JPWO2017104325A1 - ORGANIC ELECTROLUMINESCENT ELEMENT, METHOD FOR PRODUCING ORGANIC ELECTROLUMINESCENT ELEMENT, DISPLAY DEVICE, LIGHTING DEVICE, AND ORGANIC ELECTROLUMINESCENT ELEMENT MATERIAL - Google Patents

Abstract

Provided is an organic EL device having a light emission ratio of a component longer than the light emission maximum wavelength, a high light emission efficiency, a low drive voltage, a long light emission lifetime, a small voltage increase during drive, and excellent stability over time. The organic EL element includes an organic layer sandwiched between an anode and a cathode, and at least one of the organic layers contains a compound having a structure represented by the general formula (1). (Wherein R is an alkyl group, halogen atom, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, sulfinyl group, sulfonyl group, nitro group, cyano group, hydroxy group or mercapto group, and Ar is aromatic. An aromatic hydrocarbon group or an aromatic heterocyclic group, X1-L1-X2 is a bidentate ligand, and two of the adjacent R1-R4 represent any of the general formulas (2)-(4).) (Y1 to Y4 are O, S or N—R ′, Y5 or Y6 is CR ″ or N, and Z1 to Z8 are C—Rx or N.)

Description

  The present invention relates to an organic electroluminescence element, a method for producing an organic electroluminescence element, a display device, a lighting device, and an organic electroluminescence element material. In particular, the present invention is an organic compound having a small emission ratio of components longer than the emission maximum wavelength, high emission efficiency, low driving voltage, long emission lifetime, small voltage increase during driving, and excellent temporal stability. The present invention relates to an electroluminescence element, a method for manufacturing the element, a display device and a lighting device including the element, and an organic electroluminescence element material used for the element.

  An organic electroluminescence element (hereinafter also referred to as “organic EL element”) is an all-film thin film type composed of an organic thin film layer (single layer portion or multilayer portion) containing an organic light-emitting substance between an anode and a cathode. It is a solid element.

  When a voltage is applied to the organic EL element, electrons are injected from the cathode into the organic thin film layer and holes are injected from the anode, and these are recombined in the light emitting layer (organic light emitting substance-containing layer) to generate excitons. The organic EL element is a light-emitting element using light emission (fluorescence / phosphorescence) from these excitons, and is a technology expected as a next-generation flat display and illumination.

  Furthermore, since Princeton University reported an organic EL device that utilizes phosphorescence emission from an excited triplet, which in principle can achieve a luminous efficiency of about four times that of an organic EL device that utilizes fluorescence. Starting with the development of materials that exhibit phosphorescence at room temperature, research and development of light-emitting element layer configurations and electrodes are being carried out around the world.

  As described above, the phosphorescence emission method is a method having a very high potential. However, in an organic EL device using phosphorescence emission, a method for controlling the position of the emission center is significantly different from that using fluorescence emission. In order to improve the light emission efficiency and life of the organic EL element, it is important to recombine inside the light emitting layer to stabilize the light emission.

  Therefore, a multilayer stacked device including 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, etc. adjacent to the light emitting layer, or a phosphor layer on the light emitting layer. An element using a mixed layer containing a light-emitting dopant and a host compound has been developed.

From the viewpoint of materials, iridium complex-based heavy metal complexes have been studied as materials exhibiting phosphorescence at room temperature. For example, a tris (2-phenylpyridine) iridium complex is widely known, but sufficient device performance such as a light emission lifetime has not been obtained. Other than tris (2-phenylpyridine) iridium complexes, iridium complexes having a phenylimidazole ligand or a carbene ligand are known. With these ligands, the emission wavelength of the luminescent material has been shortened to achieve a blue color, and further, the emission efficiency and the emission lifetime have been greatly improved.
However, in recent years, an illumination light source with a high color temperature and a display with a wide color gamut have been demanded, and it has been demanded to further reduce the y value measured using the CIE coordinates. In order to achieve these, it is conceivable to make the emission maximum wavelength shorter and to reduce the long wave component of the emission. Until now, various studies have been made on the shortening of the emission maximum wavelength, such as changing the substituents. However, while the wavelength can be shortened to some extent, the light emission efficiency and lifetime of the device are greatly deteriorated. There was a need for improvement.

Phenyltriazole is known as a ligand that emits blue light (see, for example, Patent Document 1). Although these compounds can achieve a short wavelength of the emission maximum wavelength, the emission lifetime and emission efficiency are not sufficient values.
On the other hand, a metal complex having a triazole ligand in which a ring bonded to a metal atom with a carbon atom has a condensed ring structure is known (for example, see Patent Documents 2 and 3). In addition, a metal complex having a triazole ligand in which a ring coordinated to a metal atom has an alkyl group adjacent to the coordination atom is known (see, for example, Patent Document 4). Although these compounds have achieved a certain improvement in the light emission lifetime, there is room for further improvement.

International Publication No. 2004/101707 Japanese Patent No. 5644050 Japanese Patent No. 5099013 JP 2013-040159 A

  The present invention has been made in view of the above-described problems and situations, and its solution is a small emission ratio of components longer than the emission maximum wavelength, high emission efficiency, low drive voltage, and long emission lifetime. An organic electroluminescence element having a small voltage rise during driving and excellent stability over time, a method for producing the element, a display device and a lighting device including the element, and an organic electroluminescence element material used for the element Is to provide.

  As a result of investigating the cause of the above-mentioned problems in order to solve the above-mentioned problems according to the present invention, a metal complex having a 1H-1,2,4-triazole derivative as a ligand is bonded to a metal atom with a carbon atom. Has a condensed ring structure containing a hetero atom, and the ring coordinated to the metal atom has a specific substituent at the adjacent position of the coordination atom, thereby suppressing light emission longer than the emission maximum wavelength. It was found that the light emission efficiency and the light emission lifetime can be improved while maintaining a short wavelength maximum emission wavelength to some extent. That is, according to the present invention, the y-value measured using the CIE coordinates is suppressed while suppressing long-wave light emission, so that there is no trade-off between the shortening of the light emission maximum wavelength and the light emission efficiency / light emission lifetime of the device. An organic EL element can be provided.

That is, the present inventors include a compound having a structure represented by the following general formula (1), so that the emission ratio of components longer than the emission maximum wavelength is small, and the luminous efficiency is high. The present inventors have found that an organic electroluminescence device having a low driving voltage, a long life, a small voltage increase during driving, and an excellent stability over time can be provided.
The problems according to the present invention are solved by the following means.

1. An organic electroluminescent device comprising an organic layer sandwiched between at least one pair of an anode and a cathode,
The organic layer is composed of at least one layer including a light emitting layer, and at least one of the organic layers contains a compound having a structure represented by the following general formula (1).

(In general formula (1), R is an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group, and a mercapto group. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. , Alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxy Carbonyl, sulfamoyl, ureido, acyl, acyloxy, amide, cal Moyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group, arylsilyl group, alkylphosphino group, arylphosphino group, alkylphosphoryl group Represents any group selected from an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
However, at least two of adjacent R _{1 to} R ₄ are condensed to represent any one of the following general formulas (2) to (4). )

(In General Formulas (2) to (4), Y _{1 to} Y ₄ each independently represents O, S, or N—R ′, and Y ₅ or Y ₆ represents CR ″ or N. R 'Represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R''represents a hydrogen atom, an alkyl group, a cycloalkyl group, Z _{1 to} Z ₈ represent any group selected from an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group, and an arylphosphoryl group. Independently, it represents C-Rx or N, and the plurality of Rx may be the same or different, and each of the plurality of Rx independently represents R _{1 to} R ₄ in the general formula (1). Represents an equivalent group, and * represents a bonding position with the structure represented by the general formula (1).

  2. 2. The organic electroluminescence device according to item 1, wherein the structure represented by the general formula (1) is a structure represented by any one of the following general formulas (5) to (10).

(In the general formulas (5) to (10), R, Ar, R _{1 to} R ₄ , Y ₁ , Z _{1 to} Z ₄ , X ₁ , X ₂ , L ₁ , m and n are the same as those in the general formula (1). ) And (2) are the same as R, Ar, R _{1 to} R ₄ , Y ₁ , Z _{1 to} Z ₄ , X ₁ , X ₂ , L ₁ , m and n.)

3. 2. The organic according to item 1, wherein in the general formula (1), at least two of adjacent R _{1 to} R ₄ are condensed to represent the structure of the general formula (3) or (4). Electroluminescence element.

  4). In the general formula (1), R represents an alkyl group or a cyano group. The organic electroluminescence element according to any one of items 1 to 3, wherein R represents an alkyl group or a cyano group.

  5. In the general formula (1), Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group having a substituent at the 2-position, according to any one of items 1 to 4 The organic electroluminescent element of description.

  6). In the said General formula (1), n represents 0, The organic electroluminescent element as described in any one of 1st term | claim to 5th term | claim characterized by the above-mentioned.

  7). The said light emitting layer contains the compound which has a structure represented by the said General formula (1), The organic electroluminescent element as described in any one of Claim 1-6 characterized by the above-mentioned.

  8). The organic light-emitting device according to item 7, wherein the light-emitting layer contains at least two kinds of the compound represented by the general formula (1) and a compound having a HOMO level of −5.4 eV or less. .

9. It is a manufacturing method of the organic electroluminescent element which manufactures the organic electroluminescent element as described in any one of Claim 1 to 8,
The organic electroluminescent element manufacturing method characterized by forming the layer containing the compound which has a structure represented by the said General formula (1) among the said organic layers with a wet process.

  10. A display device comprising the organic electroluminescence element according to any one of items 1 to 8.

  11. An illuminating device comprising the organic electroluminescence element according to any one of items 1 to 8.

  12 An organic electroluminescence device material comprising a compound having a structure represented by the following general formula (1).

(In general formula (1), R is an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group, and a mercapto group. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. , Alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxy Carbonyl, sulfamoyl, ureido, acyl, acyloxy, amide, cal Moyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group, arylsilyl group, alkylphosphino group, arylphosphino group, alkylphosphoryl group Represents any group selected from an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
However, at least two of adjacent R _{1 to} R ₄ are condensed to represent any one of the following general formulas (2) to (4). )

(In General Formulas (2) to (4), Y _{1 to} Y ₄ each independently represents O, S, or N—R ′, and Y ₅ or Y ₆ represents CR ″ or N. R 'Represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R''represents a hydrogen atom, an alkyl group, a cycloalkyl group, Z _{1 to} Z ₈ represent any group selected from an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group, and an arylphosphoryl group. Independently, it represents C-Rx or N, and the plurality of Rx may be the same or different, and each of the plurality of Rx independently represents R _{1 to} R ₄ in the general formula (1). Represents an equivalent group, and * represents a bonding position with the structure represented by the general formula (1).

  According to the present invention, an organic electroluminescence device having a small light emission ratio of a component longer than the light emission maximum wavelength, high light emission efficiency, low drive voltage, and long light emission lifetime, a small voltage increase during drive, and excellent stability over time. A luminescence element and an organic electroluminescence element material used for the element can be provided. In addition, it is possible to improve the productivity of the element by a wet process. In addition, a lighting device and a display device including the element can be provided.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
In the compound having the structure represented by the general formula (1), a ring bonded to a metal atom with a carbon atom has a condensed ring structure, and a ring coordinated to a metal atom has a specific substitution at a position adjacent to the coordinate atom. It is a metal complex having a 1H-1,2,4-triazole derivative having a group as a ligand. As a result of intensive studies, the present inventors have found that a ring bonded to a metal atom with a carbon atom has a condensed ring structure containing a heteroatom, so that an effect of suppressing light emission of components longer than the emission maximum wavelength can be seen. I found.
This is because a ring bonded to a metal atom by a carbon atom is condensed, so that distortion of the ring structure in an excited state is suppressed, and a more rigid structure is obtained by including a heteroatom in the condensed ring structure. It is estimated that the emission of long wave components was suppressed. However, since the π plane spreads and aggregates easily due to the condensed ring structure, the light emission is broadened, and the effect cannot be exhibited sufficiently. Therefore, the present inventors further suppress the aggregation by allowing the ring coordinated to the metal atom to have a specific substituent (R in the general formula (1) of the present invention) adjacent to the coordination atom. Furthermore, it was found that the effect of suppressing light emission of a component longer than the light emission maximum wavelength appears more remarkably by suppressing the vibration of the ligand.

  In addition, the compound having the structure represented by the general formula (1) not only has an effect of suppressing light emission of components longer than the emission maximum wavelength, but also has high luminous efficiency, low driving voltage, and long life. In addition, it is possible to provide an organic EL element that is small in voltage rise during driving and excellent in stability over time. This is because a compound having a structure represented by the general formula (1) has a rigid structure because a ring bonded to a metal atom with a carbon atom has a condensed ring structure including a heteroatom, and thus is in an excited state. In this case, it is difficult to cause distortion, and further, since the crystallinity is suppressed by having a substituent at a specific position, the stability of the compound itself is increased, and further, crystallization and decomposition over time are less likely to occur. it is conceivable that. As a result, it is possible to provide an organic EL element that has a long life, has a small voltage rise during driving, and is excellent in stability over time. In addition, in the compound having the structure represented by the general formula (1), since a ring bonded to a metal atom with a carbon atom includes a heteroatom, charge transportability is improved unlike an aromatic condensed ring or fluorene. Therefore, the light emission efficiency is high and a low driving voltage can be achieved.

Schematic diagram showing an example of a display device composed of organic EL elements Schematic diagram of display section A in FIG. Schematic showing the pixel circuit FIG. 2 is a schematic diagram of a passive matrix type full-color display device according to display unit A of FIG. Schematic of lighting device Cross section of the lighting device Schematic configuration diagram of organic EL full-color display device Schematic configuration diagram of organic EL full-color display device Schematic configuration diagram of organic EL full-color display device Schematic configuration diagram of organic EL full-color display device Schematic configuration diagram of organic EL full-color display device

The organic electroluminescence device of the present invention is an organic electroluminescence device comprising an organic layer sandwiched between at least one pair of an anode and a cathode, wherein the organic layer comprises at least one layer including a light emitting layer, Among them, at least one layer contains a compound having a structure represented by the general formula (1). This feature is a technical feature common to or corresponding to each claim.
In the present invention, the structure represented by the general formula (1) is preferably a structure represented by any one of the general formulas (5) to (10).
In the present invention, in the general formula (1), it is preferable that at least two of the adjacent R _{1 to} R ₄ are condensed to represent the structure of the general formula (3) or (4).
In the present invention, in the general formula (1), R preferably represents an alkyl group or a cyano group. Thereby, since R has a moderate magnitude | size, the suppression effect of the vibration of a ligand improves and light emission of a component longer than a light emission maximum wavelength can be suppressed more effectively.
In the present invention, in the general formula (1), Ar preferably represents an aromatic hydrocarbon group or an aromatic heterocyclic group having a substituent at the 2-position. Thereby, the spread of the conjugated system with the ring coordinated to the metal atom can be cut, and the emission wavelength can be prevented from becoming longer.
In the present invention, in the general formula (1), n preferably represents 0. Thereby, since light emission from the same ligand is obtained, the light emission waveform becomes sharp, and light emission with a component longer than the light emission maximum wavelength can be more effectively suppressed.
Moreover, in this invention, it is preferable that the said light emitting layer contains the compound which has a structure represented by the said General formula (1).
Moreover, in this invention, it is preferable that the said light emitting layer contains at least 2 sort (s) of the compound of the said General formula (1), and the compound whose HOMO level is -5.4 eV or less. The compound having the structure represented by the general formula (1) according to the present invention has a deep HOMO level as compared with a conventional metal complex having a 4H-1,2,4-triazole derivative as a ligand. , When used together with a deep compound having a HOMO level of −5.4 eV or less, the movement of electric charges becomes smooth, leading to further improvement in light emission efficiency and driving voltage.

  Moreover, the manufacturing method of the organic electroluminescent element of this invention is a manufacturing method of the organic electroluminescent element which manufactures the said organic electroluminescent element, Comprising: The structure represented by the said General formula (1) among the said organic layers is provided. A layer containing a compound having the above is formed by a wet process. As a result, an organic electroluminescence device having a small emission ratio of components longer than the emission maximum wavelength, high luminous efficiency, low driving voltage, long emission lifetime, small voltage increase during driving, and excellent stability over time Can be manufactured.

  Moreover, the display apparatus and illumination apparatus of this invention are provided with the said organic electroluminescent element.

  Moreover, the organic electroluminescent element material of this invention contains the compound which has a structure represented by the said General formula (1), It is characterized by the above-mentioned. By using the organic electroluminescence element material, the light emission ratio of components longer than the light emission maximum wavelength is small, high light emission efficiency, low drive voltage, long light emission lifetime, small voltage rise during driving, stable over time It is possible to obtain an organic electroluminescent element excellent in the above.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" showing a numerical range is used by the meaning containing the numerical value described before and behind that as a lower limit and an upper limit.

<Outline of organic electroluminescence device>
The organic electroluminescence device of the present invention is an organic electroluminescence device comprising an organic layer sandwiched between at least one pair of an anode and a cathode, wherein the organic layer comprises at least one layer including a light emitting layer, Among them, at least one layer contains a compound having a structure represented by the general formula (1). General formula (1) will be described later.

As typical element structures in the organic EL element of the present invention, the following structures can be exemplified, but the invention is not limited thereto.
(1) Anode / light emitting layer / cathode (2) Anode / light emitting layer / electron transport layer / cathode (3) Anode / hole transport layer / light emitting layer / cathode (4) Anode / hole transport layer / light emitting layer / electron Transport layer / cathode (5) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (6) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode ( 7) Anode / hole injection layer / hole transport layer / (electron blocking layer /) luminescent layer / (hole blocking layer /) electron transport layer / electron injection layer / cathode Among the above, the configuration of (7) is preferable. Although used, it is not limited to this.

  The light emitting layer according to the present invention is composed of a single layer or a plurality of layers. When the light emitting layer is composed of a plurality of layers, a non-light emitting intermediate layer may be provided between the light emitting layers.

  If necessary, a hole blocking layer (also referred to as a hole blocking layer) or an electron injection layer (also referred to as a cathode buffer layer) may be provided between the light emitting layer and the cathode. An electron blocking layer (also referred to as an electron barrier layer) or a hole injection layer (also referred to as an anode buffer layer) may be provided therebetween.

The electron transport layer used in the present invention is a layer having a function of transporting electrons, and 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 may be composed of a plurality of layers.
The hole transport layer used in the present invention is a layer 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 may be composed of a plurality of layers.

  In the above-described typical element configuration, a layer excluding the anode and the cathode is referred to as an “organic layer”.

(Tandem structure)
The organic EL element of the present invention may be a so-called tandem element in which a plurality of light emitting units including at least one light emitting layer are stacked.
As typical element configurations of the tandem structure, for example, the following configurations can be given.

Anode / first light emitting unit / second light emitting unit / third light emitting unit / cathode Anode / first light emitting unit / intermediate layer / second light emitting unit / intermediate layer / third light emitting unit / cathode

  Here, the first light emitting unit, the second light emitting unit, and the third light emitting unit may all be the same or different. Further, the two light emitting units may be the same, and the remaining one may be different.

  Further, the third light emitting unit may not be provided, and on the other hand, a light emitting unit or an intermediate layer may be further provided between the third light emitting unit and the cathode.

As in the above configuration example, the plurality of light emitting units may be directly stacked or may be stacked via an intermediate layer.
The intermediate layer is generally called an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, or an intermediate insulating layer, and electrons are provided in an adjacent layer on the anode side and holes are provided in an adjacent layer on the cathode side. Any known material and structure can be used as long as the layer has a function of supplying.

Examples of materials used for the intermediate layer include ITO (indium tin oxide), IZO (indium zinc oxide), ZnO ₂ , TiN, ZrN, HfN, TiO _x , VO _x , CuI, InN, GaN, Conductive inorganic compound layers such as CuAlO ₂ , CuGaO ₂ , SrCu ₂ O ₂ , LaB ₆ , RuO ₂ and Al, two-layer films such as Au / Bi ₂ O ₃ , SnO ₂ / Ag / SnO ₂ , ZnO / Multi-layer film such as Ag / ZnO, Bi ₂ O ₃ / Au / Bi ₂ O ₃ , TiO ₂ / TiN / TiO ₂ , TiO ₂ / ZrN / TiO ₂ , fullerenes such as C ₆₀ , conductivity such as oligothiophene Examples include organic material layers, conductive organic compound layers such as metal phthalocyanines, metal-free phthalocyanines, metal porphyrins, and metal-free porphyrins. The present invention is not limited thereto.

  Examples of a preferable configuration in the light emitting unit include those obtained by removing the anode and the cathode from the configurations (1) to (7) described in the above representative element configurations, but the present invention is not limited thereto. Not.

  Specific examples of the tandem organic EL element include, for example, US Pat. No. 6,337,492, US Pat. No. 7,420,203, US Pat. No. 7,473,923, US Pat. No. 6,872,472, US Pat. No. 6,107,734. Specification, US Pat. No. 6,337,492, International Publication No. 2005/009087, JP-A 2006-228712, JP-A 2006-24791, JP-A 2006-49393, JP-A 2006-49394 JP-A-2006-49396, JP-A-2011-96679, JP-A-2005-340187, JP-A-4711424, JP-A-34966681, JP-A-3848564, JP-A-4421169, JP 2010-192719, JP 009-076929, JP 2008-078414 A, JP 2007-059848 A, JP 2003-272860 A, JP 2003-045676 A, International Publication No. 2005/094130, etc. Although a structure, a constituent material, etc. are mentioned, this invention is not limited to these.

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

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light when excitons generated by recombination of electrons and holes injected from the cathode or the electron transport layer or the anode or the hole transport layer are deactivated. The portion to be formed may be in the light emitting layer or at the interface between the light emitting layer and the adjacent layer.

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

  For the production of the light emitting layer, a light emitting dopant or host compound described later is used, for example, a vacuum deposition method, a wet method (also referred to as a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, Examples thereof include an inkjet method, a printing method, a spray coating method, a curtain coating method, and an LB method (Langmuir Brodgett method). Preferably, the light emitting layer is a layer formed through a wet process. By forming the layer by a wet process, damage to the light emitting layer due to heat can be reduced as compared with the vacuum deposition method.

  The light emitting layer of the organic EL device of the present invention contains a light emitting dopant and a host compound, and at least one light emitting dopant has a structure represented by the general formula (1) described above. A complex, preferably a phosphorescent organometallic complex having a structure represented by any one of the general formulas (5) to (10).

Moreover, you may use together the compound etc. which are described in the following patent gazettes in the light emitting layer which concerns on this invention.
For example, International Publication No. 00/70655, JP 2002-280178, JP 2001-181616, JP 2002-280179, JP 2001-181617, JP 2002-280180, JP 2001-247859 A, JP 2002-299060 A, JP 2001-313178 A, JP 2002-302671 A, JP 2001-345183 A, JP 2002-324679 A, International Publication. No. 02/15645, JP 2002-332291 A, JP 2002-50484 A, JP 2002-332292 A, JP 2002-83684 A, JP 2002-540572 A, JP 2002-2002 A. No. 117978, Japanese Patent Application Laid-Open No. 2002-33858 JP, JP-A-2002-170684, JP-A-2002-352960, WO01 / 93642, JP-A-2002-50483, JP-A-2002-1000047, JP-A-2002-173684. JP-A-2002-359082, JP-A-2002-175484, JP-A-2002-363552, JP-A-2002-184582, JP-A-2003-7469, JP-A-2002-525808, JP 2003-7471, JP 2002-525833, JP 2003-31366, JP 2002-226495, JP 2002-234894, JP 2002-2335076, JP 2002 No. 2411751, JP 2001-319779 A. JP, 2001-319780, 2002-62824, 2002-100474, 2002-203679, 2002-343572, 2002-203678, etc. It is.

  Next, the compound contained in the organic layer will be described, and each layer will be described.

(1) Luminescent dopant As the luminescent dopant, fluorescent dopants (also referred to as fluorescent compounds) and phosphorescent dopants (also referred to as phosphorescent dopants, phosphorescent compounds, phosphorescent compounds, etc.) can be used. .

(1.1) Phosphorescent dopant The phosphorescent dopant 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.), Although the phosphorescence quantum yield is defined to be a compound of 0.01 or more at 25 ° C., the preferred 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 emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant. It is an energy transfer type to obtain light emission from a phosphorescent dopant. 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 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.

As the phosphorescent dopant in the embodiment of the present invention, a phosphorescent organometallic complex having a structure represented by the general formula (1) described below is preferably used.
By using the phosphorescent organometallic complex having the structure represented by the general formula (1) as a phosphorescent dopant, it is possible to suppress a long wave light emitting component while maintaining a short wavelength, and a high emission luminance and a low driving voltage. In addition, the light emission life can be extended at the same time. Moreover, the organic EL element produced using the phosphorescence dopant of this invention has a small voltage rise at the time of a drive, and is improved also in terms of stability over time.

(1.1.1) Compound having structure represented by general formula (1)

In the general formula (1), R _{1 to} R ₄ each independently represent a hydrogen atom, an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a (t) butyl group, a pentyl group, a hexyl group, Octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group ( For example, propargyl group etc.), aromatic hydrocarbon group (also called aryl group, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group Group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), heterocyclic ring (For example, epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, 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, etc.), aromatic heterocyclic group (pyridyl group, pyrimidinyl group, furyl group, Piro Group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group Benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, dia A carbazolyl group (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a quinoxalinyl group, a pyridazinyl group, a triazinyl group, a quinazolinyl group, a phthalazinyl group, etc.), a halogen atom (For example, chlorine atom, bromine source , Iodine atom, fluorine atom etc.), alkoxy group (eg methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group etc.), cycloalkoxy group (eg cyclopentyloxy) Group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.) , A cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), an arylthio group (eg, phenylthio group, naphthylthio group, etc.), an alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl, etc.) Group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl) Group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.) Ureido groups (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, Nylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecyl) Carbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group) Etc.), amide groups (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonyl) Mino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group) Dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2- Pyridylaminocarbonyl group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclo Hexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group or arylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl) Group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino) Group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, diarylamino group (for example, diphenylamino group, dinaphthylamino group, phenyl group) Naphthylamino group, etc.), naphthylamino group, 2-pyridylamino group, etc.), nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group or arylsilyl group (for example, trimethylsilyl group, triethylsilyl group, (t) butyl) Dimethylsilyl group, triisopropylsilyl group, (t) butyldiphenylsilyl group, triphenylsilyl group, trinaphthylsilyl group, 2-pyridylsilyl group, etc.), alkylphosphino group or arylphosphino group (dimethylphosphino group, Diethylphosphino group, dicyclohexylphosphino group, methylphenylphosphino group, diphenylphosphino group, dinaphthylphosphino group, di (2-pyridyl) phosphino group), alkylphosphoryl group or arylphosphoryl group (dimethylphosphoryl group, diethyl) Sphoryl group, dicyclohexylphosphoryl group, methylphenylphosphoryl group, diphenylphosphoryl group, dinaphthylphosphoryl group, di (2-pyridyl) phosphoryl group), alkylthiophosphoryl group or arylthiophosphoryl group (dimethylthiophosphoryl group, diethylthiophosphoryl group, It represents any group selected from a dicyclohexylthiophosphoryl group, a methylphenylthiophosphoryl group, a diphenylthiophosphoryl group, a dinaphthylthiophosphoryl group, and a di (2-pyridyl) thiophosphoryl group). Here, a group other than the hydrogen atom is referred to as a substituent. In addition, these substituents may be further substituted by the above-mentioned substituents, and they may be condensed with each other to further form a ring.

  In addition, specific examples in parentheses in these substituents are not limited thereto. In addition, specific examples in parentheses in the alkyl group, halogen atom, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, sulfinyl group, sulfonyl group, nitro group, cyano group, hydroxy group, mercapto group in the above substituents. Examples include the alkyl group of R in the general formula (1), halogen atom, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, sulfinyl group, sulfonyl group, nitro group, cyano group, hydroxy group, mercapto The same applies to the group. Furthermore, the specific examples in parentheses in the aromatic hydrocarbon group or aromatic heterocyclic group in the above substituent are the same in the aromatic hydrocarbon group or aromatic heterocyclic group of Ar in the general formula (1). .

When R _{1 to} R ₄ represent the above substituent, an alkyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an aryloxy group, an arylthio group, an amino group, or a cyano group It is preferably any of them, particularly preferably an aromatic hydrocarbon group, an aromatic heterocyclic group, a halogen atom or a cyano group, more preferably a halogen atom or a cyano group.

  In the general formula (1), R is an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group, and a mercapto group. Represents any group selected. These groups may be further substituted with the above substituents. R is preferably any one of an alkyl group, a halogen atom, and a cyano group. In particular, R is an alkyl group or a cyano group from the viewpoint of more effectively suppressing emission of a component having a wavelength longer than the emission maximum wavelength. Is preferable, and among them, an alkyl group having 1 to 6 carbon atoms is particularly preferable.

  In General formula (1), Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group. These groups may be further substituted with the above substituents, or they may be condensed with each other to further form a ring. Ar is preferably substituted by the above substituent, and in particular, substituted by any one of an alkyl group, a cycloalkyl group, a halogen atom, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group. In particular, it is preferably substituted by an alkyl group, an aromatic hydrocarbon group or an aromatic heterocyclic group. Further, the ortho position is substituted with respect to the bonding position with the 1H-1,2,4-triazole ring of the general formula (1) (the ring represented by Ar is 1H-1,2,4- It has a substituent at the position adjacent to the bonding position with the triazole ring) from the viewpoint of shortening the emission wavelength, and is particularly preferably substituted by an alkyl group.

In the general formula (1), X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X ₂ .

Specific examples of ligands of bidentate represented by X ₁ -L ₁ -X _2, a substituted or unsubstituted phenyl pyridine, phenylpyrazole, phenylimidazole, phenyl triazole, phenyl tetrazole, pyrazabole, acetylacetone, picolinic acid However, it is not limited to these. The bidentate ligand represented by X ₁ -L ₁ -X ₂ is preferably phenylpyrazole or phenyltriazole, and particularly preferably phenyltriazole.

  In the general formula (1), m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3. n is preferably 0 or 1, and particularly preferably 0 from the viewpoint of more effectively suppressing light emission of a component longer than the light emission maximum wavelength.

In the general formula (1), at least two of adjacent R _{1 to} R ₄ are condensed to represent any one of the general formulas (2) to (4).

In the general formulas (2) to (4), Y _{1 to} Y ₄ each independently represent O, S, or N—R ′, and Y ₅ or Y ₆ represents CR ″ or N. Y ₁ or Y ₄ is particularly preferably N—R ′, Y ₂ or Y ₃ is preferably O or N—R ′, and particularly preferably N—R ′. Y ₅ is preferably CR ″, and Y ₆ is preferably N.

  In the general formulas (2) to (4), R ′ represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group, and an aromatic heterocyclic group. These groups may be further substituted with the above substituents, or they may be condensed with each other to further form a ring. R ′ is preferably any group selected from an aromatic hydrocarbon group, a heterocyclic group, and an aromatic heterocyclic group, and particularly preferably an aromatic hydrocarbon group or an aromatic heterocyclic group.

  In general formulas (2) to (4), R ″ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, or a cyano group. Represents any group selected from an arylsilyl group and an arylphosphoryl group. These groups may be further substituted with the above substituents, or they may be condensed with each other to further form a ring. R ″ is preferably any group selected from a hydrogen atom, an aromatic hydrocarbon group, and an aromatic heterocyclic group.

In the general formulas (2) to (4), Z _{1 to} Z ₈ each independently represent C—Rx or N, and the plurality of Rx may be the same or different. Z _{1 to} Z ₈ are preferably C-Rx. A plurality of Rx independently represents a _R 1 to R ₄ the same group in the general formula (1). These groups may be further substituted with the above substituents, or they may be condensed with each other to further form a ring. When one or more of Rx represent the above substituent, Rx is selected from an alkyl group, an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, and a cyano group. In particular, any group selected from an alkyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, a halogen atom, and a cyano group is preferable.

  In the general formulas (2) to (4), * represents a bonding position with the structure represented by the general formula (1).

  The compound having the structure represented by the general formula (1) may be contained in an organic layer other than the light emitting layer.

(1.1.2) Compound having structure represented by general formulas (5) to (10) The structure represented by general formula (1) is any one of the following general formulas (5) to (10). It is preferable that it is a structure represented.

In the general formulas (5) to (10), R, Ar, R _{1 to} R ₄ , Y ₁ , Z _{1 to} Z ₄ , X ₁ , X ₂ , L ₁ , m, and n are represented by the general formula (1). And (2) are synonymous with R, Ar, R _{1 to} R ₄ , Y ₁ , Z _{1 to} Z ₄ , X ₁ , X ₂ , L ₁ , m and n.

(1.1.3) Specific Examples Hereinafter, specific examples of the compound having the structure represented by the general formula (1) according to the present invention will be shown, but the present invention is not limited thereto.

(1.1.4) Synthesis Example Hereinafter, a synthesis example of a compound having a structure represented by the general formulas (1) to (10) will be described by taking the exemplified compound 3-3 as an example. It is not limited to this.
Exemplary compound 3-3 can be synthesized according to the following scheme.

  Under a nitrogen stream, 5.0 g (9.60 mmol) of Intermediate 1, 3.39 g (9.60 mmol) of iridium chloride, 40 mL of 2-ethoxyethanol and 10 mL of water were placed in a flask, and the mixture was heated and stirred at 100 ° C. for 4 hours. . The precipitated crystals were collected by filtration, and the collected crystals were washed with methanol to obtain 11.5 g of Intermediate 2.

Under a nitrogen stream, 4.73 g (9.07 mmol) of intermediate 1, 11.5 g (4.54 mmol) of intermediate 2, 2.51 g (11.4 mmol) of silver trifluoroacetate and 230 mL of phenyl acetate. And stirred with heating at 180 ° C. for 9 hours. The reaction solution was allowed to cool to room temperature and then concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain 1.27 g (yield 8%) of Exemplary Compound 3-3. The structure of Exemplified Compound 3-3 was confirmed by mass spectrum and ¹ H-NMR. In addition, what further sublimated and refined this compound was used for preparation of the organic EL element mentioned later.

  Other compounds of the present invention can also be synthesized with good yield by using appropriate raw materials and reactions as in the above synthesis examples.

(1.2) Fluorescent dopants Fluorescent dopants (hereinafter also referred to as fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, and fluorescein dyes. Examples include dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes, polythiophene dyes, rare earth complex phosphors, and compounds having high fluorescence quantum yields typified by laser dyes.

In recent years, light emitting dopants using delayed fluorescence have been developed, and these may be used.
Specific examples of the luminescent dopant using delayed fluorescence include, for example, the compounds described in International Publication No. 2011/156793, Japanese Patent Application Laid-Open No. 2011-213643, Japanese Patent Application Laid-Open No. 2010-93181, and the like. Is not limited to these.

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

(2) Host compound In the present invention, the host compound (hereinafter also referred to as a light-emitting host) has a mass ratio in the layer of 20% or more among the compounds contained in the light-emitting layer, and a room temperature (25 ° C. ) Is defined as a compound having a phosphorescence quantum yield of phosphorescence of less than 0.1. 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 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 a 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 being increased in wavelength, 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 known light-emitting hosts include Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, and 2002-334786. Gazette, 2002-8860 gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette. Gazette, 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227 , 2002-231453, 2003-3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, 2002 -29960 gazette, 2002-302516 gazette, 2002-305083 gazette, 2002-305084 gazette, 2002-308837 gazette, etc. The compound as described in literatures is mentioned.

  Further, as described above, since the compound having the structure represented by the general formula (1) according to the present invention has a deep HOMO level, a host compound having a HOMO level of −5.4 eV or less is used. It is preferable. Thereby, the movement of electric charges becomes smooth, which leads to further improvement in light emission efficiency and driving voltage.

  Next, an injection layer, a blocking layer, an electron transport layer, a hole transport layer, and the like that are preferably used as the constituent layers of the organic EL element of the present invention will be described.

《Electron transport layer》
In the present invention, the electron transport layer is made of a material having a function of transporting electrons and may have a function of transmitting electrons injected from the cathode to the light emitting layer.

  Although there is no restriction | limiting in particular about the total layer thickness of the electron carrying layer used for this invention, Usually, it is the range of 2 nm-5 micrometers, More preferably, it is 2-500 nm, More preferably, it is 5-200 nm.

Further, in the organic EL element, when the light generated in the light emitting layer is extracted from the electrode, the light extracted directly from the light emitting layer interferes with the light extracted after being reflected by the electrode from which the light is extracted and the electrode located at the counter electrode. It is known to wake up. When light is reflected by the cathode, this interference effect can be efficiently utilized by appropriately adjusting the thickness of the electron transport layer between several nanometers and several micrometers.
On the other hand, when the layer thickness of the electron transport layer is increased, the voltage is likely to increase. Therefore, particularly when the layer thickness is thick, the electron mobility of the electron transport layer is preferably 10 ⁻⁵ cm ² / Vs or more. .

  The material used for the electron transport layer (hereinafter referred to as an electron transport material) may have any of an electron injection property or a transport property, and a hole barrier property. Any one can be selected and used.

  For example, nitrogen-containing aromatic heterocyclic derivatives (carbazole derivatives, azacarbazole derivatives (one or more carbon atoms constituting the carbazole ring are substituted with nitrogen atoms), pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, pyridazine derivatives, Triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, azatriphenylene derivatives, oxazole derivatives, thiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, etc.), dibenzofuran derivatives, And dibenzothiophene derivatives, silole derivatives, aromatic hydrocarbon ring derivatives (naphthalene derivatives, anthracene derivatives, triphenylene, etc.).

  In addition, a metal complex having a quinolinol skeleton or a dibenzoquinolinol skeleton as a ligand, for example, tris (8-quinolinol) aluminum (Alq3), 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 their metal complexes A metal complex in which the central metal is replaced with In, Mg, 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 terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transport material. Distyrylpyrazine derivatives can also be used as electron transport materials, and inorganic semiconductors such as n-type-Si and n-type-SiC can be used as electron-transport materials as well as hole-injection layers and hole-transport layers. Can do.

  Further, 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 the electron transport layer used in the present invention, the electron transport layer may be doped with a doping material as a guest material to form an electron transport layer having a high n property (electron rich). Examples of the doping material include n-type dopants such as metal complexes and metal compounds such as metal halides. Specific examples of the electron transport layer having such a structure include, for example, JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J. Pat. Appl. Phys. , 95, 5773 (2004) and the like.

Specific examples of known preferable electron transport materials used in the organic EL device of the present invention include compounds described in the following documents, but the present invention is not limited thereto.
U.S. Pat. No. 6,528,187, U.S. Pat. No. 7,230,107, U.S. Patent Application Publication No. 2005/0025993, U.S. Patent Application Publication No. 2004/0036077, U.S. Patent Application Publication No. 2009/0115316. U.S. Patent Application Publication No. 2009/0101870, U.S. Patent Application Publication No. 2009/0179554, International Publication No. 2003/060956, International Publication No. 2008/120855, Appl. Phys. Lett. , 75, 4 (1999), Appl. Phys. Lett. 79, 449 (2001), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 81, 162 (2002), Appl. Phys. Lett. 79,156 (2001), U.S. Patent No. 7964293, U.S. Patent Application Publication No. 2009/030202, International Publication No. 2004/080975, International Publication No. 2004/063159, International Publication No. 2005/085387. No., International Publication No. 2006/067931, International Publication No. 2007/086552, International Publication No. 2008/114690, International Publication No. 2009/066942, International Publication No. 2009/066779, International Publication No. 2009/054253, WO2011 / 086935, WO2010 / 150593, WO2010 / 047707, EP23111826, JP2010-251675, JP2009-209133, JP 2009-124 14, JP 2008-277810, JP 2006-156445, JP 2005-340122, JP 2003-45662, JP 2003-31367, JP 2003-282270. Gazette, International Publication No. 2012/115034, and the like.

  More preferable electron transport materials in the present invention include pyridine derivatives, pyrimidine derivatives, pyrazine derivatives, triazine derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, azacarbazole derivatives, and benzimidazole derivatives.

  The electron transport material may be used alone or in combination of two or more.

《Hole blocking layer》
The hole blocking layer is a layer having the function of an electron transport layer in a broad sense, and is preferably made of a material having a function of transporting electrons and a small ability to transport holes. By blocking the holes, the probability of recombination of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned above can be used as a hole-blocking layer used for this invention as needed. The hole blocking layer provided in the organic EL device of the present invention is preferably provided adjacent to the cathode side of the light emitting layer.

  The layer thickness of the hole blocking layer used in the present invention is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.

  As the material used for the hole blocking layer, the material used for the above-described electron transport layer is preferably used, and the material used as the above-described host compound is also preferably used for the hole blocking layer.

《Electron injection layer》
The electron injection layer (also referred to as “cathode buffer layer”) used in the present invention is a layer provided between the cathode and the light emitting layer in order to lower the driving voltage and improve the light emission luminance. 2 and Chapter 2 “Electrode Materials” (pages 123 to 166) of the 2nd edition of “The Forefront of Industrialization” (issued by NTT Corporation on November 30, 1998).
In the present invention, the electron injection layer may be provided as necessary, and may be present between the cathode and the light emitting layer or between the cathode and the electron transport layer as described above.

  The electron injection layer is preferably a very thin film, and the layer thickness is preferably in the range of 0.1 to 5 nm, although it depends on the material. Further, it may be a non-uniform film in which constituent materials are present intermittently.

The details of the electron injection layer are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specific examples of materials preferably used for the electron injection layer are as follows. , Metals typified by strontium and aluminum, alkali metal compounds typified by lithium fluoride, sodium fluoride, potassium fluoride, etc., alkaline earth metal compounds typified by magnesium fluoride, calcium fluoride, etc., oxidation Examples thereof include metal oxides typified by aluminum, metal complexes typified by lithium 8-hydroxyquinolate (Liq), and the like. Further, the above-described electron transport material can also be used.
Moreover, the material used for said electron injection layer may be used independently, and may be used in combination of multiple types.

《Hole transport layer》
In the present invention, the hole transport layer is made of a material having a function of transporting holes, and may have a function of transmitting holes injected from the anode to the light emitting layer.

  Although there is no restriction | limiting in particular about the total layer thickness of the positive hole transport layer used for this invention, Usually, it is the range of 5 nm-5 micrometers, More preferably, it is 2-500 nm, More preferably, it is 5-200 nm.

  A material used for the hole transport layer (hereinafter also referred to as a hole transport material) may have any of a hole injection property or a transport property, and an electron barrier property. Any one can be selected and used.

  For example, porphyrin derivatives, phthalocyanine derivatives, oxazole derivatives, oxadiazole derivatives, triazole derivatives, imidazole derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, hydrazone derivatives, stilbene derivatives, polyarylalkane derivatives, triarylamine derivatives, carbazole derivatives , Indolocarbazole derivatives, isoindole derivatives, acene derivatives such as anthracene and naphthalene, fluorene derivatives, fluorenone derivatives, and polyvinyl carbazole, polymer materials or oligomers with aromatic amines introduced into the main chain or side chain, polysilane, conductive And polymer (for example, PEDOT / PSS, aniline copolymer, polyaniline, polythiophene, etc.).

  Examples of the triarylamine derivative include benzidine type represented by α-NPD (4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), starburst type represented by MTDATA, Examples include compounds having fluorene or anthracene in the triarylamine-linked core.

  In addition, hexaazatriphenylene derivatives such as those described in JP-A-2003-519432 and JP-A-2006-135145 can also be used as a hole transport material.

  Furthermore, a hole transport layer having a high p property doped with impurities can also 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.

JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material or an inorganic compound such as p-type-Si or p-type-SiC, as described in the literature (Appl. Phys. Lett., 80 (2002), p. 139) is used. You can also Further, ortho-metalated organometallic complexes having Ir or Pt as a central metal as typified by Ir (ppy) ₃ are also preferably used.

  Although the above-mentioned materials can be used as the hole transport material, a triarylamine derivative, a carbazole derivative, an indolocarbazole derivative, an azatriphenylene derivative, an organometallic complex, or an aromatic amine is introduced into the main chain or side chain. The polymer materials or oligomers used are preferably used.

Specific examples of known preferred hole transport materials used in the organic EL device of the present invention include the compounds described in the following documents in addition to the documents listed above, but the present invention is not limited thereto. Not.
For example, Appl. Phys. Lett. 69, 2160 (1996); Lumin. 72-74, 985 (1997), Appl. Phys. Lett. 78, 673 (2001), Appl. Phys. Lett. , 90, 183503 (2007), Appl. Phys. Lett. , 90, 183503 (2007), Appl. Phys. Lett. 51, 913 (1987), Synth. Met. , 87, 171 (1997), Synth. Met. 91, 209 (1997), Synth. Met. , 111, 421 (2000), SID Symposium Digest, 37, 923 (2006), J. Am. Mater. Chem. 3,319 (1993), Adv. Mater. 6, 677 (1994), Chem. Mater. , 15, 3148 (2003), US Patent Application Publication No. 2003/0162053, US Patent Application Publication No. 2002/0158242, US Patent Application Publication No. 2006/0240279, US Patent Application Publication No. 2008. No. 0220265, U.S. Pat. No. 5,061,569, WO 2007/002683, WO 2009/018009, EP 650955, U.S. Patent Application Publication No. 2008/0124572, U.S. Patent Application Publication No. 2007/0278938, U.S. Patent Application Publication No. 2008/0106190, U.S. Patent Application Publication No. 2008/0018221, International Publication No. 2012/115034, Special Table No. 2003-519432. JP, JP 2006 135145 JP, is US Patent Application No. 13/585981 Pat like.

  The hole transport material may be used alone or in combination of two or more.

《Electron blocking layer》
The electron blocking layer is a layer having a function of a hole transport layer in a broad sense, and is preferably made of a material having a function of transporting holes and a small ability to transport electrons, while transporting holes. By blocking electrons, the probability of recombination of electrons and holes can be improved.
Moreover, the structure of the positive hole transport layer mentioned above can be used as an electron blocking layer used for this invention as needed.
The electron blocking layer provided in the organic EL device of the present invention is preferably provided adjacent to the anode side of the light emitting layer.

  The layer thickness of the electron blocking layer used in the present invention is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.

  As the material used for the electron blocking layer, the material used for the above-described hole transport layer is preferably used, and the material used as the above-described host compound is also preferably used for the electron blocking layer.

《Hole injection layer》
The hole injection layer (also referred to as “anode buffer layer”) used in the present invention is a layer provided between the anode and the light emitting layer in order to lower the driving voltage or improve the light emission luminance. It is described in detail in Chapter 2 “Electrode Materials” (pages 123 to 166) of the second edition of “Devices and the Forefront of Industrialization (issued by NTT Corporation on November 30, 1998)”.
In the present invention, the hole injection layer may be provided as necessary, and may exist between the anode and the light emitting layer or between the anode and the hole transport layer as described above.

The details of the hole injection layer are also described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, etc. Examples of the material used for the hole injection layer include: Examples thereof include materials used for the above-described hole transport layer.
Among them, phthalocyanine derivatives typified by copper phthalocyanine, hexaazatriphenylene derivatives as described in JP-T-2003-519432 and JP-A-2006-135145, metal oxides typified by vanadium oxide, amorphous carbon Preferred are conductive polymers such as polyaniline (emeraldine) and polythiophene, orthometalated complexes represented by tris (2-phenylpyridine) iridium complex, and triarylamine derivatives.

  The materials used for the hole injection layer described above may be used alone or in combination of two or more.

《Other additive compounds》
The organic layer in the present invention described above may further contain other additive compounds. Examples of the additive compound include halogen elements such as bromine, iodine, and chlorine, halogenated compounds, alkali metals such as Pd, Ca, and Na, alkaline earth metals, transition metal compounds, complexes, and salts.

The content of the additive compound can be arbitrarily determined, but is preferably 1000 ppm or less, more preferably 500 ppm or less, still more preferably 50 ppm or less, based on the total mass% of the contained layer. .
However, it is not within this range depending on the purpose of improving the transportability of electrons and holes, the purpose of making the energy transfer of excitons advantageous.

<Method for forming organic layer>
A method for forming an organic layer (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) used in the present invention will be described.

  The formation method of the organic layer used in the present invention is not particularly limited, and a conventionally known formation method such as a vacuum deposition method or a wet method (also referred to as a wet process) can be used. A layer formed by a process is preferable. That is, it is preferable to produce an organic EL element by a wet process. By producing the organic EL element by a wet process, it is possible to obtain an effect such that a homogeneous film (coating film) is easily obtained and pinholes are hardly generated. In addition, a film | membrane (coating film) here is a thing of the state dried after application | coating by a wet process.

  Examples of the wet method include spin coating, casting, ink jet, printing, die coating, blade coating, roll coating, spray coating, curtain coating, and LB (Langmuir-Blodgett). From the viewpoint of obtaining a homogeneous thin film easily and 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.

  Examples of the liquid medium for dissolving or dispersing the organic EL material of 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, 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.

Further, a different film forming method may be applied for each layer. When employing a vapor deposition method for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a degree of vacuum of 10 ⁻⁶ to 10 ⁻² Pa, and a vapor deposition rate of 0.01 to It is desirable to select appropriately within a range of 50 nm / second, a substrate temperature of −50 to 300 ° C., and a layer thickness of 0.1 nm to 5 μm, preferably 5 to 200 nm.

  The organic layer according to the present invention is preferably formed 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. In that case, it is preferable to perform the work in a dry inert gas atmosphere.

"anode"
As the anode in the organic EL element, a material having a work function (4 eV or more, preferably 4.5 eV or more) of a metal, an alloy, an electrically conductive compound, or a mixture thereof is preferably used. Specific examples of such an electrode substance include a conductive transparent material such as a metal such as Au, 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.

As a method for forming the anode, a thin film may be formed by a method such as vapor deposition or sputtering using these electrode materials, and a pattern having a desired shape may be formed by a photolithography method, or pattern accuracy is not much required. If not (about 100 μm or more), a pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered.
Moreover, 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.

  The thickness of the anode depends on the material, but is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

"cathode"
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, aluminum, rare earth metals and the like. Among these, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value than this from the viewpoint of durability against electron injection and oxidation, 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 thickness is usually selected in the range of 10 nm to 5 μm, 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, after producing the metal in a thickness of 1 to 20 nm on the cathode, a transparent or translucent cathode can be produced by producing the conductive transparent material mentioned in the description of the anode on the cathode, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《Support substrate》
The 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 is not particularly limited in the type of glass, plastic, etc., and is transparent. Or 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 (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, 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 polyether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Film.

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)%) is preferably a gas barrier film having a value of 1 × 10 ⁻² g / (m ² · 24 h) or less, and further measured by a method based on JIS K 7126-1987. A high gas barrier film having an oxygen permeability of 1 × 10 ⁻³ mL / (m ² · 24 h · atm) or less and a water vapor permeability of 1 × 10 ⁻⁵ g / (m ² · 24 h) or less. Preferably there is.

  As a material for forming the gas barrier film, any material may be used as long as it 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, and the like can be used. Furthermore, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. 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 gas 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, ceramic substrates, and the like.

The external extraction quantum 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 the phosphor may be used in combination.

<Sealing>
Examples of the sealing means used for sealing the organic EL element of the present invention include a method of bonding a sealing member, an electrode, and a support substrate with an adhesive. The sealing member may be disposed so as to cover the display area of the organic EL element, and may be concave or flat. Moreover, 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 polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. 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 organic EL element can be thinned. Furthermore, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ mL / (m ² · 24 h · atm) or less, and a method according to JIS K 7129-1992. the measured water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)%) is preferably that of ^{1 × 10 -3 g / (m} 2 / 24h) or less.

  In order to process 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, as a material for forming the film, any material may be used as long as it has a function of suppressing infiltration 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.
Furthermore, 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. There are no particular limitations on the method of forming these films. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma A combination 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 can also be used. 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 or the sealing film on the side facing the support substrate with the organic layer interposed therebetween. In particular, when 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, etc. used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

《Light extraction enhancement technology》
An organic electroluminescence element emits light inside a layer having a refractive index higher than that of air (within a refractive index of about 1.6 to 2.1), and about 15% to 20% of light generated in the light emitting layer. It is generally said that only light can be extracted. 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 element, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light undergoes total reflection between the light, the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the side surface direction of the element.

  As a technique 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 transparent substrate and the air interface (for example, US Pat. No. 4,774,435), A method for improving efficiency by providing light condensing property (for example, JP-A-63-314795), a method for forming a reflective surface on a side surface of an element (for example, JP-A-1-220394), a substrate, etc. A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the substrate and the light emitter (for example, Japanese Patent Application Laid-Open No. 62-172691), lower refraction than the substrate between the substrate and the light emitter A method of introducing a flat layer having a refractive index (for example, Japanese Patent Application Laid-Open No. 2001-202827), and a method of forming a diffraction grating between any one of the substrate, the transparent electrode layer and the light emitting layer (including between the substrate and the outside world) ( JP-A-11 JP), etc. 283751 can be mentioned.

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 low refractive index medium 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. Become.
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 in the range of about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Furthermore, it is preferable that it is 1.35 or less.
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 diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface that causes total reflection or in any medium has a feature that the effect of improving the light extraction efficiency is high. 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 or second-order diffraction. The light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (inside a transparent substrate or transparent electrode). , Trying to extract light 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. 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.

  The position where the diffraction grating is introduced may be in any 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 within a range of 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 element of the present invention is processed in a microlens array-like structure on the light extraction side of the support substrate (substrate), or combined with a so-called condensing sheet, for example, in a specific direction, for example, By condensing in the front direction with respect to the element light emitting surface, 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 arranged two-dimensionally on the light extraction side of the substrate. One side is preferably within a range of 10 to 100 μm. If it is smaller than this, the effect of diffraction is generated and colored, and if it is too large, the thickness becomes thick, which 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, a substrate may be formed with a triangle stripe having an apex angle of 90 degrees and a pitch of 50 μm, or the apex angle is rounded and the pitch is changed randomly. Other shapes may also be used.
Moreover, in order to control the light emission angle from an organic EL element, you may use a light-diffusion plate and a film together 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 Examples include, but are not limited to, a light source of a sensor. In particular, the light source can be effectively used for 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 when forming a film, if necessary. 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.

<Display device>
The organic EL element of the present invention can be used for a display device.
One mode of the display device of the present invention that includes the organic EL element of the present invention will be described. The display device 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 emitting 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. However, the present invention is not limited to these.

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, a wiring unit C that electrically connects the display unit A and the control unit B, and the like. .
The control unit B is electrically connected to the display unit A via the wiring unit C, and sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside. Sequentially emit light according to the image data signal, scan the image, and display the image information on the display unit A.

FIG. 2 is a schematic diagram of the display unit A in FIG.
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 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 lattice shape and are connected to the pixels 3 at the orthogonal positions (details are shown in FIG. Not shown).

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 showing a pixel circuit.
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 to the drain of the switching transistor 11 from the controller B shown in FIG. 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 of 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, and the power supply line 7 connects to the organic EL element 10 according 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 if 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 element 10 of each of the plurality of pixels, and the light emission of the organic EL element 10 of each of the plurality of pixels 3. 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 type full-color display device according to the display unit A of FIG. 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.

  By using the organic EL element of the present invention, a display device with improved luminous efficiency can be obtained.

《Lighting device》
The organic EL element of the present invention can be used for a lighting device.
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 made.

  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. Without using a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas with a purity of 99.999% or higher).

  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, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "volume%" is represented. In addition, Exemplified Compounds 1-1 to 8-19 used in the Examples correspond to 1-1 to 8-19 of specific examples of the compound having the structure represented by the general formula (1). Moreover, the structure of the comparative compounds 1-4 used in the Example is shown.

Comparative Compound 1: Compound disclosed in International Publication No. 2004/101707 Comparative Compound 2: Compound disclosed in Japanese Patent No. 5644050 Comparative Compound 3: Compound disclosed in Japanese Patent No. 5099013 Comparative Compound 4: Japanese Patent Laid-Open No. 2013-2003 Compound disclosed in Japanese Patent No. 040159

[Example 1]
<< Production of Organic EL Element 1-1 >>
Patterning was performed on a substrate (NA-45, manufactured by AvanStrate Co., Ltd.) on which a film of ITO (indium tin oxide) with a thickness of 100 nm was formed as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. 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.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum evaporation apparatus, while 200 mg of HT-1 as a hole injection material is put into a molybdenum resistance heating boat, and HT- as a hole transport material is put into another molybdenum resistance heating boat. 200 mg of 2 and 200 mg of Comparative Compound 1 as a dopant in another molybdenum resistance heating boat, 200 mg of Host-1 as a host compound in another molybdenum resistance heating boat, and holes in another molybdenum resistance heating boat 200 mg of ET-1 was placed as a blocking material, and 200 mg of ET-2 was placed as an electron transport material in another molybdenum resistance heating boat, which was attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing HT-1 was heated by heating, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / second. A hole injection layer was formed.

  Furthermore, it supplied with electricity to the heating boat containing HT-2, it heated, and it vapor-deposited on the positive hole injection layer with the vapor deposition rate of 0.1 nm / second, and formed the positive hole transport layer with a layer thickness of 30 nm.

  Further, the heating boat containing the comparative compound 1 and Host-1 was heated by energization, and co-deposited on the hole transport layer at a deposition rate of 0.1 nm / second and 0.010 nm / second, respectively. A light emitting layer was formed.

  Furthermore, it supplied with electricity to the heating boat containing ET-1, and heated, and it vapor-deposited on the light emitting layer with the vapor deposition rate of 0.1 nm / sec, and formed the 10-nm-thick hole blocking layer.

  Furthermore, it supplied with electricity to the heating boat containing ET-2, it heated, and it vapor-deposited on the positive hole blocking layer with the vapor deposition rate of 0.1 nm / second, and formed the electron carrying layer with a layer thickness of 30 nm.

Subsequently, lithium fluoride is deposited on the electron transport layer to form an electron injection layer (cathode buffer layer) having a thickness of 0.5 nm, and aluminum is further deposited on the electron injection layer to form a cathode having a thickness of 110 nm. Then, an organic EL element 1-1 was produced.
The compound used in this example has the following chemical structural formula.

<< Production of Organic EL Elements 1-2 to 1-10 >>
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-10 were produced in the same manner except that the comparative compound 1 and Host-1 were changed to the compounds shown in Table 1.
Host-2 in Table 1 has the following chemical structural formula.

<< Evaluation of Organic EL Elements 1-1 to 1-10 >>
When evaluating the obtained organic EL elements 1-1 to 1-10, 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 used as a sealing substrate. Then, an epoxy photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the periphery, and this is placed on the cathode so as to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. It hardened | cured and sealed and the illuminating device as shown in FIG.5 and FIG.6 was produced.
The following evaluation was performed for each sample thus prepared. The evaluation results are shown in Table 1.

(1) External extraction quantum efficiency (also referred to as luminous efficiency)
Perform lighting at room temperature (about 23 to 25 ° C.) and a constant current of ^2.5 mA / cm ² using an organic EL element, and measure the light emission luminance (L) [cd / m ² ] immediately after the start of lighting. Thus, the external extraction quantum 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) Driving voltage The voltage when the organic EL element was driven at room temperature (about 23 ° C. to 25 ° C.) and a constant current of ^2.5 mA / cm ² was measured. The relative value with the organic EL element 1-1 as 100 was determined.
Drive voltage = (drive voltage of each element / drive voltage of the organic EL element 1-1) × 100
Note that a smaller value indicates a lower drive voltage than the comparative example.

(4) Voltage rise during driving Measure the voltage when the organic EL element is driven at room temperature (about 23 ° C. to 25 ° C.) and a constant current of ^2.5 mA / cm ^2. The voltage rise during driving was obtained from the equation. In addition, the voltage rise at the time of a drive was represented by the relative value which sets the organic EL element 1-1 to 100.
Voltage rise during driving (relative value) = drive voltage at half brightness-initial drive voltage Note that a smaller value indicates a smaller voltage rise during driving than the comparative example.

(5) Stability over time The organic EL device was stored for one month under the conditions of 60 ° C. and 70% RH, and each power efficiency before and after storage was determined. The power efficiency ratio was determined from each power efficiency according to the following formula, and this was used as a measure of stability over time.
Stability over time (%) = (power efficiency after storage / power efficiency before storage) × 100
The power efficiency was obtained by measuring the front luminance and luminance angle dependency of each organic EL element using a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing Co., Ltd.) and obtaining the front luminance of 1000 cd / m ² . Using.

(6) Second wave ratio With respect to the metal complex used as a dopant for each organic EL element, the emission spectrum at a low temperature (about 77 K) in a 2-methyl THF solution was measured using a spectrofluorometer manufactured by Hitachi High-Tech Science Co., Ltd. Measurement was performed using F-7000. The second wave ratio was calculated from the measurement results by the following formula and evaluated according to the following criteria. Thereby, it was confirmed that the light emission of the wavelength component on the long wave side from the light emission maximum wavelength was suppressed.
Second wave ratio = light emission amount at the peak wavelength next to the light emission maximum wavelength / light emission amount at the light emission maximum wavelength

A: Second wave ratio is 0.4 or less. O: Second wave ratio is more than 0.4 and less than 0.6. Δ: Second wave ratio is more than 0.6 and less than 0.8. 8 or more

  As is apparent from Table 1, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL element using the compound having the structure represented by the general formula (1) is superior in luminous efficiency and luminous lifetime and has a low driving voltage as compared with the organic EL element of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 2]
<< Preparation of Organic EL Element 2-1 >>
Patterning was performed on a substrate (NA-45, manufactured by AvanStrate Co., Ltd.) on which a film of ITO (indium tin oxide) with a thickness of 100 nm was formed as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. 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.

  A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by HC Starck Co., Ltd., CLEVIO P VPAI 4083) to 70% by mass on this transparent support substrate. After forming a thin film by spin coating under conditions of 3000 rpm and 30 seconds, the film was dried at 200 ° C. for 1 hour to form 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 deposition apparatus, while 200 mg of HT-2 was added as a hole transport material to a molybdenum resistance heating boat, and Comparative Compound 1 was added as a dopant to another molybdenum resistance heating boat. 200 mg of Host-1 was placed in another molybdenum resistance heating boat as a host compound, 200 mg of ET-1 as an electron transport material was placed in another molybdenum resistance heating boat, and attached to a vacuum deposition apparatus.

Next, after the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, the heating boat containing HT-2 was energized and heated, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / second, and the layer thickness was 20 nm. The second hole transport layer was formed.

  Further, the heating boat containing Comparative Compound 1 and Host-1 was heated by energization, and co-deposited on the second hole transport layer at the deposition rates of 0.1 nm / second and 0.006 nm / second, respectively, A 40 nm light emitting layer was formed.

  Furthermore, it supplied with electricity to the heating boat containing ET-1, and heated, and it vapor-deposited on the light emitting layer with the vapor deposition rate of 0.1 nm / second, and formed the 30-nm-thick electron carrying layer. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, lithium fluoride is vapor-deposited on the light emitting layer to form an electron injection layer having a thickness of 0.5 nm, and aluminum is vapor-deposited on the electron injection layer to form a cathode having a thickness of 110 nm. 2-1.

<< Production of Organic EL Elements 2-2 to 2-8 >>
In the production of the organic EL element 2-1, organic EL elements 2-2 to 2-8 were produced in the same manner except that the comparative compound 1 and Host-1 were changed to the compounds shown in Table 2.

<< Evaluation of Organic EL Elements 2-1 to 2-8 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and a 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, driving voltage, voltage increase during driving, stability over time, and second wave ratio in the same manner as in Example 1. The evaluation results are shown in Table 2. In addition, the measurement results of the external extraction quantum efficiency, the half-life, the driving voltage, and the voltage increase during driving in Table 2 are expressed as relative values with the measured value of the organic EL element 2-1 being 100.

  As is apparent from Table 2, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL element using the compound having the structure represented by the general formula (1) is superior in luminous efficiency and luminous lifetime and has a low driving voltage as compared with the organic EL element of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 3]
<< Production of Organic EL Element 3-1 >>
Patterning was performed on a substrate (NA-45, manufactured by AvanStrate Co., Ltd.) on which a film of ITO (indium tin oxide) with a thickness of 100 nm was formed as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. 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, 3000 rpm using a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Baytron, Baytron P Al 4083) to 70% by mass with pure water. After forming a thin film by spin coating under a condition of 30 seconds, the film was dried at 200 ° C. for 1 hour to form a first hole transport layer having a layer thickness of 20 nm.

  The substrate was transferred to a nitrogen atmosphere, and the first hole transport layer was subjected to conditions of 1500 rpm and 30 seconds using a solution of 47 mg of HT-3 and 3 mg of HT-4 dissolved in 10 mL of toluene. A thin film was formed by spin coating. Ultraviolet light was irradiated at 120 ° C. for 90 seconds to perform photopolymerization / crosslinking, and further vacuum dried at 60 ° C. for 1 hour to form a second hole transport layer having a layer thickness of about 20 nm.

  A solution of 100 mg Host-3, 20 mg Comparative Compound 1, 0.5 mg D-1 and 0.2 mg D-2 dissolved in 10 mL butyl acetate on the second hole transport layer. Was used to form a thin film by spin coating under conditions of 600 rpm and 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and formed the light emitting layer with a layer thickness of about 70 nm.

  Next, a thin film was formed on the light emitting layer by spin coating under a condition of 1500 rpm and 30 seconds using a solution of 50 mg of ET-3 dissolved in 10 mL of hexafluoroisopropanol (HFIP). Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and the electron carrying layer with a layer thickness of about 20 nm was formed.

Subsequently, this substrate is fixed to a substrate holder of a vacuum deposition apparatus, and after the vacuum chamber is depressurized to 4 × 10 ⁻⁴ Pa, potassium fluoride is deposited on the electron transport layer and an electron injection having a layer thickness of 0.4 nm is performed. Then, aluminum was deposited on the electron injection layer to form a cathode having a thickness of 110 nm, and an organic EL element 3-1 was produced.
The compound used in this example has the following chemical structural formula.

<< Production of Organic EL Elements 3-2 to 3-8 >>
In the production of the organic EL element 3-1, organic EL elements 3-2 to 3-8 were respectively produced in the same manner except that the comparative compound 1 and Host-3 were changed to the compounds shown in Table 3.
Comparative compound 5 and Host-4 in Table 3 have the following chemical structural formulas.

  Comparative compound 5: Compound disclosed in JP2013-040159A

<< Evaluation of Organic EL Elements 3-1 to 3-8 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and a 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, driving voltage, voltage increase during driving, stability over time, and second wave ratio in the same manner as in Example 1. The evaluation results are shown in Table 3. In addition, the measurement result of the external extraction quantum efficiency in Table 3, a half life, a drive voltage, 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 3-1 to 100.

  As is apparent from Table 3, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL element using the compound having the structure represented by the general formula (1) is superior in luminous efficiency and luminous lifetime and has a low driving voltage as compared with the organic EL element of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 4]
<< Preparation of Organic EL Element 4-1 >>
Patterning was performed on a substrate (NA-45, manufactured by AvanStrate Co., Ltd.) on which a film of ITO (indium tin oxide) with a thickness of 100 nm was formed as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. 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 Al4083) to 70% by mass with pure water, spin After forming a thin film by the coating method, it was dried at 200 ° C. for 1 hour to form 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 form a second hole transport layer having a layer thickness of 40 nm.

  On this second hole transport layer, a thin film is formed by spin coating using Host-3 as a host compound and a butyl acetate solution of Comparative Compound 1 as a dopant, and dried by heating at 120 ° C. for 1 hour. A light emitting layer having a thickness of 30 nm was formed.

  On this light emitting layer, a 1-butanol solution of ET-4 as an electron transporting material was used, and a thin film was formed by a spin coating method to form an electron transporting layer having a layer thickness of 20 nm.

This substrate was attached to a vacuum deposition apparatus, and the vacuum chamber was decompressed to 4 × 10 ⁻⁴ Pa. Next, lithium fluoride is vapor-deposited on the electron transport layer to form an electron injection layer having a thickness of 1.0 nm, aluminum is vapor-deposited on the electron injection layer to form a cathode having a thickness of 110 nm, and the organic EL element 4 -1 was produced.
The compound used in this example has the following chemical structural formula.

<< Production of Organic EL Elements 4-2 to 4-10 >>
In the production of the organic EL element 4-1, each of the organic EL elements 4-2 to 4-10 was produced in the same manner except that the comparative compound 1 and Host-3 were changed to the compounds shown in Table 4.
Comparative compounds 6 and 7 in Table 4 have the following chemical structural formulas.

Comparative compound 6: Compound disclosed in Japanese Patent No. 5644050 Comparative compound 7: Compound disclosed in Japanese Patent No. 50990013

<< Evaluation of Organic EL Elements 4-1 to 4-10 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and a 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, driving voltage, voltage increase during driving, stability over time, and second wave ratio in the same manner as in Example 1. The evaluation results are shown in Table 4. In addition, the measurement results of the external extraction quantum efficiency, the half life, the driving voltage, and the voltage increase during driving in Table 4 are expressed as relative values with the measured value of the organic EL element 4-1 being 100.

  As is apparent from Table 4, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL element using the compound having the structure represented by the general formula (1) is superior in luminous efficiency and luminous lifetime and has a low driving voltage as compared with the organic EL element of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 5]
<< Production of Organic EL Element 5-1 >>
Patterning was performed on a substrate (NA-45, manufactured by AvanStrate Co., Ltd.) on which a film of ITO (indium tin oxide) with a thickness of 100 nm was formed as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. 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.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum vapor deposition apparatus, while 200 mg of HT-6 as a hole injection material is put into a molybdenum resistance heating boat, and HT- as a hole transport material is put into another molybdenum resistance heating boat. 200 mg, 5 mg of Host-5 as a host compound in another molybdenum resistance heating boat, 200 mg of Comparative Compound 1 as a dopant in another molybdenum resistance heating boat, and as a dopant in another molybdenum resistance heating boat as a dopant 200 mg of D-3 was put, 200 mg of D-4 as a dopant was put in another resistance heating boat made of molybdenum, 200 mg of ET-5 was put as an electron transport material in another resistance heating boat made of molybdenum, and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum tank to 4 × 10 ⁻⁴ Pa, the heating boat containing HT-6 was energized and heated, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / second. A hole injection layer was formed.

  Furthermore, it supplied with electricity to the heating boat containing HT-5, it heated, and it vapor-deposited on the positive hole injection layer with the vapor deposition rate of 0.1 nm / sec, and formed the 20-nm-thick hole transport layer.

  Furthermore, the heating boat containing Host-5, Comparative Compound 1, D-3 and D-4 was energized and heated, and the deposition rates were 0.1 nm / second, 0.025 nm / second, 0.0007 nm / second, Co-evaporation was performed on the hole transport layer at 0.0002 nm / second to form a light emitting layer having a layer thickness of 60 nm.

  Furthermore, it supplied with electricity to the heating boat containing ET-5, heated, and vapor-deposited on the light emitting layer with the vapor deposition rate of 0.1 nm / second, and the electron carrying layer with a layer thickness of 20 nm was formed.

Subsequently, potassium fluoride is deposited on the electron transport layer to form an electron injection layer having a thickness of 0.5 nm, and aluminum is further deposited on the electron injection layer to form a cathode having a thickness of 110 nm. Element 5-1 was produced.
The compound used in this example has the following chemical structural formula.

<< Production of organic EL elements 5-2 to 5-9 >>
In the production of the organic EL element 5-1, organic EL elements 5-2 to 5-9 were produced in the same manner except that the comparative compound 1 and Host-5 were changed to the compounds shown in Table 5.
Host-6 in Table 5 has the following chemical structural formula.

<< Evaluation of Organic EL Elements 5-1 to 5-9 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and a 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, driving voltage, voltage increase during driving, stability over time, and second wave ratio in the same manner as in Example 1. The evaluation results are shown in Table 5. In addition, the measurement result of the external extraction quantum efficiency in Table 5, a half life, a drive voltage, 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 5-1 to 100.

  As is apparent from Table 5, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL element using the compound having the structure represented by the general formula (1) is superior in luminous efficiency and luminous lifetime and has a low driving voltage as compared with the organic EL element of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 6]
<< Production of Organic EL Element 6-1 >>
An ITO (indium tin oxide) film having a thickness of 120 nm was formed as an anode on a glass substrate having a size of 50 mm × 50 mm and a thickness of 0.7 mm, followed by patterning. 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. The transparent substrate was then used as a substrate holder for a commercially available vacuum deposition apparatus. Fixed to.

  Each of the resistance heating boats in the vacuum deposition apparatus was filled with the constituent material of each layer in an amount optimal for device fabrication. The resistance heating boat used was made of a resistance heating material made of molybdenum or tungsten.

After depressurizing to a vacuum degree of 1 × 10 ⁻⁴ Pa, the heating boat containing the compound HT-1 was energized and heated, and deposited on the ITO transparent electrode at a deposition rate of 0.1 nm / second. A hole injection layer was formed.

  Subsequently, compound HT-2 was vapor-deposited on the hole injection layer in the same manner to form a hole transport layer having a layer thickness of 30 nm.

  Subsequently, Comparative Compound 1 and Host-5 were co-deposited on the hole transport layer at a deposition rate of 0.1 nm / second so as to be 90% by volume and 10% by volume, respectively, to form a light emitting layer having a layer thickness of 30 nm. .

  Subsequently, ET-1 was vapor-deposited on the light emitting layer at a vapor deposition rate of 0.1 nm / second to form a first electron transport layer having a layer thickness of 10 nm, and further ET-2 was vapor-deposited at a vapor deposition rate of 0.1 nm / second. The second electron transport layer having a layer thickness of 45 nm was formed.

  Further, lithium fluoride was deposited on the second electron transport layer to form an electron injection layer having a thickness of 1.0 nm, and then aluminum was deposited on the electron injection layer to form a cathode having a thickness of 100 nm.

  An electrode extraction wiring is installed on the above element, covered with a can-shaped glass case filled with epoxy resin in a nitrogen glove box of 1 ppm or less of water and oxygen atmosphere, a moisture absorbent is incorporated in the package, and an organic EL element 6-1 was produced.

<< Production of Organic EL Elements 6-2 to 6-9 >>
Organic EL elements 6-2 to 6-9 were prepared in the same manner except that Comparative Compound 1 and Host-5 were changed to the compounds shown in Table 6 in the preparation of Organic EL element 6-1.
Comparative compound 8 in Table 6 has the following chemical structural formula.

  Comparative compound 8: Compound disclosed in JP2013-040159A

<< Evaluation of Organic EL Elements 6-1 to 6-9 >>
When evaluating the obtained organic EL element, it was sealed in the same manner as the organic EL elements 1-1 to 1-10 of Example 1, and a 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, driving voltage, voltage increase during driving, stability over time, and second wave ratio in the same manner as in Example 1. The evaluation results are shown in Table 6. In addition, the measurement results of the external extraction quantum efficiency, the half life, the driving voltage, and the voltage increase during driving in Table 6 are expressed as relative values with the measured value of the organic EL element 6-1 being 100.

  As is apparent from Table 6, it was found that when the compound having the structure represented by the general formula (1) according to the present invention was used, the second wave ratio was significantly small. Furthermore, it is clear that the organic EL element using the compound having the structure represented by the general formula (1) is superior in luminous efficiency and luminous lifetime and has a low driving voltage as compared with the organic EL element of the comparative example. It was also found that the voltage rise during driving was suppressed and the stability over time was excellent.

[Example 7]
<< Production of organic EL full-color display device >>
In this example, as shown in FIGS. 7A to 7E, an organic EL full-color display device was produced and evaluated. 7A to 7E are schematic configuration diagrams of the organic EL full-color display device.

  On the glass substrate 201, after patterning at a pitch of 100 μm (see FIG. 7A) on a substrate (NA 45 manufactured by NH Techno Glass Co., Ltd.) having a 100 nm ITO transparent electrode 202 formed as an anode on the glass substrate 201, 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 formed by a drying process for 10 minutes (see FIG. 7C).

(Hole injection layer composition)
HT-3: 20 parts by mass Cyclohexylbenzene: 50 parts by mass Isopropyl biphenyl: 50 parts by mass

  A blue light-emitting layer composition, a green light-emitting layer composition, and a red light-emitting layer composition having the following compositions are respectively ejected and injected onto the hole injection layer 204 using an inkjet head in the same manner, at 60 ° C. for 10 minutes. Drying treatment was performed to form light emitting layers 205B, 205G, and 205R for each color (see FIG. 7D).

(Blue light emitting layer composition)
Host-2: 0.7 parts by weight Exemplary compound 5-3: 0.04 parts by weight Cyclohexylbenzene: 50 parts by weight Isopropyl biphenyl: 50 parts by weight

(Green light emitting layer composition)
Host-1: 0.7 parts by mass D-3: 0.04 parts by mass Cyclohexylbenzene: 50 parts by mass Isopropylbiphenyl: 50 parts by mass

(Red light emitting layer composition)
Host-1: 0.7 parts by mass D-2: 0.04 parts by mass Cyclohexylbenzene: 50 parts by mass Isopropylbiphenyl: 50 parts by mass

  Next, an electron transport material is deposited so as to cover each of the light emitting layers 205B, 205G, and 205R to form an electron transport layer (not shown) having a layer thickness of 20 nm, and further lithium fluoride is deposited to form a layer thickness of 0.6 nm. An electron injection layer (not shown) was formed, and Al was vapor-deposited to form a cathode 206 having a thickness of 130 nm 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.

As described above, when the compound having the structure represented by the general formula (1) according to the present invention is used, it is possible to obtain light emission with a significantly small second wave ratio. Furthermore, according to the present invention, there are provided an organic electroluminescence element, an illuminating device and a display device having high luminous efficiency, low driving voltage, long life, small increase in driving voltage, and excellent stability over time. be able to.
Moreover, the organic EL element which has the said effect can be manufactured with a wet process.

  As described above, the present invention has a small light emission ratio of components longer than the light emission maximum wavelength, high light emission efficiency, low drive voltage, long light emission life, small voltage increase during driving, and stability over time. It is suitable for providing an excellent organic electroluminescence element, a method for producing the element, a display device and a lighting device including the element, and an organic electroluminescence element material used for the element.

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 part B Control part C Wiring part

Claims (12)

An organic electroluminescent device comprising an organic layer sandwiched between at least one pair of an anode and a cathode,
The organic layer is composed of at least one layer including a light emitting layer, and at least one of the organic layers contains a compound having a structure represented by the following general formula (1).

(In general formula (1), R is an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group, and a mercapto group. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. , Alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxy Carbonyl, sulfamoyl, ureido, acyl, acyloxy, amide, cal Moyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group, arylsilyl group, alkylphosphino group, arylphosphino group, alkylphosphoryl group Represents any group selected from an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
However, at least two of adjacent R _{1 to} R ₄ are condensed to represent any one of the following general formulas (2) to (4). )

(In General Formulas (2) to (4), Y _{1 to} Y ₄ each independently represents O, S, or N—R ′, and Y ₅ or Y ₆ represents CR ″ or N. R 'Represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R''represents a hydrogen atom, an alkyl group, a cycloalkyl group, Z _{1 to} Z ₈ represent any group selected from an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group, and an arylphosphoryl group. Independently, it represents C-Rx or N, and the plurality of Rx may be the same or different, and each of the plurality of Rx independently represents R _{1 to} R ₄ in the general formula (1). Represents an equivalent group, and * represents a bonding position with the structure represented by the general formula (1). 2. The organic electroluminescent element according to claim 1, wherein the structure represented by the general formula (1) is a structure represented by any one of the following general formulas (5) to (10).

(In the general formulas (5) to (10), R, Ar, R _{1 to} R ₄ , Y ₁ , Z _{1 to} Z ₄ , X ₁ , X ₂ , L ₁ , m and n are the same as those in the general formula (1). ) And (2) are the same as R, Ar, R _{1 to} R ₄ , Y ₁ , Z _{1 to} Z ₄ , X ₁ , X ₂ , L ₁ , m and n.) 2. The organic according to claim 1, wherein in the general formula (1), at least two of adjacent R _{1 to} R ₄ are condensed to represent the structure of the general formula (3) or (4). Electroluminescence element.   In the said General formula (1), R represents an alkyl group or a cyano group, The organic electroluminescent element as described in any one of Claim 1- Claim 3 characterized by the above-mentioned.   In the said General formula (1), Ar represents the aromatic hydrocarbon group or aromatic heterocyclic group which has a substituent in 2-position, It is any one of Claim 1 to 4 characterized by the above-mentioned. The organic electroluminescent element of description.   In the said General formula (1), n represents 0, The organic electroluminescent element as described in any one of Claim 1- Claim 5 characterized by the above-mentioned.   The said light emitting layer contains the compound which has a structure represented by the said General formula (1), The organic electroluminescent element as described in any one of Claim 1- Claim 6 characterized by the above-mentioned.   The organic light-emitting device according to claim 7, wherein the light-emitting layer contains at least two of the compound represented by the general formula (1) and a compound having a HOMO level of -5.4 eV or less. . It is a manufacturing method of the organic electroluminescent element which manufactures the organic electroluminescent element as described in any one of Claim 1- Claim 8,
The organic electroluminescent element manufacturing method characterized by forming the layer containing the compound which has a structure represented by the said General formula (1) among the said organic layers with a wet process.   A display device comprising the organic electroluminescence element according to claim 1.   An illuminating device comprising the organic electroluminescence element according to any one of claims 1 to 8. An organic electroluminescence device material comprising a compound having a structure represented by the following general formula (1).

(In general formula (1), R is an alkyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a sulfinyl group, a sulfonyl group, a nitro group, a cyano group, a hydroxy group, and a mercapto group. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R _{1 to} R ₄ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an alkenyl group. , Alkynyl group, aromatic hydrocarbon group, heterocyclic group, aromatic heterocyclic group, halogen atom, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxy Carbonyl, sulfamoyl, ureido, acyl, acyloxy, amide, cal Moyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, nitro group, cyano group, hydroxy group, mercapto group, alkylsilyl group, arylsilyl group, alkylphosphino group, arylphosphino group, alkylphosphoryl group Represents any group selected from an arylphosphoryl group, an alkylthiophosphoryl group, and an arylthiophosphoryl group.
X ₁ -L ₁ -X ₂ represents a bidentate ligand, and X ₁ and X ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X ₂ . m represents an integer of 1 to 3, n represents an integer of 0 to 2, and m + n is 3.
However, at least two of adjacent R _{1 to} R ₄ are condensed to represent any one of the following general formulas (2) to (4). )

(In General Formulas (2) to (4), Y _{1 to} Y ₄ each independently represents O, S, or N—R ′, and Y ₅ or Y ₆ represents CR ″ or N. R 'Represents any group selected from an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group, a heterocyclic group and an aromatic heterocyclic group, and R''represents a hydrogen atom, an alkyl group, a cycloalkyl group, Z _{1 to} Z ₈ represent any group selected from an aromatic hydrocarbon group, a heterocyclic group, an aromatic heterocyclic group, a halogen atom, an amino group, a cyano group, an arylsilyl group, and an arylphosphoryl group. Independently, it represents C-Rx or N, and the plurality of Rx may be the same or different, and each of the plurality of Rx independently represents R _{1 to} R ₄ in the general formula (1). Represents an equivalent group, and * represents a bonding position with the structure represented by the general formula (1).

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