WO2014157230A1 - Organic electroluminescent element and manufacturing method therefor - Google Patents

Abstract

Provided are an organic electroluminescent element and a manufacturing method therefor, said organic electroluminescent element having the following, in this order, on top of a positive electrode: a hole-transport band containing a conductive polymer or oligomer; a light-emitting layer; and an electron-transport band. The conductive polymer or oligomer layer is adjacent to the light-emitting layer, and the light-emitting layer is adjacent to the electron-transport band. The electron-transport band contains a plurality of electron-transport layers, and the triplet energy of a compound that forms the electron-transport layer adjacent to the light-emitting layer is at least 0.1 eV higher than the triplet energy of a host material in the light-emitting layer. The light-emitting layer contains a metal complex, and the ligands of said metal complex contain a specific structure. This organic electroluminescent element, in which layers can be formed via a coating method, excels in luminous efficacy and has a long emission lifespan.

Description

[Name of invention determined by ISA based on Rule 37.2] Organic electroluminescence device and method for manufacturing the same

The present invention relates to organic electroluminescence and a method for producing the same.

In recent years, organic electroluminescence (EL) displays have attracted attention as displays that are thinner, lighter, and higher in image quality than liquid crystal displays, and have begun to appear on the market centering on small displays for MP3 players and mobile phones. In the future, a large organic EL display having a diagonal size of about 50 inches is expected.
In order to produce a large-sized organic EL display at a low price, it is required to produce an element by a simpler film forming process, but the current mainstream method for forming an organic EL display is that This is a vapor deposition method under a high vacuum of about 10 to the fourth power (Pa), and there is a problem of high cost for manufacturing a large area device.

On the other hand, coating methods such as printing and coating methods that can form a thin film more easily than vapor deposition methods are attracting attention. In a coating type organic EL element, when a light emitting layer is applied and laminated, it is necessary that the organic layer as a base is insoluble in a solution or ink for applying the light emitting layer.
Conventionally, PEDOT: PSS or the like sold as Clevious from Heraeus has been used as a hole injection / transport material. PEDOT: PSS is a conductive polymer that can be dispersed or dissolved in water or a polar solvent.
Since such a conductive polymer is hardly soluble in an aromatic solvent, the organic EL material forming the light emitting layer of the organic EL element is dissolved in a nonpolar solvent such as toluene, and is applied and laminated. Laminate film formation is possible without eroding the PEDOT: PSS serving as the base.

However, when a light emitting layer is directly laminated on such a hole injecting / transporting polymer layer, the light emitting efficiency and the light emitting lifetime are remarkably lowered. As this mechanism, acid, metal ions, etc. are diffused from the hole injection / transport material to the light emitting layer.
As a solution to this problem, a method of inserting a polymer layer called an interlayer as described in paragraph [0211] of Patent Document 1 has been common. However, inserting an interlayer increases the number of coating layers, and the simplicity of the film forming process, which is an advantage of the coating type compared to the vapor deposition type, is impaired.

JP 2011-26237 A

The present invention has been made to solve the above-described problems, and provides an organic EL element that can form a layer of an organic EL element by a coating method and has excellent luminous efficiency and luminous lifetime, and a method for manufacturing the same. With the goal.

According to one aspect of the present invention, the following items 1 to 3 are provided.
1. On the anode, an organic electroluminescence device having a hole transport zone containing a conductive polymer or oligomer, a light emitting layer, and an electron transport zone in order,
The hole transport zone and the light emitting layer are adjacent, the light emitting layer and the electron transport zone are adjacent,
The electron transport zone includes a plurality of electron transport layers, and the triplet energy of a compound forming the electron transport layer adjacent to the light emitting layer among the electron transport layers is a triplet of a host material included in the light emitting layer. 0.1 eV or more larger than energy,
The light-emitting layer contains a metal complex, and the ligand of the metal complex contains at least one structure represented by the following formula (1).

[In Formula (1), (X ₁ , X ₂ ) is (carbon atom, nitrogen atom) or (nitrogen atom, carbon atom). That is, _one of X ₁ and X ₂ is a carbon atom and the other is a nitrogen atom.
A, B, and D are substituted or unsubstituted aromatic hydrocarbon ring groups, or substituted or unsubstituted aromatic heterocyclic groups, and these substituents may be bonded to each other to form a ring. .
m is an integer of 1 to 10, and when it is 2 or more, D may be the same or different. ]

2. A red light emitting element, a green light emitting element, and a blue light emitting element are provided in parallel,
Each of the red light emitting element, the green light emitting element, and the blue light emitting element has an anode to which a current is applied independently, and has a hole transport zone containing a conductive polymer or oligomer on each anode, A red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer are juxtaposed on the positive hole transport band, and each electron-emitting layer has an electron transport band,
The electron transport zone is adjacent to the red light emitting layer, the green light emitting layer, and the blue light emitting layer, and is provided in common.
The said green light emitting layer contains the metal complex represented by Formula (9), The organic electroluminescent element characterized by the above-mentioned.

Wherein (9), (X _1, X ₂₎ is a (carbon atom, a nitrogen atom), or (a nitrogen atom, a carbon atom).
A, B, and D are a monocyclic or condensed ring structure of a substituted or unsubstituted aromatic hydrocarbon ring group or a substituted or unsubstituted aromatic heterocyclic group, and these substituents are bonded to each other. A ring may be formed.
m is an integer of 1 to 10, and when it is 2 or more, D may be the same or different.
M is a metal of Ir or Pt, and α is 2 or 3. ]
3. The method for producing an organic electroluminescence device according to 1 or 2, wherein the hole transport zone and the light emitting layer are produced by a coating method, and the electron transport zone is produced by a vapor deposition method.

The organic EL device of the present invention can be produced by a coating method, has high luminous efficiency and long emission lifetime.

It is a figure which shows the structure of the organic EL element of a 1st embodiment. It is a figure which shows the structure of the organic EL element of a 2nd embodiment.

The organic EL device according to the first embodiment of the present invention is an organic EL device having, on the anode, a hole transport zone containing a conductive polymer or an oligomer, a light emitting layer, and an electron transport zone in this order. The hole transport zone and the light emitting layer are adjacent to each other, the light emitting layer and the electron transport zone are adjacent to each other, and the electron transport zone includes a plurality of electron transport layers, and among the electron transport layers, electrons adjacent to the light emitting layer The triplet energy of the compound forming the transport layer is 0.1 eV or more larger than the triplet energy of the host material contained in the light emitting layer, the light emitting layer contains a metal complex, and the ligand of the metal complex has the following formula An organic EL element comprising at least one structure represented by (1).
In the present invention, the triplet energy of the compound forming the electron transport layer adjacent to the light emitting layer is 0.1 eV or more higher than the triplet energy of the host material contained in the light emitting layer, so that the triplet exciton is an electron. Since diffusion into the transport band is prevented and confined in the light emitting layer, thereby efficiently emitting light, the performance of the organic EL element, such as light emission efficiency and life, is improved. In particular, when it is greater than 0.1 eV, triplet excitons are unlikely to achieve energy balance between the light emitting layer and the barrier layer due to thermal energy. In this case, in addition to diffusion to the barrier layer, it is considered that efficiency reduction due to the heat deactivation mode is prevented.
The triplet energy of this metal complex is preferably 2.7 eV or more. This metal complex is preferably a dopant material for the light emitting layer.

[In Formula (1), (X ₁ , X ₂ ) is (carbon atom, nitrogen atom) or (nitrogen atom, carbon atom).
A, B, and D are substituted or unsubstituted aromatic hydrocarbon ring groups, or substituted or unsubstituted aromatic heterocyclic groups, and these substituents may be bonded to each other to form a ring. .
m is an integer of 1 to 10, and when it is 2 or more, D may be the same or different. ]

The aromatic hydrocarbon ring groups represented by A, B, and D may each independently be a single ring or a condensed ring, and a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms. It is preferable that these are residues.
Specific examples of the aromatic hydrocarbon ring having 6 to 30 ring carbon atoms include benzene, naphthalene, biphenyl, terphenyl, fluorene, phenanthrene, triphenylene, perylene, chrysene, fluoranthene, benzofluorene, benzotriphenylene, benzochrysene, and anthracene And benzocondensates and cross-linked products thereof, and benzene, naphthalene, biphenyl, terphenyl, fluorene and phenanthrene are preferred.

The aromatic heterocyclic groups represented by A, B, and D may each independently be a monocyclic ring or a condensed ring, and the remaining aromatic heterocyclic group having 2 to 30 ring carbon atoms that is substituted or unsubstituted. It is preferably a group.
Specific examples of the aromatic heterocycle having 2 to 30 ring carbon atoms include pyrrole, pyridine, pyrazine, pyridine, pyrimidine, pyridazine, triazine, indole, isoindole, quinoline, isoquinoline, quinoxaline, acridine, pyrrolidine, dioxane, piperidine Morpholine, piperazine, carbazole, phenanthridine, phenanthroline, furan, benzofuran, isobenzofuran, thiophene, oxazole, oxadiazole, benzoxazole, thiazole, thiadiazole, benzothiazole, triazole, imidazole, benzimidazole, pyran, dibenzofuran, And dibenzothiophene, azafluorene, and azacarbazole, and benzocondensates and cross-linked products thereof, such as pyridine, pyrazine, Rimijin, pyridazine and triazine are preferred.
m is an integer of 1 to 10, and when A is a 6-membered ring, m is preferably 1, 2, 3 or 4.

In the present invention, the substituted or unsubstituted carbazolyl group includes the following carbazolyl group,

In addition to the above-described substituted carbazolyl group having an optional substituent, for example, the following substituted carbazolyl group is also included.

In the present invention, the substituted or unsubstituted dibenzofuranyl group and the substituted or unsubstituted dibenzothiophenyl group include the following dibenzofuranyl group and dibenzothiophenyl group,

In addition to the above-mentioned substituted dibenzofuranyl group and substituted dibenzothiophenyl group having an optional substituent, for example, the following substituted dibenzofuranyl group and substituted dibenzothiophenyl group are also included.

(Wherein X represents an oxygen atom or a sulfur atom, Y represents an oxygen atom, a sulfur atom, NH, NR ^a (R ^a is an alkyl group or an aryl group), CH ₂ , or CR ^b ₂ (R ^b is an alkyl group) Group or aryl group).

The metal complex represented by the formula (1) is preferably represented by the following formulas (2-1), (2-2), (2-3), and (3).

[In the formula (2-1), A, B and (X ₁ , X ₂ ) are the same as those in the formula (1).
R ₁ to R ₅ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. Next to R ₁ to R ₅ , R ₄ and / or R ₅ and A may combine to form a ring.
M is a metal of Ir or Pt, and α is 2 or 3. ]

[In the formula (2-2), D, B and (X ₁ , X ₂ ) are the same as those in the formula (1).
R ₆ to R ₈ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. R ₆ and R ₇ , R ₆ and / or R ₈ and D may be bonded to form a ring.
M is a metal of Ir or Pt, and α is 2 or 3. ]

[In the formula (2-3), D, A and (X ₁ , X ₂ ) are the same as those in the formula (1).
R ₉ to R ₁₂ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. Adjacent to R ₉ to R ₁₂ may be bonded to form a ring.
M is a metal of Ir or Pt, and α is 2 or 3. ]

[In Formula (3), (X ₁ , X ₂ ) is the same as Formulas (2-1), (2-2), and (2-3).
R ₁ to R ₁₂ are each independently the same as R ₁ to R ₅ in Formula (2-1). R ₄ and R ₆ , R ₅ and R ₈ , R ₈ and R ₁₂ , and R ₁ to R ₁₂ may be bonded together to form a ring. M is a metal of Ir or Pt, and α is 2 or 3. ]

In the above formulas (2-1), (2-2), (2-3), and (3), the alkyl groups represented by R ₁ to R ₁₂ are preferably those having 1 to 20 carbon atoms. , 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 group, n-octyl group N-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group , Neopentyl group, 1-methylpentyl group, 2-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl group, 1-heptyloctyl group, 3-methylpentyl group, etc., methyl group, ethyl group Propyl group, an isopropyl group, n- butyl group, s- butyl, isobutyl and t- butyl group.

In the above formulas (2-1), (2-2), (2-3) and (3), the aromatic hydrocarbon ring group represented by R ₁ to R ₁₂ is a substituted or unsubstituted ring-forming carbon number. A residue of 6 to 30 aromatic hydrocarbon rings is preferable, and specific examples similar to A, B and D are given.
In the formulas (2-1), (2-2), (2-3), and (3), the aromatic heterocyclic group represented by R ₁ to R ₁₂ is a substituted or unsubstituted ring-forming carbon number of 2 It is preferably a residue of 30 to 30 aromatic heterocycles, and specific examples similar to A, B and D are given.
In the formulas (2-1), (2-2), (2-3), and (3), the alkoxy group represented by R ₁ to R ₁₂ is preferably an alkoxy group having 1 to 20 carbon atoms, Specific examples include a methoxy group, an ethoxy group, an i-propoxy group, an n-propoxy group, an n-butoxy group, an s-butoxy group, a t-butoxy group, and the like, such as a methoxy group, an ethoxy group, and an i-propoxy group. And n-propoxy groups are preferred.
In the above formulas (2-1), (2-2), (2-3) and (3), the aryloxy group represented by R ₁ to R ₁₂ is preferably one having 6 to 30 ring carbon atoms, Specific examples include the same examples in which the aryl group site is the same as the aromatic hydrocarbon ring group described above, and examples thereof include a phenoxy group and a biphenyloxy group.

In the formulas (2-1), (2-2), (2-3), and (3), at least one of R ₁ to R ₅ is a substituted or unsubstituted aromatic group having 6 to 30 ring carbon atoms. A hydrocarbon ring group or a substituted or unsubstituted aromatic heterocyclic group having 2 to 30 ring carbon atoms is preferable.
In the formulas (1), (2-1), (2-2), (2-3) and (3), X ₁ is preferably a nitrogen atom and X ₂ is preferably a carbon atom.
Although the following examples are given as a metal complex containing the structure represented by said Formula (1), It is not limited to these. Hereinafter, Ph represents a phenyl group, and t-Bu represents a t-butyl group.

In the embodiment of the present invention, the material forming the electron transport layer included in the electron transport zone is not particularly limited as long as it functions as an electron transport layer, but the triplet energy of the electron transport layer adjacent to the light emitting layer emits light. It must be 0.1 eV or more larger than the triplet energy of the host material contained in the layer. As a compound which forms such an electron transport layer, for example, a compound represented by the following formula (4) is preferable.

[In the formula (4), X represents substituted or unsubstituted carbon, substituted or unsubstituted nitrogen, oxygen, sulfur, substituted or unsubstituted silicon, or substituted or unsubstituted phosphorus atom.
X may be bonded to L by a single bond or a multiple bond greater than or equal to a double bond.
R ₂₁ to R ₂₈ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 ring carbon atoms, a substituted or unsubstituted group; An unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms. R ₂₁ and R ₂₈ , R ₂₁ to R ₂₄ , and R ₂₅ to R ₂₈ may be bonded together to form a ring.
L is a single bond, a k + 1 valent residue of a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, a k + 1 of a substituted or unsubstituted aromatic heterocyclic ring having 2 to 30 ring carbon atoms. It is a valence residue.
Az is a 6-membered aromatic heterocyclic group containing a substituted or unsubstituted nitrogen atom.
k is an integer of 1 to 5. When k is plural, Xs may be the same or different. ]

In the formula (4), X is preferably substituted or unsubstituted nitrogen, oxygen, sulfur, phosphorus or silicon, more preferably substituted or unsubstituted nitrogen.

It is preferable that the compound represented by the formula (4) is represented by the following formula (5) or formula (6).

[In Formula (5), R ₂₁ to R ₂₈ , L, Az, and k are the same as those in Formula (4). ]

[In Formula (6), R ₂₁ to R ₂₈ , Az, and k are the same as those in Formula (4). n is an integer of 0 to 10, and when n is 0, it represents a single bond. ]
In formula (6), N and Az of carbazole are bonded to any position of the benzene ring to which they are bonded.

In the formulas (4) to (6), k is preferably 1 to 5, and in the formula (6), n is preferably 0 to 3, more preferably 0 or 1.
In the formulas (4) to (6), preferred carbon numbers and specific examples of the alkyl group, the aromatic hydrocarbon ring group, and the aromatic heterocyclic group represented by R ₂₁ to R ₂₈ include formulas (2-1), ( In 2-2), (2-3), and (3), the same as R ₁ to R ₁₂ can be mentioned.
In formulas (4) to (6), preferred carbon numbers and specific examples of the divalent alkyl group, aromatic hydrocarbon ring group, and aromatic heterocyclic group represented by L include those represented by formulas (2-1), ( In 2-2), (2-3), and (3), specific examples similar to R ₁ to R ₁₂ may be used as k + 1 valent residues.

In formulas (4) to (6), examples of the 6-membered ring containing nitrogen in Az include pyridine, pyrimidine, pyridazine, pyrazine, triazine and the like.
Among these, Az is preferably a group represented by the following formula (7).

(In Formula (7), Y ₁ to Y ₃ are each independently a nitrogen atom or CH, and at least one of Y ₁ to Y ₃ is a nitrogen atom.
Ar ₁₂ and Ar ₁₃ are each independently a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 18 ring carbon atoms. )
Examples of the aromatic hydrocarbon ring group represented by Ar ₁₂ and Ar ₁₃ include monovalent residues such as benzene, naphthalene, biphenyl, terphenyl, fluorene, and phenanthrene.

Specific examples of the compounds of the formulas (4) to (6) are described below, but are not limited to these specific examples.

In the embodiment of the present invention, the light emitting layer preferably contains a compound represented by the following formula (8), and particularly preferably contains this compound as a host material.

[In Formula (8), A ¹ is a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group,
L ¹ is a single bond, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group,
B ¹ is a residue having a structure represented by any of the following formulas (2-b-1), (2-a-1) to (2-a-6),
m ¹ is an integer of 1 or more, the plurality of L ¹ may be the same or different from each other, and the plurality of B ¹ may be the same or different from each other. ]
m ¹ is preferably selected from an integer of 2 to 10.
In Formula (8), the structural part of B ¹ has a hole transporting ability, and the structural part of A ¹ has an electron transporting ability.

[Wherein, Xb ¹¹ and Xb ¹² are each independently a group represented by —NR—, —O—, —S—, —SiR ₂ —,
R is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group;
Rb ¹¹ , Rb ¹² , Rb ¹³ and Rb ¹⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, substituted or unsubstituted Unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted aralkyl group having 7 to 24 carbon atoms, substituted or unsubstituted silyl group, substituted or unsubstituted aromatic carbon atom having 6 to 24 ring carbon atoms A hydrogen ring group, or a substituted or unsubstituted aromatic heterocyclic group having 2 to 24 ring carbon atoms,
s ¹ is an integer of 0 to 4, and when s ¹ is 2 or more, the plurality of Rb ¹¹ may be the same as or different from each other;
t ¹ is an integer of 0 to 3, and when t ¹ is 2 or more, the plurality of Rb ¹² may be the same as or different from each other;
u ¹ is an integer of 0 to 3, and when u ¹ is 2 or more, the plurality of Rb ¹³ may be the same or different from each other,
v ¹ is an integer of 0 to 4, and when v ¹ is 2 or more, a plurality of Rb ¹⁴ may be the same or different from each other. ]

[Xa ¹¹ and Xa ¹² in Formula (2-a-1), Xa ²¹ and Xa ²² in Formula (2-a-2), Xa ³¹ and Xa ³² in Formula (2-a-3), Formula Xa ⁴¹ and Xa ⁴² in (2-a-4), Xa ⁵¹ and Xa ⁵² in formula (2-a-5), and Xa ⁶¹ and Xa ⁶² in formula (2-a-6) are respectively Independently, —NR—, —O—, —S—, —SiR ₂ —, —CR ₂ —,
R is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group;
Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ⁴ , Ra ⁵ in formula (2-a-5) and Ra ^{6 in} formula (2-a-6) are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or Unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted aralkyl group having 7 to 24 carbon atoms, substituted or unsubstituted silyl group A substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 24 ring carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group group having 2 to 24 ring carbon atoms,
A plurality of Ra ¹ when Ra ¹ there are a plurality or different and the same as each other, a plurality of Ra ² when Ra ² there are a plurality or different and the same as each other, a plurality of Ra ³ when Ra ³ there are a plurality or different and the same as each other, a plurality of Ra ⁴ when Ra ⁴ there are a plurality or different and the same as each other, may be a plurality of Ra ⁵ is not being the same or different when Ra ⁵ there are a plurality, may be the plurality of Ra ⁶ are being the same or different when Ra ⁶ there are multiple formulas (2-a-1) p 1 in the formula (2-a-2) p 2 in the formula (2-a-3) in p ^3, formula (2-a-4) p 4 in , p ⁶ of p ^5, and wherein (2-a-6) in the formula (2-a-5) each independently an integer from 0 to 4
Formula (2-a-1) q 1 in the formula (2-a-2) q 2 in the formula (2-a-3) in the q ^3, q in the formula (2-a-4) ⁴ , q ⁵ in formula (2-a-5), and q ^{6 in} formula (2-a-6) are each independently an integer of 0 to 2,
Formula (2-a-1) r 1 in the formula (2-a-2) r 2 in the formula (2-a-3) in the r ^3, r in the formula (2-a-4) ⁴ , r ⁵ in formula (2-a-5), and r ⁶ in formula (2-a-6) are integers of 0 to 4. ]

Hereinafter, groups represented by symbols in formulas (8), (2-b-1), (2-a-1) to (2-a-6) will be described.
A ¹ and L ¹ in the formula (8), R in the formulas (2-a-1) to (2-a-6), R in the formula (2-b-1) are substituted or absent. The substituted aromatic hydrocarbon ring group is preferably each independently a substituted or unsubstituted residue of an aromatic hydrocarbon ring having 6 to 30 ring carbon atoms.
Specific examples of the aromatic hydrocarbon ring having 6 to 30 ring carbon atoms include benzene, naphthalene, biphenyl, terphenyl, fluorene, phenanthrene, triphenylene, perylene, chrysene, fluoranthene, benzofluorene, benzotriphenylene, benzochrysene, and anthracene And benzocondensates and cross-linked products thereof, and benzene, naphthalene, biphenyl, terphenyl, fluorene and phenanthrene are preferred.

A ¹ and L ¹ in the formula (8), R in the formulas (2-a-1) to (2-a-6), R in the formula (2-b-1) are substituted or absent. The substituted aromatic heterocyclic group is preferably each independently a substituted or unsubstituted residue of an aromatic heterocyclic ring having 2 to 30 ring carbon atoms.
Examples of the aromatic heterocycle having 2 to 30 ring carbon atoms include pyrrole, pyridine, pyrazine, pyridine, pyrimidine, pyridazine, triazine, indole, isoindole, quinoline, isoquinoline, quinoxaline, acridine, pyrrolidine, dioxane, piperidine, morpholine , Piperazine, carbazole, phenanthridine, phenanthroline, furan, benzofuran, isobenzofuran, thiophene, oxazole, oxadiazole, benzoxazole, thiazole, thiadiazole, benzothiazole, triazole, imidazole, benzimidazole, pyran, dibenzofuran, dibenzothiophene, And azafluorene and azacarbazole, and benzocondensates and cross-linked products thereof, such as pyridine, pyrazine, and pyrimidine. , Pyridazine and triazine are preferred.

The substituted or unsubstituted alkyl groups represented by R in formula (2-a-1) to formula (2-a-6) and R in formula (2-b-1) are each independently substituted or unsubstituted It is preferably an unsubstituted alkyl group having 1 to 30 carbon atoms.
Specific examples of the alkyl group having 1 to 30 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n -Hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n -Hexadecyl group, n-heptadecyl group, n-octadecyl group, neopentyl group, 1-methylpentyl group, 2-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl group, 1-heptyloctyl group, 3-methyl Pentyl group and the like, and methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group and t-butyl group are preferred. There.

The substituted or unsubstituted cycloalkyl groups represented by R in formula (2-a-1) to formula (2-a-6) and R in formula (2-b-1) are each independently substituted Alternatively, it is an unsubstituted cycloalkyl group having 3 to 30 ring carbon atoms.
Specific examples of the cycloalkyl group having 3 to 30 ring carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, and an adamantyl group, and a cyclopentyl group and a cyclohexyl group are preferable.

Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ^4, the formula (2-a-5) Ra 5 in the formula (2-a-6) Ra 6 in the formula (2-b-1) in Rb ¹¹ ~ Rb ¹⁴ is a substituted or unsubstituted represents the Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, isobutyl group, n-pentyl group, n -Hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n -Hexadecyl group, n-heptadecyl group, n-octadecyl group, neopentyl group, 1-methylpentyl group, 2-methyl Examples include a rupentyl group, a 1-pentylhexyl group, a 1-butylpentyl group, a 1-heptyloctyl group, a 3-methylpentyl group, and the like. A methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s- Butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl N-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, neopentyl group, 1-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl And the 1-heptyloctyl group is preferred.

Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ^4, the formula (2-a-5) Ra 5 in the formula (2-a-6) Ra 6 in the formula (2-b-1) in Rb ¹¹ ~ Rb ¹⁴ is a substituted or unsubstituted represents the Specific examples of the cycloalkyl group having 3 to 20 ring carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and the like, and a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group are preferable.

Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ^4, the formula (2-a-5) Ra 5 in the formula (2-a-6) Ra 6 in the formula (2-b-1) in Rb ¹¹ ~ Rb ¹⁴ is a substituted or unsubstituted represents the Specific examples of the alkoxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, methoxy group, i-propoxy group, n-propoxy group, n-butoxy group, s-butoxy group, t-butoxy group and the like. A methoxy group, an ethoxy group, a methoxy group, an i-propoxy group and an n-propoxy group are preferred.

Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ^4, the formula (2-a-5) Ra 5 in the formula (2-a-6) Ra 6 in the formula (2-b-1) in Rb ¹¹ ~ Rb ¹⁴ is a substituted or unsubstituted represents the Specific examples of the aralkyl group having 7 to 24 carbon atoms include benzyl group, phenethyl group and phenylpropyl group, and benzyl group is preferable.

Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ^4, the formula (2-a-5) Ra 5 in the formula (2-a-6) Ra 6 in the formula (2-b-1) in Rb ¹¹ ~ Rb ¹⁴ is a substituted or unsubstituted represents the Among the silyl groups, examples of the alkylsilyl group include a monoalkylsilyl group, a dialkylsilyl group, and a trialkylsilyl group, and specific examples of each alkyl group are the same as those described above. Examples of the arylsilyl group include a monoarylsilyl group, a diarylsilyl group, and a triarylsilyl group, and specific examples of each aryl group are the same as the aryl group described later.

Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ^4, Ra ⁵ in the formula (2-a-5), formula (2-a-6) Ra 6 in the formula (2-b-1) Rb 11 ~ Rb 14 ring-forming carbon atoms represented in the 6 As the aromatic hydrocarbon ring group of ˜24, aromatic hydrocarbon rings such as benzene, naphthalene, biphenyl, terphenyl, fluorene, phenanthrene, triphenylene, perylene, chrysene, fluoranthene, benzofluorene, benzotriphenylene, benzochrysene, anthracene, etc. Residues are mentioned, and benzene, naphthalene, biphenyl, terphenyl, fluorene and phenanthrene residues are preferred.

Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ^4, the formula (2-a-5) Ra 5 in the formula (2-a-6) Ra 6 in the formula (2-b-1) in the Rb ¹¹ ~ Rb ¹⁴ represent ring-forming carbon atoms 2 The aromatic heterocyclic group of ˜24 includes aromatic heterocyclic residues such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine and dihydroacridine. Pyridine, pyridazine, pyrimidine, pyrazine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine and dihydroacridine residues are preferred.

In the present specification, in the expression “substituted or unsubstituted” in the formulas above and below, the substituent in the case of being substituted includes a halogen atom (fluorine, chlorine, bromine, iodine), cyano group, carbon number An alkyl group having 1 to 20 (preferably 1 to 6), a cycloalkyl group having 3 to 20 carbon atoms (preferably 5 to 12), an alkoxy group having 1 to 20 carbon atoms (preferably 1 to 5), and one carbon atom A haloalkyl group having 20 to 20 (preferably 1 to 5), a haloalkoxy group having 1 to 20 carbon atoms (preferably 1 to 5), an alkylsilyl group having 1 to 10 carbon atoms (preferably 1 to 5), a ring-forming carbon An aryl group having 6 to 30 (preferably 6 to 18) aryloxy group having 6 to 30 ring carbon atoms (preferably 6 to 18), an aryl having 6 to 30 ring carbon atoms (preferably 6 to 18 carbon atoms) Silyl group, Prime 7 to 30 (preferably 7 to 20) aralkyl group, and ring-forming carbon number of 2 to 30 (preferably 2 to 18) and the heteroaryl group.

In this specification, the number of ring-forming carbon atoms constitutes the ring itself of a compound having a structure in which atoms are bonded cyclically (for example, a monocyclic compound, a condensed ring compound, a bridged compound, a carbocyclic compound, or a heterocyclic compound). Represents the number of carbon atoms in the atom. When the ring is substituted with a substituent, the carbon contained in the substituent is not included in the number of ring-forming carbons. The “ring carbon number” described above and below is the same unless otherwise specified. For example, the benzene ring has 6 ring carbon atoms, the naphthalene ring has 10 ring carbon atoms, the pyridinyl group has 5 ring carbon atoms, and the furanyl group has 4 ring carbon atoms. Further, when an alkyl group is substituted as a substituent on the benzene ring or naphthalene ring, the carbon number of the alkyl group is not included in the number of ring-forming carbons. In addition, for example, when a fluorene ring is bonded to the fluorene ring as a substituent (including a spirofluorene ring), the carbon number of the fluorene ring as a substituent is not included in the number of ring-forming carbons.
In the present specification, the “carbon number XX to YY” in the expression “substituted or unsubstituted ZZ group having XX to YY” represents the number of carbon atoms in the case where the ZZ group is unsubstituted. The carbon number of the substituent in the case where it is present is not included. Here, “YY” is larger than “XX”, and “XX” and “YY” each mean an integer of 1 or more.
In the present specification, the term “unsubstituted ZZ group” in the case of “substituted or unsubstituted ZZ group” means that the hydrogen atom of the ZZ group is not substituted with a substituent.
In the present specification, the aromatic hydrocarbon ring group and the aromatic heterocyclic group include a condensed aromatic hydrocarbon ring group and a condensed aromatic heterocyclic group.
In the present specification, the “hydrogen atom” includes isotopes having different neutron numbers, that is, light hydrogen (protium), deuterium (triuterium), and tritium.

Although the specific example of a compound of Formula (8) is described below, it is not limited to these specific examples.

In the embodiment of the present invention, the hole injection / transport compound used in the hole transport zone is formed of a conductive polymer or an oligomer. The conductive polymer or oligomer is usually composed of a mixture of an electron donating compound and an electron accepting compound or an acidic compound. Examples of conductive polymers and oligomers that can be used in the present invention are shown below.
The form of the mixture is not limited to the type of solid or liquid, but a method of obtaining a solid film by forming a film of a solution, dispersion, colloid, ink, varnish or the like by a coating method is suitably used. In addition, for the purpose of improving hole injection / transport properties and for improving film formability, additives are added, light irradiation is performed after film formation, and interaction with hole injection / transport materials is performed. Such a compound may be bonded or deposited on the surface layer, or may be subjected to a surface treatment such as a rinsing (cleaning) treatment with a solvent.
Representative examples of electron donating compounds contained in hole injecting / transporting compounds include aromatic amine derivatives, phthalocyanine derivatives, porphyrin derivatives, thiophene derivatives, benzylphenyl derivatives, compounds in which tertiary amines are linked by a fluorene group. Hydrazone derivatives, silazane derivatives, silanamine derivatives, phosphamine derivatives, quinacridone derivatives, aniline derivatives, pyrrole derivatives, phenylene vinylene derivatives, thienylene vinylene derivatives, quinoline derivatives, quinoxaline derivatives, carbon and the like. These derivatives correspond to low molecules having a molecular weight of less than 1000, oligomers having a molecular weight of 1000 to 10,000, dendrimers, and polymers having a molecular weight of 10,000 or more. Of these, aromatic amine derivatives, polythiophene derivatives, polyaniline derivatives, and oligoaniline derivatives are preferably used.

Representative examples of electron-accepting compounds or acidic compounds include triaryl boron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, arylamines and Examples thereof include one or more compounds selected from the group consisting of salts with Lewis acids. More specifically, onium salts substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pendafluorophenyl) borate, triphenylsulfonium tetrafluoroborate; iron (III) chloride, ammonium peroxodisulfate High valent inorganic compounds such as tetracyanoethylene, aromatic boron compounds such as tris (pendafluorophenyl) borane, fullerene derivatives, iodine, polystyrene sulfonate ions, alkylbenzene sulfonate ions, camphor sulfonate ions And the like, and the like.
As in the case of the electron-donating compound, these derivatives correspond to low molecular weight molecules having a molecular weight of less than 1000, oligomers having a molecular weight of 1000 to 10,000, dendrimers, and polymers having a molecular weight of 10,000 or more.

These electron accepting compounds can improve the conductivity of the hole injection layer by oxidizing the hole transporting compound. The content of the electron-accepting compound in the hole-injecting layer or the composition for forming a hole-injecting layer with respect to the hole-transporting compound is usually 0.1 mol% or more, preferably 1 mol% or more. However, it is usually 100 mol% or less, preferably 40 mol% or less.
Hereinafter, representative examples (i) to (xi) of the hole injecting / transporting compounds that can be used in the embodiments of the present invention are shown. These can be used alone or in combination, but it is desirable to mix a relatively electron-donating material and a relatively electron-accepting material. Furthermore, an additive for promoting charge transfer between the electron donating compound and the electron accepting compound or improving the coating film formability can be added as a third component. A plurality of third components may be used.

Wherein R ₁ and R ₁ ′ are each independently selected from a hydrogen atom and alkyl having 1 to 4 carbon atoms, or R ₁ and R ₁ ′ taken together are 1 to Forming an alkylene chain having 4 carbon atoms, optionally substituted with an alkyl or aromatic group having 1 to 12 carbon atoms, or a 1,2-cyclohexylene group. And n is greater than about 6)

Polyaniline having monomer units (ii) and / or (iii)

(Where n is an integer from 0 to 4,
m-1 is an integer of 1 to 5, n + (m-1) = 5,
R ¹ is independently the same or different and is alkyl, alkenyl, alkoxy, cycloalkyl, cycloalkenyl, alkanoyl, alkylthio, aryloxy, alkylthioalkyl, alkylaryl, arylalkyl, amino, alkylamino, dialkylamino, aryl , Alkylsulfinyl, alkoxyalkyl, alkylsulfonyl, arylthio, arylsulfinyl, alkoxycarbonyl, arylsulfonyl, carboxylic acid, halogen, cyano, or substituted by one or more sulfonic acid, carboxylic acid, halo, nitro, cyano or epoxy moieties Or any two R ¹ groups taken together may contain one or more divalent nitrogen, sulfur or oxygen atoms, An alkylene or alkenylene chain that completes a 4, 5, 6 or 7 membered aromatic or alicyclic ring may be formed)

Wherein R ¹ is independently a hydrogen atom, alkyl, alkenyl, alkoxy, alkanoyl, alkylthio, aryloxy, alkylthioalkyl, alkylaryl, arylalkyl, amino, alkylamino, dialkylamino, aryl, alkylsulfinyl, Alkoxyalkyl, alkylsulfonyl, arylthio, arylsulfinyl, alkoxycarbonyl, arylsulfonyl, acrylic acid, phosphoric acid, phosphonic acid, halogen, nitro, cyano, hydroxyl, epoxy, silane, siloxane, alcohol, benzyl, carboxylate, ether, ether A group selected from carboxylate, amide sulfonate, ether sulfonate, and urethane; or both R ¹ groups together, a 3-membered ring, a 4-membered ring, An alkylene chain or alkenylene chain that completes a 5-membered ring, 6-membered ring or 7-membered aromatic ring or alicyclic ring may be formed, and this ring may contain one or more divalent nitrogen, sulfur or An oxygen atom may be included.
R ² is independently a hydrogen atom, alkyl, alkenyl, aryl, alkanoyl, alkylthioalkyl, alkylaryl, arylalkyl, amino, epoxy, silane, siloxane, amide sulfonate, alcohol, benzyl, carboxylate, ether, ether carboxy A group selected from rate, amide sulfonate, ether sulfonate, and urethane. )

Wherein Q is selected from the group consisting of S, Se, and Te, and R ¹ is independently a hydrogen atom, alkyl, alkenyl, alkoxy, alkanoyl, alkthio, aryloxy, alkylthioalkyl, alkylaryl, Arylalkyl, amino, alkylamino, dialkylamino, aryl, alkylsulfinyl, alkoxyalkyl, alkylsulfonyl, arylthio, arylsulfinyl, alkoxycarbonyl, arylsulfonyl, acrylic acid, phosphoric acid, phosphonic acid, halogen, nitro, cyano, hydroxyl, Epoxy, silane, siloxane, alcohol, benzyl, carboxylate, ether, ether carboxylate, amide sulfonate, ether sulfonate, ester sulfonate, and urea Is a group selected from; or both R ¹ groups may form an alkylene or alkenylene chain together, 3, 4, 5, 6, or 7 membered aromatic or alicyclic ring And the ring may optionally contain one or more divalent nitrogen, selenium, tellurium, sulfur, or oxygen atoms.)

(Wherein R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group, a t-butoxycarbonyl group, or a benzyloxycarbonyl group, and R ³ to R ³⁴ represent Each independently a hydrogen atom, hydroxyl group, silanol group, thiol group, carboxyl group, phosphate group, phosphate ester group, ester group, thioester group, amide group, nitro group, substituted or unsubstituted monovalent hydrocarbon group , An organooxy group, an organoamino group, an organosilyl group, an organothio group, an acyl group, a sulfone group, or a halogen atom, and m and n are each independently an integer of 1 or more and satisfy m + n ≦ 20.)

(Wherein X represents O, S or NH, A represents a naphthalene ring or anthracene ring which may have a substituent other than X and n (SO ₃ H) groups, and B represents An unsubstituted or substituted hydrocarbon group, a 1,3,5-triazine group, or an unsubstituted or substituted formula (vii-1) or (vii-2)

(Wherein W ¹ and W ² are each independently O, S, S (O) group, S (O ₂ ) group, or unsubstituted or substituted N, Si, P represents a P (O) group), n represents the number of sulfonic acid groups bonded to A, is an integer satisfying 1 ≦ n ≦ 4, and q represents the number of bonds between B and X. 1 is an integer satisfying 1 ≦ q. )

In consideration of improving durability and charge transporting property, B is a divalent or higher-valent unsubstituted or substituted hydrocarbon group containing one or more aromatic rings, a divalent or trivalent 1, A 3,5-triazine group, a substituted or unsubstituted divalent sulfone group is preferred, and in particular, a divalent or trivalent substituted or unsubstituted benzyl group, a divalent substituted or unsubstituted p-xylylene group, divalent Or a trivalent substituted or unsubstituted naphthyl group, a divalent or trivalent 1,3,5-triazine group, a divalent substituted or unsubstituted diphenylsulfone group, a 2 to 4 valent perfluorobiphenyl group, a divalent A substituted or unsubstituted 2,2-bis ((hydroxypropoxy) phenyl) propyl group and a substituted or unsubstituted polyvinylbenzyl group are preferred.
Of the formula (vii), a compound represented by the following formula (vii-3) is particularly preferable.

(Wherein R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, a silanol group, a thiol group, a carboxyl group, a phosphate group, a phosphate ester group, an ester) Group, thioester group, amide group, nitro group, monovalent hydrocarbon group, organooxy group, organoamino group, organosilyl group, organothio group, acyl group or sulfonic acid group, and A and B are each independently Represents a divalent group represented by the general formula (viii-1) or (viii-2).

Wherein R ⁴ to R ¹¹ are each independently a hydrogen atom, halogen atom, hydroxyl group, amino group, silanol group, thiol group, carboxyl group, phosphate group, phosphate ester group, ester group, thioester Group, amide group, nitro group, monovalent hydrocarbon group, organooxy group, organoamino group, organosilyl group, organothio group, acyl group or sulfonic acid group.) M and n are each independently 1 With the above integers, m + n ≦ 20 is satisfied. )

(Ix) Mixture of the following ingredients

(N is an integer of 3 or more.)

(X) A mixture of the following components

(N is an integer of 3 or more.)

The organic EL device 1 according to the first embodiment of the present invention will be described with reference to the drawings. For example, as shown in FIG. 1, holes containing a conductive polymer or oligomer on the anode 3 on the substrate 2. The structure which has the transport zone 4, the light emitting layer 5, the electron transport zone 6, and the cathode 7 in order is mentioned.

The organic EL device according to the second embodiment of the present invention is provided with a red light emitting device, a green light emitting device, and a blue light emitting device juxtaposed, and the red light emitting device, the green light emitting device, and the blue light emitting device are independent of each other. Each having an anode to which a current is applied, a hole transport zone on each anode, and a red light emitting layer, a green light emitting layer, and a blue light emitting layer arranged in parallel on each hole transport zone. Each of the light-emitting layers has an electron transport zone, and the electron transport zone is adjacent to the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer, and is provided in common. A green light emitting layer contains the metal complex represented by Formula (9).

Wherein (9), (X _1, X ₂₎ is a (carbon atom, a nitrogen atom), or (a nitrogen atom, a carbon atom).
A, B, and D are a monocyclic or condensed ring structure of a substituted or unsubstituted aromatic hydrocarbon ring group or a substituted or unsubstituted aromatic heterocyclic group, and these substituents are bonded to each other. A ring may be formed.
m is an integer of 1 to 10, and when it is 2 or more, D may be the same or different.
M is a metal of Ir or Pt, and α is 2 or 3. ]

Preferable carbon numbers and specific examples of the aromatic hydrocarbon ring group and the aromatic heterocyclic group represented by A, B, and D include the same examples as A, B, and D in the formula (1).
m is an integer of 1 to 10, and when A is a 6-membered ring, m is preferably 1 to 4.
The metal complex represented by the formula (9) is preferably represented by the formula (2-1), (2-2), (2-3), or (3), and the formula (2-1), ( 2-2), (2-3), and preferred examples of the number of carbon atoms and specific examples of the groups indicated by symbols (3) are the same.
Moreover, the example of Formula (9) is also the same as that of the first embodiment.

Also in the second embodiment of the present invention, as in the first embodiment, it is preferable that the hole transport zone and the light emitting layer are adjacent to each other.
Further, the electron transport zone includes a plurality of electron transport layers, and the triplet energy of the compound that forms the electron transport layer adjacent to the light emitting layer among the electron transport layers is that of the host material included in the light emitting layer. It is preferably 0.1 eV or more larger than the triplet energy.
Moreover, it is preferable that the said light emitting layer contains a metal complex and the ligand of this metal complex contains at least 1 or more structures represented by Formula (1).
By satisfying such a configuration, the luminous efficiency and the lifetime can be further improved.

The organic EL device 10 according to the second embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 2, the red light emitting device, the green light emitting device, and the blue light emitting device are each applied with a current independently. The anode 21 has a hole transport zone 30 on each anode 21, and a red light emitting layer 27, a green light emitting layer 28, and a blue light emitting layer 29 are juxtaposed on each hole transport zone 30. The electron transport zone 31 is adjacent to the red light emitting layer 27, the green light emitting layer 28, and the blue light emitting layer 29. As shown in FIG. 2, the hole transport zone 30 may be composed of a plurality of layers of a hole injection layer 22 and a hole transport layer 23, and the electron transport zone 31 is composed of an electron transport layer 24 and an electron injection layer 25. It may consist of multiple layers.
Further, there may be a plurality of electron transport layers, electron injection layers, hole transport layers, and hole injection layers. The electron injection layer and the hole injection layer may be omitted.

The organic EL device according to the first and second aspects of the present invention has an electron-accepting dopant in an interface region between the anode and the organic thin film layer (for example, a hole transport zone, an electron transport zone, and a light emitting layer). Is preferred. The electron accepting dopant is selected from alkali metals, alkali metal complexes, alkali metal compounds, alkaline earth metals, alkaline earth metal complexes, alkaline earth metal compounds, rare earth metals, rare earth metal complexes, rare earth metal compounds, and the like. There is at least one kind.

As an alkali metal, the work function is 2.9 eV or less, Na (work function: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16 eV), Cs (work function: 1.95 eV) and the like are preferable. Of these, K, Rb, and Cs are more preferable, Rb or Cs is more preferable, and Cs is most preferable.

As alkaline earth metals, the work function is 2.9 eV or less, Ca (work function: 2.9 eV), Sr (work function: 2.0 to 2.5 eV), Ba (work function: 2.52 eV) Etc. are preferable.
As the rare earth metal, Sc, Y, Ce, Tb, Yb and the like having a work function of 2.9 eV or less are preferably exemplified.
Among these metals, preferred metals are particularly high in reducing ability, and can improve the light emission luminance and extend the life of the organic EL element by adding a relatively small amount to the electron injection region.

Examples of the alkali metal compound include alkali oxides such as Li ₂ O, Cs ₂ O, and K ₂ O, and alkali halides such as LiF, NaF, CsF, and KF. Among these, LiF, Li ₂ O, NaF is preferred.
Examples of the alkaline earth metal compound include BaO, SrO, CaO, and Ba _m Sr _1-m O (0 <m <1), Ba _m Ca _1-m O (0 <m <1), and the like obtained by mixing these. Of these, BaO, SrO, and CaO are preferable.
The rare earth metal _{compound, YbF 3, ScF 3, ScO} 3, Y 2 O 3, Ce 2 O 3, GdF 3, TbF 3 and the like, and among _{these, YbF 3, ScF 3, TbF} 3 are preferable.

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

The addition form of the electron-accepting dopant is preferably formed in a layered or island shape in the interface region. As a formation method, there is a method in which an electron-accepting dopant is deposited by a resistance heating vapor deposition method, and a light-emitting material that forms an interface region and an organic material that is an electron-injecting material are simultaneously deposited, and the electron-accepting dopant is dispersed in the organic material. preferable. The dispersion concentration in terms of molar ratio is preferably organic substance: electron accepting dopant = 100: 1 to 1: 100, more preferably 5: 1 to 1: 5.

When forming the electron-accepting dopant in layers, after forming the light-emitting material or electron-injecting material, which is an organic layer at the interface, in layers, the electron-accepting dopant is vapor-deposited by resistance heating vapor deposition alone, preferably the layer It is formed with a thickness of 0.1 to 15 nm.
When the electron-accepting dopant is formed in an island shape, the light-emitting material or electron injection material that is the organic layer at the interface is formed in an island shape, and then the electron-accepting dopant is vapor-deposited by a resistance heating vapor deposition method alone, preferably The island is formed with a thickness of 0.05 to 1 nm.

In the organic EL device of the present invention, as an electron transport material used for an electron transport layer that forms an electron transport band or an electron transport layer that is not adjacent to a light emitting layer, as a component other than the above-described compounds, one hetero atom is present in the molecule. The aromatic heterocyclic compounds contained above are preferred, and nitrogen-containing ring derivatives are particularly preferred.
As this nitrogen-containing ring derivative, for example, a nitrogen-containing ring metal chelate complex represented by the following formula (A) is preferable.

R ² to R ⁷ each independently represents a hydrogen atom, a halogen atom, an amino group, a hydrocarbon group having 1 to 40 carbon atoms, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, or a heterocyclic group, May be substituted.
M is aluminum (Al), gallium (Ga), or indium (In), and is preferably indium.
L ⁴ in the formula (A) is a group represented by the following formula (A ′) or (A ″).

(Wherein R ⁸ to R ¹² each independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 40 carbon atoms, and groups adjacent to each other may form a cyclic structure. R ¹³ to R ²⁷ each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group having 1 to 40 carbon atoms, and groups adjacent to each other may form a cyclic structure. )

Examples of nitrogen-containing ring derivatives include nitrogen-containing compounds that are not metal complexes. Examples thereof include a 5-membered ring or 6-membered ring containing a skeleton represented by the formula (a) and a structure represented by the formula (b).

(In the formula (b), 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.)

Preferably, it is an organic compound having a nitrogen-containing aromatic polycyclic group consisting of a 5-membered ring or a 6-membered ring. Furthermore, in the case of such a nitrogen-containing aromatic polycyclic group having a plurality of nitrogen atoms, the nitrogen-containing aromatic polycyclic organic compound having a skeleton obtained by combining the above (a) and (b) or (a) and (c) It is.

The nitrogen-containing group of the nitrogen-containing heterocyclic derivative is selected from, for example, nitrogen-containing heterocyclic groups represented by the following formulae.

(In each formula, R ²⁸ is an aryl group having 6 to 40 carbon atoms, a heteroaryl group having 3 to 40 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms, and n is When it is an integer of 0 to 5 and n is an integer of 2 or more, the plurality of R ²⁸ may be the same or different from each other.)

Furthermore, preferred specific compounds include nitrogen-containing heterocyclic derivatives represented by the following formula.

(Wherein, HAr ^a is a nitrogen-containing heterocyclic ring optionally 3 carbon atoms which may be ~ 40 substituted, L ⁶ is a single bond, to 6 carbon atoms which may have a substituent 40 An arylene group or a heteroarylene group having 3 to 40 carbon atoms which may have a substituent, and Ar ^b is a divalent aromatic hydrocarbon having 6 to 40 carbon atoms which may have a substituent A cyclic group, and Ar ^c is an optionally substituted aryl group having 6 to 40 carbon atoms or an optionally substituted heteroaryl group having 3 to 40 carbon atoms.)
HAr ^a is selected from, for example, the following group.

L ⁶ is selected from the following group, for example.

Ar ^c is exemplarily selected from the following group.

Ar ^b is, for example, selected from the following arylanthranyl groups.

(Wherein R ²⁹ to R ⁴² each independently represents a hydrogen atom, a halogen atom, 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 carbon atoms, An aryl group having 6 to 40 carbon atoms or a heteroaryl group having 3 to 40 carbon atoms which may have a substituent, and Ar ^d is an aryl having 6 to 40 carbon atoms which may have a substituent Or a heteroaryl group having 3 to 40 carbon atoms.)
Further, in Ar ^b represented by the above formula, each of R ²⁹ to R ³⁶ is preferably a nitrogen-containing heterocyclic derivative which is a hydrogen atom.

In addition, the following compounds are also preferably used.

Wherein R ⁴³ to R ⁴⁶ are each independently a hydrogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted aliphatic cyclic group, or a substituted or unsubstituted carbocyclic aromatic ring group. Represents a substituted or unsubstituted heterocyclic group, and X ¹ and X ² each independently represents an oxygen atom, a sulfur atom or a dicyanomethylene group.)

The following compounds are also preferably used.

In the formula, R ⁴⁷ , R ⁴⁸ , R ⁴⁹ and R ⁵⁰ are the same or different groups and are aryl groups represented by the following formulae.

(In the formula, R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ and R ⁵⁵ are the same or different from each other, and a hydrogen atom or at least one of them is a saturated or unsaturated alkoxyl group, an alkyl group, an amino group. Or an alkylamino group.)
Further, it may be a polymer compound containing the nitrogen-containing heterocyclic group or nitrogen-containing heterocyclic derivative.

Moreover, it is preferable that the electron carrying layer which is not adjacent to a light emitting layer contains a nitrogen-containing heterocyclic derivative, especially a nitrogen-containing 5-membered ring derivative. Examples of the nitrogen-containing 5-membered ring include an imidazole ring, a triazole ring, a tetrazole ring, an oxadiazole ring, a thiadiazole ring, an oxatriazole ring, and a thiatriazole ring. Examples of the nitrogen-containing 5-membered ring derivative include benzimidazole And a ring, a benzotriazole ring, a pyridinoimidazole ring, a pyrimidinoimidazole ring, and a pyridazinoimidazole ring.
Specifically, it is preferable to contain at least one of nitrogen-containing heterocyclic derivatives represented by the following formulas (201) to (203).

In the formulas (201) to (203), R ⁵⁶ represents a hydrogen atom, an aryl group having 6 to 60 carbon atoms which may have a substituent, a pyridyl group which may have a substituent, or a substituent. A quinolyl group which may have, a C 1-20 alkyl group which may have a substituent or a C 1-20 alkoxy group which may have a substituent, wherein n is 0 to 4 is an integer, and R ⁵⁷ is an aryl group having 6 to 60 carbon atoms which may have a substituent, a pyridyl group which may have a substituent, and quinolyl which may have a substituent. Group, an optionally substituted alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, R ⁵⁸ and R ⁵⁹ each independently have a hydrogen atom or a substituent. An aryl group having 6 to 60 carbon atoms, a pyridyl group which may have a substituent, and a substituent. Good quinolyl group optionally, an alkoxy group an alkyl group or 1 carbon atoms which may have a substituent to 20 substituents to 1 carbon atoms which may have a 20, L ⁷ represents a single A bond, an arylene group having 6 to 60 carbon atoms which may have a substituent, a pyridinylene group which may have a substituent, a quinolinylene group which may have a substituent or a substituent. Ar ^e may be an optionally substituted arylene group having 6 to 60 carbon atoms, an optionally substituted pyridinylene group or a substituent. Ar ^f is a good quinolinylene group, and Ar ^f has a hydrogen atom, an aryl group having 6 to 60 carbon atoms which may have a substituent, a pyridyl group which may have a substituent, or a substituent. A quinolyl group, which may have a substituent, 1 carbon atom Have an alkyl group or a substituent of 20 is also an alkoxy group which may having 1 to 20 carbon atoms.

Ar ^g has an aryl group having 6 to 60 carbon atoms which may have a substituent, a pyridyl group which may have a substituent, a quinolyl group which may have a substituent, and a substituent. An optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted alkoxy group having 1 to 20 carbon atoms, or a group represented by —Ar ^e —Ar ^f (Ar ^e and Ar ^f Are the same as above.

As the compound constituting the electron injection layer and the electron transport layer not adjacent to the light emitting layer, in addition to the compound of the formula (1) in the present invention, an electron-deficient nitrogen-containing 5-membered ring or an electron-deficient nitrogen-containing 6-membered ring skeleton And a compound having a structure in which a substituted or unsubstituted indole skeleton, a substituted or unsubstituted carbazole skeleton, or a substituted or unsubstituted azacarbazole skeleton is combined. Suitable electron-deficient nitrogen-containing 5-membered ring or electron-deficient nitrogen-containing 6-membered ring skeleton includes, for example, pyridine, pyrimidine, pyrazine, triazine, triazole, oxadiazole, pyrazole, imidazole, quinoxaline, pyrrole skeleton, and Examples thereof include molecular skeletons such as benzimidazole and imidazopyridine in which they are condensed with each other. Among these combinations, pyridine, pyrimidine, pyrazine, triazine skeleton, and carbazole, indole, azacarbazole, and quinoxaline skeleton are preferable. The aforementioned skeleton may be substituted or unsubstituted.

The electron transport layer that is not adjacent to the electron injection layer and the light emitting layer may have a single layer structure composed of one or more of the above materials, or a multilayer structure composed of a plurality of layers having the same composition or different compositions. Also good. The material of these layers preferably has a π-electron deficient nitrogen-containing heterocyclic group.

In addition to the nitrogen-containing ring derivative, it is preferable to use an insulator or a semiconductor as an inorganic compound as a constituent component of the electron transport layer that is not adjacent to the electron injection layer and the light emitting layer. As a result, 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, preferable alkali metal chalcogenides include, for example, Li ₂ O, K ₂ O, Na ₂ S, Na ₂ Se, and Na ₂ O, and preferable alkaline earth metal chalcogenides include, for example, CaO, BaO, and SrO. , BeO, BaS and CaSe. Further, preferable alkali metal halides include, for example, LiF, NaF, KF, LiCl, KCl, and NaCl. Examples of preferable alkaline earth metal halides include fluorides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ and BeF ₂ , and halides other than fluorides.

As the semiconductor, for example, an oxide containing at least one element selected from the group consisting of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb, and Zn. Products, nitrides, oxynitrides and the like, and these may be used alone or in combination of two or more. 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, and 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.
Moreover, the above-mentioned reducing dopant can be preferably contained in the electron injection layer in the present invention.
The film thickness of the electron injection layer or the electron transport layer is not particularly limited, but is preferably 1 to 100 nm.

In the organic EL device of the present invention, an aromatic amine compound, for example, an aromatic amine derivative represented by the formula (I) is suitably used for the hole injection layer or the hole transport layer forming the hole transport zone.

In the formula (I), Ar ¹ to Ar ⁴ represent a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 50 ring carbon atoms.
L is a linking group. Specifically, a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, a substituted or unsubstituted heteroarylene group having 2 to 50 ring carbon atoms, or two or more arylene groups or heteroarylene groups. A divalent group obtained by bonding with a single bond, an ether bond, a thioether bond, an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 20 carbon atoms, or an amino group.

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

In the formula (II), the definitions of Ar ₁ to Ar ₃ are the same as the definitions of Ar ¹ to Ar ^{4 in} the formula (I).
Since the compound of the formula (1) in the present invention is a compound that transports holes and electrons, it can also be used for a hole injection layer or a transport layer, an electron injection layer, or a transport layer.

In the present invention, the anode (lower electrode) of the organic EL element plays a role of injecting holes into the hole transport layer or the light emitting layer, and it is effective to have a work function of 4.5 eV or more. . Specific examples of the anode material used in the present invention include indium tin oxide alloy (ITO), tin oxide (NESA), gold, silver, platinum, copper and the like. As the cathode (upper electrode), a material having a small work function is preferable for the purpose of injecting electrons into the electron injection 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.

The film thickness of each organic layer of the organic EL element of the present invention is not particularly limited. Generally, if the film thickness is too thin, defects such as pinholes are likely to occur. Conversely, if it is too thick, a high applied voltage is required and the efficiency deteriorates. Therefore, the range of several nm to 1 μm is usually preferable.

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 thin film layer containing the composition for organic EL of the present invention used for the organic EL device of the present invention is a dipping method, a spin coating method, a casting method, a bar coating method, a roll coating method in which the organic thin film layer is dissolved in a solvent. It can form by well-known coating methods, such as.
In the present invention, it is preferable that the hole transport zone and the light emitting layer are produced by a coating method, and the electron transport zone is produced by a vapor deposition method. In addition, in this 2nd aspect, a light emitting layer here is a red, green, and blue light emitting layer.

As a film forming method by the coating method, a known coating method can be used effectively. For example, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a slit coating method. Method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexographic printing method, offset printing method, ink jet method, nozzle printing method and the like. In the case of pattern formation, a screen printing method, a flexographic printing method, an offset printing method, and an ink jet printing method are preferable. Film formation by these methods can be performed under conditions well known to those skilled in the art.
After the film formation, heating (upper limit 250 ° C.) and drying under vacuum may be performed to remove the solvent, and polymerization reaction by light or high temperature heating exceeding 250 ° C. is unnecessary. Therefore, it is possible to suppress deterioration of the performance of the element due to light or high temperature heating exceeding 250 ° C.

The film-forming solution may contain additives such as other hole transport materials, electron transport materials, light-emitting materials, acceptor materials, solvents, and stabilizers in addition to the materials essential for the present invention.
Film-forming solutions are additives for adjusting viscosity and / or surface tension, such as thickeners (high molecular weight compounds, poor solvents, etc.), viscosity reducing agents (low molecular weight compounds, etc.), surfactants, etc. May be contained. Moreover, in order to improve storage stability, you may contain antioxidants which do not influence the performance of organic EL elements, such as a phenolic antioxidant and phosphorus antioxidant.
The content of the organic EL element material in the film forming solution is preferably 0.1 to 15% by mass, and more preferably 0.5 to 10% by mass with respect to the entire film forming solution.

High molecular weight compounds that can be used as thickeners include insulating resins such as polystyrene, polycarbonate, polyarylate, polyester, polyamide, polyurethane, polysulfone, polymethyl methacrylate, polymethyl acrylate, cellulose, zeonore, zeonex, and their co-polymers. Examples thereof include photoconductive resins such as polymers, poly-N-vinylcarbazole and polysilane, and conductive resins such as polythiophene and polypyrrole.

Examples of the solvent for the film-forming solution include chloro solvents such as chloroform, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, o-dichlorobenzene; tetrahydrofuran, dioxane, dioxolane, anisole and the like. Ether solvents; aromatic hydrocarbon solvents such as toluene and xylene; cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, etc. Aliphatic hydrocarbon solvents; ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, benzophenone and acetophenone; ester solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, methyl benzoate and phenyl acetate; ethylene Glycol, ethylene glycol Polyhydric alcohols such as butyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethoxyethane, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, 1,2-hexanediol and derivatives thereof; methanol, Examples thereof include alcohol solvents such as ethanol, propanol, isopropanol and cyclohexanol; sulfoxide solvents such as dimethyl sulfoxide; amide solvents such as N-methyl-2-pyrrolidone and N, N-dimethylformamide. Moreover, these solvents can be used alone or in combination of two or more.

Of these solvents, aromatic hydrocarbon solvents, ether solvents, aliphatic hydrocarbon solvents, ester solvents, ketone solvents are preferable from the viewpoints of solubility, film formation uniformity, viscosity characteristics, and the like. Toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, n-propylbenzene, isopropylbenzene, n-butylbenzene, isobutylbenzene, 5-butylbenzene, n-hexylbenzene, cyclohexylbenzene, 1-methylnaphthalene, tetralin, 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, anisole, ethoxybenzene, cyclohexane, bicyclohexyl, cyclohexenylcyclohexanone, n-heptylcyclohexane, n-hexylcyclohexane, decalin, Methyl benzoate Cyclohexanone, heptanone 2-propyl cyclohexanone, to 2-heptanone, to 3, heptanone to 4, 2-octanone, 2-nonanone, 2-decanone, Kishiruketon dicyclohexyl, acetophenone, benzophenone more preferable.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to these Examples.
The materials used in the examples are as follows.

Example 1
(Formation of underlayer)
As a hole transport zone, CLEVIOUS AI4083 (trade name) manufactured by HERAEUS Co. was formed on an ITO substrate with a thickness of 30 nm by spin coating. After film formation, unnecessary portions were removed with acetone, and then baked on a hot plate at 200 ° C. in the atmosphere for 10 minutes to prepare a base substrate.
(Formation of light emitting layer)
Compound 1 (triplet energy is 2.8 eV) as the host material, Compound 2 as the dopant material, and 1.6% by mass of toluene in a mixing ratio such that the host material: dopant material is 9: 1 by mass. A solution was made. Using this toluene solution, it was applied and laminated on the base substrate by spin coating so as to have a film thickness of 50 nm. After the coating film formation, unnecessary portions were removed with toluene, and dried by heating on a hot plate at 150 ° C. to prepare a coated laminated substrate on which a light emitting layer was formed. Note that all operations for forming the light emitting layer were performed in a glove box in a nitrogen atmosphere.
(Vapor deposition, sealing)
The coated laminated substrate is conveyed into a vapor deposition chamber, and 5 nm of compound 4 (triplet energy is 2.9 eV) is deposited on the light emitting layer as a first electron transport layer, and then compound 5 is further formed as a second electron transport layer. Was evaporated at 45 nm. Further, 1 nm of lithium fluoride and 80 nm of aluminum were deposited. After completing all the vapor deposition steps, sealing with counterbore glass was performed in a glove box in a nitrogen atmosphere to produce an organic EL device.
The obtained organic EL element is caused to emit light by direct current driving, and the lifetime (LT70, light emission efficiency (cd / A), emission color CIE (x, y) and luminance at current density of 1 mA / cm ² is reduced to 70%. An initial luminance of 5000 cd / m ² ) was measured. The measurement results are shown in Table 1.

Comparative Example 1
An organic EL device was produced in the same manner as in Example 1 except that Compound 3 was used as the dopant material.
The results of evaluating the obtained organic EL device in the same manner as in Example 1 are shown in Table 1.
Comparative Example 2
An organic EL device was produced in the same manner as in Example 1 except that Compound 5 (triplet energy was 1,8 eV) was used instead of Compound 4 as the first electron transport layer.
The results of evaluating the obtained organic EL device in the same manner as in Example 1 are shown in Table 1.

As described in Table 1, the light emitting layer contains the metal complex represented by the formula (1) as a dopant material, and the triplet energy of the compound that forms the electron transport layer adjacent to the light emitting layer is included in the light emitting layer. The organic EL device of Example 1, which is 0.1 eV or more larger than the triplet energy of the host material, was superior in luminous efficiency and lifetime to Comparative Examples 1 and 2.

1. 1. Organic EL element Substrate 3. Anode 4. 4. Hole transport band Light emitting layer 6. 6. Electronic transport band Cathode 10. Organic EL element 20. Substrate 21. Anode 22. Hole injection layer 23. Hole transport layer 24. Electron transport layer 25. Electron injection layer 26. Cathode 27. Red light emitting layer 28. Green light emitting layer 29. Blue light emitting layer 30. Hole transport zone 31. Electronic transport band

Claims (23)

1. On the anode, an organic electroluminescence device having a hole transport zone containing a conductive polymer or oligomer, a light emitting layer, and an electron transport zone in order,
   The hole transport zone and the light emitting layer are adjacent, the light emitting layer and the electron transport zone are adjacent,
   The electron transport zone includes a plurality of electron transport layers, and the triplet energy of a compound forming the electron transport layer adjacent to the light emitting layer among the electron transport layers is a triplet of a host material included in the light emitting layer. 0.1 eV or more larger than energy,
   The light-emitting layer contains a metal complex, and the ligand of the metal complex contains at least one structure represented by the following formula (1).
   

   

   [In Formula (1), (X ₁ , X ₂ ) is (carbon atom, nitrogen atom) or (nitrogen atom, carbon atom).
   A, B, and D are substituted or unsubstituted aromatic hydrocarbon ring groups, or substituted or unsubstituted aromatic heterocyclic groups, and these substituents may be bonded to each other to form a ring. .
   m is an integer of 1 to 10, and when it is 2 or more, D may be the same or different. ]
2. The organic electroluminescence device according to claim 1, wherein the metal complex is represented by the following (2-1).
   

   

   [In the formula (2-1), A, B and (X ₁ , X ₂ ) are the same as those in the formula (1).
   R ₁ to R ₅ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. Next to R ₁ to R ₅ , R ₄ and / or R ₅ and A may combine to form a ring.
   M is a metal of Ir or Pt, and α is 2 or 3. ]
3. The organic electroluminescence device according to claim 1, wherein the metal complex is represented by the following (2-2).
   

   

   [In the formula (2-2), D, B and (X ₁ , X ₂ ) are the same as those in the formula (1).
   R ₆ to R ₈ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. R ₆ and R ₇ , R ₆ and / or R ₈ and D may be bonded to form a ring.
   M is a metal of Ir or Pt, and α is 2 or 3. ]
4. The organic electroluminescence device according to claim 1, wherein the metal complex is represented by the following (2-3).
   

   

   [In the formula (2-3), D, A and (X ₁ , X ₂ ) are the same as those in the formula (1).
   R ₉ to R ₁₂ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. Adjacent to R ₉ to R ₁₂ may be bonded to form a ring.
   M is a metal of Ir or Pt, and α is 2 or 3. ]
5. The organic electroluminescence device according to claim 1, wherein the metal complex is represented by the following (3).
   

   

   [In Formula (3), (X ₁ , X ₂ ) is the same as Formulas (2-1), (2-2), and (2-3).
   R ₁ ~ R ₁₂ are each independently formula (2-1), (2-2), the same as R ₁ ~ R ₁₂ of (2-3). R ₄ and R ₆ , R ₅ and R ₈ , R ₈ and R ₁₂ , and R ₁ to R ₁₂ may be bonded together to form a ring.
   M is a metal of Ir or Pt, and α is 2 or 3. ]
6. In the formulas (2-1), (2-2), (2-3), and (3), at least one of R ₁ to R ₁₂ is a substituted or unsubstituted aromatic group having 6 to 30 ring carbon atoms. 6. The organic electroluminescent device according to claim 2, which is a hydrocarbon ring group or a substituted or unsubstituted aromatic heterocyclic group having 2 to 30 ring carbon atoms.
7. The formula (1), (2-1), (2-2), (2-3), or (3), wherein X ₁ is a nitrogen atom, and X ₂ is a carbon atom. The organic electroluminescent element of description.
8. The organic electroluminescence device according to any one of claims 1 to 5, wherein the compound forming the electron transport layer adjacent to the light emitting layer is represented by the following formula (4).
   

   

   [In the formula (4), X represents substituted or unsubstituted carbon, substituted or unsubstituted nitrogen, oxygen, sulfur, substituted or unsubstituted silicon, or substituted or unsubstituted phosphorus atom. R ₂₁ to R ₂₈ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 ring carbon atoms, a substituted or unsubstituted group; An unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms. R ₂₁ and R ₂₈ , R ₂₁ to R ₂₄ , and R ₂₅ to R ₂₈ may be bonded together to form a ring.
   L is a single bond, a k + 1 valent residue of a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, a k + 1 of a substituted or unsubstituted aromatic heterocyclic ring having 2 to 30 ring carbon atoms. It is a valence residue.
   Az is a 6-membered aromatic heterocyclic group containing a substituted or unsubstituted nitrogen atom.
   k is an integer of 1 to 5. When k is plural, Xs may be the same or different. ]
9. The organic electroluminescence device according to claim 8, wherein the compound represented by (4) is represented by the following (5).
   

   

   [In Formula (5), R ₂₁ to R ₂₈ , L, Az, and k are the same as those in Formula (4). ]
10. The organic electroluminescence device according to claim 8, wherein the compound represented by (4) is represented by the following (6).
    

    

    [In Formula (6), R ₂₁ to R ₂₈ , Az, and k are the same as those in Formula (4). n is an integer of 0 to 10. ]
11. In the formulas (4), (5) and (6), the organic electroluminescence device according to any one of claims 8 to 10, wherein Az is a group represented by the following formula (7).
    

    

    (In Formula (7), Y ₁ to Y ₃ are each independently a nitrogen atom or CH, and at least two of Y ₁ to Y ₃ are nitrogen atoms.
    Ar ₁₂ and Ar ₁₃ are each independently a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 18 ring carbon atoms. )
12. The organic electroluminescence device according to any one of claims 1 to 11, wherein the light emitting layer contains a compound represented by the formula (8).
    

    

    [In Formula (8), A ¹ is a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group,
    L ¹ is a single bond, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group,
    B ¹ is a residue having a structure represented by any of the following formulas (2-b-1), (2-a-1) to (2-a-6),
    m ¹ is an integer of 1 or more, the plurality of L ¹ may be the same or different from each other, and the plurality of B ¹ may be the same or different from each other. ]
    

    

    [In the formula (2-b-1), Xb ¹¹ and Xb ¹² are each independently a group represented by —NR—, —O—, —S—, —SiR ₂ —,
    R is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group;
    Rb ¹¹ , Rb ¹² , Rb ¹³ and Rb ¹⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, substituted or unsubstituted Unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted aralkyl group having 7 to 24 carbon atoms, substituted or unsubstituted silyl group, substituted or unsubstituted aromatic carbon atom having 6 to 24 ring carbon atoms A hydrogen ring group, or a substituted or unsubstituted aromatic heterocyclic group having 2 to 24 ring carbon atoms,
    s ¹ is an integer of 0 to 4, and when s ¹ is 2 or more, the plurality of Rb ¹¹ may be the same as or different from each other;
    t ¹ is an integer of 0 to 3, and when t ¹ is 2 or more, the plurality of Rb ¹² may be the same as or different from each other;
    u ¹ is an integer of 0 to 3, and when u ¹ is 2 or more, the plurality of Rb ¹³ may be the same or different from each other,
    v ¹ is an integer of 0 to 4, and when v ¹ is 2 or more, a plurality of Rb ¹⁴ may be the same or different from each other. ]
    

    

    [Xa ¹¹ and Xa ¹² in Formula (2-a-1), Xa ²¹ and Xa ²² in Formula (2-a-2), Xa ³¹ and Xa ³² in Formula (2-a-3), Formula Xa ⁴¹ and Xa ⁴² in (2-a-4), Xa ⁵¹ and Xa ⁵² in formula (2-a-5), and Xa ⁶¹ and Xa ⁶² in formula (2-a-6) are respectively Independently, —NR—, —O—, —S—, —SiR ₂ —, —CR ₂ —,
    R is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group;
    Formula (2-a-1) Ra 1 in the formula (2-a-2) Ra 2 in the formula (2-a-3) in the Ra ^3, Ra in the formula (2-a-4) ⁴ , Ra ⁵ in formula (2-a-5) and Ra ^{6 in} formula (2-a-6) are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or Unsubstituted cycloalkyl group having 3 to 20 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, substituted or unsubstituted aralkyl group having 7 to 24 carbon atoms, substituted or unsubstituted silyl group A substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 24 ring carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group group having 2 to 24 ring carbon atoms,
    A plurality of Ra ¹ when Ra ¹ there are a plurality or different and the same as each other, a plurality of Ra ² when Ra ² there are a plurality or different and the same as each other, a plurality of Ra ³ when Ra ³ there are a plurality or different and the same as each other, a plurality of Ra ⁴ when Ra ⁴ there are a plurality or different and the same as each other, may be a plurality of Ra ⁵ is not being the same or different when Ra ⁵ there are a plurality, may be the plurality of Ra ⁶ are being the same or different when Ra ⁶ there are multiple formulas (2-a-1) p 1 in the formula (2-a-2) p 2 in the formula (2-a-3) in p ^3, formula (2-a-4) p 4 in , p ⁶ of p ^5, and wherein (2-a-6) in the formula (2-a-5) each independently an integer from 0 to 4
    Formula (2-a-1) q 1 in the formula (2-a-2) q 2 in the formula (2-a-3) in the q ^3, q in the formula (2-a-4) ⁴ , q ⁵ in formula (2-a-5), and q ^{6 in} formula (2-a-6) are each independently an integer of 0 to 2,
    Formula (2-a-1) r 1 in the formula (2-a-2) r 2 in the formula (2-a-3) in the r ^3, r in the formula (2-a-4) ⁴ , r ⁵ in formula (2-a-5), and r ⁶ in formula (2-a-1) are integers of 0 to 4. ]
13. A red light emitting element, a green light emitting element, and a blue light emitting element are provided in parallel,
    Each of the red light emitting element, the green light emitting element, and the blue light emitting element has an anode to which a current is applied independently, and has a hole transport zone containing a conductive polymer or oligomer on each anode, A red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer are juxtaposed on the positive hole transport band, and each electron-emitting layer has an electron transport band,
    The electron transport zone is adjacent to the red light emitting layer, the green light emitting layer, and the blue light emitting layer, and is provided in common.
    The said green light emitting layer contains the metal complex represented by Formula (9), The organic electroluminescent element characterized by the above-mentioned.
    

    

    Wherein (9), (X _1, X ₂₎ is a (carbon atom, a nitrogen atom), or (a nitrogen atom, a carbon atom).
    A, B, and D are a monocyclic or condensed ring structure of a substituted or unsubstituted aromatic hydrocarbon ring group or a substituted or unsubstituted aromatic heterocyclic group, and these substituents are bonded to each other. A ring may be formed.
    m is an integer of 1 to 10, and when it is 2 or more, D may be the same or different.
    M is a metal of Ir or Pt, and α is 2 or 3. ]
14. The organic electroluminescence device according to claim 13, wherein the metal complex is represented by the following (2-1).
    

    

    [In the formula (2-1), A, B and (X ₁ , X ₂ ) are the same as those in the formula (9).
    R ₁ to R ₅ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms. A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms It is. Next to R ₁ to R ₅ , R ₄ and / or R ₅ and A may combine to form a ring.
    M is a metal of Ir or Pt, and α is 2 or 3. ]
15. The organic electroluminescence device according to claim 13, wherein the metal complex is represented by the following (2-2).
    

    

    [In the formula (2-2), D, B and (X ₁ , X ₂ ) are the same as in the formula (9).
    R ₆ to R ₈ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. R ₆ and R ₇ , R ₆ and / or R ₈ and D may be bonded to form a ring.
    M is a metal of Ir or Pt, and α is 2 or 3. ]
16. The organic electroluminescence device according to claim 13, wherein the metal complex is represented by the following (2-3).
    

    

    [In Formula (2-3), D, A and (X ₁ , X ₂ ) are the same as those in Formula (9).
    R ₉ to R ₁₂ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 ring carbon atoms, A substituted or unsubstituted aromatic heterocyclic group having 2 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms; is there. Adjacent to R ₉ to R ₁₂ may be bonded to form a ring.
    M is a metal of Ir or Pt, and α is 2 or 3. ]
17. The organic electroluminescence device according to claim 13, wherein the metal complex is represented by the following (3).
    

    

    [In Formula (3), (X ₁ , X ₂ ) and M are the same as in Formulas (2-1), (2-2) and (2-3).
    R ₁ ~ R ₁₂ are each independently formula (2-1), (2-2), the same as R ₁ ~ R ₁₂ of (2-3). R ₄ and R ₆ , R ₅ and R ₈ , R ₈ and R ₁₂ , and R ₁ to R ₁₂ may be bonded together to form a ring.
    M is a metal of Ir or Pt, and α is 2 or 3. ]
18. In the formulas (9), (2-1), (2-2), (2-3), (3), X ₁ is a nitrogen atom and X ₂ is a carbon atom. The organic electroluminescent element of description.
19. In the formulas (2-1), (2-2), (2-3), and (3), at least one of R ₁ to R ₁₂ is a substituted or unsubstituted aromatic group having 6 to 30 ring carbon atoms. The organic electroluminescence device according to any one of claims 14 to 17, which is a hydrocarbon ring group or a substituted or unsubstituted aromatic heterocyclic group having 2 to 30 ring carbon atoms.
20. In the formulas (1), (2-1), (2-2), (2-3), (3), X ₁ is a nitrogen atom and X ₂ is a carbon atom. The organic electroluminescent element of description.
21. The organic electroluminescence device according to any one of claims 13 to 18, wherein the hole transport zone and the light emitting layer are adjacent to each other.
22. The electron transport zone includes a plurality of electron transport layers, and a triplet energy of a compound forming the electron transport layer adjacent to the light emitting layer among the electron transport layers is triple of the host material included in the green light emitting layer. The organic electroluminescence device according to any one of claims 13 to 21, wherein the organic electroluminescence device is 0.1 eV or more larger than the term energy.
23. The method for producing an organic electroluminescent element according to any one of claims 1 to 22, wherein the hole transport zone and the light emitting layer are produced by a coating method, and the electron transport zone is produced by a vapor deposition method.

Images