JPWO2013114966A1 - Iridium complex compound, organic electroluminescence device material, organic electroluminescence device, lighting device and display device - Google Patents

Abstract

That at least one organic layer including a light emitting layer is sandwiched between the anode and the cathode, and that the iridium complex compound represented by the general formula (5 ′) is contained in at least one of the organic layers. An organic electroluminescence device characterized. [Ring An, Bm and Bn each represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring. R1m, R2m, R1n and R2n each independently represent a substituent. Ra, Rb and Rc each independently represent a substituent. na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 represent substituents. m represents 1 or 2, n represents 1 or 2, and m + n is 3. Note that the structures of the three ligands coordinated to Ir are not all the same. ]

Description

  The present invention relates to an iridium complex compound, an organic electroluminescence element material, an organic electroluminescence element, an illumination device, and a display device.

  An organic electroluminescence element (hereinafter also referred to as an organic EL element) has a configuration in which a light-emitting layer containing a light-emitting compound is sandwiched between a cathode and an anode, and a positive electrode injected from the anode by applying an electric field. This is a light emitting device that uses the emission of light (fluorescence / phosphorescence) when excitons are generated by recombining electrons injected from holes and cathodes in the light emitting layer to generate excitons. is there. The organic EL element is an all-solid-state element composed of an organic material film having a thickness of only a submicron between the electrodes, and can emit light at a voltage of several volts to several tens of volts. It is expected to be used for next-generation flat display and lighting.

  As for development of organic EL elements for practical use, Princeton University has reported organic EL elements that use phosphorescence emission from excited triplets (see, for example, Non-Patent Document 1), and since then phosphorescence at room temperature. Research on materials exhibiting the above has become active (see, for example, Patent Document 1 and Non-Patent Document 2).

  Furthermore, organic EL elements that utilize phosphorescence emission can in principle achieve a light emission efficiency that is approximately four times that of organic EL elements that utilize previous fluorescence emission. Research and development of device layer configurations and electrodes are performed all over the world. For example, many compounds have been studied focusing on heavy metal complexes such as iridium complexes (see Non-Patent Document 3, for example).

  As described above, the phosphorescence emission method is a method having a very high potential. However, an organic EL device using phosphorescence emission is greatly different from an organic EL device using fluorescence emission, and controls the position of the emission center. The method, particularly how to recombine within the light emitting layer and how to stably emit light, is an important technical issue in capturing the efficiency and lifetime of the device.

  Therefore, in recent years, a multi-layered element having a hole transport layer located on the anode side of the light emitting layer and an electron transport layer located on the cathode side of the light emitting layer in a form adjacent to the light emitting layer is well known. (For example, refer to Patent Document 2). In addition, a mixed layer using a host compound and a phosphorescent compound as a dopant is often used for the light emitting layer.

  On the other hand, from the viewpoint of materials, high carrier transportability and thermally and electrically stable materials are required. In particular, when using blue phosphorescence, since the blue phosphorescent compound itself has high triplet excitation energy (T1), it is possible to develop applicable peripheral materials and precisely control the emission center. There is a strong demand.

  FIrpic is known as a typical blue phosphorescent compound, and a short wave is realized by substituting fluorine for the main ligand phenylpyridine and using picolinic acid as a secondary ligand. Yes. These dopants have achieved high-efficiency devices by combining carbazole derivatives and triarylsilanes as host compounds. However, since the light emission lifetime of the devices is greatly deteriorated, improvement of the trade-off has been demanded. .

  In recent years, Patent Document 3 and Patent Document 4 disclose metal complexes having specific ligands as blue phosphorescent compounds having high potential.

  In these documents, the stability of an organic EL device is improved by using a specific host compound in combination with a blue phosphorescent compound having a 2-phenylimidazole ligand having a twisted aryl component with extended conjugation. It is described that high luminous efficiency and low driving voltage can be realized. In addition, by introducing a bulky substituent such as a branched alkyl group at the ortho position of the twisted aryl component bonded to the imidazole ring, the steric effect inhibits packing between molecules, and there are few decomposition products at a lower temperature. It has been described that sublimation of can now be performed.

  However, when a device that emits different light emission colors, for example, white light emission, is produced by using a plurality of light emitting materials including these blue phosphorescent light emitting materials in combination, the problem of chromaticity stability during continuous driving of the device is a new problem. (Chromaticity shift) occurred.

  Further, in the organic EL element, when the doping concentration of the phosphorescent material in the light emitting layer changes from several% to several tens%, the light emission efficiency and the light emission lifetime of the element vary. When the dope concentration is low, the carrier transportability and recombination probability are lowered, and the drive voltage and the light emission efficiency are liable to be lowered. Therefore, the carrier transportability needs to be improved.

On the other hand, the light-emitting material tends to aggregate at a high doping concentration, resulting in triplet-triplet annihilation (TT annihilation), generation of trap sites with low energy levels, etc., resulting in luminous efficiency. In addition, there is a problem that the emission lifetime is reduced. In particular, since the blue phosphorescent light emitting material has a high T ₁ , it is easily affected by external factors such as trap sites, and the aggregation between the light emitting materials is suppressed and uniform regardless of the concentration adjustment. It is important to disperse.

  Considering from the viewpoint of production suitability, a material having a large dependence on the doping concentration with respect to the performance of these elements is preferable because it has a low production suitability because a slight change in the doping concentration during production affects the performance of the device. I can't say that.

  Further, when the dispersibility of the light emitting material is low, the carrier transportability in the light emitting layer is also lowered, and as a result, the light emitting life of the device tends to be shortened.

US Pat. No. 6,097,147 JP 2005-112765 A US Patent Application Publication No. 2011/0057559 US Patent Application Publication No. 2011/0204333

M.M. A. Baldo et al. , Nature, 395, 151-154 (1998) M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) S. Lamansky et al. , J .; Am. Chem. Soc. 123, 4304 (2001)

However, in the techniques described in Patent Document 3 and Patent Document 4, the luminous efficiency and lifetime of the organic EL element are improved, but the thermal stability and sublimation property of the metal complex that is the organic EL element material. In some cases, the decomposition lifetime is generated when an organic layer is formed by vapor deposition using the metal complex, so that the light emission lifetime of the device may be reduced.
In addition, the white light-emitting organic EL device using a plurality of light-emitting materials has problems such as the chromaticity stability during continuous driving and the dependency of the doping concentration on the device performance, and the relationship between the dispersibility of the light-emitting materials and the lifetime. It has not been done.

Accordingly, an object of the present invention is to improve the thermal stability and sublimation property of an organometallic complex as an organic electroluminescence element material, thereby providing an organic electroluminescence element having a high luminous efficiency and a long lifetime, and an illumination device using the element And providing a display device.
A further object of the present invention is to eliminate the problem of chromaticity stability (chromaticity shift) during continuous driving in a white light-emitting organic electroluminescence device, and to improve the dope concentration dependency in device performance. Another object of the present invention is to provide a long-life organic electroluminescence device by providing an iridium complex compound having high dispersibility.

In order to achieve the above object of the present invention, according to one aspect of the present invention,
An iridium complex compound represented by the following general formula (5 ′) is provided.

[In general formula (5 ′), ring An, ring Bm and ring Bn each independently represent a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle. R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or It represents a non-aromatic heterocyclic group and may further have a substituent. Ra, Rb, Rc and Ra ₃ are each independently hydrogen atom, halogen atom, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, silyl group, arylalkyl group, aryl group, heteroaryl. Represents a group, a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. Note that the structures of the three ligands coordinated to Ir are not all the same. ]

According to another aspect of the invention,
An iridium complex compound represented by the following general formula (5) is provided.

[In General Formula (5), R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. Ra, Rc and Ra ₃ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, a silyl group, an arylalkyl group, an aryl group, a heteroaryl group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. ]

According to still another aspect of the present invention,
An electroluminescence element material represented by the following general formula (5 ′) is provided.

[In general formula (5 ′), ring An, ring Bm and ring Bn each independently represent a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle. R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or It represents a non-aromatic heterocyclic group and may further have a substituent. Ra, Rb, Rc and Ra ₃ are each independently hydrogen atom, halogen atom, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, silyl group, arylalkyl group, aryl group, heteroaryl. Represents a group, a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. Note that the structures of the three ligands coordinated to Ir are not all the same. ]

According to still another aspect of the present invention,
An organic electroluminescence element material represented by the following general formula (5) is provided.

[In General Formula (5), R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. Ra, Rc and Ra ₃ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, a silyl group, an arylalkyl group, an aryl group, a heteroaryl group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. ]

According to still another aspect of the present invention,
In an organic electroluminescence device in which at least one organic layer including a light emitting layer is sandwiched between an anode and a cathode,
An organic electroluminescence device characterized in that an iridium complex compound represented by the following general formula (5 ′) is contained in at least one of the organic layers.

[In general formula (5 ′), ring An, ring Bm and ring Bn each independently represent a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle. R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or It represents a non-aromatic heterocyclic group and may further have a substituent. Ra, Rb, Rc and Ra ₃ are each independently hydrogen atom, halogen atom, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, silyl group, arylalkyl group, aryl group, heteroaryl. Represents a group, a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. Note that the structures of the three ligands coordinated to Ir are not all the same. ]

According to still another aspect of the present invention,
In an organic electroluminescence device in which at least one organic layer including a light emitting layer is sandwiched between an anode and a cathode,
An organic electroluminescence device characterized in that an iridium complex compound represented by the following general formula (5) is contained in at least one of the organic layers.

[In General Formula (5), R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. Ra, Rc and Ra ₃ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, a silyl group, an arylalkyl group, an aryl group, a heteroaryl group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. ]

According to still another aspect of the present invention,
Provided is a lighting device comprising the organic electroluminescence element.

According to still another aspect of the present invention,
A display device comprising the organic electroluminescence element is provided.

According to the present invention, it is possible to provide an organometallic complex as an organic electroluminescence device material having excellent thermal stability and sublimation properties, and by using this, an organic electroluminescence device having high emission efficiency and a long lifetime, An illumination device and a display device using the element can be provided.
Furthermore, the compound of the present invention has high carrier transportability and dispersibility, and as a result, a longer life can be achieved by improving carrier balance. In addition, an organic electroluminescence element having a small chromaticity shift at the time of continuous driving in a white light emitting organic EL element using a plurality of light emitting materials and having a small dependence on the doping concentration of the light emitting material, and an illumination device and a display device using the element Can be provided.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. 4 is a schematic diagram of a display unit A. FIG. It is a schematic diagram of a pixel. It is a schematic diagram of a passive matrix type full color display device. It is the schematic of an illuminating device. It is a schematic diagram of an illuminating device. The schematic block diagram of an organic electroluminescent full color display apparatus is shown. The schematic block diagram of an organic electroluminescent full color display apparatus is shown. The schematic block diagram of an organic electroluminescent full color display apparatus is shown. The schematic block diagram of an organic electroluminescent full color display apparatus is shown. The schematic block diagram of an organic electroluminescent full color display apparatus is shown.

  Hereinafter, although the form for implementing this invention is demonstrated in detail, this invention is not limited to these.

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described. In the organic EL device of the present invention, preferred specific examples of the layer structure of various organic layers sandwiched between the anode and the cathode are shown below, but the present invention is not limited thereto.

(I) Anode / light emitting layer unit / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer unit / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer unit / hole blocking Layer / electron transport layer / cathode (iv) anode / hole transport layer / light emitting layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emission Layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode

Furthermore, the light emitting layer unit may have a non-light emitting intermediate layer between a plurality of light emitting layers, and may have a multi-photon unit configuration in which the intermediate layer is a charge generation layer. In this case, the charge generation layer includes ITO (indium tin oxide), IZO (indium zinc oxide), ZnO ₂ , TiN, ZrN, HfN, TiO _x , VO _x , CuI, InN, GaN, CuAlO _2. , CuGaO ₂ , SrCu ₂ O ₂ , LaB ₆ , RuO _{2 and} other conductive inorganic compound layers, Au / Bi ₂ O _{3 and} other two-layer films, SnO ₂ / Ag / SnO ₂ , ZnO / Ag / ZnO, Bi ₂ O ₃ / Au / Bi ₂ O ₃ , TiO ₂ / TiN / TiO ₂ , TiO ₂ / ZrN / TiO _{2 and} other multilayer films, C60 and other fullerenes, conductive organic layers such as oligothiophene, metal phthalocyanine , Conductive organic compound layers such as metal-free phthalocyanines, metal porphyrins, metal-free porphyrins, and the like.

  The light emitting layer in the organic EL device of the present invention is preferably a white light emitting layer, and an illumination device using these is preferable.

  Each layer which comprises the organic EL element of this invention is demonstrated below.

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode or the electron transport layer and the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May also be the interface between the light emitting layer and the adjacent layer.

  Although the total thickness of the light emitting layer is not particularly limited, from the viewpoint of improving the stability of the emitted color against the uniformity of the film, preventing unnecessary application of high voltage during light emission, and driving current. It is preferably adjusted to a range of 2 to 5000 nm, more preferably adjusted to a range of 2 to 200 nm, and particularly preferably adjusted to a range of 5 to 100 nm.

  For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is used. Or the like, the ink jet method, the printing method, the spray coating method, the curtain coating method, the LB method (Langmuir Brodgett method, etc.). In addition, when using the hexadentate ortho metal iridium complex based on this invention as a material of a light emitting layer, it is preferable to form into a film by a wet process.

  The light emitting layer of the organic EL device of the present invention contains a light emitting dopant (phosphorescent dopant (also referred to as phosphorescent dopant, phosphorescent dopant group) or fluorescent dopant) compound and a light emitting host compound. Is preferred.

(1) Luminescent dopant compound The luminescent dopant compound (a luminescent dopant, a dopant compound, and also only a dopant) is demonstrated.
As the light-emitting dopant, a fluorescent dopant (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used.

(1.1) Phosphorescent dopant (also called phosphorescent dopant)
The phosphorescent dopant according to the present invention will be described.
The phosphorescent dopant compound according to the present invention is a compound in which light emission from an excited triplet is observed, specifically, a compound that emits phosphorescence at room temperature (25 ° C.), and has a phosphorescence quantum yield of 25. Although it is defined as a compound of 0.01 or more at ° C., a preferable phosphorescence quantum yield is 0.1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. It ’s fine.

  There are two types of light emission of the phosphorescent dopant in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the luminescent host compound, and this energy is used as the phosphorescent dopant. It is an energy transfer type in which light emission from a phosphorescent dopant is obtained by moving to. The other is a carrier trap type in which a phosphorescent dopant serves as a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant compound is obtained. In any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

Here, as a result of intensive studies to achieve the above-described object of the present invention, the present inventors contain an iridium complex dopant represented by the following general formula (5 ′) in the organic layer of the organic EL element. It was clarified that the thermal stability and sublimation property of the organic EL element can be improved. That is, any one of the plurality of ligands coordinated to the iridium atom is made different from each other, and R ₁ m, R ₂ m, R ₁ n and R ₂ n in the general formula (5 ′) are carbon atoms. By setting the number of substituents to 2 or more, the interaction between the iridium complexes was relaxed to improve the sublimation property, and further the thermal stability of the iridium complex was improved. Thereby, when the said iridium complex dopant was formed into a film by vapor deposition and an organic layer was formed, continuous repetition vapor deposition became possible. Furthermore, the present inventors have found that the iridium complex dopant is contained in the organic EL element, thereby achieving high emission luminance and longer emission lifetime of the organic EL element.

  Therefore, the organic EL element of the present invention is constituted by containing an iridium complex compound represented by the following general formula (5 ′) as an organic EL element material in at least one of the organic layers. Is one in which an iridium complex compound represented by the following general formula (5 ′) is contained as an organic EL element material in the light emitting layer of the organic layer.

(1.1.1) Iridium Complex Compound Represented by General Formula (5 ′) The iridium complex compound contained as the organic EL element material in the organic EL element of the present invention will be described. The iridium complex compound according to the present invention is represented by the following general formula (5 ′).

In general formula (5 ′), each of ring An, ring Bn, and ring Bm independently represents a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle.
In the general formula (5 ′), examples of the 5-membered or 6-membered aromatic hydrocarbon ring represented by the ring An, the ring Bn, and the ring Bm include a benzene ring.
In the general formula (5 ′), examples of the 5-membered or 6-membered aromatic heterocycle represented by ring An, ring Bn and ring Bm include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, Examples include pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring and the like. Preferably, at least one of the rings Bn and Bm is a benzene ring, more preferably the ring An is a benzene ring.

In General Formula (5 ′), R ₁ m and R ₂ m are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group, or It represents a non-aromatic heterocyclic group and may further have a substituent.

In the general formula (5 ′), examples of the alkyl group represented by R ₁ m and R ₂ m include an ethyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-hexyl group, and 2-methyl. Examples include a hexyl group, a pentyl group, an adamantyl group, an n-decyl group, and an n-dodecyl group.

In the general formula (5 ′), examples of the aromatic hydrocarbon ring group represented by R ₁ m or R ₂ m include a benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, and pyrene ring. , Chrysene ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring , A monovalent group derived from a pentaphen ring, a picene ring, a pyrene ring, a pyranthrene ring, an anthraanthrene ring, or the like.

In the general formula (5 ′), examples of the aromatic heterocyclic group represented by R ₁ m or R ₂ m include a silole ring, a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, Pyrimidine ring, pyrazine ring, triazine ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzthiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, Thienothiophene ring, carbazole ring, azacarbazole ring (representing any one or more of the carbon atoms constituting the carbazole ring replaced by a nitrogen atom), dibenzosilole ring, dibenzofuran ring, dibenzothiophene ring, benzothiophene ring, Charcoal constituting the dibenzofuran ring Rings in which any one or more of atoms are replaced by nitrogen atoms, benzodifuran ring, benzodithiophene ring, acridine ring, benzoquinoline ring, phenazine ring, phenanthridine ring, phenanthroline ring, cyclazine ring, kindrin ring, tepenidine ring, Quinindrine ring, triphenodithiazine ring, triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, naphthofuran ring, naphthothiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthra And monovalent groups derived from a thiophene ring, an anthradithiophene ring, a thianthrene ring, a phenoxathiin ring, a dibenzocarbazole ring, an indolocarbazole ring, a dithienobenzene ring, and the like.

In the general formula (5 ′), examples of the non-aromatic hydrocarbon ring group represented by R ₁ m or R ₂ m include a cycloalkane (for example, a cyclopentane ring, a cyclohexane ring, etc.), a cycloalkoxy group (for example, , Cyclopentyloxy group, cyclohexyloxy group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), cyclohexylaminosulfonyl group, tetrahydronaphthalene ring, 9,10-dihydroanthracene ring, biphenylene ring, etc. And monovalent groups.

In the general formula (5 ′), examples of the non-aromatic heterocyclic group represented by R ₁ m or R ₂ m include an epoxy ring, an aziridine ring, a thiirane ring, an oxetane ring, an azetidine ring, a thietane ring, and a tetrahydrofuran ring. , Dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, Piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-1,1-dioxide ring, pyranose ring, diazabicyclo [2,2,2] Octane ring, a phenoxazine ring, a phenothiazine ring, Okisantoren ring, thioxanthene ring, and a monovalent group derived from phenoxathiin ring.

In general formula (5 ′), these groups represented by R ₁ m or R ₂ m may have a substituent, and the substituents may be bonded to each other to form a ring. good.

In the general formula (5 ′), it is preferable that both R ₁ m and R ₂ m are an alkyl group or a cycloalkyl group having 2 or more carbon atoms, and _one of R ₁ m and R ₂ m is A branched alkyl group having 3 or more carbon atoms is also preferred. More preferably, R ₁ m and R ₂ m are both branched alkyl groups having 3 or more carbon atoms.

In general formula (5 ′), R ₁ n and R ₂ n have the same meanings as R ₁ m and R ₂ m in general formula (5 ′).

In the general formula (5 ′), Ra, Rb, Rc and Ra ₃ are each independently a hydrogen atom, halogen atom, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, silyl group, aryl. It represents an alkyl group, an aryl group, a heteroaryl group, a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent.
In the general formula (5 ′), the aryl group and heteroaryl group represented by Ra, Rb, Rc, and Ra ₃ include the aromatic hydrocarbon ring group represented by the above R ₁ m or R ₂ m and the aromatic group. Group heterocyclic group.
In the general formula (5 ′), the non-aromatic hydrocarbon ring group and the non-aromatic heterocyclic group represented by Ra, Rb, Rc and Ra ₃ are represented by the above-mentioned R ₁ m or R ₂ m. Non-aromatic hydrocarbon ring group and non-aromatic heterocyclic group are mentioned.

  In general formula (5 '), na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4.

In the general formula (5 ′), X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic group Represents an aromatic hydrocarbon ring group or a non-aromatic heterocyclic group.
The aromatic hydrocarbon ring group, aromatic heterocyclic group, non-aromatic hydrocarbon ring group or non-aromatic heterocyclic group represented by Rz1 or Rz2 is represented by the above-mentioned R ₁ m or R ₂ m. An aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic hydrocarbon ring group may be mentioned.

  In the general formula (5 ′), m represents 1 or 2, n represents 1 or 2, and m + n = 3.

  In the general formula (5 ′), the structures of the three ligands coordinated to Ir are not all the same.

(1.1.2) Iridium Complex Compound Represented by General Formula (5) The iridium complex compound represented by the above general formula (5 ′) is preferably represented by the following general formula (5).

In the general formula (5), R ₁ m, R ₂ m, R ₁ n, R ₂ n, Ra, Rc, Ra ₃ , na, nc, nR 3, X, m, and n are the same as those in the general formula (5 ′). _{R 1 m, R 2 m,} R 1 n, R 2 n, Ra, Rc, Ra 3, na, is nc, nR3, X, same meaning as m and n.

(1.1.3) Specific Examples Specific examples of the iridium complex compound represented by the general formula (5 ′) or (5) are given below, but the present invention is not limited thereto.

(1.1.4) Synthesis Example Hereinafter, a synthesis method of the compound DP-1 will be described. The compound represented by the general formula (5 ′) or (5) can be synthesized with reference to the synthesis method of the compound DP-1.
DP-1 can be synthesized according to the following scheme.

(Process 1)
A three-headed flask was charged with 5 g of intermediate A, 1.9 g of iridium chloride, 100 ml of ethoxyethanol, and 30 ml of water, and heated and stirred at 100 ° C. for 4 hours in a nitrogen atmosphere.
The precipitated crystals were collected by filtration, and the collected crystals were washed with methanol to obtain 4.5 g of Intermediate B.

(Process 2)
In a three-headed flask, 4.0 g of the intermediate B obtained in Step 1, 2.5 g of acetylacetone, 7 g of potassium carbonate, and 100 ml of ethoxyethanol were placed and heated and stirred at 80 ° C. for 5 hours under a nitrogen atmosphere.
The precipitated crystals were collected by filtration, and the collected crystals were washed with methanol and then washed with water to obtain 2.8 g of Intermediate C.

(Process 3)
In a three-headed flask, 2.8 g of intermediate C obtained in step 2, 1.6 g of intermediate D and 50 ml of ethylene glycol were placed, and the mixture was heated and stirred at 150 ° C. for 7 hours in a nitrogen atmosphere.
The precipitated crystals were collected by filtration, washed with methanol, and then separated and purified by silica gel chromatography to obtain 0.7 g of DP-1.

The structure of Compound Example DP-1 was confirmed by mass spectrum and ¹ H-NMR.
MASS spectrum (ESI): m / z = 1179 [M ⁺ ]
¹ H-NMR (CD ₂ Cl ₂ , 400 MHz) δ: 7.71 (2H, d, J = 28.3 Hz), 7.42 (1H, t, J = 28.3 Hz), 7.33-7. 57 (6H, m), 7.34 (4H, t, J = 33.2 Hz), 6.96 (2H, S), 6.81-6.86 (6H, m), 6.69 (2H, d, J = 33.2 Hz), 6.56-6.60 (2H, m), 6.44 (1H, t, J = 23.4 Hz), 6.38 (2H, d, J = 17.6 Hz) ), 6.32 (1H, d, J = 23.4 Hz), 6.16 (2H, d, J = 44.9 Hz), 2.65-2.80 (3H, m, CHofiso-Pr), 2.29-2.41 (3H, m, CHof iso -Pr), 1.26 (3H, d, J = 26.3Hz, CH 3 of iso-Pr), 1.2 _{1 (6H, d, J =} 20.5Hz, CH 3 of iso-Pr), 0.92-1.08 (m, 27H, CH 3 of iso-Pr)

(1.2) Fluorescent dopant (also called fluorescent compound)
Fluorescent dopants include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes , Polythiophene dyes, rare earth complex phosphors, and the like, and compounds having a high fluorescence quantum yield such as laser dyes.

(1.3) Combined use with conventionally known dopants In addition, the light-emitting dopant according to the present invention may be used in combination with a plurality of types of compounds, a combination of phosphorescent dopants having different structures, a phosphorescent dopant and A combination of fluorescent dopants may also be used.

  Here, specific examples of conventionally known luminescent dopants that may be used in combination with the iridium complex compound represented by the general formula (5 ′) or (5) according to the present invention will be given as the luminescent dopant. Is not limited to these.

(2) Luminescent host compound (also referred to as luminescent host or host compound)
In the present invention, the host compound has a mass ratio of 20% or more among the compounds contained in the light emitting layer, and a phosphorescence quantum yield of phosphorescence emission is 0 at room temperature (25 ° C.). Defined as less than 1 compound. The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  There is no restriction | limiting in particular as a light emission host which can be used for this invention, The compound conventionally used with an organic EL element can be used. Typically, a carbazole derivative, a triarylamine derivative, an aromatic derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligoarylene compound or the like having a basic skeleton, or a carboline derivative or a diazacarbazole derivative (here And the diazacarbazole derivative represents one in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom.

  As the known light-emitting host that can be used in the present invention, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from becoming longer, and has a high Tg (glass transition temperature) is preferable.

  In the present invention, a conventionally known light emitting host may be used alone, or a plurality of types may be used in combination. By using a plurality of types of light-emitting hosts, the movement of charges can be adjusted, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of the metal complex of this invention used as the said phosphorescence dopant, and / or a conventionally well-known compound, and, thereby, arbitrary luminescent colors can be obtained.

  In addition, the light emitting host used in the present invention may be a low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable light emitting host). It is also possible to use one or a plurality of such compounds.

Specific examples of the known light-emitting host include compounds described in the following documents.
JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  Hereinafter, although the specific example used as a light emission host of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

  Furthermore, a compound represented by the following general formula (B) or general formula (E) is particularly preferable as a light-emitting host of the light-emitting layer of the organic EL device of the present invention.

  In the general formulas (B) and (E), Xa represents O or S, Xb, Xc, Xd and Xe each represents a hydrogen atom, a substituent or a group represented by the following general formula (C), Xb , Xc, Xd and Xe represent a group represented by the following general formula (C), and at least one of the groups represented by the following general formula (C) represents Ar as a carbazolyl group.

General formula (C)
Ar- _{(L 4)} n - *

In general formula (C), L ₄ represents a divalent linking group derived from an aromatic hydrocarbon ring or an aromatic heterocyclic ring. n represents an integer of 0 to 3, and when n is 2 or more, the plurality of L ₄ may be the same or different. * Represents a linking site with the general formula (B) or (E). Ar represents a group represented by the following general formula (D).

In general formula (D), Xf represents N (R ″), O or S, E _{1 to} E ₈ represent C (R ″ ₁ ) or N, R ″ and R ″ ₁ are hydrogen atoms, substituents or it represents a linking site with L ₄ in formula (C). * Represents a linking site with L ₄ in the general formula (C).

  In the compound represented by the general formula (B), preferably at least two of Xb, Xc, Xd and Xe are represented by the general formula (C), and more preferably Xc is represented by the general formula (C). And Ar in the general formula (C) represents a carbazolyl group which may have a substituent.

  Specific examples of the compound represented by the general formula (B) preferably used as a host compound (also referred to as a light emitting host) of the light emitting layer of the organic EL device of the present invention are shown below, but the present invention is not limited thereto.

  In addition, a compound represented by the following general formula (B ′) is also particularly preferably used as a light-emitting host of the light-emitting layer of the organic EL device of the present invention.

In General Formula (B ′), Xa represents O or S, and Xb and Xc each represents a substituent or a group represented by General Formula (C).
At least one of Xb and Xc represents a group represented by the above general formula (C), and at least one of the groups represented by the general formula (C) represents Ar as a carbazolyl group.

In the compound represented by the general formula (B ′), preferably, Ar in the general formula (C) represents a carbazolyl group which may have a substituent, and more preferably, in the general formula (C). Ar may have a substituent and represents a carbazolyl group linked to L ₄ in formula (C) at the N-position.

  The compound represented by the general formula (B ′) that is preferably used as the host compound (also referred to as a light-emitting host) of the light-emitting layer of the organic EL device of the present invention is specifically a specific example that is previously used as a light-emitting host. OC-9, OC-11, OC-12, OC-14, OC-18, OC-18, OC-29, OC-30, OC-31, OC-32 mentioned, but the present invention is not limited thereto. .

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons. In a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided with a single layer or a plurality of layers.

  The electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer. As a constituent material of the electron transport layer, any one of conventionally known compounds may be selected and used in combination. Is possible.

Examples of conventionally known materials used for the electron transport layer (hereinafter referred to as electron transport materials) include polycyclic aromatic hydrocarbons such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, Ring tetracarboxylic anhydride, carbodiimide, fluorenylidenemethane derivative, anthraquinodimethane and anthrone derivative, oxadiazole derivative, carboline derivative, or at least carbon atoms of the hydrocarbon ring constituting the carboline ring of the carboline derivative Derivatives having a ring structure, one of which is substituted with a nitrogen atom, hexaazatriphenylene derivatives and the like.
Furthermore, in the oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron transport material.
It is also possible to use a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as the electron transport material.

In addition, metal-free or metal phthalocyanine, or those having a terminal substituted with an alkyl group or a sulfonic acid group can also be used as the electron transport material.
In addition, inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as the electron transport material.

  The electron transport layer is made of an electron transport material such as a vacuum deposition method, a wet method (also referred to as a wet process, such as a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, or a spray method. The film is preferably formed by thinning by a coating method, a curtain coating method, an LB method (such as Langmuir Brodgett method)).

  Although there is no restriction | limiting in particular about the layer thickness of an electron carrying layer, Usually, about 5-5000 nm, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an n-type dopant such as a metal compound such as a metal complex or a metal halide may be doped.

  Hereinafter, although the specific example of the conventionally well-known compound (electron transport material) preferably used for formation of the electron carrying layer of the white organic EL element of this invention is given, this invention is not limited to these.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.

  The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the layer thickness is usually selected in the range of 10 to 5000 nm, preferably 50 to 200 nm.

In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.
In addition, a transparent or translucent cathode can be produced by producing a conductive transparent material mentioned in the explanation of the anode described later on the cathode after producing the metal with a layer thickness of 1 to 20 nm. By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

<< Injection layer: electron injection layer (cathode buffer layer), hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer, and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166), and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Representative phthalocyanine buffer layer, hexaazatriphenylene derivative buffer layer, oxide buffer layer typified by vanadium oxide, amorphous carbon buffer layer, polyaniline Examples thereof include a polymer buffer layer using a conductive polymer such as (emeraldine) or polythiophene, an ortho-metalated complex layer represented by tris (2-phenylpyridine) iridium complex, and the like.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by, alkali metal compound buffer layer typified by lithium fluoride and potassium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride and cesium fluoride, typified by aluminum oxide Examples thereof include an oxide buffer layer. The buffer layer (injection layer) is preferably a very thin film, and the layer thickness is preferably in the range of 0.1 to 5000 nm, although it depends on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking.

  Moreover, the structure of the electron carrying layer mentioned above can be used as a hole-blocking layer concerning this invention as needed.

  The hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.

  The hole blocking layer includes a carbazole derivative, a carboline derivative, a diazacarbazole derivative (the diazacarbazole derivative is a nitrogen atom in which any one of carbon atoms constituting the carboline ring is mentioned as the host compound described above. It is preferable to contain (represented by).

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

The ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied orbital) level of the compound to the vacuum level, and can be determined by, for example, the following method.
(1) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA As a value (eV unit converted value) calculated by performing structure optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.
(2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved.

  Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The layer thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.
Further, azatriphenylene derivatives such as those described in JP-T-2003-519432 and JP-A-2006-135145 can also be used as a hole transport material.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbene; N-phenylcarbazole and also two condensations described in US Pat. No. 5,061,569 Having an aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308688 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) in which three triphenylamine units described in the publication are linked in a starburst type Etc.

Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.
In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can.
Although there is no restriction | limiting in particular about the layer thickness of a positive hole transport layer, Usually, about 5-5000 nm, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.
In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.

Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) that can form a transparent conductive film may be used. The anode may be a thin film formed by vapor deposition or sputtering of these electrode materials, and a pattern of a desired shape may be formed by photolithography, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the layer thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

《Support substrate》
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones, Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

An inorganic film, an organic film, or a hybrid film of both may be formed on the surface of the resin film, and the water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and further, oxygen measured by a method according to JIS K 7126-1987. A high barrier film having a permeability of 10 ⁻³ ml / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less is preferable.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.

  The external extraction efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, and more preferably 5% or more.

  Here, external extraction quantum efficiency (%) = number of photons emitted to the outside of the organic EL element / number of electrons flowed to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

<< Method for producing organic EL element >>
As an example of a method for producing an organic EL device, a device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / cathode Will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate so as to have a thickness of 1 μm or less, preferably 10 to 200 nm, and an anode is manufactured.

  Next, a thin film containing an organic compound such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, or a cathode buffer layer, which is an element material, is formed thereon.

As a method for forming the thin film, for example, the thin film can be formed by a vacuum deposition method, a wet method (also referred to as a wet process), or the like.
Wet methods include spin coating, casting, die coating, blade coating, roll coating, ink jet, printing, spray coating, curtain coating, and LB, but precise thin films can be formed. In view of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Further, a different film formation method may be applied for each layer.

Examples of the liquid medium for dissolving or dispersing the organic EL material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene. Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used.
Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  After the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

  Further, the order can be reversed, and the cathode, cathode buffer layer, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode can be formed in this order.

  The organic EL device of the present invention is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but it may be taken out halfway and subjected to different film forming methods. At that time, it is preferable to perform the work in a dry inert gas atmosphere.

<Sealing>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.

  The sealing member may be disposed so as to cover the display area of the organic EL element, and may be a concave plate shape or a flat plate shape. Further, transparency and electrical insulation are not particularly limited.

Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.
Examples of the polymer plate include those formed from polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like.
Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned.
Furthermore, the polymer film has an oxygen permeability of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less measured by a method according to JIS K 7126-1987, and a method according to JIS K 7129-1992. It is preferable that the water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured in (1) is 1 × 10 ⁻³ g / (m ² · 24 h) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application of the adhesive to the sealing portion may use a commercially available dispenser, or may be printed like screen printing.

In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.
Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  In the gap between the sealing member and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided outside the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the outside of the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, and the like used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

  In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.

  In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium with a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. .

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.

  Further, the thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low-refractive index layer is reduced when the thickness of the low-refractive index medium is about the wavelength of light and the thickness of the electromagnetic wave exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

  The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much.

  However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condenser sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used.
As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe with a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Although the light source of a sensor etc. are mentioned, It is not limited to this, Especially, it can use effectively for the use as a backlight of a liquid crystal display device, and a light source for illumination.

  In the organic EL element of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. Can do.

  The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with a total CS-1000 (Konica Minolta Sensing Co., Ltd.) is applied to the CIE chromaticity coordinates.

Further, when the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

<Display device>
The display device of the present invention will be described. The display device of the present invention comprises the organic EL element of the present invention. The display device of the present invention may be single color or multicolor, but here, the multicolor display device will be described.

In the case of a multicolor display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, or the like.
In the case of patterning only the light emitting layer, the method is not limited. However, the vapor deposition method, the ink jet method, the spin coating method, and the printing method are preferable.

  The configuration of the organic EL element provided in the display device is selected from the above-described configuration examples of the organic EL element as necessary.

  Moreover, the manufacturing method of an organic EL element is as having shown to the one aspect | mode of manufacture of the organic EL element of said invention.

  When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

  The multicolor display device can be used as a display device, a display, and various light emission sources. In a display device or display, full-color display is possible by using three types of organic EL elements of blue, red, and green light emission.

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

  Light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. The present invention is not limited to these examples.

Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a display device composed of organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.
The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside. The image information is sequentially emitted to scan the image and display the image information on the display unit A.

FIG. 2 is a schematic diagram of the display unit A.
The display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below.
FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at orthogonal positions (details are shown in the figure). Not)
When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data.
Full-color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region on the same substrate.

Next, the light emission process of the pixel will be described. FIG. 3 is a schematic diagram of a pixel.
The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

  In FIG. 3, an image data signal is applied from the control unit B to the drain of the switching transistor 11 through the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

  By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10. The power supply line 7 connects the organic EL element 10 to the potential of the image data signal applied to the gate. Current is supplied.

When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, since the capacitor 13 holds the charged potential of the image data signal even when the driving of the switching transistor 11 is turned off, the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When the scanning signal is next applied by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.
That is, the organic EL element 10 emits light by the switching transistor 11 and the drive transistor 12 that are active elements for the organic EL elements 10 of the plurality of pixels, and the organic EL elements 10 of the plurality of pixels 3 emit light. It is carried out. Such a light emitting method is called an active matrix method.

Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or by turning on / off a predetermined light emission amount by a binary image data signal. good. The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.
In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

FIG. 4 is a schematic diagram of a passive matrix display device. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.
When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal.
In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

《Lighting device》
The lighting device of the present invention will be described. The illuminating device of this invention has the said organic EL element.
The organic EL element of the present invention may be used as an organic EL element having a resonator structure. The purpose of use of the organic EL element having such a resonator structure is as follows. The light source of a machine, the light source of an optical communication processing machine, the light source of a photosensor, etc. are mentioned, However, It is not limited to these. Moreover, you may use for the said use by making a laser oscillation.
Further, the organic EL device of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display).
When used as a display device for reproducing moving images, either a simple matrix (passive matrix) method or an active matrix method may be used. Alternatively, it is possible to produce a full-color display device by using two or more organic EL elements of the present invention having different emission colors.

The organic EL material of the present invention can be applied to an organic EL element that emits substantially white light as a lighting device. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. As a combination of a plurality of light emission colors, one containing three light emission maximum wavelengths of three primary colors of red, green, and blue may be used, or two of the complementary colors such as blue and yellow, blue green and orange may be used. The thing containing the light emission maximum wavelength may be used.
In addition, a combination of light emitting materials for obtaining a plurality of emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and light from the light emitting material as excitation light. In combination with a dye material that emits light as a white organic EL element according to the present invention, a plurality of light emitting dopants may be mixed and mixed.

It is only necessary to provide a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since the other layers are common, patterning of the mask or the like is unnecessary. In addition, for example, an electrode film can be formed by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, or the like, and productivity is also improved.
According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.
There is no restriction | limiting in particular as a luminescent material used for a light emitting layer, For example, if it is a backlight in a liquid crystal display element, the metal complex which concerns on this invention so that it may suit the wavelength range corresponding to CF (color filter) characteristic, Any one of known luminescent materials may be selected and combined to whiten.

<< One Embodiment of Lighting Device of the Present Invention >>
One aspect of the lighting device of the present invention that includes the organic EL element of the present invention will be described.
The non-light emitting surface of the organic EL device of the present invention is covered with a glass case, a 300 μm thick glass substrate is used as a sealing substrate, and an epoxy photocurable adhesive (LUX The track LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured, sealed, and illuminated as shown in FIGS. A device can be formed.

  FIG. 5 shows a schematic diagram of a lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102 (in addition, the sealing operation with the glass cover is to bring the organic EL element 101 into contact with the atmosphere. And a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more).

  FIG. 6 shows a cross-sectional view of the lighting device. In FIG. 6, 105 denotes a cathode, 106 denotes an organic EL layer, and 107 denotes a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
Moreover, the structure of the compound used in the Example demonstrated below is shown below.

<< Production of Organic EL Element 1-1 >>
This ITO transparent electrode was patterned after patterning on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (Indium Tin Oxide) as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. The transparent support substrate provided with was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by HC Starck Co., Ltd., CLEVIO P VP AI 4083) to 70% with pure water on the transparent support substrate. After forming a thin film by spin coating at 3000 rpm for 30 seconds, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a layer thickness of 20 nm.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of α-NPD is placed in a molybdenum resistance heating boat as a hole transport material, and OC- 200 mg of 30 was put, 200 mg of ET-8 as an electron transport material was put in another resistance heating boat made of molybdenum, and 100 mg of Comparative 1 was put as a dopant compound in another resistance heating boat made of molybdenum, and attached to a vacuum deposition apparatus.

Next, the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, and the heating boat containing α-NPD was energized and heated, evaporated on the transparent support substrate at a deposition rate of 0.1 nm / second, and a layer thickness of 20 nm. The second hole transport layer was provided.

  Furthermore, the heating boat containing OC-30 as a host compound and Comparative 1 as a dopant compound was heated by heating, and the second hole transport layer was heated at a deposition rate of 0.1 nm / second and 0.006 nm / second, respectively. A light emitting layer having a layer thickness of 40 nm was provided by co-evaporation.

Further, the heating boat containing ET-8 was energized and heated, and was deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide an electron transport layer having a layer thickness of 30 nm.
In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a layer thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a layer thickness of 110 nm. Thus, an organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 and 1-13 >>
In preparation of the organic EL element 1-1, the host compound and dopant compound in the light emitting layer were changed to the compounds shown in Table 1.
Other than that produced the organic EL element 1-2 and 1-13 similarly.

<< Evaluation of Organic EL Elements 1-1, 1-2, 1-13 >>
When evaluating the obtained organic EL elements 1-1, 1-2, and 1-13, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was sealed. Used as a substrate, an epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material around the substrate, and this is overlaid on the cathode and brought into close contact with the transparent support substrate. It was cured by irradiation with UV light and sealed, and an illumination device as shown in FIGS. 5 and 6 was produced and evaluated.
The following evaluation was performed for each sample thus prepared. The evaluation results are shown in Table 1.

(1) External extraction quantum efficiency (also simply referred to as efficiency)
The organic EL device is turned on at room temperature (25 ° C.) under a constant current condition of ^2.5 mA / cm ² and the emission luminance (L) [cd / m ² ] immediately after the start of lighting is measured. Efficiency (η) was calculated.
Here, the measurement of emission luminance was performed using CS-1000 (manufactured by Konica Minolta Sensing), and the external extraction quantum efficiency was expressed as a relative value where the organic EL element 1-1 was 100.

(2) Half-life The half-life was evaluated according to the measurement method shown below.
Each organic EL device driven with a constant current at a current giving an initial luminance 1000 cd / ^{m 2,} obtains the time to be 1/2 (500cd / ^{m 2)} of the initial luminance, which was used as a measure of the half-life.
The half life was expressed as a relative value with the organic EL element 1-1 as 100.

(3) Voltage rise at the time of driving The voltage when the organic EL element was driven at room temperature (25 ° C.) and a constant current condition of ^2.5 mA / cm ² was measured, respectively, and the measurement result was calculated by the calculation formula shown below. The results obtained are shown in Table 1.
It represents with the relative value which sets the organic EL element 1-1 to 100.
Voltage rise at the time of driving (relative value) = drive voltage at half brightness-initial drive voltage Note that a smaller value indicates a smaller voltage rise at the time of driving for comparison.

(4) Thermal Stability Evaluation For each of the organic EL elements 1-1, 1-2, and 1-13, five elements having the same configuration were prepared using the same vapor deposition boat (molybdenum resistance heating boat) (for example, Organic EL elements 1-1, 1-1b, 1-1c, 1-1d, 1-1e).
Each of the first fabricated elements (for example, the organic EL element 1-1), the third fabricated element (for example, the organic EL element 1-1c), and the fifth fabricated element (for example, the organic EL element 1-1e). ) Was measured for the half-life by the same method as above. The half-life of each element was expressed as a relative value with the organic EL element 1-1 produced at the first time being 100.

(5) Summary From Table 1, the organic EL device 1-13 of the present invention exhibits higher luminous efficiency and longer life than the organic EL devices 1-1 and 1-2 of the comparative example, and the voltage rise during driving. It can be seen that the characteristics as an element are improved. Furthermore, the organic EL elements 1-1 and 1-2 of the comparative example are the elements manufactured for the first time, the elements manufactured for the third time, the elements manufactured for the fifth time, and the half-life gradually decreased. On the other hand, the organic EL device 1-13 of the present invention is almost the same as the first device, the third device, the fifth device, and the half-life. It can be seen that the dopant compound used in the organic EL device of the present invention is excellent in thermal stability.

<< Preparation of White Light-Emitting Organic EL Element 2-1 >>
A transparent substrate provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of α-NPD is placed in a molybdenum resistance heating boat as a hole transport material, and OC- 200 mg of 11 and 200 mg of ET-11 as an electron transport material in another molybdenum resistance heating boat, 100 mg of Comparative 1 as a dopant compound in another molybdenum resistance heating boat, and dopant in another molybdenum resistance heating boat 100 mg of D-10 was added as a compound and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, each of the heating boats containing α-NPD was separately energized, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / second. A first hole transport layer was provided.

  Further, the heating boat containing OC-11 as the host compound and Comparative 1 and D-10 as the dopant compound was energized, and the deposition rate of Compound 9, Comparative 1, and D-10 was 100: 5: 0.6. The light emitting layer was provided by vapor deposition so as to have a layer thickness of 30 nm.

Furthermore, it supplied with electricity to the said heating boat containing ET-11, it heated, and it vapor-deposited on the said light emitting layer with the vapor deposition rate of 0.1 nm / second, and provided the electron carrying layer with a layer thickness of 30 nm.
In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a layer thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a layer thickness of 110 nm. Thus, an organic EL element 2-1 was produced.

  When the produced organic EL element 2-1 was energized, almost white light was obtained, and it was found that it could be used as a lighting device. In addition, it turned out that white light emission is obtained similarly even if it replaces with the other compound of illustration.

<< Preparation of organic EL elements 2-2 and 2-9 >>
In preparation of the organic EL element 2-1, the host compound and dopant compound in the light emitting layer were changed to the compounds shown in Table 2.
Other than that produced the organic EL element 2-2 and 2-9 similarly.

<< Evaluation of Organic EL Elements 2-1, 2-2, 2-9 >>
When evaluating the obtained organic EL elements 2-1, 2-2, 2-9, the organic EL elements were sealed in the same manner as the organic EL elements 1-1, 1-2, 1-13 of Example 1. The lighting device as shown in FIGS. 5 and 6 was produced and evaluated.
Each sample thus produced was evaluated for external extraction quantum efficiency, half life, voltage increase during driving, and thermal stability in the same manner as in Example 1. The evaluation results are shown in Table 2. In addition, the measurement result of the external extraction quantum efficiency in Table 2, the light emission lifetime, and the voltage rise at the time of a drive was represented by the relative value which sets the measured value of the organic EL element 2-1 (element produced in the 1st time) to 100.

  From Table 2, the organic EL element 2-9 of the present invention shows high luminous efficiency and long life with respect to the organic EL elements 2-1 and 2-2 of the comparative example, and suppresses a voltage increase during driving. It turns out that the characteristic as an element is improving. Furthermore, the organic EL elements 2-1 and 2-2 of the comparative example are the first fabricated element, the third fabricated element, the fifth fabricated element, and the half-life gradually decreased. On the other hand, the organic EL device 2-9 of the present invention has a half-life that is almost the same as that of the first device, the third device, the fifth device, and the fifth device. It can be seen that the dopant compound used in the organic EL device of the present invention is excellent in thermal stability.

<< Production of organic EL full-color display device >>
FIG. 7 shows a schematic configuration diagram of an organic EL full-color display device.
After patterning at a pitch of 100 μm on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) having a 100 nm thick ITO transparent electrode 202 as an anode on a glass substrate 201 (see FIG. 7A), on this glass substrate 201 Then, a non-photosensitive polyimide partition wall 203 (width 20 μm, thickness 2.0 μm) was formed between the ITO transparent electrodes 202 by photolithography (see FIG. 7B).

  A hole injection layer composition having the following composition is ejected and injected on the ITO electrode 202 between the partition walls 203 using an inkjet head (manufactured by Epson Corporation; MJ800C), irradiated with ultraviolet light for 200 seconds, and 60 ° C. A hole injection layer 204 having a layer thickness of 40 nm was provided by a drying process for 10 minutes (see FIG. 7C).

  A blue light-emitting layer composition, a green light-emitting layer composition, and a red light-emitting layer composition having the following compositions are similarly ejected and injected onto the hole injection layer 204 using an inkjet head, and dried at 60 ° C. for 10 minutes. In addition, light emitting layers 205B, 205G, and 205R for each color were provided (see FIG. 7D).

  Next, an electron transport material (ET-10) is deposited so as to cover the light emitting layers 205B, 205G, and 205R to provide an electron transport layer (not shown) having a layer thickness of 20 nm, and further lithium fluoride is deposited to form a layer. A cathode buffer layer (not shown) with a thickness of 0.6 nm was provided, Al was vapor-deposited, and a cathode 106 with a layer thickness of 130 nm was provided to produce an organic EL device (see FIG. 7E).

  It was found that the produced organic EL elements each emitted blue, green, and red light when a voltage was applied to the electrodes, and could be used as a full-color display device.

(Hole injection layer composition)
Hole transport material 7 20 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (blue light emitting layer composition)
Host material 1 0.7 parts by mass DP-38 0.04 parts by mass cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (green light emitting layer composition)
Host material 1 0.7 parts by mass D-1 0.04 parts by mass cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (red light emitting layer composition)
Host material 1 0.7 parts by mass D-10 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass

<< Preparation of Organic EL Element 4-1 >>
In the production of the organic EL element 1-1, the same applies except that the dopant is changed from Comparative 1 to Comparative 5, the deposition rate is changed from 0.006 nm / second to 0.005 nm / second, and the thickness of the light emitting layer is changed from 40 nm to 50 nm. Thus, an organic EL element 4-1 was produced.

<< Production of Organic EL Elements 4-2 to 4-12 >>
In production of the organic EL element 4-1, the dopant and the deposition rate thereof were changed as shown in Table 3.
Other than that produced the organic EL element 4-2 to 4-12 similarly.

<< Evaluation of Organic EL Elements 4-1 to 4-12 >>
When evaluating the obtained organic EL elements 4-1 to 4-12, the organic EL elements were sealed in the same manner as the organic EL elements 1-1, 1-2, and 1-13 of Example 1, 5 and FIG. 6 were produced and evaluated.
Each sample thus prepared was evaluated for external extraction quantum efficiency and half life in the same manner as in Example 1, and the driving voltage was evaluated as follows. The evaluation results are shown in Table 3. In addition, the measurement results of the external extraction quantum efficiency and the half life in Table 3 are expressed as relative values with the measured value of the organic EL element 6-3 being 100.

[Measurement of drive voltage]
Each voltage was measured when the organic EL element was driven at room temperature (25 ° C.) and a constant current condition of ^2.5 mA / cm ^2. As shown in Table 3, the organic EL element 4-3 was measured as 100 It was expressed as a relative value.
Note that a smaller value indicates that the voltage during driving is smaller for comparison.

  From Table 3, since the dopant of the present invention has a high carrier transport property, the driving voltage does not increase greatly even in a region where the dopant concentration is low, and the external extraction quantum efficiency is also high. On the other hand, high external quantum efficiency and half-life are obtained even in a high doping concentration region, which is presumed to be because the dispersibility of the dopant of the present invention is improved and aggregation is suppressed. Furthermore, due to the effects described above, the element according to the present invention is less dependent on the concentration of the dopant in the external quantum efficiency, the driving voltage, and the half-life compared to the comparative example.

<< Production of Organic EL Element 5-1 >>
A transparent substrate provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

  A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by HC Starck Co., Ltd., CLEVIO P VP AI 4083) to 70% with pure water on the transparent support substrate. After forming a thin film by spin coating at 3000 rpm for 30 seconds, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a layer thickness of 20 nm.

  This transparent support substrate was fixed to a substrate holder of a commercially available vacuum evaporation apparatus, while 200 mg of α-NPD was added as a hole transport material to a molybdenum resistance heating boat, and Compound 30 as a host compound was added to another molybdenum resistance heating boat. 200 mg of ET-8 as an electron transport material in another molybdenum resistance heating boat, 100 mg of Comparative 3 as a blue dopant compound in another molybdenum resistance heating boat, and red in another molybdenum resistance heating boat 100 mg of D-10 was added as a dopant compound, and the compound 24 was added as a hole blocking material to another molybdenum resistance heating boat, which was attached to a vacuum deposition apparatus.

Next, the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, and the heating boat containing α-NPD was energized and heated, evaporated on the transparent support substrate at a deposition rate of 0.1 nm / second, and a layer thickness of 20 nm. The second hole transport layer was provided.

  Further, the heating boat containing compound 30 as a host compound, comparison 3 as a blue dopant compound and D-10 as a red dopant was energized and heated, and the deposition rates were 0.1 nm / sec, 0.010 nm / sec, 0, respectively. A light emitting layer having a layer thickness of 40 nm was provided by co-evaporation on the second hole transport layer at a rate of .0002 nm / second.

  Furthermore, on the light emitting layer, the compound 24 was vapor-deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide a hole blocking layer having a layer thickness of 5 nm.

Further, the heating boat containing ET-8 was energized and heated, and deposited on the hole blocking layer at a deposition rate of 0.1 nm / second to provide an electron transport layer having a layer thickness of 30 nm.
In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a layer thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a layer thickness of 110 nm. Thus, an organic EL element 5-1 was produced.

<< Production of Organic EL Elements 5-2 to 5-16 >>
In the production of the organic EL element 5-1, the host compound, the dopant compound and the deposition rate in the light emitting layer were changed as shown in Table 4.
Other than that produced the organic EL element 5-2 to 5-16 similarly.

<< Evaluation of Organic EL Elements 5-1 to 5-16 >>
When evaluating the obtained organic EL elements 5-1 to 5-16, the organic EL element was sealed in the same manner as the organic EL element 1-1 of Example 1, and as shown in FIGS. A lighting device was fabricated and evaluated.
Each sample thus prepared was evaluated for external extraction quantum efficiency and half-life in the same manner as in Example 1, and chromaticity stability (chromaticity deviation) over time was as follows. Evaluation was performed. The evaluation results are shown in Table 4. In addition, the measurement results of the external extraction quantum efficiency, half-life, and chromaticity shift in Table 4 were expressed as relative values with the measured value of the organic EL element 5-2 being 100.

[Evaluation of chromaticity stability (chromaticity deviation) over time]
The luminance fluctuation at the time of continuous driving is traced with the front luminance of 4000 cd / m ² as the initial luminance, and the spectral radiance meter CS-1000 (Konica Minolta Sensing Co., Ltd.) is used to measure the chromaticity at t = 0 (initial) and the luminance at half luminance. And the chromaticity difference ΔE was determined from the following formula. As shown in Table 4, the measurement results are shown as relative values with the organic EL element 5-2 as 100. In the following formula, x and y are chromaticity x and y in the CIE 1931 color system.
ΔE = (Δx ² + Δy ² ) ^1/2

  From Table 4, it can be seen that the dopant of the present invention has high emission efficiency, good emission lifetime in a region where the dopant concentration is high, and small chromaticity deviation during continuous driving.

<< Production of Organic EL Element 6-1 >>
A quartz substrate of 100 mm × 100 mm × 1.1 mm was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

  This quartz substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of OC-29 as a host compound was put in a molybdenum resistance heating boat, and 100 mg of Comparative 4 was put as a dopant in another molybdenum resistance heating boat, It was attached to a vacuum evaporation system.

  Then, after reducing the vacuum tank to 4 × 10 −4 Pa, the heating boat containing OC-29 and Comparative 4 was energized and heated, and the deposition rate was 0.1 nm / second and 0.005 nm / second, respectively. The organic EL element 6-1 was obtained by co-evaporation on a quartz substrate to provide a light-emitting layer having a layer thickness of 40 nm. The density | concentration of the comparison 4 after vapor deposition was 5%.

<< Production of Organic EL Elements 6-2 to 6-6 >>
In production of the organic EL element 6-1, the dopant and the dopant concentration were changed as shown in Table 5.
Other than that produced the organic EL element 6-2 to 6-6 similarly.

<< Evaluation of Organic EL Elements 6-1 to 6-6 >>
When evaluating the obtained organic EL elements 6-1 to 6-6, the organic EL elements were sealed in the same manner as the organic EL elements 1-1, 1-2, and 1-13 of Example 1, 5 and FIG. 6 were produced and evaluated.
Thus, PL intensity | strength was measured as follows with respect to each produced sample. The evaluation results are shown in Table 5.

[Measurement of PL intensity]
Measure the absorption spectrum of the dopant in advance using a dichloromethane solution of the dopant (dichloromethane for absorption analysis, Spectrozole, Wako Pure Chemical Industries, Ltd.), and set the absorption maximum wavelength in the range of 300 nm to 350 nm as the excitation light. To do. At this time, the concentration of the solution is about 10 ⁻⁵ mol / l.
About the illuminating device of the produced organic EL elements 6-1 to 6-6, the dopant was excited by irradiation with excitation light at room temperature, and the peak area value of the obtained emission spectrum was obtained. This area value is a value obtained by correcting absorption by excitation light. The measurement was performed with Hitachi spectrophotometer U-3300 and fluorimeter F-4500.
The peak areas obtained with the organic EL elements 6-1 and 6-4 having a dopant concentration of 5% were set to 100, and the evaluation was performed by comparing the dopant concentrations of 15% and 25%.

From Table 5, it can be seen that the dopant of the present invention exhibits high PL intensity even in a region where the dopant concentration is high. This is presumably because the dispersibility of the dopant of the present invention is high and aggregation is suppressed even in a high concentration region.
Furthermore, about the said organic EL element 6-3 and 6-6, the stability at the time of high temperature / humidity storage shown below was also evaluated.

[Stability during storage at high temperature and high humidity]
The organic EL elements 6-3 and 6-6 were stored under conditions of 60 ° C. and 70% RH for 24 hours, and then the PL intensity before and after storage was compared, and this was evaluated as stability during high temperature and high humidity storage.
The results are shown in Table 6.

  From Table 6, it can be seen that the dopant of the present invention exhibits high PL strength even after storage, and has high stability during storage at high temperature and high humidity.

<< Production of Organic EL Element 7-1 >>
Patterning was performed on a substrate (NA-45, manufactured by AvanState Co., Ltd.) on which a 100 nm ITO (indium tin oxide) film was formed as an anode on a 100 mm × 100 mm × 1.1 mm glass substrate. Thereafter, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, using a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by Bayer, Baytron P Al 4083) to 70% with pure water, spin After forming a thin film by the coating method, it was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a layer thickness of 30 nm.

  On the first hole transport layer, a hole transport material Poly (N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl)) benzidine (manufactured by American Dye Source, ADS- A thin film was formed by spin coating using the chlorobenzene solution of No. 254). Heat drying at 150 ° C. for 1 hour to provide a second hole transport layer having a layer thickness of 30 nm.

  This transparent support substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of OC-29 as a host compound was placed in a molybdenum resistance heating boat, and ET-42 as an electron transport material in another molybdenum resistance heating boat. 200 mg was added, and 100 mg of Comparative 2 was added as a dopant to another molybdenum resistance heating boat and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing OC-29 as the host compound and Comparative 2 as the dopant was energized and heated, and the deposition rate was 0.1 nm / second, respectively. A light emitting layer having a layer thickness of 40 nm was provided by co-evaporation on the second hole transport layer at 009 nm / second.

Further, the heating boat containing ET-42 was energized and heated, and deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide an electron transport layer having a layer thickness of 30 nm.
In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a layer thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a layer thickness of 110 nm. Thus, an organic EL element 7-1 was produced.

<< Production of Organic EL Elements 7-2 to 7-16 >>
In preparation of the organic EL element 7-1, the host compound and dopant in the light emitting layer were changed to the compounds shown in Table 7.
Other than that produced the organic EL elements 7-2 to 7-16 in the same manner.

<< Evaluation of Organic EL Elements 7-1 to 7-16 >>
When evaluating the obtained organic EL elements 7-1 to 7-16, the organic EL element was sealed in the same manner as the organic EL element 1-1 of Example 1, and as shown in FIGS. A lighting device was fabricated and evaluated.
Each sample thus produced was evaluated for external extraction quantum efficiency, half life, voltage increase during driving, and thermal stability in the same manner as in Example 1. Table 7 shows the evaluation results. In addition, the measurement results of the external extraction quantum efficiency, the half life, and the voltage increase during driving in Table 7 are expressed as relative values with the measured value of the organic EL element 7-1 being 100.

  From Table 7, the organic EL elements 7-3 to 7-16 of the present invention show higher luminous efficiency and longer life than the organic EL elements 7-1 and 7-2 of the comparative example, and the voltage rise during driving. It can be seen that the characteristics of the device are improved, such as suppressing the above.

As described above, the present invention improves the thermal stability and sublimation property of the organometallic complex as the organic electroluminescence element material, thereby providing a high-emission efficiency and long-life organic electroluminescence element, and illumination using the element Suitable for providing a device and a display device.
In addition, the present invention is suitable for solving the problem of chromaticity stability (chromaticity shift) during continuous driving in a white light emitting organic electroluminescence device and improving the doping concentration dependency in device performance. In addition, by providing an iridium complex compound having high dispersibility, it is suitable for extending the lifetime of the organic electroluminescence device.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate with a transparent electrode 108 Nitrogen gas 109 Water capture Agent 201 Glass substrate 202 ITO transparent electrode 203 Partition wall 204 Hole injection layer 205B, 205G, 205R Light emitting layer 206 Cathode A Display unit B Control unit

Claims (17)

An iridium complex compound represented by the following general formula (5 ′).

[In general formula (5 ′), ring An, ring Bm and ring Bn each independently represent a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle. R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or It represents a non-aromatic heterocyclic group and may further have a substituent. Ra, Rb, Rc and Ra ₃ are each independently hydrogen atom, halogen atom, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, silyl group, arylalkyl group, aryl group, heteroaryl. Represents a group, a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. Note that the structures of the three ligands coordinated to Ir are not all the same. ] An iridium complex compound represented by the following general formula (5):

[In General Formula (5), R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. Ra, Rc and Ra ₃ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, a silyl group, an arylalkyl group, an aryl group, a heteroaryl group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. ] An electroluminescent element material represented by the following general formula (5 ′).

[In general formula (5 ′), ring An, ring Bm and ring Bn each independently represent a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle. R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or It represents a non-aromatic heterocyclic group and may further have a substituent. Ra, Rb, Rc and Ra ₃ are each independently hydrogen atom, halogen atom, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, silyl group, arylalkyl group, aryl group, heteroaryl. Represents a group, a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. Note that the structures of the three ligands coordinated to Ir are not all the same. ] An organic electroluminescence element material represented by the following general formula (5).

[In General Formula (5), R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. Ra, Rc and Ra ₃ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, a silyl group, an arylalkyl group, an aryl group, a heteroaryl group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. ] In an organic electroluminescence device in which at least one organic layer including a light emitting layer is sandwiched between an anode and a cathode,
An organic electroluminescence device, wherein an iridium complex compound represented by the following general formula (5 ′) is contained in at least one of the organic layers.

[In general formula (5 ′), ring An, ring Bm and ring Bn each independently represent a 5-membered or 6-membered aromatic hydrocarbon ring or aromatic heterocycle. R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or It represents a non-aromatic heterocyclic group and may further have a substituent. Ra, Rb, Rc and Ra ₃ are each independently hydrogen atom, halogen atom, cyano group, alkyl group, alkenyl group, alkynyl group, alkoxy group, amino group, silyl group, arylalkyl group, aryl group, heteroaryl. Represents a group, a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, nb represents an integer of 1 to 4, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. Note that the structures of the three ligands coordinated to Ir are not all the same. ] In an organic electroluminescence device in which at least one organic layer including a light emitting layer is sandwiched between an anode and a cathode,
An organic electroluminescence device, wherein an iridium complex compound represented by the following general formula (5) is contained in at least one of the organic layers.

[In General Formula (5), R ₁ m, R ₂ m, R ₁ n and R ₂ n are each independently an alkyl group having 2 or more carbon atoms, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. Ra, Rc and Ra ₃ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an amino group, a silyl group, an arylalkyl group, an aryl group, a heteroaryl group, It represents a non-aromatic hydrocarbon ring group or a non-aromatic heterocyclic group, and may further have a substituent. na and nc represent 1 or 2, and nR3 represents an integer of 1 to 4. X represents O, S, SiRz1Rz2, NRz1 or CRz1Rz2, and Rz1 and Rz2 each independently represents an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, a non-aromatic hydrocarbon ring group or a non-aromatic group. Represents a heterocyclic group. m represents 1 or 2, n represents 1 or 2, and m + n = 3. ]   The organic electroluminescent element according to claim 5 or 6, wherein X is O or S in the general formula (5 ') or (5). In the general formula (5 ′) or (5), R ₁ n and R ₂ n are both alkyl groups or cycloalkyl groups having 2 or more carbon atoms, The organic electroluminescent element as described in any one. In the general formula (5 ′) or (5), R ₁ m and R ₂ m are both an alkyl group or a cycloalkyl group having 2 or more carbon atoms, The organic electroluminescent element as described in any one. In the general formula (5 ′) or (5), at least one of R ₁ n and R ₂ n is a branched alkyl group having 3 or more carbon atoms. The organic electroluminescent element according to claim 1. The general formula (5 ′) or (5), wherein at least one of R ₁ m and R ₂ m is a branched alkyl group having 3 or more carbon atoms. The organic electroluminescent element according to claim 1. 6. In the general formula (5 ′) or (5), all of R ₁ m, R ₂ m, R ₁ n and R ₂ n are branched alkyl groups having 3 or more carbon atoms. The organic electroluminescent element according to claim 1.   13. The organic electroluminescent element according to claim 5, wherein in the general formula (5 ′) or (5), m is 2 and n is 1. 13.   13. The organic electroluminescent element according to claim 5, wherein in the general formula (5 ′) or (5), m is 1 and n is 2. 13.   The organic electroluminescence element according to any one of claims 5 to 14, wherein the emission color is white.   An illuminating device comprising the organic electroluminescent element according to any one of claims 5 to 15.   A display device comprising the organic electroluminescence element according to any one of claims 5 to 15.

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