polarization between the metal-nitrogen and the polarization between the carbon and nitrogen in the molecule under physical adsorption which is not chemically adsorbed. It should be noted that the life in Figure 26 becomes extremely short. From this, it can be considered that the annealing process in the present invention which causes the life extension is not only accompanied by a change in solvent removal or morphology, but also has a high possibility of chemical change (which chemical change is as follows).

Figure 25: Based on the results of the above investigations, it is speculated that the annealing conditions, the materials are self-evident, and also depend on the molecular weight, so the results were investigated.

The liquid branched polyethyleneimine (low molecular weight) is annealed at a temperature lower than the optimum temperature for a long time, and as a result, brightness and efficiency are obtained in terms of initial characteristics, and the results are close to those in Fig. 17, but The current density value was observed to be higher under the previous voltage and reverse bias. The above case indicates that there is a useless current flow (hereinafter referred to as "leakage current") which does not contribute to light emission, and in many cases, there is a problem in long-term stability. This time, the life is shortened due to a sudden drop in brightness from the beginning, and the above leakage current is considered to be the cause.

From this result, it is clear that the material is self-evident about the optimum value of the annealing condition, and it also depends on the molecular weight. In addition, even if annealing is performed for a long time below the optimum temperature, good characteristics are not obtained, thereby suggesting that there is also a threshold depending on the temperature of the material or molecular weight.

Fig. 27: When the rinsing effect under the above-described optimum conditions (conditions of Example 14) was confirmed, the initial characteristics (brightness, efficiency) were substantially the same as those of Fig. 17 (Example 14), but the leakage current was slightly large. It is considered that the life characteristics of the system are worse than those of FIG. 17 (Example 14). However, although not shown in the figure, the variation in the characteristics between the fabrication elements is small, and the reproducibility is improved. It is considered that the above aspects are important processes from the viewpoint of practical use. Regarding the longevity, it is also believed that an improvement will be obtained by finding better rinsing conditions.

Figure 32 and Figure 33: For the use of linear polyethyleneimine as a nitrogen-containing compound fruit. Good initial properties (brightness, efficiency) were exhibited with or without annealing. This situation is different from branched polyethyleneimine, and it is considered that the main reason is that it is a solid. That is, it is estimated that the effect of annealing is as follows. (i) to cure it. (ii) Preparing a strong bond type by enriching the metal-nitrogen bond. (iii) Changing the carbon element ratio of nitrogen to the relative increase in the ratio of the presence of nitrogen.

The effects of these annealings are further as follows.

Figure 34: For the application of melamine resin as a material with a high nitrogen ratio The results of the study. As compared with Fig. 18, good results were obtained, and it was confirmed that there was an effect. Since there is also unevenness in light emission, it is considered that better results can be obtained if detailed conditions are found.

Figure 35: Results for the application of a nitrogen-free organic film. It can be seen that the brightness and efficiency are inferior to those in Fig. 19 in terms of initial characteristics. From this, it is considered that the organic film functions only as an insulating layer. also, The life of the device is extremely short for a few minutes. The mechanism of electron injection is expected to cause the band of the luminescent layer to bend by the charge storage in the luminescent layer. According to the detailed study of the conditions, it is considered that the polystyrene can also improve the initial characteristics. However, since the driving mechanism is as described above, it is considered that the long-term reliability cannot be expected as the element of the present invention.

Next, FIGS. 28 to 31 (manufacturing examples 1 to 4) will be described.

In Production Examples 1 to 4, the liquid branched polyethyleneimine was not measured in all cases before the annealing of the nitrogen-containing film. On the other hand, it becomes measurable by annealing. This suggests that the annealing is cured by an effect (only the result cannot be decomposed) (the above effect (i)).

The results of X-ray photoelectron spectroscopy (d) of the carbon 1s orbital domain of FIGS. 28 to 31 and the results of X-ray photoelectron spectroscopy of the nitrogen 1s orbital domain (e) are all measurement results after annealing. It can be confirmed that all of C:N≒2:1 except for Fig. 30 before annealing. In Fig. 30, before annealing, it is C:N≒4:1. These ratios are values consistent with stoichiometric ratios estimated from chemical structures. The element presence ratio is estimated from the ratio of the peak areas of the respective orbital domains. In the comparison between FIG. 28 and FIG. 29, it can be confirmed that there is a change in the ratio and a change in the ratio according to the presence or absence of annealing. By annealing, the peak areas of carbon and nitrogen are all reduced, but the reduction of the carbon wave peak is large, resulting in a relative increase in the ratio of nitrogen elements. In Fig. 30, there was no change after annealing and before annealing (stoichiometric ratio), and it was found that there was no major chemical change. The above-mentioned circumstances suggest that the effect of the film formed of the compound modified with polyethyleneimine or polyethyleneimine described in the above Non-Patent Documents 1 to 3 is performed by annealing in the present invention to make the liquid The film formed by the change of branched polyethyleneimine (low molecular weight) is different. Fig. 31 shows the results of the same annealing treatment by thinning the liquid branched polyethyleneimine (high molecular weight) to the same or higher than those of the low molecular weight. In the present results, the ratio of the elements in the high molecular weight polyethyleneimine did not change. This suggests that the ratio of the presence of the carbon element: nitrogen element does not change under certain conditions, for example, at a non-low molecular weight (effect (iii) above).

Figs. 28 to 30(f) are diagrams showing the results of peak division of the results of X-ray photoelectron spectroscopy of the nitrogen 1s orbital region. Imagine that the type of nitrogen atom bond in this system is carbon-nitrogen. The bond is two kinds of metal-nitrogen bonds. According to the previous literature, the peak of the lowest energy side belongs to the metal-nitrogen bond. Further, regarding the next peak, if it belongs to the carbon-nitrogen bond, the energy difference between all the two peaks is approximately 0.6 eV to 0.7 eV, which is substantially identical, suggesting that the peak division and attribution are correct.

Further, although not shown here, the full width at half maximum of all of Figs. 28 to 30 before annealing was 1.2 eV. From this, it is considered that in the case of Figs. 28 and 30, the full width at half maximum is increased, which prolongs the life (the above effect (i)).

From the above, it can be considered that the examples of FIG. 28 exhibit all the effects (i) to (iii) described above, and can realize initial characteristics (brightness, efficiency) and long-term reliability (life). It is estimated that in Fig. 30, initial characteristics and a certain degree of life can be achieved under (i) and (i), and in Fig. 29, initial characteristics and a certain degree of life can be achieved under the effect of (i). According to these circumstances, it is considered that although the result of the X-ray photoelectron spectroscopy is not obtained, since the solid linear polyethyleneimine used in FIGS. 32 and 33 achieves (i), even if there is no annealing effect, A certain degree of life can be achieved. The same is true in Fig. 34.

Based on the above results, the following can be clarified.

From the comparison of Fig. 18 with the other figures, it was confirmed that when the nitrogen-containing film is disposed on the oxide on the lower cathode, the characteristics of the organic electroluminescence element such as brightness or efficiency are improved. Regarding the annealing treatment, according to Fig. 33, it was confirmed that there is no need to anneal depending on the material, and it is not essential. However, it has been confirmed that by performing annealing, in many cases, the life characteristics corresponding to long-term reliability are improved. Further, regarding the materials used, it was also confirmed that a rich nitrogen-containing compound such as polyethyleneimine (different molecular weight or shape <linear and branched>), diethylenetriamine or melamine resin can be used. Further, it has been confirmed that the method and the like must be selected depending not only on the material but also on the molecular weight or shape. In particular, linear polyethylenimine is a solid unlike other polyethylenes, and therefore it is considered to exhibit an effect even without annealing. Further, it was confirmed that it was effective to perform rinsing after film formation.

Claims (18)

An organic electroluminescent device having a structure in which a plurality of layers are laminated, wherein the organic electroluminescent device has a metal oxide layer between the first electrode and the second electrode, and the metal oxide layer is formed on the metal oxide layer Having a buffer layer formed of an organic compound, the buffer layer being a layer formed by coating a solution containing an organic compound, except that the organic compound does not contain a decane compound represented by the following formula, In the formula, A ¹ , A ² , A ³ and A ⁴ are each independently an alkyl group, an aryl group, a heteroaryl group or an alkynyl group. The organic electroluminescent device according to claim 1, wherein the first electrode is a cathode formed on the substrate, and the metal oxide layer is sequentially provided between the anode and the anode of the second electrode. A buffer layer formed of an organic compound. The organic electroluminescent device according to claim 1 or 2, wherein the buffer layer is a layer having an average thickness of 3 nm or more formed by coating a solution containing an organic compound, and the buffer layer is adjacent to the metal oxide. On the floor. The organic electroluminescent device of claim 1 or 2, wherein the buffer layer is a layer having an average thickness of 5 to 50 nm. An organic electroluminescent device according to claim 1 or 2, wherein the organic compound is an organic compound having a boron atom. The organic electroluminescent device of claim 5, wherein the organic compound having a boron atom is a boron-containing compound represented by the following formula (1) or contains boron represented by the following formula (2) a boron-containing polymer obtained by polymerizing a monomer component of a compound, (wherein, the arc of the dotted line indicates a ring structure together with the skeleton portion indicated by the solid line; the broken line portion of the skeleton portion indicated by the solid line indicates that the pair of atoms connected by a broken line may also be double-bonded; the boron atom is directed to boron. the arrow represents a nitrogen atom atom is coordinated to a boron atom; Q ¹ and Q ² are the same or different, represents a part of the skeleton as a solid line in the linking group, at least part of a ring structure together with the arc portion of the broken line, also having a substituent; X ¹ , X ² , X ³ and X ^{4 are the} same or different and each represents a hydrogen atom or a monovalent substituent which is a substituent of a ring structure, and may also bond to a ring structure forming a circular arc portion of a broken line. n ^{1 is} an integer of 2 to 10; Y ¹ is a direct bond or a n ¹ valent linkage, indicating that the structural portion other than the n ¹ Y ¹ existing is independently independent of the arc portion forming the dotted line Ring structure, any of Q ¹ , Q ² , X ¹ , X ² , X ³ , X ⁴ bonding) (wherein, the circular arc of the dotted line indicates a ring structure together with a portion of the skeleton portion linking the boron atom and the nitrogen atom; and the broken line portion in the skeleton portion connecting the boron atom and the nitrogen atom indicates that at least one pair of atoms are linked by a double bond, The double bond may also be conjugated to the ring structure; the arrow from the nitrogen atom to the boron atom indicates that the nitrogen atom coordinates the boron atom; and X ⁵ and X ^{6 are the} same or different, and represent a hydrogen atom or a substituent which becomes a ring structure. a valence substituent may also be bonded to a ring structure forming a circular arc portion of a broken line; R ¹ and R ^{2 are the} same or different and represent a hydrogen atom or a monovalent substituent; X ⁵ , X ⁶ , R ¹ and R At least one of ² is a substituent having a reactive group). The organic electroluminescent device of claim 1 or 2, wherein the buffer layer contains a reducing agent. The organic electroluminescent device of claim 7, wherein the buffer layer is a layer having an average thickness of 5 to 100 nm formed by coating a solution containing an organic compound. The organic electroluminescent device of claim 7, wherein the reducing agent is a hydride reducing agent. The organic electroluminescent device of claim 9, wherein the hydride reducing agent is selected from the group consisting of 2,3-dihydrobenzo[d]imidazole compounds, 2,3-dihydrobenzo[d]thiazole Compound, 2,3-dihydrobenzo[d] At least one compound selected from the group consisting of an azole compound, a triphenylmethane compound, and a dihydropyridine compound. The organic electroluminescent device of claim 1 or 2, wherein the buffer layer is a layer composed of a nitrogen-containing film and having an average thickness of 3 to 150 nm. The organic electroluminescent device of claim 11, wherein the nitrogen-containing film is formed of a nitrogen-containing compound, or contains a nitrogen element and a carbon element as elements constituting the film, and constitutes a nitrogen atom and a carbon atom of the film. The existence ratio satisfies the following relationship: the number of nitrogen atoms / (number of nitrogen atoms + number of carbon atoms) > 1/8. The organic electroluminescent device of claim 11, wherein the nitrogen-containing film is formed by decomposing a nitrogen-containing compound by heating. The organic electroluminescent device of claim 11, wherein the nitrogen-containing compound is a polyamine or contains three a compound of the ring. The organic electroluminescent device of claim 1 or 2, wherein the metal oxide is selected from the group consisting of magnesium, calcium, strontium, barium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, It is composed of metal elements such as tungsten, manganese, indium, gallium, iron, cobalt, nickel, copper, zinc, cadmium, aluminum, antimony and tin. A display device formed by using the organic electroluminescent device of any one of claims 1 to 15. A lighting device formed by using the organic electroluminescent device of any one of claims 1 to 15. A method of manufacturing an organic electroluminescence device, which is a method for producing an organic electroluminescence device having a structure in which a plurality of layers are laminated, characterized in that the method includes the steps of: causing an organic electroluminescence device to be The first electrode and the second electrode are sequentially provided with a first metal oxide layer, a buffer layer, a low molecular compound layer including a light-emitting layer laminated on the buffer layer, and a second metal oxide layer. Each of the layers constituting the organic electroluminescent device includes a step of applying a solution containing an organic compound to form a buffer layer having an average thickness of 3 nm or more.