WO2014057659A1 - Compound, and organic electroluminescent element produced using same - Google Patents

Abstract

A compound represented by formula (1).

Description

Compound and organic electroluminescence device using the same

The present invention relates to a novel compound, an organic electroluminescence element material using the compound, and an organic electroluminescence element.

Organic electroluminescence (EL) elements include a fluorescent type and a phosphorescent type, and an optimum element design has been studied according to each light emission mechanism. With respect to phosphorescent organic EL elements, it is known from their light emission characteristics that high-performance elements cannot be obtained by simple diversion of fluorescent element technology. The reason is generally considered as follows.
First, since phosphorescence emission is emission using triplet excitons, the energy gap of the compound used in the light emitting layer must be large. This is because the value of the energy gap (hereinafter also referred to as singlet energy) of a compound usually refers to the triplet energy of the compound (in the present invention, the energy difference between the lowest excited triplet state and the ground state). This is because it is larger than the value of).

Therefore, in order to efficiently confine the triplet energy of the phosphorescent dopant material in the light emitting layer, a host material having a triplet energy larger than the triplet energy of the phosphorescent dopant material must first be used for the light emitting layer. I must. Furthermore, an electron transport layer and a hole transport layer adjacent to the light emitting layer are provided, and a compound having a triplet energy higher than that of the phosphorescent dopant material must be used for the electron transport layer and the hole transport layer.
Thus, when based on the element design concept of the conventional organic EL element, a compound having a larger energy gap than the compound used for the fluorescent organic EL element is used for the phosphorescent organic EL element. The drive voltage of the entire element increases.

In addition, hydrocarbon compounds having high oxidation resistance and reduction resistance useful for fluorescent elements have a large energy gap due to the large spread of π electron clouds. Therefore, in a phosphorescent organic EL element, it is difficult to select such a hydrocarbon compound, and an organic compound containing a heteroatom such as oxygen or nitrogen is selected. As a result, the phosphorescent organic EL element is There is a problem that the lifetime is shorter than that of a fluorescent organic EL element.

Furthermore, the fact that the exciton relaxation rate of the triplet exciton of the phosphorescent dopant material is much longer than that of the singlet exciton also greatly affects the device performance. That is, since light emitted from singlet excitons has a high relaxation rate that leads to light emission, the diffusion of excitons to the peripheral layers of the light-emitting layer (for example, a hole transport layer or an electron transport layer) hardly occurs and is efficient. Light emission is expected. On the other hand, light emission from triplet excitons is spin-forbidden and has a slow relaxation rate, so that excitons are likely to diffuse into the peripheral layer, and thermal energy deactivation occurs from other than specific phosphorescent compounds. End up. That is, control of the recombination region of electrons and holes is more important than the fluorescent organic EL element.

For the above reasons, in order to improve the performance of phosphorescent organic EL elements, material selection and element design different from those of fluorescent organic EL elements are required.
In particular, in the case of a phosphorescent organic EL element that emits blue light, it is necessary to use a compound having a large triplet energy in the light emitting layer and its peripheral layer as compared with a phosphorescent organic EL element that emits green to red light. Specifically, in order to obtain blue phosphorescence without loss of efficiency, the triplet energy of the host material used for the light-emitting layer needs to be approximately 3.0 eV or more. In order to obtain a compound satisfying the performance required as an organic EL material while having such a high triplet energy, not simply combining molecular parts having a high triplet energy such as a heterocyclic compound, Molecular design based on a new concept that considers the electronic state of π electrons is required.

Under such circumstances, as materials for phosphorescent organic EL elements, for example, Patent Documents 1 to 3 disclose materials having an arylamine structure containing a carbazole skeleton.

European Patent Application Publication No. 2450975 JP 2012-28548 A International Publication No. 2012/011756

As a result of diligent research, the present inventors have found that materials having an arylamine structure are generally poor in durability against electrons.
In particular, in the case of a phosphorescent device, the injection level of holes and electrons into the light emitting layer has a high LUMO level and a low HOMO level because the S1 energy level of the light emitting layer is higher than that of the fluorescent device. Therefore, since electrons or holes once injected into the light emitting layer are likely to reach the hole transport layer and the electron transport layer around the light emitting layer, the hole transport layer and the electrons adjacent to the light emitting layer The materials used for the transport layer need to be durable against electrons and holes, respectively.
An object of the present invention is to provide a novel material having electron resistance and excellent hole injection and hole transport performance to a light emitting layer, and an organic EL device having a long lifetime and high light emission efficiency.

According to the present invention, the following compounds and the like are provided.
1. A compound represented by the following formula (1).

[In Formula (1),
Ar is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted arylcarbazolyl group, a substituted or unsubstituted aryldibenzofuranyl group, a substituted or unsubstituted aryldibenzothiophenyl A group selected from the group consisting of a group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted dibenzothiophenyl group.
R ₁ to R ₁₄ each independently represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon; An alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkoxy group having 1 to 20 carbon atoms, a cyano group, and a substituted or unsubstituted arylcarbazolyl group; Substituted or unsubstituted aryl dibenzofuranyl group, substituted or unsubstituted aryl dibenzothiophenyl group, substituted or unsubstituted carbazolyl group, substituted or unsubstituted dibenzofuranyl group, substituted or unsubstituted dibenzothiophenyl group Substituted or unsubstituted alkylsilyl group, substituted or unsubstituted arylsilyl group, substituted or unsubstituted Conversion aralkyl silyl group, a substituted or unsubstituted alkyl germanium group, a substituted or unsubstituted aryl germanium group, and a substituted or unsubstituted group selected from the group consisting of aralkyl germanium group.
X represents an oxygen atom or a sulfur atom. ]
2. R ₁ to R ₁₄ each independently represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon; An alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkoxy group having 1 to 20 carbon atoms, a cyano group, and a substituted or unsubstituted arylcarbazolyl group; Substituted or unsubstituted aryl dibenzofuranyl group, substituted or unsubstituted aryl dibenzothiophenyl group, substituted or unsubstituted carbazolyl group, substituted or unsubstituted dibenzofuranyl group, and substituted or unsubstituted dibenzothiophenyl 2. The compound according to 1, which represents a group selected from the group consisting of groups.
3. The compound of 1 or 2 represented by following formula (2), (3) or (4).

[In the formulas (2) to (4), Ar, R ₁ to R ₁₄ and X are the same as those in the formula (1). ]
4). The compound according to any one of 1 to 3 represented by the following formula (5), (6) or (7):

[In the formulas (5) to (7), Ar, R ₁ , R ₂ , R ₆ , R ₇ , R ₉ to R ₁₁ and X are the same as those in the formula (1). ]
5. In the above formulas (5) to (7), Ar represents an unsubstituted aryl group having 6 to 30 ring carbon atoms, an unsubstituted arylcarbazolyl group, an unsubstituted aryldibenzofuranyl group, or an unsubstituted aryldibenzo. 5. The compound according to 4, which represents a group selected from the group consisting of a thiophenyl group, an unsubstituted carbazolyl group, an unsubstituted dibenzofuranyl group, and an unsubstituted dibenzothiophenyl group.
6). Ar is an unsubstituted phenyl group, an unsubstituted biphenylyl group, an unsubstituted phenylcarbazolyl group, an unsubstituted phenyldibenzofuranyl group, an unsubstituted phenyldibenzothiophenyl group, an unsubstituted carbazolyl group, an unsubstituted group 6. The compound according to 5, which represents a group selected from the group consisting of a dibenzofuranyl group and an unsubstituted dibenzothiophenyl group.
7.1 A material for an organic electroluminescence device comprising the compound according to any one of 1 to 6.
8). 8. An organic electroluminescence device comprising one or more organic thin film layers including a light emitting layer between a cathode and an anode, wherein at least one of the organic thin film layers comprises the material for an organic electroluminescence device according to 7.
9. 9. The organic electroluminescence device according to 8, wherein the light emitting layer contains the material for an organic electroluminescence device.
10. The organic thin film layer includes one or more light emitting layers,
10. The organic electroluminescence device according to 8 or 9, wherein at least one layer of the light emitting layer contains the material for an organic electroluminescence device according to 7, and a phosphorescent material.
11. 11. The organic electroluminescence device according to 10, wherein the triplet energy of the phosphorescent material is 1.8 eV or more and less than 2.9 eV.
12 The phosphorescent material contains a metal complex compound;
The organic electroluminescence device according to 10 or 11, wherein the metal complex compound has a metal atom and a ligand selected from the group consisting of Ir, Pt, Os, Au, Cu, Re, and Ru.
13. 13. The organic electroluminescence device according to 12, wherein the ligand has an ortho metal bond with the metal atom.
14 14. The organic electroluminescence device according to any one of 8 to 13, wherein the maximum value of the emission wavelength is 430 nm or more and 720 nm or less.
15. The organic electroluminescence device according to claim 7, wherein the organic EL device has a hole transport zone between the light emitting layer and the anode, the hole transport zone has one or more organic thin film layers, and at least one of the organic thin film layers has 7. 15. The organic electroluminescence device according to any one of 8 to 14, comprising a material.
16. 16. The organic electroluminescence device according to 15, wherein the hole transport zone is adjacent to the light emitting layer.

According to the present invention, it is possible to provide a novel material having electron resistance and excellent hole transport ability, and an organic EL element having a long lifetime and high luminous efficiency.

It is the schematic which shows one Embodiment of the organic EL element of this invention.

The compound of the present invention is represented by the following formula (1).

The compound of the present invention eliminates an arylamine structure having poor electron resistance from the structure, thereby providing an organic EL device with electron resistance that can be used as a hole transport material as an electron blocking (blocking) layer and a host material in a light emitting layer. Can be granted.
In addition, the compound of the present invention can provide an organic EL device having a high excited triplet energy level, a long lifetime, and high luminous efficiency.

In the above formula (1), Ar represents a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted arylcarbazolyl group, a substituted or unsubstituted aryldibenzofuranyl group, substituted or unsubstituted It represents a group selected from the group consisting of an unsubstituted aryl dibenzothiophenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted dibenzothiophenyl group.

R ₁ to R ₁₄ each independently represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon; An alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkoxy group having 1 to 20 carbon atoms, a cyano group, and a substituted or unsubstituted arylcarbazolyl group; Substituted or unsubstituted aryl dibenzofuranyl group, substituted or unsubstituted aryl dibenzothiophenyl group, substituted or unsubstituted carbazolyl group, substituted or unsubstituted dibenzofuranyl group, substituted or unsubstituted dibenzothiophenyl group Substituted or unsubstituted alkylsilyl group, substituted or unsubstituted arylsilyl group, substituted or unsubstituted Conversion aralkyl silyl group, a substituted or unsubstituted alkyl germanium group, a substituted or unsubstituted aryl germanium group, and a substituted or unsubstituted group selected from the group consisting of aralkyl germanium group.

In the formula (1), R ₁ to R ₁₄ are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, Substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, substituted or unsubstituted haloalkoxy group having 1 to 20 carbon atoms, cyano group, substituted or unsubstituted Arylcarbazolyl group, substituted or unsubstituted aryldibenzofuranyl group, substituted or unsubstituted aryldibenzothiophenyl group, substituted or unsubstituted carbazolyl group, substituted or unsubstituted dibenzofuranyl group, and substituted or unsubstituted It may be a group selected from the group consisting of unsubstituted dibenzothiophenyl groups.

X represents an oxygen atom or a sulfur atom.
In the present invention, “unsubstituted” in “substituted or unsubstituted...” Means that a hydrogen atom is bonded, and “ring-forming carbon” means a saturated ring, an unsaturated ring, or A carbon atom constituting an aromatic ring means “ring-forming atom” means an atom constituting a saturated ring, an unsaturated ring, or an aromatic ring.
In the present invention, the hydrogen atom includes isotopes having different numbers of neutrons, that is, light hydrogen (protium), deuterium (deuterium), and tritium (tritium).

Of the compounds of the above formula (1), compounds represented by the following formula (2), (3) or (4) are preferred.

In the above formulas (2) to (4), Ar, R ₁ to R ₁₄ and X are the same as those in the formula (1).

Of the compounds of the above formula (1), compounds represented by the following formula (5), (6) or (7) are more preferred.

[In the formulas (5) to (7), Ar, R ₁ , R ₂ , R ₆ , R ₇ , R ₉ to R ₁₁ and X are the same as those in the formula (1). ]

In the formulas (5) to (7), Ar represents an unsubstituted aryl group having 6 to 30 ring carbon atoms, an unsubstituted arylcarbazolyl group, an unsubstituted aryldibenzofuranyl group, an unsubstituted aryldibenzothio group. A group selected from the group consisting of a phenyl group, an unsubstituted carbazolyl group, an unsubstituted dibenzofuranyl group, and an unsubstituted dibenzothiophenyl group is preferable.

In the formulas (5) to (7), Ar represents an unsubstituted phenyl group, an unsubstituted biphenylyl group, an unsubstituted phenylcarbazolyl group, an unsubstituted phenyldibenzofuranyl group, an unsubstituted phenyldibenzothio group. A group selected from the group consisting of a phenyl group, an unsubstituted carbazolyl group, an unsubstituted dibenzofuranyl group, and an unsubstituted dibenzothiophenyl group is preferable.

Hereinafter, examples of the groups of the above formulas (1) to (7) will be described.
Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n -Hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n -Hexadecyl group, n-heptadecyl group, n-octadecyl group, neopentyl group, 1-methylpentyl group, 2-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl group, 1-heptyloctyl group, 3-methyl Examples thereof include a pentyl group, and among these, those having 1 to 6 carbon atoms are preferred.

Examples of the alkoxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group and the like, and those having 3 or more carbon atoms are linear, cyclic or branched Among them, those having 1 to 6 carbon atoms are preferable.

Examples of the haloalkyl group having 1 to 20 carbon atoms include groups in which one or more halogen atoms are substituted on the above alkyl group having 1 to 20 carbon atoms. Specific examples include a trifluoromethyl group and a pentafluoromethyl group. Etc. are preferred.

Examples of the haloalkoxy group having 1 to 20 carbon atoms include groups in which one or more halogen atoms are substituted on the above-described alkoxy group having 1 to 20 carbon atoms. Specific examples include trifluoromethoxy groups, pentafluoroethoxy groups. Groups and the like are preferred.

Specific examples of the aryl group having 6 to 30 ring carbon atoms include phenyl group, tolyl group, xylyl group, mesityl group, o-biphenylyl group, m-biphenylyl group, p-biphenylyl group, o-terphenylyl group, m- Examples thereof include a terphenylyl group, a p-terphenylyl group, a naphthyl group, a phenanthryl group, and a triphenylene group. Of these, phenyl, m-biphenylyl and m-terphenylyl are preferred.

The arylcarbazolyl group is a group in which the carbazolyl group is substituted with an aryl group (for example, the above aryl group having 6 to 30 ring carbon atoms). For example, a phenyl carbazolyl group, a diphenyl carbazolyl group, etc. are mentioned.
The aryl dibenzofuranyl group is a group in which the dibenzofuranyl group is substituted with an aryl group (for example, the above aryl group having 6 to 30 ring carbon atoms). Examples thereof include a phenyl dibenzofuranyl group and a diphenyl dibenzofuranyl group.
The aryl dibenzothiophenyl group is a group in which a dibenzothiophenyl group is substituted with an aryl group (for example, the above aryl group having 6 to 30 ring carbon atoms). For example, a phenyl dibenzothiophenyl group, a diphenyl dibenzothiophenyl group, etc. are mentioned.

The alkylsilyl group is a group in which the silyl group is substituted with an alkyl group (for example, the above alkyl group having 1 to 20 carbon atoms). For example, a trimethylsilyl group, a triethylsilyl group, t-butyldimethylsilyl and the like can be mentioned.

The arylsilyl group is a group in which the silyl group is substituted with an aryl group (for example, the above aryl group having 6 to 30 ring carbon atoms). For example, a triphenylsilyl group etc. are mentioned.

The aralkylsilyl group is a group in which a silyl group is substituted with an alkyl group (for example, the above alkyl group having 1 to 20 carbon atoms) and an aryl group (for example, the above aryl group having 6 to 30 ring carbon atoms). Examples thereof include t-butyldiphenylsilyl group, diphenylmethylsilyl group, diphenylethylsilyl group and the like.

The alkylgermanium group is a group in which the germanium group is substituted with an alkyl group (for example, the above alkyl group having 1 to 20 carbon atoms). For example, a trimethyl germanium group, a triethyl germanium group, etc. are mentioned.

The aryl germanium group is a group in which a germanium group is substituted with an aryl group (for example, the above-mentioned aryl group having 6 to 30 ring carbon atoms). For example, a triphenyl germanium group etc. are mentioned.

The aralkyl germanium group is a group in which a germanium group is substituted with an alkyl group (for example, the above alkyl group having 1 to 20 carbon atoms) and an aryl group (for example, the above aryl group having 6 to 30 ring carbon atoms). For example, t-butyldiphenylgermanium group, diphenylmethylgermanium group, diphenylethylgermanium group and the like can be mentioned.

In the compounds represented by the above formulas, as the substituents of “substituted or unsubstituted...” Of each group, the above alkyl group, aryl group, heteroaryl group (for example, carbazolyl group, dibenzofuranyl group) , Dibenzothiophenyl groups, etc.), alkoxy groups, fluoroalkyl groups, alkylsilyl groups, arylsilyl groups, aralkylsilyl groups, alkylgermanium groups, arylgermanium groups, aralkylgermanium groups, and other halogen atoms (fluorine, chlorine, bromine) Iodine, and preferably a fluorine atom.), Hydroxyl group, nitro group, cyano group, carboxy group, aryloxy group, aralkyl group, fluoroalkoxy group, diarylphosphino group, diarylphosphine oxide group, diarylphosphine group Examples include finoaryl groups. Properly is a substituent described as the _R 1 _{~ R 14.}

Examples of the substituted aryl group include an aryl group substituted with a carbazolyl group, an aryl group substituted with a dibenzothiophenyl group, and an aryl group substituted with a dibenzofuranyl group. A carbazolylphenyl group, a dibenzothiophenylphenyl group, a dibenzofuranylphenyl group and the like are preferable.
Examples of the substituted carbazolyl group include a methyl carbazolyl group, a dimethyl carbazolyl group, a carbazolyl carbazolyl group, and the like.
Examples of the substituted dibenzofuranyl group include a cyanodibenzofuranyl group and a carbazolyl dibenzofuranyl group.
Examples of the substituted dibenzothiophenyl group include a cyanodibenzothiophenyl group and a carbazolyl dibenzothiophenyl group.

Specific examples of the compound represented by the above formula (1) are shown below.

The compounds of the present invention can be synthesized by the methods described in the synthesis examples of the examples.

The material for an organic EL device of the present invention (hereinafter sometimes referred to as “the material of the present invention”) includes the compound of the present invention.
By using the organic EL device material of the present invention, the obtained organic EL device has a long life.
The material for an organic EL device of the present invention is particularly suitable as a material for an organic thin film layer constituting the organic EL device, specifically as a host material and a hole transport material for a light emitting layer of the organic EL device. In particular, when applied to a hole transport layer adjacent to the light emitting layer, high luminous efficiency can be maintained even in a high current density region.

Next, the organic EL element of the present invention will be described.
The organic EL device of the present invention has one or more organic thin film layers including a light emitting layer between an anode and a cathode. At least one of the organic thin film layers contains the material of the present invention. Thereby, the lifetime of an organic EL element can be lengthened.

Examples of the organic thin film layer containing the material of the present invention include, but are not limited to, a hole transport layer, a light emitting layer, an electron transport layer, a space layer, and a barrier layer. The material of the present invention is preferably contained in the light emitting layer, and particularly preferably used as a host material for the light emitting layer. Further, the light emitting layer preferably contains a fluorescent light emitting material or a phosphorescent light emitting material, and particularly preferably contains a phosphorescent light emitting material.

Moreover, in the organic EL element of this invention, it has an organic thin film layer in the positive hole transport zone between a cathode and a light emitting layer, and at least 1 layer of this organic thin film layer contains the organic EL element material of this invention. It is preferable (hereinafter, an organic thin film layer which is in the hole transport zone and contains the organic EL device material of the present invention is referred to as an organic thin film layer A). Examples of the organic thin film layer A include an electron injection layer, an electron transport layer, and a hole blocking layer. The organic thin film layer A and the light emitting layer are preferably adjacent to each other.

The organic EL element of the present invention may be a fluorescent or phosphorescent monochromatic light emitting element, a fluorescent / phosphorescent hybrid white light emitting element, or a simple type having a single light emitting unit. A tandem type having a plurality of light emitting units may be used, and among them, a phosphorescent type is preferable. Here, the “light emitting unit” refers to a minimum unit that includes one or more organic layers, one of which is a light emitting layer, and can emit light by recombination of injected holes and electrons.

Accordingly, typical element configurations of simple organic EL elements include the following element configurations.
(1) Anode / light emitting unit / cathode The above light emitting unit may be a laminated type having a plurality of phosphorescent light emitting layers and fluorescent light emitting layers. In that case, the light emitting unit is generated by a phosphorescent light emitting layer between the light emitting layers. In order to prevent the excitons from diffusing into the fluorescent light emitting layer, a space layer may be provided. A typical layer structure of the light emitting unit is shown below.
(A) Hole transport layer / light emitting layer (/ electron transport layer)
(B) Hole transport layer / first phosphorescent light emitting layer / second phosphorescent light emitting layer (/ electron transport layer)
(C) Hole transport layer / phosphorescent layer / space layer / fluorescent layer (/ electron transport layer)
(D) Hole transport layer / first phosphorescent light emitting layer / second phosphorescent light emitting layer / space layer / fluorescent light emitting layer (/ electron transport layer)
(E) Hole transport layer / first phosphorescent light emitting layer / space layer / second phosphorescent light emitting layer / space layer / fluorescent light emitting layer (/ electron transport layer)
(F) Hole transport layer / phosphorescent layer / space layer / first fluorescent layer / second fluorescent layer (/ electron transport layer)
(G) Hole transport layer / electron barrier layer / light emitting layer (/ electron transport layer)
(H) Hole transport layer / light emitting layer / hole barrier layer (/ electron transport layer)
(I) Hole transport layer / fluorescent light emitting layer / triplet barrier layer (/ electron transport layer)

Each phosphorescent or fluorescent light-emitting layer may have a different emission color. Specifically, in the laminated light emitting layer (d), hole transport layer / first phosphorescent light emitting layer (red light emitting) / second phosphorescent light emitting layer (green light emitting) / space layer / fluorescent light emitting layer (blue light emitting) / Examples include a layer configuration such as an electron transport layer.
An electron barrier layer may be appropriately provided between each light emitting layer and the hole transport layer or space layer. Further, a hole blocking layer may be appropriately provided between each light emitting layer and the electron transport layer. By providing an electron barrier layer or a hole barrier layer, electrons or holes can be confined in the light emitting layer, the recombination probability of charges in the light emitting layer can be increased, and the lifetime can be improved.

The following element structure can be mentioned as a typical element structure of a tandem type organic EL element.
(2) Anode / first light emitting unit / intermediate layer / second light emitting unit / cathode Here, as the first light emitting unit and the second light emitting unit, for example, the same light emitting unit as that described above is selected independently. can do.
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 has electrons in the first light emitting unit and holes in the second light emitting unit. A known material structure to be supplied can be used.

FIG. 1 is a schematic view showing a layer structure of an embodiment of the organic EL device of the present invention.
The organic EL element 1 has a configuration in which an anode 20, a hole transport zone 30, a light emitting layer 40, an electron transport zone 50, and a cathode 60 are laminated on a substrate 10 in this order. The hole transport zone 30 refers to a layer sandwiched between the anode 20 and the light emitting layer 40 and means, for example, a hole transport layer, a hole injection layer, an electron barrier layer, or the like. Similarly, the electron transport zone 50 refers to a layer sandwiched between the cathode 60 and the light emitting layer 40 and means, for example, an electron transport layer, an electron injection layer, a hole barrier layer, or the like. The barrier layer can confine electrons and holes in the light emitting layer 40 and increase the probability of exciton generation in the light emitting layer 40. These need not be formed, but are preferably formed in one or more layers. In this element, the organic thin film layer is each organic layer provided in the hole transport zone 30, each light emitting layer 40, and each organic layer provided in the electron transport zone 50. Among these organic thin film layers, at least one layer contains the organic EL element material of the present invention. The content of this material with respect to one organic thin film layer containing the organic EL device material of the present invention is preferably 1 to 100% by weight.

In this specification, a host combined with a fluorescent dopant is referred to as a fluorescent host, and a host combined with a phosphorescent dopant is referred to as a phosphorescent host. The fluorescent host and the phosphorescent host are not distinguished only by the molecular structure. That is, the phosphorescent host means a material constituting a phosphorescent light emitting layer containing a phosphorescent dopant, and does not mean that it cannot be used as a material constituting a fluorescent light emitting layer. The same applies to the fluorescent host.

In the organic EL element of the present invention, the configuration other than the layer using the organic EL element material of the present invention described above is not particularly limited, and a known material or the like can be used. Hereinafter, although the structural member of an organic EL element is demonstrated easily, the material applied to the organic EL element of this invention is not limited to the following.

(substrate)
The organic EL element of the present invention is produced on a translucent substrate. The light-transmitting substrate is a substrate that supports the organic EL element, and is preferably a smooth substrate having a light transmittance in the visible region of 400 nm to 700 nm of 50% or more. Specifically, a glass plate, a polymer plate, etc. are mentioned. Examples of the glass plate include those using soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz and the like as raw materials. Examples of the polymer plate include those using polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like as raw materials.

(anode)
The anode of the organic EL element plays a role of injecting holes into the hole transport layer or the light emitting layer, and it is effective to use a material having a work function of 4.5 eV or more. Specific examples of the anode material include indium tin oxide alloy (ITO), tin oxide (NESA), indium zinc oxide, gold, silver, platinum, copper, and the like. The anode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. When light emitted from the light emitting layer is extracted from the anode, it is preferable that the transmittance of light in the visible region of the anode is greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. The film thickness of the anode depends on the material, but is usually selected in the range of 10 nm to 1 μm, preferably 10 nm to 200 nm.

(cathode)
The cathode plays a role of injecting electrons into the electron injection layer, the electron transport layer or the light emitting layer, and is preferably formed of a material having a small work function. The cathode material is not particularly limited, and specifically, indium, aluminum, magnesium, magnesium-indium alloy, magnesium-aluminum alloy, aluminum-lithium alloy, aluminum-scandium-lithium alloy, magnesium-silver alloy and the like can be used. Similarly to the anode, the cathode can be produced by forming a thin film by a method such as vapor deposition or sputtering. Moreover, you may take out light emission from the cathode side as needed.

(Light emitting layer)
An organic layer having a light emitting function, and when a doping system is employed, includes a host material and a dopant material. At this time, the host material mainly has a function of encouraging recombination of electrons and holes and confining excitons in the light emitting layer, and the dopant material efficiently emits excitons obtained by recombination. It has a function.
In the case of a phosphorescent element, the host material mainly has a function of confining excitons generated by the dopant in the light emitting layer.

Here, the light emitting layer employs, for example, a double host (also referred to as host / cohost) that adjusts the carrier balance in the light emitting layer by combining an electron transporting host and a hole transporting host. The light emitting layer preferably contains a first host material and a second host material, and the first host material is preferably the organic EL device material of the present invention.
Moreover, you may employ | adopt the double dopant from which each dopant light-emits by putting in 2 or more types of dopant materials with a high quantum yield. Specifically, a mode in which yellow emission is realized by co-evaporating a host, a red dopant, and a green dopant to make the light emitting layer common is used.

The above light-emitting layer is a laminate in which a plurality of light-emitting layers are stacked, so that electrons and holes are accumulated at the light-emitting layer interface, and the recombination region is concentrated at the light-emitting layer interface to improve quantum efficiency. Can do.
The ease of injecting holes into the light emitting layer may be different from the ease of injecting electrons, and the hole transport ability and electron transport ability expressed by the mobility of holes and electrons in the light emitting layer may be different. May be different.

The light emitting layer can be formed by a known method such as a vapor deposition method, a spin coating method, or an LB method (Langmuir Broadgett method). The light emitting layer can also be formed by thinning a solution obtained by dissolving a binder such as a resin and a material compound in a solvent by a spin coating method or the like.
The light emitting layer is preferably a molecular deposited film. The molecular deposited film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidifying from a material compound in a solution state or a liquid phase state. The thin film (molecular accumulation film) formed by the LB method can be classified by the difference in the aggregation structure and the higher-order structure, and the functional difference resulting therefrom.

The dopant material is selected from known fluorescent dopants exhibiting fluorescent emission or phosphorescent dopants exhibiting phosphorescent emission.
The fluorescent dopant is selected from fluoranthene derivatives, pyrene derivatives, arylacetylene derivatives, fluorene derivatives, boron complexes, perylene derivatives, oxadiazole derivatives, anthracene derivatives, chrysene derivatives, and the like. Preferably, a fluoranthene derivative, a pyrene derivative, and a boron complex are used.

The phosphorescent dopant (phosphorescent material) that forms the light emitting layer is a compound that can emit light from the triplet excited state, and is not particularly limited as long as it emits light from the triplet excited state, but Ir, Pt, Os, Au, Cu An organometallic complex containing at least one metal selected from the group consisting of, Re and Ru and a ligand is preferable. The ligand preferably has an ortho metal bond. A metal complex containing a metal atom selected from Ir, Os and Pt is preferable in that the phosphorescent quantum yield is high and the external quantum efficiency of the light-emitting element can be further improved, and an iridium complex, an osmium complex, or a platinum complex. More preferred are metal complexes such as orthometalated complexes (the ligand has a metal atom and an orthometal bond), more preferred are iridium complexes and platinum complexes, and particularly preferred are orthometalated iridium complexes.

The triplet energy of the phosphorescent material is preferably 1.8 eV or more and less than 2.9 eV.

The content of the phosphorescent dopant in the light emitting layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is preferably 0.1 to 70% by mass, more preferably 1 to 30% by mass. If the phosphorescent dopant content is 0.1% by mass or more, sufficient light emission can be obtained, and if it is 70% by mass or less, concentration quenching can be avoided.

The phosphorescent host is a compound having a function of efficiently emitting the phosphorescent dopant by efficiently confining the triplet energy of the phosphorescent dopant in the light emitting layer. The organic EL device material of the present invention is suitable as a phosphorescent host. The light emitting layer may contain 1 type of organic EL element material of this invention, and may contain 2 or more types of organic EL element material of this invention.

In the organic EL device of the present invention, a compound other than the material for the organic EL device of the present invention can be appropriately selected as the phosphorescent host according to the purpose.
The organic EL device material of the present invention and other compounds may be used in combination as a phosphorescent host material in the same light emitting layer, and when there are a plurality of light emitting layers, the phosphorescent host of one of the light emitting layers. The material for an organic EL device of the present invention may be used as a material, and a compound other than the material for an organic EL device of the present invention may be used as a phosphorescent host material for another light emitting layer. Moreover, the organic EL device material of the present invention can be used for organic layers other than the light emitting layer. In that case, a compound other than the organic EL device material of the present invention is used as the phosphorescent host of the light emitting layer. May be.

Specific examples of compounds other than the organic EL device material of the present invention and suitable as a phosphorescent host include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, Pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrins Compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidene derivatives And metal complexes of heterocyclic tetracarboxylic anhydrides, phthalocyanine derivatives, 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles as ligands Various metal complexes such as polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, etc. Examples thereof include polymer compounds. A phosphorescent host may be used independently and may use 2 or more types together. Specific examples include the following compounds.

When the light emitting layer contains the first host material and the second host material, the organic EL element material of the present invention is used as the first host material, and the organic EL element material other than the organic EL element material of the present invention is used as the second host material. A compound may be used. In the present invention, the terms “first host material” and “second host material” mean that the plurality of host materials contained in the light emitting layer have different structures from each other. It is not specified by the material content.
It does not specifically limit as said 2nd host material, It is a compound other than the organic EL element material of this invention, and the same thing as the above-mentioned compound as a compound suitable as a phosphorescent host is mentioned. As the second host material, a compound having no cyano group is preferable. The second host is preferably a carbazole derivative, arylamine derivative, fluorenone derivative, or aromatic tertiary amine compound.

The thickness of the light emitting layer is preferably 5 to 50 nm, more preferably 7 to 50 nm, and still more preferably 10 to 50 nm. When the thickness is 5 nm or more, it is easy to form a light emitting layer, and when the thickness is 50 nm or less, an increase in driving voltage can be avoided.

(Electron transport layer)
The electron transport layer is an organic layer formed between the light emitting layer and the cathode, and has a function of transporting electrons from the cathode to the light emitting layer. When the electron transport layer is composed of a plurality of layers, an organic layer close to the cathode may be defined as an electron injection layer. The electron injection layer has a function of efficiently injecting electrons from the cathode into the organic layer unit.

As the electron transporting material used for the electron transporting layer, an aromatic heterocyclic compound containing one or more heteroatoms in the molecule is preferably used, and a nitrogen-containing ring derivative is particularly preferable. The nitrogen-containing ring derivative is preferably an aromatic ring having a nitrogen-containing 6-membered ring or 5-membered ring skeleton, or a condensed aromatic ring compound having a nitrogen-containing 6-membered ring or 5-membered ring skeleton.

The electron transport layer of the organic EL device of the present invention particularly preferably contains at least one nitrogen-containing heterocyclic derivative represented by the following formulas (E) to (G).

(In the formulas (E) to (G), Z ¹ , Z ² and Z ³ are each independently a nitrogen atom or a carbon atom.
R ¹ and R ² are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms, substituted or unsubstituted carbon An alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms.

n is an integer of 0 to 5, and when n is an integer of 2 or more, the plurality of R ¹ may be the same or different from each other. Further, two adjacent R ¹ may be bonded to each other to form a substituted or unsubstituted hydrocarbon ring.
Ar ¹ is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms.
Ar ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted Alternatively, it is an unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms.

However, either Ar ¹ or Ar ² is a substituted or unsubstituted condensed aromatic hydrocarbon ring group having 10 to 50 ring carbon atoms or a substituted or unsubstituted condensed aromatic group having 9 to 50 ring atoms. It is a heterocyclic group.
Ar ³ is a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroarylene group having 5 to 50 ring atoms.
L ¹ , L ² and L ³ are each independently a single bond, a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted divalent ring having 9 to 50 ring atoms. A condensed aromatic heterocyclic group. )

Examples of the aryl group having 6 to 50 ring carbon atoms include phenyl group, naphthyl group, anthryl group, phenanthryl group, naphthacenyl group, chrysenyl group, pyrenyl group, biphenylyl group, terphenylyl group, tolyl group, fluoranthenyl group, fluorenyl group Etc.
Examples of heteroaryl groups having 5 to 50 ring atoms include pyrrolyl, furyl, thienyl, silolyl, pyridyl, quinolyl, isoquinolyl, benzofuryl, imidazolyl, pyrimidyl, carbazolyl, selenophenyl Group, oxadiazolyl group, triazolyl group, pyrazinyl group, pyridazinyl group, triazinyl group, quinoxalinyl group, acridinyl group, imidazo [1,2-a] pyridinyl group, imidazo [1,2-a] pyrimidinyl group and the like.

Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.
Examples of the haloalkyl group having 1 to 20 carbon atoms include groups obtained by substituting one or more hydrogen atoms of the alkyl group with at least one halogen atom selected from fluorine, chlorine, iodine and bromine.
Examples of the alkoxy group having 1 to 20 carbon atoms include groups having the above alkyl group as an alkyl moiety.
Examples of the arylene group having 6 to 50 ring carbon atoms include groups obtained by removing one hydrogen atom from the aryl group.
Examples of the divalent condensed aromatic heterocyclic group having 9 to 50 ring atoms include groups obtained by removing one hydrogen atom from the condensed aromatic heterocyclic group described as the heteroaryl group.

The thickness of the electron transport layer is not particularly limited, but is preferably 1 nm to 100 nm.
Moreover, it is preferable to use an insulator or a semiconductor as an inorganic compound in addition to the nitrogen-containing ring derivative as a component of the electron injection layer that can be provided adjacent to the electron transport layer. If the electron injection layer is made of an insulator or a semiconductor, current leakage can be effectively prevented and the electron injection property can be improved.

(Hole transport layer)
An organic layer formed between the light emitting layer and the anode, and has a function of transporting holes from the anode to the light emitting layer. When the hole transport layer is composed of a plurality of layers, an organic layer close to the anode may be defined as a hole injection layer. The hole injection layer has a function of efficiently injecting holes from the anode into the organic layer unit.

As another material for forming the hole transport layer, an aromatic amine compound, for example, an aromatic amine derivative represented by the following formula (H) is preferably used.

In the formula ^{(H), Ar 1 ~ Ar} 4 is a substituted or an aromatic hydrocarbon group or fused aromatic hydrocarbon group unsubstituted ring carbon atoms 6 to 50, a substituted or unsubstituted ring atoms of 5 to 50 aromatic heterocyclic groups or condensed aromatic heterocyclic groups, or a group in which these aromatic hydrocarbon groups or condensed aromatic hydrocarbon groups and aromatic heterocyclic groups or condensed aromatic heterocyclic groups are bonded.
In the formula (H), L represents a substituted or unsubstituted aromatic hydrocarbon group or condensed aromatic hydrocarbon group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted ring forming atom number of 5 to 50. Represents an aromatic heterocyclic group or a condensed aromatic heterocyclic group.

Specific examples of the compound of formula (H) are shown below.

An aromatic amine represented by the following formula (J) is also preferably used for forming the hole transport layer.

In the formula (J), the definitions of Ar ¹ to Ar ³ are the same as the definitions of Ar ¹ to Ar ^{4 in} the formula (H). Specific examples of the compound of formula (J) are shown below, but are not limited thereto.

The hole transport layer of the organic EL device of the present invention may have a two-layer structure of a first hole transport layer (anode side) and a second hole transport layer (cathode side).
The thickness of the hole transport layer is not particularly limited, but is preferably 10 to 200 nm.

In the organic EL device of the present invention, a layer containing an acceptor material may be bonded to the anode side of the hole transport layer or the first hole transport layer. This is expected to reduce drive voltage and manufacturing costs.
As the acceptor material, a compound represented by the following formula (K) is preferable.

(In the formula (K), R ₂₁ to R ₂₆ may be the same as or different from each other, and each independently represents a cyano group, —CONH ₂ , a carboxyl group, or —COOR ₂₇ (R ₂₇ is a group having 1 to 20 carbon atoms) Represents an alkyl group or a cycloalkyl group having 3 to 20 carbon atoms, provided that one or more pairs of R ₂₁ and R ₂₂ , R ₂₃ and R ₂₄ , and R ₂₅ and R ₂₆ are combined together. A group represented by —CO—O—CO— may be formed.)
Examples of R ₂₇ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a cyclopentyl group, and a cyclohexyl group.
The thickness of the layer containing the acceptor material is not particularly limited, but is preferably 5 to 20 nm.

(N / p doping)
In the hole transport layer and the electron transport layer described above, as described in Japanese Patent No. 3695714, the carrier injection ability is improved by doping the donor material (n) and acceptor material (p). Can be adjusted.
A typical example of n doping is a method of doping a metal such as Li or Cs into an electron transport material, and a typical example of p doping is F ₄ TCNQ (2, 3, 5, 6) as a hole transport material. -Tetrafluor-7,7,8,8-tetracyanoquinodimethane) and the like.

(Space layer)
For example, when the fluorescent layer and the phosphorescent layer are laminated, the space layer is a fluorescent layer for the purpose of adjusting the carrier balance so that excitons generated in the phosphorescent layer are not diffused into the fluorescent layer. It is a layer provided between the layer and the phosphorescent light emitting layer. In addition, the space layer can be provided between the plurality of phosphorescent light emitting layers.
Since the space layer is provided between the light emitting layers, a material having both electron transport properties and hole transport properties is preferable. In order to prevent diffusion of triplet energy in the adjacent phosphorescent light emitting layer, the triplet energy is preferably 2.6 eV or more. Examples of the material used for the space layer include the same materials as those used for the above-described hole transport layer.

(Barrier layer)
The organic EL device of the present invention preferably has a barrier layer such as an electron barrier layer, a hole barrier layer, or a triplet barrier layer in a portion adjacent to the light emitting layer. Here, the electron barrier layer is a layer that prevents electrons from leaking from the light emitting layer to the hole transport layer, and the hole barrier layer is a layer that prevents holes from leaking from the light emitting layer to the electron transport layer. is there.
The triplet barrier layer prevents the triplet excitons generated in the light emitting layer from diffusing into the surrounding layers, and confins the triplet excitons in the light emitting layer, thereby transporting electrons other than the light emitting dopant of the triplet excitons. It has a function of suppressing energy deactivation on the molecules of the layer.

When providing the triplet barrier layer, the phosphorescent devices, triplet energy E ^{T d} of the phosphorescent dopant in the light emitting layer _and the triplet energy of the compound used as a triplet barrier layer and E ^T _TB, E ^T _d < If the energy magnitude relationship of E ^T _TB is satisfied, the triplet exciton of the phosphorescent dopant is confined (cannot move to other molecules) and the energy deactivation path other than light emission on the dopant is interrupted. It is assumed that light can be emitted with high efficiency. However, even if the relationship of E ^T _d <E ^T _TB is satisfied, if this energy difference ΔE ^T = E ^T _TB −E ^T _d is small, under the environment of room temperature, which is the actual element driving environment, , endothermically triplet excitons overcame this energy difference Delta] E ^T by thermal energy near is considered to be possible to move to another molecule. In particular, in the case of phosphorescence emission, the exciton lifetime is longer than that of fluorescence emission, so that the influence of the endothermic exciton transfer process is likely to appear. The energy difference ΔE ^T is preferably as large as possible relative to the thermal energy at room temperature, more preferably 0.1 eV or more, and particularly preferably 0.2 eV or more. On the other hand, in the fluorescent element, the organic EL element material of the present invention can be used as a triplet barrier layer having a TTF element structure described in International Publication WO2010 / 134350A1.

In addition, the electron mobility of the material constituting the triplet barrier layer is desirably 10 ⁻⁶ cm ² / Vs or more in the range of electric field strength of 0.04 to 0.5 MV / cm. As a method for measuring the electron mobility of an organic material, several methods such as the Time of Flight method are known. Here, the electron mobility is determined by impedance spectroscopy.
The electron injection layer is desirably 10 ⁻⁶ cm ² / Vs or more in the range of electric field strength of 0.04 to 0.5 MV / cm. This facilitates the injection of electrons from the cathode into the electron transport layer, and also promotes the injection of electrons into the adjacent barrier layer and the light emitting layer, thereby enabling driving at a lower voltage.

In the organic EL device of the present invention, it is preferable that at least one of an electron donating dopant and an organometallic complex is added to the interface region between the cathode and the organic thin film layer. According to such a configuration, it is possible to improve the light emission luminance and extend the life of the organic EL element.
Examples of the electron donating dopant include at least one selected from alkali metals, alkali metal compounds, alkaline earth metals, alkaline earth metal compounds, rare earth metals, rare earth metal compounds, and the like.
Examples of the organometallic complex include at least one selected from an organometallic complex containing an alkali metal, an organometallic complex containing an alkaline earth metal, an organometallic complex containing a rare earth metal, and the like.

Examples of the alkali metal include lithium (Li) (work function: 2.93 eV), sodium (Na) (work function: 2.36 eV), potassium (K) (work function: 2.28 eV), rubidium (Rb) (work Function: 2.16 eV), cesium (Cs) (work function: 1.95 eV) and the like, and those having a work function of 2.9 eV or less are particularly preferable. Of these, K, Rb, and Cs are preferred, Rb and Cs are more preferred, and Cs is most preferred.
Examples of the alkaline earth metal include calcium (Ca) (work function: 2.9 eV), strontium (Sr) (work function: 2.0 eV to 2.5 eV), barium (Ba) (work function: 2.52 eV). A work function of 2.9 eV or less is particularly preferable.
Examples of the rare earth metal include scandium (Sc), yttrium (Y), cerium (Ce), terbium (Tb), ytterbium (Yb) and the like, and those having a work function of 2.9 eV or less are particularly preferable.
Among the above metals, preferred metals are particularly high in reducing ability, and by adding a relatively small amount to the electron injection region, it is possible to improve the light emission luminance and extend the life of the organic EL element.

Examples of the alkali metal compound include lithium oxide (Li ₂ O), cesium oxide (Cs ₂ O), alkali oxides such as potassium oxide (K ₂ O), lithium fluoride (LiF), sodium fluoride (NaF), fluorine. Examples thereof include alkali halides such as cesium fluoride (CsF) and potassium fluoride (KF), and lithium fluoride (LiF), lithium oxide (Li ₂ O), and sodium fluoride (NaF) are preferable.
Examples of the alkaline earth metal compound include barium oxide (BaO), strontium oxide (SrO), calcium oxide (CaO), and barium strontium oxide (Ba _x Sr _1-x O) (0 <x <1), Examples thereof include barium calcium oxide (Ba _x Ca _1-x O) (0 <x <1), and BaO, SrO, and CaO are preferable.
The rare earth metal compound, ytterbium fluoride _(YbF 3), scandium fluoride _(ScF 3), scandium oxide _(ScO 3), yttrium oxide _{(Y 2 O} 3), cerium oxide _{(Ce 2 O} 3), gadolinium fluoride _(GdF 3), include such terbium fluoride (TbF _{3) is, YbF 3, ScF 3, TbF} 3 are preferable.

The organometallic complex is not particularly limited as long as it contains at least one of an alkali metal ion, an alkaline earth metal ion, and a rare earth metal ion as a metal ion as described above. The ligands include quinolinol, benzoquinolinol, acridinol, phenanthridinol, hydroxyphenyl oxazole, hydroxyphenyl thiazole, hydroxydiaryl thiadiazole, hydroxydiaryl thiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxybenzotriazole, Hydroxyfulborane, bipyridyl, phenanthroline, phthalocyanine, porphyrin, cyclopentadiene, β-diketones, azomethines, and derivatives thereof are preferred, but are not limited thereto.

As the addition form of the electron donating dopant and the organometallic complex, it is preferable to form a layer or an island in the interface region. As a forming method, while depositing at least one of an electron donating dopant and an organometallic complex by a resistance heating vapor deposition method, an organic material as a light emitting material or an electron injection material for forming an interface region is simultaneously deposited, and an electron is deposited in the organic material. A method of dispersing at least one of a donor dopant and an organometallic complex reducing dopant is preferable. The dispersion concentration is usually organic substance: electron donating dopant and / or organometallic complex in a molar ratio of 100: 1 to 1: 100, preferably 5: 1 to 1: 5.

In the case where at least one of the electron donating dopant and the organometallic complex is formed in a layered form, after forming the light emitting material or the electron injecting material that is the organic layer at the interface in a layered form, at least one of the electron donating dopant and the organometallic complex is formed. These are vapor-deposited by a resistance heating vapor deposition method alone, preferably with a layer thickness of 0.1 nm to 15 nm.

In the case where at least one of an electron donating dopant and an organometallic complex is formed in an island shape, a light emitting material or an electron injecting material which is an organic layer at the interface is formed in an island shape, and then the electron donating dopant and the organometallic complex are formed. At least one of them is vapor-deposited by a resistance heating vapor deposition method, preferably with an island thickness of 0.05 nm to 1 nm.

In the organic EL device of the present invention, the ratio of at least one of the main component (light-emitting material or electron injection material), the electron-donating dopant, and the organometallic complex is, as a molar ratio, the main component: the electron-donating dopant. And / or organometallic complex = 5: 1 to 1: 5, preferably 2: 1 to 1: 2.

For the formation of each layer of the organic EL device of the present invention, a known method such as a dry film forming method such as vacuum deposition, sputtering, plasma, or ion plating, or a wet film forming method such as spin coating, dipping, or flow coating is applied. be able to.
The thickness of each layer is not particularly limited, but must be set to an appropriate thickness. If the film thickness is too thick, a large applied voltage is required to obtain a constant light output, resulting in poor efficiency. If the film thickness is too thin, pinholes and the like are generated, and sufficient light emission luminance cannot be obtained even when an electric field is applied. The normal film thickness is suitably in the range of 5 nm to 10 μm, but more preferably in the range of 10 nm to 0.2 μm.

The organic EL device of the present invention preferably has a maximum emission wavelength of 430 nm or more and 720 nm or less.

Next, the present invention will be described in further detail using synthesis examples and examples. However, the present invention is not limited to the following synthesis examples and examples.

Synthesis Example 1 [Synthesis of Compound A]

(1) Synthesis of Intermediate 1 Under a stream of argon, 33.7 g (116 mmol) of Compound 1, 76.4 g (291 mmol) of triphenylphosphine, and 300 ml of orthodichlorobenzene were added to a 1 L flask, and stirred at 190 ° C. for 12 hours. Allowed to cool to room temperature. The volume was half concentrated, 180 ml of methanol was added and stirred for 2 hours, and the precipitated crystals were filtered. The crystals separated by filtration were purified by heating with 180 ml of toluene to obtain 15.7 g (61 mmol) of Intermediate 1 in a yield of 52%.

(2) Synthesis of Intermediate 2 10 g (39 mmol) of Intermediate 1 in the 500 ml flask under argon flow, 8.75 g (43 mmol) of iodobenzene, 357 mg (0.39 mmol) of tris (dibenzylideneacetone) dipalladium (0) Then, 0.78 ml of a 2.0 M toluene solution of tributylphosphine and 7.5 g (78 mmol) of t-butoxy sodium were added, 200 ml of toluene was added, and the mixture was heated to reflux for 12 hours.
The mixture was allowed to cool to room temperature, extracted with toluene, and purified by column chromatography to obtain 11.5 g (34.5 mmol) of Intermediate 2 in a yield of 88%.

(3) Synthesis of Intermediate 3 Under a stream of argon, 11.5 g (34.5 mmol) of Intermediate 2 was dissolved in 80 ml of dehydrated DMF in a 500 ml flask, and 6.14 g (34.5 mmol) of N-bromosuccinimide was dissolved in 70 ml of dehydrated DMF. The solution was added dropwise with stirring at 0 ° C. over 10 minutes. After gradually warming and stirring at 160 ° C. for 19 hours, the product was extracted and purified by column chromatography to obtain 10.3 g (24.6 mmol), intermediate 3 in 71% yield. .

(4) Synthesis of Compound A Under a stream of argon, 3.3 g (8 mmol) of Intermediate 3 and 1.6 g (9.6 mmol) of carbazole, 293 mg of tris (dibenzylideneacetone) dipalladium (0) (0. 32 mmol), tributylphosphine 2.0M toluene solution 0.32 ml, t-butoxy sodium 1.5 g (16 mmol) were added, toluene 40 ml was added, and the mixture was heated to reflux for 8 hours. The mixture was allowed to cool to room temperature, extracted with toluene, purified by column chromatography, and recrystallized to obtain 2.1 g (4.2 mmol) of Compound A in a yield of 52%. When the FD mass spectrum of the product was measured, it was molecular weight 498.

Synthesis Example 2 [Synthesis of Compound B]

(1) Synthesis of Intermediate 4 Under a stream of argon, 5 g (20 mmol) of Intermediate 1, 5.76 g (22 mmol) of 2-bromodibenzothiophene, 183 mg of tris (dibenzylideneacetone) dipalladium (0) ( 0.20 mmol), tributylphosphine 2.0 M toluene solution 0.4 ml, t-butoxy sodium 3.85 g (40 mmol) was added, toluene 100 ml was added, and the mixture was heated to reflux for 12 hours.
The mixture was allowed to cool to room temperature, extracted with toluene, and purified by column chromatography to obtain Intermediate 4 (6.5 g, 14.8 mmol) in a yield of 74%.

(2) Synthesis of Intermediate 5 Under an argon stream, 6.5 g (14.8 mmol) of Intermediate 4 was dissolved in 40 ml of dehydrated DMF in a 200 ml flask, and 2.63 g (14.8 mmol) of N-bromosuccinimide was dissolved in 30 ml of dehydrated DMF. The solution was added dropwise with stirring at 0 ° C. over 10 minutes. After gradually warming and stirring at 160 ° C. for 15 hours, the product was extracted and purified by column chromatography to obtain Intermediate 5 in a yield of 6.1 g (11.8 mmol) 79%.

(3) Synthesis of Compound B Under an argon stream, 6.1 g (11.8 mmol) of Intermediate 5, 2.4 g (14.2 mmol) of carbazole, 430 mg of tris (dibenzylideneacetone) dipalladium (0) (200 mg) 0.47 mmol), tributylphosphine 2.0M toluene solution 0.47 ml, t-butoxy sodium 2.2 g (24 mmol) were added, toluene 70 ml was added, and the mixture was heated to reflux for 8 hours. The mixture was allowed to cool to room temperature, extracted with toluene, purified by column chromatography, and recrystallized to obtain 4.6 g (7.6 mmol) of Compound B in a yield of 64%. When the FD mass spectrum of the product was measured, it was molecular weight 604.

Synthesis Example 3 [Synthesis of Compound C]

(1) Synthesis of Intermediate 6 Under a stream of argon, Compound 2 8.0 g (21 mmol), Carbazole 4.2 g (25.2 mmol), Tris (dibenzylideneacetone) dipalladium (0) 770 mg (0.84 mmol) in a 500 ml flask. ), 0.84 ml of a 2.0 M toluene solution of tributylphosphine and 3.9 g (42 mmol) of t-butoxy sodium, 120 ml of toluene was added, and the mixture was heated to reflux for 15 hours. The mixture was allowed to cool to room temperature, extracted with toluene, and purified by column chromatography to obtain Intermediate 6 (4.3 g, 9.1 mmol) in a yield of 44%.

(2) Synthesis of Intermediate 7 Under a stream of argon, 4.3 g (9.1 mmol) of Intermediate 6, 6.0 g (22.7 mmol) of triphenylphosphine and 120 ml of orthodichlorobenzene were added to a 300 ml flask at 190 ° C. After stirring for 12 hours, the mixture was allowed to cool to room temperature. The volume was concentrated by half, 20 ml of methanol was added and stirred for 2 hours, and the precipitated crystals were filtered. The crystal separated by filtration was washed with 30 ml of toluene and purified by heating to obtain 2.6 g (5.9 mmol) of Intermediate 7 in a yield of 65%.

(3) Synthesis of Compound C 2.6 g (5.9 mmol) of Intermediate 7 in the 200 ml flask, 1.71 g (6.5 mmol) of 4-bromodibenzothiophene, tris (dibenzylideneacetone) dipalladium (Argon stream) 0) 55 mg (0.06 mmol), tributylphosphine 2.0 M toluene solution 0.12 ml, t-butoxy sodium 1.15 g (12 mmol) were added, toluene 60 ml was added, and the mixture was heated to reflux for 12 hours.

The mixture was allowed to cool to room temperature, extracted with toluene, purified by column chromatography, and recrystallized to obtain 1.8 g (2.9 mmol) of Compound C in a yield of 49%. When the FD mass spectrum of the product was measured, it was molecular weight 620.

Synthesis Example 4 [Synthesis of Compound D]

(1) Synthesis of Intermediate 8 Under a stream of argon, 12 g (33 mmol) of Compound 3, 21.5 g (82 mmol) of triphenylphosphine, and 120 ml of orthodichlorobenzene were added to a 500 ml flask, stirred at 190 ° C. for 14 hours, and then room temperature. It was left to cool. The volume was concentrated by half, 80 ml of methanol was added and stirred for 2 hours, and the precipitated crystals were filtered. The crystals separated by filtration were purified by washing with 60 ml of toluene and purified to obtain Intermediate 8 (6.2 g, 18.6 mmol) in a yield of 56%.

(2) Synthesis of Intermediate 9 6.2 g (18.6 mmol) of Intermediate 8, 4.5 g (22 mmol) of iodobenzene, 170 mg of tris (dibenzylideneacetone) dipalladium (0) in a 500 ml flask under an argon stream. 0.186 mmol), tributylphosphine 2.0 M toluene solution 0.37 ml, t-butoxy sodium 3.55 g (37 mmol) were added, toluene 150 ml was added, and the mixture was heated to reflux for 12 hours. The mixture was allowed to cool to room temperature, extracted with toluene, and purified by column chromatography to obtain Intermediate 9 (6.5 g, 15.9 mmol) in a yield of 85%.

(2) Synthesis of intermediate 10 Under argon flow, 6.5 g (15.9 mmol) of intermediate 9 was dissolved in 40 ml of dehydrated DMF in a 300 ml flask, and 2.85 g (16 mmol) of N-bromosuccinimide was dissolved in 30 ml of dehydrated DMF. Was added dropwise at 0 ° C. over 10 minutes with stirring. After gradually warming up and stirring at 160 ° C. for 15 hours, the product was extracted and purified by column chromatography to obtain Intermediate 10 in a yield of 4.8 g (9.8 mmol) and 62%. .

(3) Synthesis of Compound D Under a stream of argon, 4.8 g (9.8 mmol) of Intermediate 10; 1.9 g (11.7 mmol) of carbazole; 360 mg of tris (dibenzylideneacetone) dipalladium (0) (0) .39 mmol), tributylphosphine 2.0 M toluene solution 0.39 ml, t-butoxy sodium 1.9 g (19.6 mmol) were added, toluene 40 ml was added, and the mixture was heated to reflux for 8 hours. The mixture was allowed to cool to room temperature, extracted with toluene, purified by column chromatography, and recrystallized to obtain 3.2 g (5.5 mmol) of Compound D in a yield of 56%. When the FD mass spectrum of the product was measured, it was molecular weight 574.

Synthesis Example 5 [Synthesis of Compound E]

(1) Synthesis of Intermediate 11 In a 300 ml flask under an argon stream, 5.1 g (20 mmol) of Intermediate 1, 7 g (21.5 mmol) of 4- (4-bromophenyl) dibenzofuran, tris (dibenzylideneacetone) dipalladium ( 0) 183 mg (0.20 mmol), tributylphosphine 2.0 M toluene solution 0.4 ml, t-butoxy sodium 3.8 g (40 mmol) were added, toluene 100 ml was added, and the mixture was heated to reflux for 12 hours. The mixture was allowed to cool to room temperature, extracted with toluene, and purified by column chromatography to obtain 7.0 g (14.2 mmol) of intermediate 11 in a 71% yield.

(2) Synthesis of Intermediate 12 Under an argon stream, 7.0 g (14.2 mmol) of Intermediate 11 was dissolved in 40 ml of dehydrated DMF in a 300 ml flask, and 2.58 g (14.5 mmol) of N-bromosuccinimide was dissolved in 30 ml of dehydrated DMF. The solution was added dropwise with stirring at 0 ° C. over 10 minutes. After gradually raising the temperature and stirring at 160 ° C. for 16 hours, the product was extracted and purified by column chromatography to obtain Intermediate 12 in a yield of 5.3 g (9.1 mmol) 64%.

(3) Synthesis of Compound E In a 200 ml flask under argon stream, Intermediate 12 5.3 g (9.1 mmol), carbazole 1.76 g (10.8 mmol), tris (dibenzylideneacetone) dipalladium (0) 335 mg (0 .36 mmol), tributylphosphine 2.0 M toluene solution 0.36 ml, t-butoxy sodium 1.8 g (18.2 mmol) were added, toluene 40 ml was added, and the mixture was heated to reflux for 8 hours. The mixture was allowed to cool to room temperature, extracted with toluene, purified by column chromatography, and recrystallized to obtain 3.6 g (5.4 mmol) of material E in a yield of 59%. When the FD mass spectrum of the product was measured, it was molecular weight 664.

Example 1
A 25 mm × 75 mm × 1.1 mm glass substrate with an ITO transparent electrode (manufactured by Geomatech) was subjected to ultrasonic cleaning for 5 minutes in isopropyl alcohol, and further subjected to UV (Ultraviolet) ozone cleaning for 30 minutes.

The glass substrate with the transparent electrode thus cleaned is attached to the substrate holder of the vacuum evaporation apparatus, and first, on the surface of the glass substrate on which the transparent electrode line is formed, the transparent electrode is covered, Material 1 was deposited with a thickness of 20 nm to obtain a hole injection layer. Subsequently, the material 2 was vapor-deposited on this film | membrane by thickness 60nm, and the positive hole transport layer was obtained.

On this hole transport layer, compound A as a phosphorescent host material and material 3 which is a phosphorescent material were co-evaporated at a thickness of 50 nm to obtain a phosphorescent layer. The concentration of Compound A in the phosphorescent light emitting layer was 80% by mass, and the concentration of Material 3 was 20% by mass.

Subsequently, the material 5 was deposited on the phosphorescent layer at a thickness of 10 nm to obtain a hole blocking layer. Furthermore, after depositing material 4 with a thickness of 10 nm to obtain an electron transport layer, LiF with a thickness of 1 nm and metal Al with a thickness of 80 nm were sequentially laminated to obtain a cathode. Note that LiF, which is an electron injecting electrode, was formed at a rate of 1 Å / min.

When the produced organic EL element was made to emit light by direct current drive, the luminance and current density were measured, and the emission wavelength at a current density of 1 mA / cm ² was measured, the emission wavelength was 473 nm. Table 1 shows the evaluation results of the voltage and light emission efficiency (external quantum efficiency) at a current density of 1 mA / cm ² and the luminance 50% lifetime (time during which the luminance is reduced to 50%) at an initial luminance of 3,000 cd / m ² .

Examples 2-5
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that compounds B to E shown in Table 1 below were used in place of compound A as the phosphorescent host material. The results are shown in Table 1.

Comparative Examples 1 and 2
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that Comparative Compounds 1 and 2 shown in Table 1 below were used as the phosphorescent host material instead of Compound A. The results are shown in Table 1.

Examples 6 to 10
In Example 1, the material 2 for the hole transport layer was vapor-deposited with a thickness of 50 nm, and further, the compounds A to E shown in Table 2 below were vapor-deposited with a thickness of 10 nm on the compound A as a host material for the light-emitting layer. An organic EL device was prepared and evaluated in the same manner as in Example 1 except that the material 5 was used instead of the above. The results are shown in Table 2.

Comparative Examples 3-4
In Example 6, an organic EL device was prepared and evaluated in the same manner as in Example 6 except that Comparative Compounds 1 and 2 shown in Table 2 below were used instead of Compound A in the hole transport layer. The results are shown in Table 2.

Examples 11-15
In Examples 6 to 10, organic EL elements were produced and evaluated in the same manner as in Examples 6 to 10 except that the material 6 was used instead of the material 5 as the host material of the light emitting layer. The results are shown in Table 3.

Comparative Examples 5-6
In Example 11, an organic EL device was prepared and evaluated in the same manner as in Example 11 except that Comparative Compounds 1 and 2 shown in Table 3 below were used instead of Compound A in the hole transport layer. The results are shown in Table 3.

From the results of Examples 1 to 5, the organic EL device using the compound of the present invention as the phosphorescent host material of the phosphorescent light emitting layer has a significantly longer life than the case of using the comparative compound, and the voltage is high. Low and high external quantum efficiency was obtained.
Further, from the results of Examples 6 to 15, the organic EL device using the compound of the present invention as the hole transport layer has a significantly longer life than the case of using the comparative compound, and has a high external quantum efficiency. Efficiency was obtained.

The compound of the present invention can be used for organic EL devices, organic EL displays, lighting, organic semiconductors, organic solar cells, and the like.
The material for an organic EL device of the present invention is useful as a material for realizing an organic EL device with high efficiency and long life.
The organic EL device of the present invention can be used for a flat light emitter such as a flat panel display of a wall-mounted television, a light source such as a copying machine, a printer, a backlight of a liquid crystal display or instruments, a display board, a marker lamp, and the like.

Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will appreciate that these exemplary embodiments and / or embodiments are substantially without departing from the novel teachings and advantages of the present invention. It is easy to make many changes to the embodiment. Accordingly, many of these modifications are within the scope of the present invention.
All the contents of the Japanese application specification that is the basis of the priority of Paris in this application are incorporated herein.

Claims (16)

1. A compound represented by the following formula (1).
   

   

   [In Formula (1),
   Ar is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted arylcarbazolyl group, a substituted or unsubstituted aryldibenzofuranyl group, a substituted or unsubstituted aryldibenzothiophenyl A group selected from the group consisting of a group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted dibenzothiophenyl group.
   R ₁ to R ₁₄ each independently represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon; An alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkoxy group having 1 to 20 carbon atoms, a cyano group, and a substituted or unsubstituted arylcarbazolyl group; Substituted or unsubstituted aryl dibenzofuranyl group, substituted or unsubstituted aryl dibenzothiophenyl group, substituted or unsubstituted carbazolyl group, substituted or unsubstituted dibenzofuranyl group, substituted or unsubstituted dibenzothiophenyl group Substituted or unsubstituted alkylsilyl group, substituted or unsubstituted arylsilyl group, substituted or unsubstituted Conversion aralkyl silyl group, a substituted or unsubstituted alkyl germanium group, a substituted or unsubstituted aryl germanium group, and a substituted or unsubstituted group selected from the group consisting of aralkyl germanium group.
   X represents an oxygen atom or a sulfur atom. ]
2. R ₁ to R ₁₄ each independently represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon; An alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkoxy group having 1 to 20 carbon atoms, a cyano group, and a substituted or unsubstituted arylcarbazolyl group; Substituted or unsubstituted aryl dibenzofuranyl group, substituted or unsubstituted aryl dibenzothiophenyl group, substituted or unsubstituted carbazolyl group, substituted or unsubstituted dibenzofuranyl group, and substituted or unsubstituted dibenzothiophenyl The compound according to claim 1, which represents a group selected from the group consisting of groups.
3. The compound of Claim 1 or 2 represented by following formula (2), (3) or (4).
   

   

   [In the formulas (2) to (4), Ar, R ₁ to R ₁₄ and X are the same as those in the formula (1). ]
4. The compound according to any one of claims 1 to 3, which is represented by the following formula (5), (6) or (7):
   

   

   [In the formulas (5) to (7), Ar, R ₁ , R ₂ , R ₆ , R ₇ , R ₉ to R ₁₁ and X are the same as those in the formula (1). ]
5. In the above formulas (5) to (7), Ar represents an unsubstituted aryl group having 6 to 30 ring carbon atoms, an unsubstituted arylcarbazolyl group, an unsubstituted aryldibenzofuranyl group, or an unsubstituted aryldibenzo. The compound according to claim 4, which represents a group selected from the group consisting of a thiophenyl group, an unsubstituted carbazolyl group, an unsubstituted dibenzofuranyl group, and an unsubstituted dibenzothiophenyl group.
6. Ar is an unsubstituted phenyl group, an unsubstituted biphenylyl group, an unsubstituted phenylcarbazolyl group, an unsubstituted phenyldibenzofuranyl group, an unsubstituted phenyldibenzothiophenyl group, an unsubstituted carbazolyl group, an unsubstituted group 6. The compound according to claim 5, which represents a group selected from the group consisting of a dibenzofuranyl group and an unsubstituted dibenzothiophenyl group.
7. A material for an organic electroluminescence element comprising the compound according to any one of claims 1 to 6.
8. An organic electroluminescence device comprising one or more organic thin film layers including a light emitting layer between a cathode and an anode, wherein at least one of the organic thin film layers comprises the material for an organic electroluminescence device according to claim 7.
9. The organic electroluminescent element according to claim 8, wherein the light emitting layer contains the material for the organic electroluminescent element.
10. The organic thin film layer includes one or more light emitting layers,
    The organic electroluminescent device according to claim 8 or 9, wherein at least one of the light emitting layers contains the material for an organic electroluminescent device according to claim 7 and a phosphorescent material.
11. The organic electroluminescence device according to claim 10, wherein the triplet energy of the phosphorescent material is 1.8 eV or more and less than 2.9 eV.
12. The phosphorescent material contains a metal complex compound;
    The organic electroluminescence device according to claim 10 or 11, wherein the metal complex compound has a metal atom and a ligand selected from the group consisting of Ir, Pt, Os, Au, Cu, Re, and Ru.
13. The organic electroluminescence device according to claim 12, wherein the ligand has an ortho metal bond with the metal atom.
14. 14. The organic electroluminescence device according to claim 8, wherein the maximum value of the emission wavelength is 430 nm or more and 720 nm or less.
15. The organic electroluminescence according to claim 7, wherein the organic electroluminescence has a hole transport zone between the light emitting layer and the anode, the hole transport zone has one or more organic thin film layers, and at least one of the organic thin film layers. The organic electroluminescence device according to any one of claims 8 to 14, comprising a device material.
16. The organic electroluminescence device according to claim 15, wherein the hole transport zone is adjacent to the light emitting layer.

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