JP2015216135A - Organic electroluminescent element and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL element having high luminous efficiency and a long service life.SOLUTION: In the organic electroluminescent element, an organic layer includes a hole transport layer and a light-emitting layer in this order from an anode side. The hole transport layer contains a biscarbazole derivative represented by general formula (1), and the light-emitting layer contains an anthracene derivative represented by general formula (2) and a light-emitting material.

Description

  The present invention relates to an organic electroluminescence element and an electronic device.

  When a voltage is applied to an organic electroluminescence element (hereinafter sometimes referred to as an organic EL element), holes from the anode and electrons from the cathode are injected into the light emitting layer. Then, in the light emitting layer, the injected holes and electrons are recombined to form excitons. At this time, singlet excitons and triplet excitons are generated at a ratio of 25%: 75% according to the statistical rule of electron spin. When classified according to the light emission principle, the fluorescence type uses light emission by singlet excitons. On the other hand, in the phosphorescent type, since light emission by triplet excitons is used, it is known that the internal quantum efficiency can be increased to 100% when intersystem crossing is efficiently performed from singlet excitons.

Conventionally, in an organic EL element, an optimal element design has been made according to a light emission mechanism of a fluorescent type and a phosphorescent type.
For example, Patent Document 1 attempts to provide a fluorescent organic EL element having high emission efficiency and a long lifetime by setting an anthracene derivative as a host material of the light emitting layer to a specific structure.

JP 2009-40776 A

  However, in recent years, an organic EL element having higher efficiency and longer life than the organic EL element described in Patent Document 1 has been desired.

  An object of the present invention is to provide an organic EL device having high luminous efficiency and long life. Another object of the present invention is to provide an electronic apparatus provided with the organic EL element of the present invention.

An organic electroluminescence device according to an embodiment of the present invention is
The anode,
A cathode provided opposite to the anode;
An organic layer provided between the anode and the cathode,
The organic layer includes a hole transport layer and a light emitting layer in this order from the anode side,
The hole transport layer includes a biscarbazole derivative represented by the following general formula (1),
The light emitting layer includes an anthracene derivative represented by the following general formula (2) and a light emitting material.

In the general formula (1), A ₁ and A ₂ are each independently
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 2 to 30 ring carbon atoms.
Y _{1 to} Y ₁₆ each independently represent C (R) or a nitrogen atom, and each R independently represents a bond bonded to a hydrogen atom, a substituent, or a carbazole skeleton.
L ₁ and L ₂ each independently represent a single bond or a divalent linking group.
However, at least one of A ₁ , A ₂ and R is
A substituted or unsubstituted fluoranthenyl group,
A substituted or unsubstituted triphenylenyl group,
A substituted or unsubstituted benzophenanthrenyl group,
A substituted or unsubstituted benzotriphenylenyl group,
A substituted or unsubstituted dibenzotriphenylenyl group,
A substituted or unsubstituted chrysenyl group,
A substituted or unsubstituted benzocrisenyl group,
A substituted or unsubstituted picenyl group,
A substituted or unsubstituted benzo [b] fluoranthenyl group,
A substituted or unsubstituted benzofuranyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted benzothiophenyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted phenanthrenyl group,
It represents a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted binaphthyl group.
In addition, when Y _{1 to} Y ₁₆ are all C (R), Y ₆ and Y ₁₁ are bonded by a single bond, L ₁ and L ₂ are a single bond, and A ₁ is a phenanthrenyl group, A ₂ Is not a phenanthrenyl group.
Further, when Y _{1 to} Y ₁₆ are all C (R), Y ₆ and Y ₁₁ are bonded by a single bond, and L ₁ and L ₂ are a single bond, R is not a fluorenyl group. In addition, when A ₁ is a fluorenyl group, A ₂ is not a phenyl group, a naphthyl group, or a fluorenyl group.

In the general formula (2), R ^{101 to} R ¹⁰⁸ are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms.

In the general formula (2), any one of R ^{109 to} R ¹¹³ is
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
Selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms;
The other R ^{109 to} R ¹¹³ are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms,
A substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms,
It is selected from either a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.

In the general formula (2), Ar ¹⁰¹ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
It is selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms.

  According to the present invention, it is possible to provide an organic EL element with high luminous efficiency and long life.

It is a figure which shows schematic structure of an example of the organic EL element in 1st embodiment of this invention.

Hereinafter, the present invention will be specifically described.
(Configuration of organic EL element)
First, the element configuration of the organic EL element will be described.
As typical element configurations of the organic EL element, for example, the following configurations (a) to (e) can be given.
(A) Anode / light emitting layer / cathode (b) Anode / hole injection / transport layer / light emitting layer / cathode (c) Anode / light emitting layer / electron injection / transport layer / cathode (d) Anode / hole injection / transport Layer / light emitting layer / electron injection / transport layer / cathode (e) anode / hole injection / transport layer / light emitting layer / barrier layer / electron injection / transport layer / cathode Among the above, the configuration of (d) is preferably used. However, of course, it is not limited to these.
The “light emitting layer” is an organic layer having a light emitting function, and includes a host material and a dopant material when a doping system is employed. 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.
The “hole injection / transport layer” means “at least one of a hole injection layer and a hole transport layer”, and “electron injection / transport layer” means “an electron injection layer and an electron transport layer”. "At least one of them". Here, when it has a positive hole injection layer and a positive hole transport layer, it is preferable that the positive hole injection layer is provided in the anode side. Moreover, when it has an electron injection layer and an electron carrying layer, it is preferable that the electron injection layer is provided in the cathode side.
In the present invention, the term “electron transport layer” refers to an organic layer having the highest electron mobility among the organic layers in the electron transport region existing between the light emitting layer and the cathode. When the electron transport region is composed of one layer, the layer is an electron transport layer. In addition, in the phosphorescent organic EL device, as shown in the configuration (e), a barrier layer that does not necessarily have high electron mobility is used to prevent diffusion of excitation energy generated in the light emitting layer. The organic layer adjacent to the light emitting layer does not necessarily correspond to the electron transport layer.

In FIG. 1, schematic structure of an example of the organic EL element in embodiment of this invention is shown.
The organic EL element 1 includes a translucent substrate 2, an anode 3, a cathode 4, and an organic layer 10 disposed between the anode 3 and the cathode 4.
The organic layer 10 includes a hole transport layer 5 and a light emitting layer 6 in this order from the anode 3 side. In the present embodiment, the hole transport layer 5 and the light emitting layer 6 are adjacent to each other. Further, the organic EL element 1 includes a hole injection layer 7 between the anode 3 and the hole transport layer 5, and includes an electron injection / transport layer 8 between the cathode 4 and the light emitting layer 6. . Note that another hole transport layer different from the hole transport layer 5 may be provided between the hole injection layer 7 and the hole transport layer 5.
The light emitting layer 6 includes a host material and a fluorescent dopant material as a fluorescent light emitting material.
Further, an electron barrier layer may be provided on the phosphorescent light emitting layer 5 on the anode 3 side, and a hole barrier layer may be provided on the phosphorescent light emitting layer 5 on the cathode 4 side. With such a barrier layer, electrons and holes can be confined in the light emitting layer 6 and the exciton generation probability in the light emitting layer 6 can be increased.
The organic layer 10 may contain an inorganic compound.

(substrate)
The organic EL element of the present invention is produced on a light-transmitting substrate. The translucent substrate referred to here 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 and cathode)
The anode of the organic EL element plays a role of injecting holes into the hole injection layer, the hole transport layer, or the light emitting layer, and it is effective to have 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 as in the present embodiment, it is preferable that the light transmittance in the visible region of the anode be greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ (Ω / sq. Ohm per square) 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.

As the cathode, a material having a small work function is preferable for the purpose of injecting electrons into the electron injection layer, the electron transport layer, or the light emitting layer.
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 a method such as vapor deposition, for example, by forming a thin film on the electron transport layer or the electron injection layer. Moreover, the aspect which takes out light emission from a light emitting layer from a cathode side is also employable. When light emitted from the light emitting layer is extracted from the cathode side, it is preferable that the light transmittance in the visible region of the cathode be greater than 10%.
The sheet resistance of the cathode is preferably several hundred Ω / □ or less.
The layer thickness of the cathode depends on the material, but is usually selected in the range of 10 nm to 1 μm, preferably 50 nm to 200 nm.

(Hole transport layer)
The hole transport layer 5 of the present embodiment is adjacent to the light emitting layer 6 on the anode 3 side and includes a biscarbazole derivative represented by the following general formula (1).

In the general formula (1), A ₁ and A ₂ are independently of each other,
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 2 to 30 ring carbon atoms.

In the general formula (1), Y _{1 to} Y ₁₆ each independently represent C (R) or a nitrogen atom, and each R independently represents a bond bonded to a hydrogen atom, a substituent, or a carbazole skeleton. Represents. That is, the biscarbazole derivative represented by the general formula (1) includes a case of having a carbazole skeleton and a case of having an azalated carbazole skeleton.

In the general formula (1), L ₁ and L ₂ each independently represent a single bond or a divalent linking group.
However, in the general formula (1), at least one of A ₁ , A ₂ and R is
A substituted or unsubstituted fluoranthenyl group,
A substituted or unsubstituted triphenylenyl group,
A substituted or unsubstituted benzophenanthrenyl group,
A substituted or unsubstituted benzotriphenylenyl group,
A substituted or unsubstituted dibenzotriphenylenyl group,
A substituted or unsubstituted chrysenyl group,
A substituted or unsubstituted benzocrisenyl group,
A substituted or unsubstituted picenyl group,
A substituted or unsubstituted benzo [b] fluoranthenyl group,
A substituted or unsubstituted benzofuranyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted benzothiophenyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted phenanthrenyl group,
It represents a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted binaphthyl group.

In the general formula (1), Y _{1 to} Y ₁₆ are all C (R), Y ₆ and Y ₁₁ are bonded by a single bond, L ₁ and L ₂ are a single bond, and A ₁ Is a phenanthrenyl group, A ₂ is not a phenanthrenyl group.

Further, in the general formula (1), when Y _{1 to} Y ₁₆ are all C (R), Y ₆ and Y ₁₁ are bonded by a single bond, and L ₁ and L ₂ are a single bond, R Are not fluorenyl groups, and when A ₁ is a fluorenyl group, A ₂ is not a phenyl group, a naphthyl group, or a fluorenyl group.

In the general formula (1), at least one of Y _{1 to} Y ₄ is C (R), at least one of Y _{5 to} Y ₈ is C (R), and Y ₉ at least one of to Y ₁₂ is a C _(R), at least one of Y 13 _{to Y 16} is C (R).
One of Y _{5 to} Y ₈ is C (R), and one of Y _{9 to} Y ₁₂ is C (R). These Rs represent bonds that are bonded to each other.
Several R in the said General formula (1) may mutually be same or different.

  The biscarbazole derivative contained in the hole transport layer 5 is preferably represented by the following general formula (1-2), the following general formula (1-3), or the following general formula (1-4).

In the general formulas (1) and (1-2) to (1-4), at least one of A ₁ and A ₂ is
A substituted or unsubstituted fluoranthenyl group,
A substituted or unsubstituted triphenylenyl group,
A substituted or unsubstituted benzophenanthrenyl group,
A substituted or unsubstituted benzotriphenylenyl group,
A substituted or unsubstituted dibenzotriphenylenyl group,
A substituted or unsubstituted chrysenyl group,
A substituted or unsubstituted benzocrisenyl group,
A substituted or unsubstituted picenyl group,
A substituted or unsubstituted benzo [b] fluoranthenyl group,
A substituted or unsubstituted benzofuranyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted benzothiophenyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted phenanthrenyl group,
It is preferably a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted binaphthyl group.

In the general formulas (1) and (1-2) to (1-4), A ₁ and A ₂ are each independently
A substituted or unsubstituted fluoranthenyl group,
A substituted or unsubstituted triphenylenyl group,
A substituted or unsubstituted benzotriphenylenyl group,
A substituted or unsubstituted benzophenanthrenyl group,
A substituted or unsubstituted dibenzofuranyl group or a substituted or unsubstituted dibenzothiophenyl group is preferred.
Further, in the general formulas (1) and (1-2) to (1-4), the structure of the portion represented by L ₁ -A ₁ of the biscarbazole derivative and L ₂ -A ₂ It is preferable that the structures of the parts are different from each other.

Specific examples of the substituents represented by A ₁ and A ₂ in the general formulas (1) and (1-2) to (1-4) and the substituent represented by R include:
Halogen atoms,
A cyano group,
A substituted or unsubstituted C1-C20 linear, branched or cyclic alkyl group,
A substituted or unsubstituted C1-C20 linear, branched or cyclic haloalkyl group,
A linear, branched or cyclic alkylene group having 1 to 20 carbon atoms,
A linear, branched or cyclic divalent unsaturated hydrocarbon group having 1 to 20 carbon atoms,
A substituted or unsubstituted linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted linear, branched or cyclic haloalkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 30 ring carbon atoms,
A substituted or unsubstituted C1-C10 linear, branched or cyclic alkylsilyl group,
A substituted or unsubstituted arylsilyl group having 6 to 30 carbon atoms,
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms,
Examples thereof include substituted or unsubstituted aromatic heterocyclic groups having 2 to 30 ring carbon atoms. These substituents may be plural, and when plural, they may be the same as or different from each other.
Note that Rs on adjacent ring-forming carbons may be bonded to each other to form a ring structure together with the ring-forming carbons.

  Examples of the halogen atom in the general formulas (1) and (1-2) to (1-4) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkyl group having 1 to 20 carbon atoms in the general formulas (1) and (1-2) to (1-4) may be linear, branched or cyclic, and is linear or branched. As the alkyl group, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n- Heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n- Heptadecyl group, n-octadecyl group, neopentyl group, 1-methylpentyl group, 2-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl group, 1-heptyloctyl group, 3-methylpentene Group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group, 1,2-dihydroxyethyl group, 1,3-dihydroxyisopropyl group, 2,3-dihydroxy-t-butyl Group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group, 1,3-dichloroisopropyl group, 2 , 3-dichloro-t-butyl group, 1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3 -Dibromoisopropyl group, 2,3-dibromo-t-butyl group, 1,2,3-tribromopropyl group, iodomethyl group 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-tri Iodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropyl group, 2,3-diamino-t- Butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group, 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2 , 3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group, nitromethyl group, 1-nitroethyl group, 2-nitroethyl group, 1,2-dinito Roethyl group, 2,3-dinitro-t-butyl group, 1,2,3-trinitropropyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, 1,1,1,3,3 , 3-hexafluoro-2-propyl group and the like.
Examples of the cyclic alkyl group (cycloalkyl group) include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentyl group, a cyclohexyl group,
Examples include cyclooctyl group, 4-methylcyclohexyl group, 3,5-tetramethylcyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1-norbornyl group, 2-norbornyl group and the like.

  Examples of the linear, branched or cyclic haloalkyl group having 1 to 20 carbon atoms in the general formulas (1) and (1-2) to (1-4) include, for example, the alkyl having 1 to 20 carbon atoms. And those in which the group is substituted with one or more halogen atoms. Specific examples include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a fluoroethyl group, and a trifluoromethylmethyl group.

Examples of the linear, branched or cyclic alkylene group having 1 to 20 carbon atoms in the general formulas (1) and (1-2) to (1-4) include an ethylene group, a propylene group, and a butylene group. Etc.
Examples of the linear, branched or cyclic divalent unsaturated hydrocarbon group having 1 to 20 carbon atoms in the general formulas (1) and (1-2) to (1-4) include 1, Examples include 3-butadiene-1,4-diyl group.

The linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms in the general formulas (1) and (1-2) to (1-4) is represented as —OZ ¹ . Examples of ^{Z 1,} include an alkyl group having 1 to 20 carbon atoms. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group.
Formula (1), (1-2) - aryloxy group ring forming C6-30 in (1-4) is expressed as -OZ ^2. Examples of Z ² include the following aromatic hydrocarbon groups having 6 to 30 ring carbon atoms. Examples of the aryloxy group include a phenoxy group.
The arylthio group having 6 to 30 ring carbon atoms in the general formulas (1) and (1-2) to (1-4) is represented by —SZ ³ . Examples of Z ³ include the following aromatic hydrocarbon groups having 6 to 30 ring carbon atoms.

  Examples of the linear, branched or cyclic haloalkoxy group having 1 to 20 carbon atoms in the general formulas (1) and (1-2) to (1-4) include, for example, the above 1 to 20 carbon atoms. Examples include those in which an alkoxy group is substituted with one or more halogen groups.

  Examples of the linear, branched or cyclic alkylsilyl group having 1 to 10 carbon atoms in the general formulas (1) and (1-2) to (1-4) include a trimethylsilyl group, a triethylsilyl group, Examples include tributylsilyl group, dimethylethylsilyl group, dimethylisopropylsilyl group, dimethylpropylsilyl group, dimethylbutylsilyl group, dimethyltertiarybutylsilyl group, diethylisopropylsilyl group and the like.

  Examples of the arylsilyl group having 6 to 30 carbon atoms in the general formulas (1) and (1-2) to (1-4) include, for example, a phenyldimethylsilyl group, a diphenylmethylsilyl group, a diphenyl tertiary butylsilyl group, A triphenylsilyl group etc. are mentioned.

  Examples of the aromatic hydrocarbon group having 6 to 30 ring carbon atoms in the general formulas (1) and (1-2) to (1-4) include a non-condensed aromatic hydrocarbon group and a condensed aromatic hydrocarbon group. More specifically, phenyl group, naphthyl group, phenanthryl group, biphenyl group, terphenyl group, quarterphenyl group, fluoranthenyl group, triphenylenyl group, phenanthrenyl group, 9,9-dimethylfluorenyl group, Benzo [c] phenanthrenyl group, benzo [a] triphenylenyl group, naphtho [1,2-c] phenanthrenyl group, naphtho [1,2-a] triphenylenyl group, dibenzo [a, c] triphenylenyl group, benzo [b] full An oranthenyl group, and the like.

  Examples of the aromatic heterocyclic group having 2 to 30 ring carbon atoms in the general formulas (1) and (1-2) to (1-4) include a non-condensed aromatic heterocyclic ring and a condensed aromatic heterocyclic ring. More specifically, pyrrolyl group, pyrazinyl group, pyridinyl group, indolyl group, isoindolyl group, furyl group, benzofuranyl group, isobenzofuranyl group, dibenzofuranyl group, dibenzothiophenyl group, quinolyl group, isoquinolyl group, Quinoxalinyl group, carbazolyl group, phenanthridinyl group, acridinyl group, phenanthrolinyl group, thienyl group, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, indole ring, quinoline ring, acridine ring, pyrrolidine Ring, dioxane ring, piperidine ring, morpholine ring, piperazine ring, carbazole ring, furan , Thiophene ring, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole ring, thiadiazole ring, benzothiazole ring, triazole ring, imidazole ring, benzimidazole ring, pyran ring, dibenzofuran ring, benzo [c] dibenzofuran ring Group to be used.

The divalent linking group represented by L ₁ and L ₂ in the general formulas (1) and (1-2) to (1-4) is a substituted or unsubstituted 2 having 6 to 30 ring carbon atoms. And a substituted or unsubstituted divalent aromatic heterocyclic group having 2 to 10 ring carbon atoms.
Specific examples of the divalent aromatic hydrocarbon group having 6 to 30 ring carbon atoms include those having a divalent group as the above-described aromatic hydrocarbon group having 6 to 30 ring carbon atoms. Can be mentioned.
In addition, as specific examples of the divalent aromatic heterocyclic group having 2 to 30 ring carbon atoms, those mentioned as the above aromatic heterocyclic group having 2 to 30 ring carbon atoms are divalent groups. Things.

In the general formulas (1) and (1-2) to (1-4), it is preferable that Y _{1 to} Y ₁₆ are all C (R). That is, the biscarbazole derivative contained in the hole transport layer 5 preferably has a structure in which two carbazole skeletons that are not azalated are connected. Further, the biscarbazole derivative preferably has two carbazole skeletons in the molecule.

In each of Y ₁ to Y ₈ and Y _{9 to} Y _{16 in} the general formulas (1) and (1-2) to (1-4), the number of substituents represented by R is 0 to 2 Preferably, it is 0 or 1, more preferably.
In addition, as the biscarbazole derivatives represented by the general formulas (1) and (1-2) to (1-4),
A substituted or unsubstituted fluoranthenyl group,
A substituted or unsubstituted triphenylenyl group,
A substituted or unsubstituted benzotriphenylenyl group,
A substituted or unsubstituted benzophenanthrenyl group,
A group selected from the group consisting of a substituted or unsubstituted dibenzofuranyl group and a substituted or unsubstituted dibenzothiophenyl group is preferably bonded.

In the present invention, “ring-forming carbon” means a carbon atom constituting a saturated ring, an unsaturated ring, or an aromatic ring. “Ring-forming atom” means a carbon atom and a hetero atom constituting a hetero ring (including a saturated ring, an unsaturated ring, and 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).

In the case of “substituted or unsubstituted”, examples of the substituent include the aromatic hydrocarbon group, aromatic heterocyclic group, alkyl group (straight chain or branched chain alkyl group, cycloalkyl group, haloalkyl group). Group), alkoxy group, aryloxy group, aralkyl group, haloalkoxy group, alkylsilyl group, dialkylarylsilyl group, alkyldiarylsilyl group, triarylsilyl group, halogen atom, cyano group, hydroxyl group, nitro group, and carboxy group Groups. In addition, an alkenyl group and an alkynyl group are also included.
Among the substituents mentioned here, an aromatic hydrocarbon group, an aromatic heterocyclic group, an alkyl group, a halogen atom, an alkylsilyl group, an arylsilyl group, and a cyano group are preferable. Further, in the description of each substituent, Specific substituents that are preferred are preferred.
The term “unsubstituted” in the case of “substituted or unsubstituted” means that a hydrogen atom is bonded without being substituted with the substituent.
In the present specification, “carbon number ab” in the expression “XX group having a substituted or unsubstituted carbon number ab” represents the number of carbon atoms when the XX group is unsubstituted. The number of carbon atoms of the substituent when the XX group is substituted is not included.
In the compound described below or a partial structure thereof, the case of “substituted or unsubstituted” is the same as described above.

  Specific examples of the biscarbazole derivative of the present invention represented by the general formulas (1) to (4) include the compounds shown below. In the following structural formula, D represents deuterium.

(Light emitting layer)
The light emitting layer of the organic EL element has the following functions.
That is,
(1) injection function; a function capable of injecting holes from the anode or hole injection layer when an electric field is applied, and a function of injecting electrons from the cathode or electron injection layer;
(2) Transport function; function to move injected charges (electrons and holes) by the force of electric field,
(3) Luminescent function; a function to provide a field for recombination of electrons and holes and connect this to light emission,
There is.

However, there may be a difference in the ease with which holes are injected and the ease with which electrons are injected, and the transport capability represented by the mobility of holes and electrons may be large or small.
As a method for forming the light emitting layer, for example, a known method such as an evaporation method, a spin coating method, or an LB method can be applied.

The light emitting layer is preferably a molecular deposited film.
Here, the molecular deposition film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidification from a material compound in a solution state or a liquid phase state. Can be classified from a thin film (accumulated film) formed by the LB method according to a difference in an agglomerated structure and a higher-order structure and a functional difference resulting therefrom.
The light emitting layer can also be formed by dissolving a binder such as a resin and a material compound in a solvent to form a solution, and then thinning the solution by a spin coating method or the like.

-Host material The host material contained in the light emitting layer of this embodiment is an anthracene derivative represented by the following general formula (2).

In the general formula (2), R ^{101 to} R ¹⁰⁸ are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms.

In the general formula (2), any one of R ^{109 to} R ¹¹³ is
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
Selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms;
The other R ^{109 to} R ¹¹³ are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms,
A substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms,
It is selected from either a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.

In the general formula (2), Ar ¹⁰¹ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
It is selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms.

The host material contained in the light emitting layer is preferably an anthracene derivative represented by the following general formula (3), the following general formula (4), or the following general formula (5).

In the general formula (3), Ar ¹¹¹ and Ar ¹¹² are each independently
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
It is selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms.
In the general formula (3), R ^{121 to} R ¹³² are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms.

In the general formula (4), Ar ¹²¹ and Ar ¹²² are each independently
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
Selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms;
In the general formula (4), R ^{141 to} R ¹⁵² are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms.

In the general formula (5),
Ar ¹³¹ is a substituted or unsubstituted phenyl group;
Ar ¹³² is
It is selected from a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms,
R ^{161 to} R ¹⁷² are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms.

  Examples of the aromatic hydrocarbon group having 6 to 30 ring carbon atoms in the general formulas (2) to (5) are exemplified in the description of the general formulas (1) and (1-2) to (1-4). An aromatic hydrocarbon group is mentioned. Among these, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, and a substituted or unsubstituted phenanthryl group are particularly preferable, and more specifically, a phenyl group, 2- A biphenylyl group, a 3-biphenylyl group, a 4-biphenylyl group, a 1-naphthyl group, a 2-naphthyl group, and a 9-phenanthryl group are preferable.

  Examples of the heterocyclic group having 5 to 30 ring atoms in the general formulas (2) to (5) include the aromatics exemplified in the description of the general formulas (1) and (1-2) to (1-4). A heterocyclic group is mentioned.

  Examples of the alkyl group having 1 to 20 carbon atoms in the general formulas (2) to (5) include the alkyl groups exemplified in the description of the general formulas (1) and (1-2) to (1-4). .

  In general formulas (2) to (5), the linear or branched alkyl group preferably has 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. Among the linear or branched alkyl groups, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group Is preferred.

  The number of carbon atoms forming the cycloalkyl group in the general formulas (2) to (5) is preferably 3 to 10, and more preferably 5 to 8. Among the cycloalkyl groups, a cyclopentyl group and a cyclohexyl group are preferable.

  Examples of the alkoxy group having 1 to 20 carbon atoms in the general formulas (2) to (5) include the alkoxy groups exemplified in the description of the general formulas (1) and (1-2) to (1-4). .

  Examples of the aryloxy group having 6 to 30 ring carbon atoms in the general formulas (2) to (5) include aryloxy exemplified in the description of the general formulas (1) and (1-2) to (1-4). Groups.

  Examples of the arylthio group having 6 to 30 ring carbon atoms in the general formulas (2) to (5) include the arylthio groups exemplified in the description of the general formulas (1) and (1-2) to (1-4). Can be mentioned.

  Examples of the trialkylsilyl group having 3 to 40 carbon atoms in the general formulas (2) to (5) include trialkylsilyl exemplified in the description of the general formulas (1) and (1-2) to (1-4). Groups.

Examples of the arylsilyl group having 8 to 60 carbon atoms in the general formulas (2) to (5) include a dialkylarylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group.
Examples of the dialkylarylsilyl group having 8 to 50 carbon atoms in the general formulas (2) to (5) include two alkyl groups exemplified as the alkyl group having 1 to 20 carbon atoms, and the ring-forming carbon. A dialkylarylsilyl group having one aromatic hydrocarbon group of 6 to 20 is mentioned. The carbon number of the dialkylarylsilyl group is preferably 8-30. The two alkyl groups in the dialkylarylsilyl group may be the same or different.
Examples of the alkyldiarylsilyl group having 13 to 50 carbon atoms in the general formulas (2) to (5) include one alkyl group exemplified as the alkyl group having 1 to 20 carbon atoms, and the ring-forming carbon. An alkyldiarylsilyl group having two aromatic hydrocarbon groups of 6 to 20 can be mentioned. The alkyldiarylsilyl group preferably has 13 to 30 carbon atoms. In the alkyldiarylsilyl group, the two aryl groups may be the same or different from each other.
Examples of the triarylsilyl group having 18 to 60 carbon atoms in the general formulas (2) to (5) include a triarylsilyl group having three aromatic hydrocarbon groups having 6 to 30 ring carbon atoms. It is done. The carbon number of the triarylsilyl group is preferably 18-30. In the triarylsilyl group, the three aromatic hydrocarbon groups may be the same or different.

  Next, specific examples of the anthracene derivatives represented by the general formulas (2) to (5) are shown, but the present invention is not limited to these specific examples.

(Dopant material)
The dopant material is selected from fluorescent materials that exhibit fluorescent emission.
Specific examples of the dopant material include naphthalene derivatives, anthracene derivatives, pyrene derivatives, chrysene derivatives, fluoranthene derivatives, indenoperylene derivatives, pyromethene boron complex compounds, compounds having a pyromethene skeleton or metal complexes thereof, diketopyrrolo Examples include pyrrole derivatives and perylene derivatives.
Examples of naphthalene derivatives include bisarylaminonaphthalene derivatives and aryl-substituted naphthalene derivatives, and examples of anthracene derivatives include bisarylaminoanthracene derivatives and aryl group-substituted anthracene derivatives. Examples of the pyrene derivative include bisarylaminopyrene derivatives and aryl group-substituted pyrene derivatives. Examples of the chrysene derivatives include bisarylaminochrysene derivatives and aryl-substituted chrysene derivatives. It 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.

  There is no restriction | limiting in particular in content in the light emitting layer of dopant material, Although it can select suitably according to the objective, For example, 0.1 to 70 mass% is preferable, and 1 to 30 mass% is preferable. Is more preferable. When the content of the dopant material is 0.1% by mass or more, sufficient light emission can be obtained, and when it is 70% by mass or less, concentration quenching can be avoided.

In the present embodiment, the emission color of the dopant material contained in the light emitting layer is not particularly limited, but is preferably a fluorescent light emitting dopant material that emits blue light having a main peak wavelength of 480 nm or less. The main peak wavelength refers to the peak wavelength of the emission spectrum that maximizes the emission intensity in the emission spectrum measured in a toluene solution having a concentration of 10 ⁻⁵ mol / liter to 10 ⁻⁶ mol / liter.
A dopant material having such a main peak wavelength is doped into the host material represented by the general formula (2) to form a light emitting layer, and the hole transport layer adjacent to the anode side of the light emitting layer has the general formula By including the biscarbazole derivative represented by (1), the organic EL element has high efficiency and long life.

(Hole injection / transport layer)
The hole injection / transport layer is a layer that assists hole injection into the light emitting layer and transports it to the light emitting region, and has a high hole mobility and a low ionization energy.
In the present embodiment, the hole injection / transport layer has at least a hole transport layer containing a compound represented by the general formula (2), and may have a hole injection layer in addition to this. Or may have another hole transport layer. Further, the hole injection / transport layer is formed from the anode side, the hole injection layer, the first hole transport layer, the second hole transport layer (a hole transport layer containing a compound represented by the general formula (2)) ) May be laminated in this order.
As a material for forming the hole injection layer and the hole transport layer, a material that transports holes to the light emitting layer with lower electric field strength is preferable. For example, an aromatic amine compound is preferably used. Further, as the material for the hole injection layer, it is preferable to use a porphyrin compound, an aromatic tertiary amine compound or a styrylamine compound. In particular, an aromatic tertiary amine compound such as hexacyanohexaazatriphenylene (HAT) is used. It is preferable to use it.
As the aromatic amine compound, for example, an aromatic amine derivative represented by the following general formula (A1) is preferably used.

In the general formula (A1), Ar ¹ to Ar ⁴ are each independently
An aromatic hydrocarbon group having 6 to 50 ring carbon atoms,
An aromatic heterocyclic group having 2 to 40 ring carbon atoms,
It represents a group in which these aromatic hydrocarbon groups and these aromatic heterocyclic groups are bonded, or a group in which these aromatic hydrocarbon groups and these aromatic heterocyclic groups are bonded. However, the aromatic hydrocarbon group and aromatic heterocyclic group mentioned here may have a substituent.

In the general formula (A1), L is a linking group,
A divalent aromatic hydrocarbon group having 6 to 50 ring carbon atoms,
A single bond of a divalent aromatic heterocyclic group having 5 to 50 ring carbon atoms, or two or more aromatic hydrocarbon groups or aromatic heterocyclic groups,
Ether bond,
Thioether bond,
An alkylene group having 1 to 20 carbon atoms,
An alkenylene group having 2 to 20 carbon atoms, or a divalent group obtained by bonding with an amino group,
Represents. However, the divalent aromatic hydrocarbon group and divalent aromatic heterocyclic group mentioned here may have a substituent.

  Specific examples of the compound represented by the general formula (A1) are shown below, but are not limited thereto.

  An aromatic amine represented by the following general formula (A2) is also preferably used for forming the hole injection / transport layer.

In the general formula (A2), the definitions from Ar ¹ to Ar ³ are the same as the definitions from Ar ¹ to Ar ^{4 in} the general formula (A1). Although the specific example of a compound represented by general formula (A2) below is described, it is not limited to these.

(Electron injection / transport layer)
The electron injection / transport layer is a layer that assists injection of electrons into the light emitting layer, and has a high electron mobility. The electron injection layer is provided to adjust the energy level, for example, to alleviate a sudden change in the energy level. The electron injection / transport layer includes at least one of an electron injection layer and an electron transport layer.
This embodiment preferably has an electron injection layer between the light emitting layer and the cathode, and the electron injection layer preferably contains a nitrogen-containing ring derivative as a main component. Here, the electron injection layer may be a layer that functions as an electron transport layer.
“As a main component” means that the electron injection layer contains 50% by mass or more of a nitrogen-containing ring derivative.

As the electron transporting material used for the electron injection layer, an aromatic heterocyclic compound containing at least one hetero atom in the molecule is preferably used, and a nitrogen-containing ring derivative is particularly preferable. Further, as the nitrogen-containing ring derivative, 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 is preferable.
As this nitrogen-containing ring derivative, for example, a nitrogen-containing ring metal chelate complex represented by the following general formula (B1) is preferable.

R ² to R ⁷ in the general formula (B1) are independently
Hydrogen atom,
Halogen atoms,
An oxy group,
An amino group,
A hydrocarbon group having 1 to 40 carbon atoms,
An alkoxy group,
An aryloxy group,
An alkoxycarbonyl group, or
An aromatic heterocyclic group,
These may have a substituent.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine. Examples of the optionally substituted amino group include an alkylamino group, an arylamino group, and an aralkylamino group.

The alkoxycarbonyl group is represented as —COOY ′, and examples of Y ′ include the same as the alkyl group. The alkylamino group and the aralkylamino group are represented as —NQ ¹ Q ² . Specific examples of Q ¹ and Q ² are independently the same as those described for the alkyl group and the aralkyl group, and preferred examples are also the same. One of Q ¹ and Q ² may be a hydrogen atom. The aralkyl group is a group in which a hydrogen atom of the alkyl group is substituted with the aryl group.
The arylamino group is represented by —NAr ¹ Ar ^2, and specific examples of Ar ¹ and Ar ² are the same as those described for the non-condensed aromatic hydrocarbon group and the condensed aromatic hydrocarbon group, respectively. . One of Ar ¹ and Ar ² may be a hydrogen atom.

M is aluminum (Al), gallium (Ga) or indium (In), and is preferably In.
L in the general formula (B1) is a group represented by the following general formula (B2) or (B3).

In the general formula (B2), R ⁸ to R ¹² are independently
A hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms, and groups adjacent to each other may form a cyclic structure. This hydrocarbon group may have a substituent.
In the general formula (B3), R ¹³ to R ²⁷ are independently
A hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms,
Adjacent groups may form a cyclic structure. This hydrocarbon group may have a substituent.
Examples of the hydrocarbon group having 1 to 40 carbon atoms represented by R ⁸ to R ¹² and R ¹³ to R ^{27 in the} general formula (B2) and the general formula (B3) include those in the general formula (B1). those from R ² similar to the specific examples to R ⁷ can be exemplified.
In addition, as the divalent group in the case where the groups adjacent to each other from R ⁸ to R ¹² and R ¹³ to R ²⁷ form a cyclic structure, a tetramethylene group, a pentamethylene group, a hexamethylene group, diphenylmethane- A 2,2′-diyl group, a diphenylethane-3,3′-diyl group, a diphenylpropane-4,4′-diyl group and the like can be mentioned.

  Moreover, it is preferable that an electron carrying layer contains at least any one of the nitrogen-containing heterocyclic derivative represented by the following general formula (B4) to (B6).

In the general formulas (B4) to (B6), R is
Hydrogen atom,
An aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
A condensed aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
Pyridyl group,
A quinolyl group,
An alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms.
n is an integer of 0 or more and 4 or less.

In the general formulas (B4) to (B6), R ¹ is
An aromatic hydrocarbon group having 6 to 60 ring carbon atoms, a condensed aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
Pyridyl group,
A quinolyl group,
An alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms.

In the general formulas (B4) to (B6), R ² and R ³ are independently
Hydrogen atom,
An aromatic hydrocarbon group having 6 to 60 ring carbon atoms, a condensed aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
Pyridyl group,
A quinolyl group,
An alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms.

In the general formulas (B4) to (B6), L is
An aromatic hydrocarbon group having 6 to 60 ring carbon atoms, a condensed aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
A pyridinylene group,
It is a quinolinylene group or a fluorenylene group.

In the general formulas (B4) to (B6), Ar ¹ is
An aromatic hydrocarbon group having 6 to 60 ring carbon atoms, a condensed aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
A pyridinylene group,
It is a quinolinylene group.

In the general formulas (B4) to (B6), Ar ² is
An aromatic hydrocarbon group having 6 to 60 ring carbon atoms, a condensed aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
Pyridyl group,
A quinolyl group,
An alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms.

In the general formulas (B4) to (B6), Ar ³ is
An aromatic hydrocarbon group having 6 to 60 ring carbon atoms, a condensed aromatic hydrocarbon group having 6 to 60 ring carbon atoms,
Pyridyl group,
A quinolyl group,
An alkyl group having 1 to 20 carbon atoms,
An alkoxy group having 1 to 20 carbon atoms or a group represented by “—Ar ¹ —Ar ² ” (Ar ¹ and Ar ² are the same as described above).

Further, the condensed aromatic hydrocarbons mentioned in the description of R, R ¹ , R ² , R ³ , L, Ar ¹ , Ar ² , and Ar ^{3 in} the formulas (B4) to (B6) The group, pyridyl group, quinolyl group, alkyl group, alkoxy group, pyridinylene group, quinolinylene group and fluorenylene group may have a substituent.

  As the electron transporting compound used for the electron injecting layer or the electron transporting layer, a metal complex of 8-hydroxyquinoline or a derivative thereof, an oxadiazole derivative, or a nitrogen-containing heterocyclic derivative is preferable. As a specific example of the metal complex of 8-hydroxyquinoline or a derivative thereof, a metal chelate oxinoid compound containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline), for example, tris (8-quinolinol) aluminum is used. Can do. And as an oxadiazole derivative, the following can be mentioned.

In each general formula of these oxadiazole derivatives, Ar ¹⁷ , Ar ¹⁸ , Ar ¹⁹ , Ar ²¹ , Ar ²² and Ar ²⁵ are
It is an aromatic hydrocarbon group having 6 to 40 ring carbon atoms or a condensed aromatic hydrocarbon group having 6 to 40 ring carbon atoms.
However, the aromatic hydrocarbon group and condensed aromatic hydrocarbon group mentioned here may have a substituent. Ar ¹⁷ and Ar ¹⁸ , Ar ¹⁹ and Ar ²¹ , Ar ²² and Ar ²⁵ may be the same as or different from each other.
Examples of the aromatic hydrocarbon group or condensed aromatic hydrocarbon group mentioned here include a phenyl group, a naphthyl group, a biphenyl group, an anthranyl group, a perylenyl group, and a pyrenyl group. And as a substituent to these, a C1-C10 alkyl group, a C1-C10 alkoxy group, a cyano group, etc. are mentioned.

In each general formula of these oxadiazole derivatives, Ar ²⁰ , Ar ²³ and Ar ²⁴ are
A divalent aromatic hydrocarbon group having 6 to 40 ring carbon atoms or a divalent condensed aromatic hydrocarbon group having 6 to 40 ring carbon atoms.
However, the aromatic hydrocarbon group and condensed aromatic hydrocarbon group mentioned here may have a substituent.
Ar ²³ and Ar ²⁴ may be the same as or different from each other.
Examples of the divalent aromatic hydrocarbon group or the divalent condensed aromatic hydrocarbon group mentioned here include a phenylene group, a naphthylene group, a biphenylene group, an anthranylene group, a peryleneylene group, and a pyrenylene group. And as a substituent to these, a C1-C10 alkyl group, a C1-C10 alkoxy group, a cyano group, etc. are mentioned.

  As these electron transfer compounds, those having good thin film forming properties are preferably used. Specific examples of these electron transfer compounds include the following.

  The nitrogen-containing heterocyclic derivative as the electron transfer compound is a nitrogen-containing heterocyclic derivative composed of an organic compound having the following general formula, and includes a nitrogen-containing compound that is not a metal complex. For example, a 5-membered or 6-membered ring containing a skeleton represented by the following general formula (B7) and a structure represented by the following general formula (B8) can be given.

In the general formula (B8), X represents a carbon atom or a nitrogen atom. Z ₁ and Z ₂ each independently represents an atomic group capable of forming a nitrogen-containing heterocycle.

  The nitrogen-containing heterocyclic derivative is more preferably an organic compound having a nitrogen-containing aromatic polycyclic group consisting of a 5-membered ring or a 6-membered ring. Further, in the case of such a nitrogen-containing aromatic polycyclic group having a plurality of nitrogen atoms, a skeleton obtained by combining the general formulas (B7) and (B8) or the general formula (B7) with the following general formula (B9) is used. The nitrogen-containing aromatic polycyclic organic compound having is preferable.

  The nitrogen-containing group of the nitrogen-containing aromatic polycyclic organic compound is selected from, for example, nitrogen-containing heterocyclic groups represented by the following general formula.

In each general formula of these nitrogen-containing heterocyclic groups, R is
An aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
A condensed aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
An aromatic heterocyclic group having 2 to 40 ring carbon atoms,
A condensed aromatic heterocyclic group having 2 to 40 ring carbon atoms,
An alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms.
In each general formula of these nitrogen-containing heterocyclic groups, n is an integer of 0 or more and 5 or less, and when n is an integer of 2 or more, a plurality of R may be the same or different from each other.

Furthermore, preferred specific compounds include nitrogen-containing heterocyclic derivatives represented by the following general formula (B10).
HAr-L ¹ -Ar ¹ -Ar ² (B10)
In the general formula (B10), HAr is
A nitrogen-containing heterocyclic group having 1 to 40 ring carbon atoms.
In the general formula (B10), L ¹ is
Single bond,
An aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
A condensed aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
An aromatic heterocyclic group having 2 to 40 ring carbon atoms or a condensed aromatic heterocyclic group having 2 to 40 ring carbon atoms.

In the general formula (B10), Ar ¹ is
A divalent aromatic hydrocarbon group having 6 to 40 ring carbon atoms.
In the general formula (B10), Ar ² is
An aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
A condensed aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
An aromatic heterocyclic group having 2 to 40 ring carbon atoms or a condensed aromatic heterocyclic group having 2 to 40 ring carbon atoms.

In addition, the nitrogen-containing heterocyclic group, the aromatic hydrocarbon group, the condensed aromatic hydrocarbon group, and the aromatic complex mentioned in the description of HAr, L ¹ , Ar ¹ , and Ar ^{2 in} the general formula (B10) The ring group and the condensed aromatic heterocyclic group may have a substituent.

  HAr in the formula of the general formula (B10) is selected from the following group, for example.

L ¹ in the formula (B10) is, for example, selected from the following group.

Ar ¹ in the formula (B10) is, for example, selected from the following arylanthranyl groups.

In the general formula of the arylanthranyl group, R ¹ to R ¹⁴ are independently
Hydrogen atom,
Halogen atoms,
An alkyl group having 1 to 20 carbon atoms,
An alkoxy group having 1 to 20 carbon atoms,
An aryloxy group having 6 to 40 ring carbon atoms,
An aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
A condensed aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
An aromatic heterocyclic group having 2 to 40 ring carbon atoms or a condensed aromatic heterocyclic group having 2 to 40 ring carbon atoms.

In the general formula of the arylanthranyl group, Ar ³ is
An aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
A condensed aromatic hydrocarbon group having 6 to 40 ring carbon atoms,
An aromatic heterocyclic group having 2 to 40 ring carbon atoms or a condensed aromatic heterocyclic group having 2 to 40 ring carbon atoms.

However, R ¹ to R ^{14 in} the general formula of the arylanthranyl group, and the aromatic hydrocarbon group, condensed aromatic hydrocarbon group, aromatic heterocyclic group, and condensed aromatic heterocyclic group mentioned in the description of Ar ³ The cyclic group may have a substituent.
Further, any of R ¹ to R ⁸ may be a nitrogen-containing heterocyclic derivative which is a hydrogen atom.

In the general formula of the arylanthranyl group, Ar ² is selected from the following group, for example.

  In addition to the nitrogen-containing aromatic polycyclic organic compound as the electron transfer compound, the following compounds (see JP-A-9-3448) are also preferably used.

In the general formula of this nitrogen-containing aromatic polycyclic organic compound, R ¹ to R ⁴ are independently
Hydrogen atom,
Aliphatic groups,
An aliphatic cyclic group,
Represents a carbocyclic aromatic ring group or a heterocyclic group. However, the aliphatic group, aliphatic cyclic group, carbocyclic aromatic ring group, and heterocyclic group mentioned here may have a substituent.
In the general formula of this nitrogen-containing aromatic polycyclic organic compound, X ¹ and X ² independently represent an oxygen atom, a sulfur atom, or a dicyanomethylene group.

  In addition, the following compounds (see Japanese Patent Application Laid-Open No. 2000-173774) are also preferably used as the electron transfer compound.

In the general formula, R ¹ , R ² , R ^3, and R ⁴ are the same or different groups, and are an aromatic hydrocarbon group or a condensed aromatic hydrocarbon group represented by the following general formula.

In the above general formula, R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are the same or different groups, and hydrogen atom or at least one of them is a saturated or unsaturated alkoxyl group, alkyl group, amino group A group or an alkylamino group.

  Further, the electron transport compound may be a polymer compound containing the nitrogen-containing heterocyclic group or the nitrogen-containing heterocyclic derivative.

The thickness of the electron injection layer or the electron transport layer is not particularly limited, but is preferably 1 nm or more and 100 nm or less.
Moreover, as a constituent component of the electron injection layer, it is preferable to use an insulator or a semiconductor as an inorganic compound in addition to the nitrogen-containing ring derivative. 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.

As such an insulator, it is preferable to use at least one metal compound selected from the group consisting of alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides. If the electron injection layer is composed of these alkali metal chalcogenides or the like, it is preferable in that the electron injection property can be further improved. Specifically, preferred alkali metal chalcogenides include, for example, lithium oxide (Li ₂ O), potassium oxide (K ₂ O), sodium sulfide (Na ₂ S), sodium selenide (Na ₂ Se), and sodium oxide (Na ₂ O). Preferred alkaline earth metal chalcogenides include, for example, calcium oxide (CaO), barium oxide (BaO), strontium oxide (SrO), beryllium oxide (BeO), barium sulfide (BaS), and calcium selenide (CaSe). . Examples of preferable alkali metal halides include lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), lithium chloride (LiCl), potassium chloride (KCl), and sodium chloride (NaCl). ) And the like. Examples of preferable alkaline earth metal halides include calcium fluoride (CaF ₂ ), barium fluoride (BaF ₂ ), strontium fluoride (SrF ₂ ), magnesium fluoride (MgF ₂ ), and beryllium fluoride. Examples thereof include fluorides such as (BeF ₂ ) and halides other than fluorides.

Moreover, as a semiconductor, barium (Ba), calcium (Ca), strontium (Sr), ytterbium (Yb), aluminum (Al), gallium (Ga), indium (In), lithium (Li), sodium (Na) , Cadmium (Cd), magnesium (Mg), silicon (Si), tantalum (Ta), antimony (Sb), oxide containing at least one element of zinc (Zn), nitride or oxynitride alone Or the combination of 2 or more types is mentioned. In addition, the inorganic compound constituting the electron injection layer is preferably a microcrystalline or amorphous insulating thin film. If the electron injection layer is composed of these insulating thin films, a more uniform thin film is formed, so that pixel defects such as dark spots can be reduced. Examples of such inorganic compounds include alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides.
When such an insulator or semiconductor is used, the preferable thickness of the layer is about 0.1 nm to 15 nm. Moreover, even if the electron injection layer in this invention contains the above-mentioned reducing dopant material, it is preferable.

(Electron donating dopant and organometallic complex)
The organic EL device of the present invention preferably has at least one of an electron donating dopant and an organometallic complex in the interface region between the cathode and the organic 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 or Cs is 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), such as terbium fluoride (TbF ₃₎ can be _{mentioned, YbF 3, ScF 3, TbF} 3 are preferable.

  As described above, the organometallic complex is not particularly limited as long as it contains at least one of alkali metal ions, alkaline earth metal ions, and rare earth metal ions as metal ions. 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 preferable, but not limited thereto.

The addition form of the electron donating dopant and the organometallic complex is preferably formed in a layered or island shape 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 which is a light-emitting material or an electron injection material for forming an interface region is vapor-deposited at the same time. A method of dispersing at least one of a donor dopant and an organometallic complex reducing dopant is preferable. The dispersion concentration is organic substance: electron-donating dopant, organometallic complex = 100: 1 to 1: 100, preferably 5: 1 to 1: 5 in molar ratio.
When forming at least one of the electron donating dopant and the organometallic complex in a layered form, after forming the light emitting material or the electron injecting material as 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 the electron donating dopant and the organometallic complex is formed in an island shape, after the light emitting material or the electron injecting material, which is the organic layer at the interface, is formed in an island shape, the electron donating dopant and the organometallic complex 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 the main component to at least one of the electron donating dopant and the organometallic complex is, as a molar ratio, the main component: the electron donating dopant, the organometallic complex = 5: 1 to 1. Is preferably up to 5, more preferably from 2: 1 to 1: 2.

(Method for forming each layer of organic EL element)
The formation method of each layer of the organic EL element of the present invention is not particularly limited. Conventionally known methods such as vacuum deposition and spin coating can be used. The organic layer used in the organic EL device of the present invention is formed by a vacuum deposition method, a molecular beam deposition method (MBE method, MBE; Molecular Beam Epitaxy), a solution dipping method in a solvent, a spin coating method, a casting method, or a bar coating method. It can be formed by a known method using a coating method such as a roll coating method.

(Thickness of each layer of organic EL element)
The thickness of the light emitting layer is preferably 5 nm to 50 nm, more preferably 7 nm to 50 nm, and most preferably 10 nm to 50 nm. By setting the thickness of the light emitting layer to 5 nm or more, it becomes easy to form the light emitting layer and adjust the chromaticity. By setting the film thickness of the light emitting layer to 50 nm or less, an increase in driving voltage can be suppressed.
The film thickness of each of the other organic layers is not particularly limited, but usually a range of several nm to 1 μm is preferable. By making such a film thickness range, defects such as pinholes caused by the film thickness being too thin are prevented, and an increase in driving voltage caused by the film thickness being too thick is suppressed, resulting in deterioration of efficiency. Can be prevented.

[Modification of Embodiment]
In addition, this invention is not limited to the above-mentioned embodiment, The change in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.

The light emitting layer is not limited to one layer, and a plurality of light emitting layers may be stacked. When the organic EL device has a plurality of light emitting layers, at least one light emitting layer contains the compound represented by the general formula (2), and the hole transport layer adjacent to the anode side of the light emitting layer is the general What is necessary is just to contain the compound represented by Formula (1), and the other light emitting layer may be a fluorescent light emitting type light emitting layer, or a phosphorescent light emitting type light emitting layer.
In addition, when the organic EL element has a plurality of light emitting layers, these light emitting layers may be provided adjacent to each other, or a so-called tandem organic material in which a plurality of light emitting units are stacked via an intermediate layer. It may be an EL element.

In the present invention, it is also preferable that the light emitting layer contains a charge injection auxiliary material.
When a light emitting layer is formed using a host material having a wide energy gap, the difference between the ionization potential (Ip) of the host material and Ip of the hole injection / transport layer, etc. increases, and holes are injected into the light emitting layer. This may make it difficult to increase the driving voltage for obtaining sufficient luminance.
In such a case, by adding a hole injection / transport charge injection auxiliary agent to the light emitting layer, hole injection into the light emitting layer can be facilitated and the driving voltage can be lowered.

As the charge injection auxiliary agent, for example, a general hole injection / transport material or the like can be used.
Specific examples include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, fluorenone derivatives, hydrazone derivatives, stilbenes. Derivatives, silazane derivatives, polysilane-based, aniline-based copolymers, conductive polymer oligomers (particularly thiophene oligomers), and the like can be given.

  Examples of the hole-injecting material include those described above, and porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds, particularly aromatic tertiary amine compounds are preferred.

In addition, for example, 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl (hereinafter abbreviated as NPD) having two condensed aromatic rings in the molecule, or triphenylamine 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) -N-phenylamino) triphenylamine (hereinafter abbreviated as MTDATA) and the like in which three units are connected in a starburst type. it can.
A hexaazatriphenylene derivative or the like can also be suitably used as the hole injecting material.
In addition, inorganic compounds such as p-type Si and p-type SiC can also be used as the hole injection material.

  The organic EL element of the present invention can be suitably used as an electronic device such as a display device such as a television, a mobile phone, or a personal computer, or a light emitting device for lighting or a vehicular lamp.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated in more detail, this invention is not restrict | limited at all to the description content of these Examples.

[Synthesis Example]
(Synthesis of Compound 1)

Synthesis of Intermediate 1-2 Under an argon atmosphere, 4-iodobromobenzene (28.3 g, 100.0 mmol), dibenzofuran-4-boronic acid (22.3 g, 105 mmol), tetrakis (triphenylphosphine) palladium ( 0) (2.31 g, 2.00 mmol) was added toluene (150 mL), dimethoxyethane (150 mL), and 2M aqueous sodium carbonate (150 mL), and the mixture was heated at reflux for 10 hours.
After completion of the reaction, the mixture was immediately filtered and the aqueous layer was removed. The organic layer was dried over sodium sulfate and concentrated. The residue was purified by silica gel column chromatography to obtain intermediate 1-2 (26.2 g, yield 81%).
According to the FD-MS analysis, m / e = 322 with respect to the molecular weight 322.

Synthesis of Compound 1 In a three-necked flask under an argon atmosphere, Intermediate 1-2 (2.36 g, 7.3 mmol), Intermediate 1-1 (3.0 g, 7.3 mmol), CuI (1.4 g , 7.3 mmol), tripotassium phosphate (2.3 g, 11 mmol), anhydrous dioxane (30 mL) and cyclohexanediamine (0.84 g, 7.3 mmol) were added in this order, and the mixture was stirred at 100 ° C. for 8 hours. Water was added to the reaction solution to precipitate a solid, which was washed with hexane and then with methanol. Furthermore, the obtained solid was purified by silica gel column chromatography to obtain compound 1 (2.9 g, yield 60%).
As a result of FD-MS analysis, m / e = 650 with respect to the molecular weight of 650.

[Example of manufacturing organic EL element]
Example 1
A glass substrate with an ITO transparent electrode of 25 mm × 75 mm × thickness 1.1 mm (manufactured by Geomatic Co., Ltd.) was subjected to ultrasonic cleaning in isopropyl alcohol for 5 minutes and then UV ozone cleaning for 30 minutes. The thickness of the ITO transparent electrode was 130 nm.
The glass substrate with the ITO transparent electrode line after washing is mounted on the substrate holder of the vacuum evaporation apparatus, and the following compound (HI-1) is first covered so as to cover the transparent electrode on the surface on which the ITO transparent electrode line is formed. ) To form a HI-1 film having a thickness of 5 nm to form a hole injection layer.
Next, on the HI-1 film, the following compound HT-1 was deposited as a first hole transport material to form an HT-1 film having a thickness of 80 nm to form a first hole transport layer.
Next, on this HT-1 film, the following compound HT-2 (compound 1 obtained in Synthesis Example 1) is deposited to form an HT-2 film having a film thickness of 15 nm, and the second hole transport A layer was formed.
Furthermore, on this HT-2 film | membrane, compound BH-1 was vapor-deposited and the light emitting layer with a film thickness of 25 nm was formed into a film. At the same time, the following compound (BD1) was co-deposited as a fluorescent material. The concentration of Compound BD1 was 5.0% by mass. This co-deposited film functions as a light emitting layer.
And on this light emitting layer, the following compound ET-1 was vapor-deposited and the ET-1 film | membrane with a film thickness of 20 nm was formed into a film, and the 1st electron carrying layer was formed.
Next, the following compound ET-2 was vapor-deposited on this ET-1 film to form an ET-2 film having a thickness of 5 nm, thereby forming a second electron transport layer.
Next, LiF was deposited on the ET-2 film at a deposition rate of 0.1 angstrom / min to form a 1 nm-thick LiF film to form an electron injecting electrode (cathode).
And metal Al was vapor-deposited on this LiF film | membrane, the metal Al film | membrane with a film thickness of 80 nm was formed into a film, and the metal Al cathode was formed.

  The compound used for manufacture of an organic EL element is shown below.

・ Comparative Examples 1-3
The organic EL elements of Comparative Examples 1 to 3 except that at least one of the compound HT-2 of the second hole transport layer and the compound BH-1 of the light emitting layer in Example 1 was changed to the compounds shown in Table 1. Was prepared in the same manner as in Example 1.

[Evaluation of organic EL elements]
About the produced organic EL element, brightness | luminance (unit: cd / m < ² >), CIE1931 chromaticity, current efficiency L / J, external quantum efficiency EQE, main peak wavelength (lambda) _p , and lifetime were evaluated. Table 2 shows the results when the current density is 1.00 mA / cm ² for each evaluation item. The values of brightness, current efficiency L / J, external quantum efficiency EQE, and lifetime shown in Table 2 are the values of the evaluation items of Example 1 and Comparative Examples 1 to 3 with respect to the values of the evaluation items of Comparative Example 1. It is the value obtained by calculating the ratio.

CIE1931 chromaticity CIE1931 chromaticity coordinates (x, y) when a voltage is applied to the element so that the current density is 1.00 mA / cm ² is measured with a spectral radiance meter CS-1000 (manufactured by Konica Minolta). did.

・ Current efficiency L / J
The spectral radiance spectrum when a voltage is applied to the device so that the current density is 1.00 mA / cm ² is measured by the spectral radiance meter, and the current efficiency (unit: cd) is obtained from the obtained spectral radiance spectrum. / A) was calculated.

・ Main peak wavelength λ _p
The main peak wavelength λ _p (unit: nm) was determined from the obtained spectral radiance spectrum.

・ External quantum efficiency EQE
The external quantum efficiency EQE (unit:%) was calculated from the obtained spectral radiance spectrum on the assumption that Lambtian radiation was performed.

・ Lifetime LT80
A voltage was applied to the device so that the current density was 50.00 mA / cm ^2, and the time (unit: h) until the luminance became 80% with respect to the initial luminance was measured.

  As Table 2 shows, it was found that the organic EL element of Example 1 was a long-life organic EL element with higher luminous efficiency than the organic EL elements of Comparative Examples 1 to 3. For example, the organic EL element of Example 1 has an external quantum efficiency EQE of 2.3 times, a lifetime LT80 of 1.3 times, a high luminous efficiency, and a long lifetime compared to the organic EL element of Comparative Example 1. It turns out that.

  The organic EL element of the present invention has high luminous efficiency and can be used for electronic devices such as lighting devices and display devices as long-life organic EL elements.

DESCRIPTION OF SYMBOLS 1 ... Organic electroluminescent element 2 ... Substrate 3 ... Anode 4 ... Cathode 5 ... Phosphorescent light emitting layer 6 ... Hole injection / transport layer 7 ... Electron injection / transport layer 10 ... Organic thin film layer

Claims (9)

The anode,
A cathode provided opposite to the anode;
An organic layer provided between the anode and the cathode,
The organic layer includes a hole transport layer and a light emitting layer in this order from the anode side,
The hole transport layer includes a biscarbazole derivative represented by the following general formula (1),
The said light emitting layer contains the anthracene derivative represented by following General formula (2), and a luminescent material. The organic electroluminescent element characterized by the above-mentioned.

(In the general formula (1), A ₁ and A ₂ are each independently
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 2 to 30 ring carbon atoms.
Y _{1 to} Y ₁₆ each independently represent C (R) or a nitrogen atom, and each R independently represents a bond bonded to a hydrogen atom, a substituent, or a carbazole skeleton.
L ₁ and L ₂ each independently represent a single bond or a divalent linking group.
However, at least one of A ₁ , A ₂ and R is
A substituted or unsubstituted fluoranthenyl group,
A substituted or unsubstituted triphenylenyl group,
A substituted or unsubstituted benzophenanthrenyl group,
A substituted or unsubstituted benzotriphenylenyl group,
A substituted or unsubstituted dibenzotriphenylenyl group,
A substituted or unsubstituted chrysenyl group,
A substituted or unsubstituted benzocrisenyl group,
A substituted or unsubstituted picenyl group,
A substituted or unsubstituted benzo [b] fluoranthenyl group,
A substituted or unsubstituted benzofuranyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted benzothiophenyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted phenanthrenyl group,
It represents a substituted or unsubstituted fluorenyl group or a substituted or unsubstituted binaphthyl group.
In addition, when Y _{1 to} Y ₁₆ are all C (R), Y ₆ and Y ₁₁ are bonded by a single bond, L ₁ and L ₂ are a single bond, and A ₁ is a phenanthrenyl group, A ₂ Is not a phenanthrenyl group.
Further, when Y _{1 to} Y ₁₆ are all C (R), Y ₆ and Y ₁₁ are bonded by a single bond, and L ₁ and L ₂ are a single bond, R is not a fluorenyl group. In addition, when A ₁ is a fluorenyl group, A ₂ is not a phenyl group, a naphthyl group, or a fluorenyl group. )

(In the general formula (2), R ^{101 to} R ¹⁰⁸ are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
Either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms, or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms,
Any one of R ^{109 to} R ¹¹³ is
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
Selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms;
The other R ^{109 to} R ¹¹³ are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms,
A substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms,
Selected from a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;
Ar ¹⁰¹ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
It is selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms. ) The organic electroluminescent device according to claim 1,
In the general formula (1), at least one of A ₁ and A ₂ is
A substituted or unsubstituted fluoranthenyl group,
A substituted or unsubstituted triphenylenyl group,
A substituted or unsubstituted benzophenanthrenyl group,
A substituted or unsubstituted benzotriphenylenyl group,
A substituted or unsubstituted dibenzotriphenylenyl group,
A substituted or unsubstituted chrysenyl group,
A substituted or unsubstituted benzocrisenyl group,
A substituted or unsubstituted picenyl group,
A substituted or unsubstituted benzo [b] fluoranthenyl group,
A substituted or unsubstituted benzofuranyl group,
A substituted or unsubstituted dibenzofuranyl group,
A substituted or unsubstituted benzothiophenyl group,
A substituted or unsubstituted dibenzothiophenyl group,
A substituted or unsubstituted phenanthrenyl group,
It is a substituted or unsubstituted fluorenyl group, or a substituted or unsubstituted binaphthyl group. The organic electroluminescent element characterized by the above-mentioned. In the organic electroluminescent element according to claim 1 or 2,
The organic electroluminescent element characterized by the biscarbazole derivative contained in the said positive hole transport layer being represented by following General formula (1-2).
In the organic electroluminescent element according to claim 1 or 2,
The organic electroluminescent element characterized by the biscarbazole derivative contained in the said positive hole transport layer being represented by the following general formula (1-3) or the following general formula (1-4).


In the organic electroluminescent element according to any one of claims 1 to 4,
The structure of the portion represented by L ₁ -A ₁ of the biscarbazole derivative contained in the hole transport layer and the structure of the portion represented by L ₂ -A ₂ are different from each other. Luminescence element. In the organic electroluminescent element according to any one of claims 1 to 5,
An anthracene derivative contained in the light emitting layer is represented by the following general formula (3).

(In the general formula (3), Ar ¹¹¹ and Ar ¹¹² are each independently
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
Selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms;
R ^{121 to} R ¹³² are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms. ) In the organic electroluminescent element according to any one of claims 1 to 5,
The organic electroluminescent element characterized by the anthracene derivative contained in the said light emitting layer being shown by following General formula (4).


(In the general formula (4), Ar ¹²¹ and Ar ¹²² are each independently
A substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or
Selected from substituted or unsubstituted heterocyclic groups having 5 to 30 ring atoms;
R ^{141 to} R ¹⁵² are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms. ) In the organic electroluminescent element according to any one of claims 1 to 5,
The organic electroluminescent element characterized by the anthracene derivative contained in the said light emitting layer being represented by following General formula (5).

(In the general formula (5),
Ar ¹³¹ is a substituted or unsubstituted phenyl group;
Ar ¹³² is
It is selected from a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms,
R ^{161 to} R ¹⁷² are each independently
Hydrogen atom,
Halogen atoms,
Hydroxyl group,
A cyano group,
A substituted or unsubstituted amino group,
A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms,
A substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,
A substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms,
A substituted or unsubstituted arylthio group having 6 to 20 ring carbon atoms,
It is selected from either a substituted or unsubstituted trialkylsilyl group having 3 to 40 carbon atoms or a substituted or unsubstituted arylsilyl group having 8 to 50 carbon atoms. )   An electronic apparatus comprising the organic electroluminescence element according to any one of claims 1 to 8.