JP7216482B2 - organic electroluminescent element - Google Patents

Description

The present invention relates to organic electroluminescent devices. More specifically, the present invention relates to an organic electroluminescence device that can be used as a display device such as a display unit of electronic equipment, a lighting device, or the like.

Organic electroluminescence elements (organic EL elements) are expected as new light-emitting elements that can be applied to thin, flexible display devices and lighting.
An organic electroluminescent device has a structure in which one or more layers including a light-emitting layer containing a light-emitting organic compound are sandwiched between an anode and a cathode, and holes injected from the anode and emitted from the cathode The energy generated when the injected electrons recombine is used to excite a light-emitting organic compound to obtain light emission. An organic electroluminescence device is a current-driven device, and in order to use the flowing current more efficiently, various investigations have been made on the device structure and the materials of the layers constituting the device.

An organic electroluminescence device in which all layers between a cathode and an anode are made of an organic compound is, as a result, easily deteriorated by oxygen and water, and strict sealing is essential to prevent entry of these substances. This causes the manufacturing process of the organic electroluminescence device to be complicated.

Furthermore, recently, in order to improve the durability while ensuring the performance of the organic EL element, as an electron injection layer that does not contain an alkali metal, for example, Non-Patent Document 1 discloses an organic EL device having an electron injection layer made of polyethyleneimine. An EL device is described. In addition, Non-Patent Document 2 describes that the electrolyte membrane is effective in improving the electron injection rate, and Non-Patent Document 3 describes the effect of those amino groups on electron injection at the interface between the electrode and the organic layer. Are listed.

Jiangshan Chen and 6 others "Journal Of Materials Chemistry", Vol.22, 2012, p.5164-5170 Hyosung Choi and eight others, "Advanced Materials", Vol. 23, 2011, p2759 Yinhua Zho and 21 others "Science", Vol.336, 2012, p327

As described above, the use of polyethyleneimine or the like as a material for the electron injection layer is disclosed. For reasons such as low durability due to poor conductivity, devices using polyethyleneimine as the material for the electron injection layer are not suitable for practical use. Therefore, there is a demand for an organic electroluminescence device that is more practical than devices using polyethyleneimine and has excellent electron injection properties. In particular, organic electroluminescence devices include those with a forward structure in which an anode is formed on a substrate and those with a reverse structure in which a cathode is formed on a substrate. Therefore, there is a demand for an element that is more practical than an element using polyethyleneimine and has excellent electron injection properties.

The present invention has been made in view of the above-mentioned current situation, and it is an object of the present invention to provide an organic electroluminescence device having a forward structure that is more practical than devices using polyethyleneimine and has excellent electron injection properties. and

The present inventors have studied an organic electroluminescence device with a forward structure that is excellent in practicality and electron injection properties. The inventors have focused on the fact that a compound having a specific structure having a tertiary amine that can express is conductive and excellent in electron injection and electron transport properties. Various investigations were conducted on organic electroluminescent devices using this compound, and it was found that when a layer adjacent to the cathode was formed by coating a solution containing this compound, the resulting organic electroluminescent device had excellent electron injection properties. It was discovered that it can be used as an element. It is believed that this is because the liquid phase process, which is coating film formation, has a higher degree of structural freedom in the film of the amino group-containing compound after film formation than the gas phase process such as vapor deposition. In addition, since the compound having this specific structure is conductive, the element having a coating layer of this compound having this specific structure has a larger film thickness tolerance than the case of using polyethyleneimine, and is practical. The present inventors have also found that the element has a high value, and arrived at the present invention.

That is, the present invention provides an organic electroluminescence device having a structure in which a plurality of organic compound layers are laminated between a cathode and an anode formed on a substrate, and among the organic compound layers, a layer adjacent to the cathode is the following general formula (1);
(X)-[(L)-(NR ¹ R ² )] _n (1)
(In the formula, X represents an n-valent group derived from an electron-transporting compound. L represents a linking group or a direct bond that links X and the amino group represented by NR ¹ R ² . R ¹ and R ² is the same or different and represents a hydrocarbon group optionally having a substituent.n represents a number from 1 to 8.) A solution containing an amino group-containing compound having a structure represented by It is an organic electroluminescence device characterized by being a layer of a coating film of.

In the above general formula (1), the electron-transporting compound-derived n-valent group represented by X preferably has a structure of a pyridine ring at the terminal portion that bonds to L.

The present invention is also a display device comprising the organic electroluminescence device of the present invention.

The present invention also provides a lighting device comprising the organic electroluminescence device of the present invention.

The present invention also provides a method for producing an organic electroluminescence device having a structure in which a plurality of organic compound layers are laminated between a cathode and an anode formed on a substrate, the production method comprising the following general formula ( 1);
(X)-[(L)-(NR ¹ R ² )] _n (1)
(In the formula, X represents an n-valent group derived from an electron-transporting compound. L represents a linking group or a direct bond that links X and the amino group represented by NR ¹ R ² . R ¹ and R ² is the same or different and represents a hydrocarbon group optionally having a substituent.n represents a number from 1 to 8.) A solution containing an amino group-containing compound having a structure represented by and a step of forming a cathode adjacent to the layer containing the amino group-containing compound.

The organic electroluminescent device of the present invention is a forward-structured organic electroluminescent device in which an anode is formed on a substrate, and is excellent in electron injection properties, so that it can be suitably used as a material for display devices and lighting devices. .

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which showed an example of the lamination structure of the organic electroluminescent element of this invention. 2 is a graph showing measurement results of voltage-current density/luminance characteristics of the organic electroluminescence device produced in Example 1. FIG. 2 is a graph showing measurement results of voltage-current density/luminance characteristics of an organic electroluminescence device produced in Comparative Example 1. FIG.

The present invention will be described in detail below.
A combination of two or more of the individual preferred embodiments of the invention described below is also a preferred embodiment of the invention.

The organic electroluminescence device of the present invention is a device having a structure in which a plurality of organic compound layers are laminated between a cathode and an anode formed on a substrate, wherein the layer adjacent to the cathode has the following general formula (1);
(X)-[(L)-(NR ¹ R ² )] _n (1)
(In the formula, X represents an n-valent group derived from an electron-transporting compound. L represents a linking group or a direct bond that links X and the amino group represented by NR ¹ R ² . R ¹ and R ² is the same or different and represents a hydrocarbon group optionally having a substituent.n represents a number from 1 to 8.) A solution containing an amino group-containing compound having a structure represented by It is characterized by being a layer of a coating film of The organic electroluminescent device of the present invention is highly practical and excellent in electron injection properties. These points are also excellent points of the organic electroluminescence device of the present invention.
As a method for forming a layer of an amino group-containing compound having a structure represented by general formula (1), in addition to a method of forming a coating film layer by applying a solution containing the compound, vapor deposition to be described later can be used. However, in the organic electroluminescence device having a forward structure having an anode on a substrate, an amino group-containing compound having such a specific structure is made into a solution, and the solution is applied to form a coating film layer. By forming a cathode thereon, the obtained organic electroluminescence device becomes particularly excellent in electron injection properties. This is presumed to be due to the arrangement of the terminal N atoms in the electron injection layer formed by coating during the coating and film formation time so as to be advantageous for charge injection, and it is presumed that this is why the light emission initiation voltage is low. be done. As a candidate for the arrangement, a dipole between the coating film layer and the metal constituting the cathode adjacent to the layer is considered, and the number of dipoles is considered to be a factor that causes a difference in the characteristics of the device. It is difficult to directly observe the dipole difference with the current technology.
Hereinafter, the amino group-containing compound represented by formula (1) will be described first, and then the structure of the organic electroluminescent device of the present invention and materials other than the amino group-containing compound will be described.

1. Amino Group-Containing Compound The amino group-containing compound of the present invention has a structure represented by the general formula (1).
X in general formula (1) represents an n-valent group derived from an electron-transporting compound. An electron-transporting compound is an n-type organic semiconductor having a heterocyclic ring with a lowest unoccupied molecular orbital (LUMO) level of 2.0 eV to 4.0 eV. Among them, compounds having a LUMO level of 2.5 eV to 3.5 eV or compounds in which the heterocycle is a nitrogen-containing heterocycle are preferred.

As the electron-transporting compound that forms the n-valent group derived from the electron-transporting compound represented by X in the general formula (1), any compound that can be usually used as a material for the electron-transporting layer can be used. can.

It is one of preferred embodiments of the present invention that X in the general formula (1) is represented by the following general formula (2).

In general formula (2) above, Z represents a group obtained by removing n hydrogen atoms from a triazine ring, benzene ring, or pyrimidine ring, and P represents an alkylene group, an arylene group, or a heterocyclic ring. Q represents a heterocyclic ring and is bonded to L in general formula (1). n1 represents a repeating unit of P and is a number from 0 to 3; n2 represents a repeating unit of Q and is 0 or 1; n represents the number of substituents represented by the following general formula (3) that Z has, and is the same number as n in formula (1). When a plurality of P and Q are present in n, the repeating units and structures of P and Q may be the same or different, and Q may be present in at least one of the plurality of n.

P, Q, n1 and n2 in general formula (3) are the same as in general formula (2).

The alkylene group, arylene group, heterocyclic ring for P in the general formula (2) and the heterocyclic ring for Q are preferably groups having 3 to 15 carbon atoms.
The heterocyclic ring in Q in the general formula (2) is preferably an electron transporting group, such as imidazole ring, thiazole ring, oxazole ring, oxadiazole ring, triazole ring, pyrazole ring, pyridine ring, pyrazine It is preferably a group obtained by removing two hydrogen atoms from a ring, triazine ring, benzimidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, benzothiadiazole ring, etc., and two hydrogen atoms are removed from the pyridine ring. It is more preferable that the groups are excluded.
The alkylene group, arylene group and heterocyclic ring for P above and the heterocyclic ring for Q above may have one or more substituents. Examples of substituents are the same as the substituents for R ¹ and R ² in the general formula (1).

Examples of the electron-transporting compound that forms an n-valent group derived from the electron-transporting compound represented by X in the general formula (1) include tris-1,3,5-(3′-(pyridine-3 Pyridine derivatives such as ''-yl)phenyl)benzene (TmPhPyB), 2,4-bis(4-biphenyl)-6-(4'-(2-pyridinyl)-4-biphenyl)-[1,3, 5] triazine derivatives such as triazine (MPT).
Still other examples include phosphine oxide derivatives such as phenyl-dipyrenylphosphine oxide (POPy ₂ ), quinoline derivatives such as (2-(3-(9-carbazolyl)phenyl)quinoline (mCQ)), 2 - pyrimidine derivatives such as phenyl-4,6-bis(3,5-dipyridylphenyl)pyrimidine (BPyPPM), pyrazine derivatives, phenanthroline derivatives such as bathophenanthroline (BPhen), 3-phenyl-4-(1'- naphthyl)-5-phenyl-1,2,4-triazole (TAZ), oxazole derivatives, 2-(4-biphenylyl)-5-(4-tert-butylphenyl-1,3,4- oxadiazole derivatives such as oxadiazole) (PBD), 2,2′,2″-(1,3,5-benzotriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBI) and silole derivatives such as 2,5-bis(6′-(2′,2″-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy) organic silane derivatives, and boron-containing compounds described in Japanese Patent Application Nos. 2012-228460, 2015-503053, 2015-053872, 2015-081108 and 2015-081109.
Among these, a pyridine derivative having a pyridyl group at the terminal such as TmPhPyB is preferable. That is, it is preferable that X is an n-valent group derived from a pyridine derivative having a pyridyl group at the terminal, and is bonded to L of general formula (1) at the terminal pyridyl group.
That is, in the general formula (1), it is one of preferred embodiments of the present invention that the n-valent group derived from the electron-transporting compound represented by X has a pyridine ring structure at the terminal portion that bonds to L. is.

In general formula (1) above, L represents a linking group or a direct bond that couples X and an amino group. When L is a linking group, the linking group is a group that connects an atom at an arbitrary position constituting an n-valent group derived from the electron-transporting compound represented by X and an amino group. When L is a direct bond, the bonding position between the n-valent group derived from the electron-transporting compound and the amino group is also arbitrary.

Examples of the linking group represented by L in the general formula (1) include alkylene linking groups having 1 to 18 carbon atoms (e.g., methylene group, ethylene group, propylene group, butylene group, etc.), and 6 to 18 carbon atoms. arylene linking group (e.g., phenylene group, naphthylene group, etc.), heterocyclic linking group having 2 to 18 carbon atoms (e.g., furyl group, thienylene group, pyridyl group, pyrimidyl group, triazyl group, imidazolyl group, pyrazolyl group, oxazolyl group, morpholyl group, etc.), an alkenylene linking group having 1 to 4 carbon atoms (vinylene group, etc.), an alkynylene linking group, a nitrogen atom, an oxygen atom, and the like. The linking group represented by L may be a combination of two or more of the linking groups listed above.
As the linking group represented by L, among the above linking groups, an alkylene linking group having 1 to 6 carbon atoms is particularly preferable. If the linking group represented by L is an alkylene linking group, the solubility of the organic material can be improved, which is preferable. Further, the hydrogen atom contained in the above linking group L may be replaced with a monovalent substituent. The number of carbon atoms in the linking group means the number of carbon atoms of only the linking group having no substituent, and does not include the number of carbon atoms of the substituent when the linking group has a monovalent substituent.

In general formula (1) above, R ¹ and R ² are the same or different and represent a hydrocarbon group which may have a substituent. As the hydrocarbon group, those having 1 to 6 carbon atoms are preferred. More preferably, it has 1 to 2 carbon atoms. The number of carbon atoms referred to herein means the number of carbon atoms of only the hydrocarbon group, and does not include the number of carbon atoms of the substituents when the hydrocarbon groups have substituents.
A hydrocarbon group may be an alkyl group, an alkenyl group, an alkynyl group, or an aryl group.
In general formula (1), n represents a number of 1 to 8, preferably 1 to 6, more preferably 2 or 3.

In the above general formula (1), the linking groups L may each have the same or different monovalent substituents. In the linking group L, the position and number of monovalent substituents bonded are not particularly limited. The monovalent substituent that may be bonded to one or more of the linking groups L is not particularly limited, but examples thereof include a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, and a halogenated group having 1 to 12 carbon atoms. hydrocarbon group, heterocyclic group having 0 to 12 carbon atoms, cyano group, alkoxy group having 1 to 12 carbon atoms, alkoxycarbonyl group having 2 to 12 carbon atoms, aryloxy group having 6 to 12 carbon atoms, aryloxy group having 6 to 12 carbon atoms, 2 to 30 N-disubstituted amino groups and the like.
When the hydrocarbon groups of R ¹ and R ² in formula (1) have substituents, the substituents are the same as those described above.

The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

The hydrocarbon group having 1 to 20 carbon atoms is a straight chain having 1 to 12 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, octyl group, and the like. linear or branched alkyl group; alkenyl group having 2 to 12 carbon atoms such as vinyl group, 1-propenyl group, allyl group and styryl group; Alkynyl group; Cyclic alkyl group having 5 to 12 carbon atoms such as cyclopentyl group, cyclohexyl group and cycloheptyl group; be done.
Among the above-described hydrocarbon groups having 1 to 20 carbon atoms, the hydrocarbon group preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 6 carbon atoms. 4. Among the above hydrocarbon groups having 1 to 20 carbon atoms, one having 1 carbon atom is particularly preferable.

The halogenated hydrocarbon group having 1 to 12 carbon atoms is a haloalkyl group having 1 to 12 carbon atoms such as a fluoromethyl group, a difluoromethyl group, and a trifluoromethyl group; groups.
The above halogenated hydrocarbon group having 1 to 12 carbon atoms preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, among those mentioned above.

The heterocyclic group having 0 to 12 carbon atoms is a five-membered ring nitrogen-containing ring group such as pentazole; triazole, tetrazole, imidazole, oxazole, isoxazole, thiazole, isothiazole, pyrazole, pyrrole, pyrrolidine, oxazoline, furan, thiophene. and 6-membered heterocyclic groups such as pyridine, pyrazine, piperidine, morpholine and thiazine. These heterocyclic groups may be substituted with halogen atoms, alkyl groups, aryl groups, alkoxy groups, alkenyl groups, alkynyl groups and the like.
Among the above heterocyclic groups having 0 to 12 carbon atoms, the heterocyclic group preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms.

The alkoxy group having 1 to 12 carbon atoms is a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group and an octyloxy group. A straight-chain or branched chain such as is preferable.
The alkoxy group having 1 to 12 carbon atoms preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 3 carbon atoms among those mentioned above.

The alkoxycarbonyl group having 2 to 12 carbon atoms is a linear or branched group such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, tert-butoxycarbonyl group, hexyloxycarbonyl group, and octyloxycarbonyl group. is mentioned.
Among the above-described alkoxycarbonyl groups having 2 to 12 carbon atoms, the number of carbon atoms is preferably 2.

Examples of the aryloxy group having 6 to 12 carbon atoms include a phenyloxy group and a benzyloxy group. In the aryloxy group having 6 to 12 carbon atoms, for example, the aryl group portion of the aryloxy group may be substituted with a halogen atom, an alkyl group, an aryl group, an alkoxy group, an alkenyl group, an alkynyl group, or the like.
The aryloxy group having 6 to 12 carbon atoms preferably has 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms, and still more preferably 6 carbon atoms among those mentioned above.

Examples of the N-disubstituted amino group having 2 to 30 carbon atoms include dialkylamino groups having 2 to 12 carbon atoms such as dimethylamino group, diethylamino group, pyrrolidinyl group and morpholinyl group; N-methyl-N-phenylamino group; N-alkyl-N-arylamino groups having 6 to 20 carbon atoms such as N-ethyl-N-naphthylamino group; A diarylamino group, a cyclic diarylamino group, or the like is preferred.
In addition, the non-cyclic diarylamino group refers to a group that does not have a ring structure other than an aromatic ring. A cyclic diarylamino group refers to a group having a ring structure other than an aromatic ring. In the above N-disubstituted amino group having 2 to 30 carbon atoms, for example, the alkyl group or aryl group portion of the N-disubstituted amino group is substituted with a halogen atom, an alkyl group, an alkoxy group, an alkenyl group, an alkynyl group, or the like. may have been

The dialkylamino group having 2 to 12 carbon atoms preferably has 2 to 8 carbon atoms among those mentioned above. More preferably, it is 2-6. More preferably, it is 2-4.
Among those mentioned above, the N-alkyl-N-arylamino group having 6 to 20 carbon atoms preferably has 7 to 18 carbon atoms. More preferably, it is 7-15. More preferably, it is 7-11.
Among the above-described noncyclic diarylamino groups or cyclic diarylamino groups having 11 to 30 carbon atoms, the number of carbon atoms is preferably 11 to 20, more preferably 12 to 18, and still more preferably , 12-16.

In addition, the monovalent substituents that may be bonded to one or more of the linking groups L, and the substituents when the hydrocarbon groups of R ¹ and R ² have substituents are an acetyl group, a propionyl group, Acyl groups such as butyryl groups; N,N-dimethylcarbamoyl groups, N,N-dialkylcarbamoyl groups such as N,N-diethylcarbamoyl groups; Thioacetyl groups, thiobenzoyl groups, thiocarbonyl groups such as methoxythiocarbonyl groups; It may be an oxaborolanyl group, a stannyl group, a silyl group, an ester group, a formyl group, a thioether group, an epoxy group, an isocyanate group, a sulfo group, a sulfonyl group, a phosphoryl group, or the like.

The above monovalent substituents (monovalent substituents that may be bonded to one or more of the linking groups L, and substituents in the case where the hydrocarbon groups of R ¹ and R ² have substituents) are It may be substituted with a monovalent substituent such as a halogen atom, a heteroatom, an alkyl group, an alkoxy group, an alkenyl group, an alkynyl group, or an aromatic ring as long as the effects of the present invention can be exhibited. The above monovalent substituents (monovalent substituents that may be bonded to one or more of the linking groups L, and substituents when the hydrocarbon groups of R ¹ and R ² have substituents) are further When it has a valent substituent, the position and number of the monovalent substituent that may be bonded to one or more of the linking groups L are not particularly limited.

2. Organic Electroluminescence Device Next, the structure of the organic electroluminescence device of the present invention and materials other than the amino group-containing compound will be described.
The organic electroluminescence device of the present invention has a structure in which a plurality of organic compound layers are laminated between a cathode and an anode formed on a substrate.
The structure of the organic electroluminescent device of the present invention is not particularly limited, but an anode, a hole-transporting layer and/or a hole-injecting layer, a light-emitting layer, and optionally an electron-transporting layer, an electron-injecting layer, and a cathode are arranged in this order. Adjacent elements are preferred. In addition, each of these layers may consist of one layer, and may consist of two or more layers.
In the organic electric field element having the above structure, when the element does not have an electron transport layer, the electron injection layer and the light emitting layer are adjacent to each other. In addition, when the device has only one of the hole transport layer and the hole injection layer, the one layer is laminated adjacent to the light emitting layer and the anode, so that the device has a hole transport layer. In the case of having both a layer and a hole-injecting layer, these layers are laminated adjacent to each other in the order of anode, hole-injecting layer, hole-transporting layer, and light-emitting layer.
The organic electroluminescence device of the present invention may be of a top emission type in which light is extracted to the side opposite to the substrate, or may be of a bottom emission type in which light is extracted to the substrate side.

In the organic electroluminescent device of the present invention, the layer of the coating film formed by applying the solution containing the amino group-containing compound represented by the general formula (1) is formed as a layer adjacent to the cathode. , the coating film layer containing the amino group-containing compound becomes an electron injection layer. Since the amino group-containing compound represented by the general formula (1) is a compound with excellent electron injection properties, by having a layer containing this compound as an electron injection layer, the device has a low driving voltage and excellent characteristics. It becomes an element having

FIG. 1 is a schematic cross-sectional view for explaining an example of the forward-structured organic electroluminescence device of the present invention. The organic electroluminescence device of this embodiment shown in FIG. 1 has a light-emitting layer 5 between an anode 2 and a cathode 8 . The organic electroluminescent device shown in FIG. 1 has an electron injection layer 7 between the cathode 8 and the light emitting layer 5 .
The organic electroluminescence device of this embodiment comprises an anode 2, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6, an electron injection layer 7, and an anode 2 on a substrate 1. It has a laminate structure in which the cathode 8 is formed in this order.

"substrate"
Materials for the substrate in the organic electroluminescence device of the present invention include resin materials and glass materials.
Resin materials used for the substrate include polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethyl methacrylate, polycarbonate, and polyarylate. When a resin material is used as the material of the substrate, it is preferable because an organic electroluminescence device having excellent flexibility can be obtained.
Examples of glass materials used for the substrate include quartz glass and soda glass.

When the organic electroluminescence device of the present invention is of the bottom emission type, a transparent substrate is used as the substrate material.
When the organic electroluminescence device of the present invention is of the top emission type, the material of the substrate may be not only a transparent substrate but also an opaque substrate. Examples of opaque substrates include substrates made of ceramic materials such as alumina, substrates made of metal plates such as stainless steel with an oxide film (insulating film) formed thereon, and substrates made of resin materials.

The average thickness of the substrate can be determined according to the material of the substrate, and is preferably 0.1 to 30 mm, more preferably 0.1 to 10 mm.
The average thickness of the substrate can be measured with a digital multimeter and vernier calipers.

"anode"
In the organic electroluminescence device of the present invention, materials used for the anode include ITO, IZO, Au, Pt, Ag, Cu, Al, and alloys containing these. Among these, it is preferable to use ITO, IZO, Au, Ag, and Al as the anode material.

Although the average thickness of the anode is not particularly limited, it is preferably 10 to 1000 nm, more preferably 30 to 150 nm. Even when an opaque material is used as the material for the anode, it can be used as a transparent anode in a top-emission type organic electroluminescence device by setting the average thickness to, for example, about 10 to 30 nm.
The average thickness of the anode can be measured during deposition of the anode using a crystal oscillator film thickness gauge.

"hole injection layer"
In the organic electroluminescent device of the present invention, materials used for the hole injection layer include dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11- hexacarbonitrile (HAT-CN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4-TCNQ) and the like.

Although the average thickness of the hole injection layer is not particularly limited, it is preferably 1 to 1000 nm, more preferably 5 to 50 nm.
The average thickness of the hole injection layer can be measured during film formation with a crystal oscillator film thickness meter.

"hole transport layer"
In the organic electroluminescence device of the present invention, as the hole-transporting organic material used for the hole-transporting layer, various p-type polymeric materials (organic polymers) and various p-type low-molecular-weight materials may be used singly or in combination. can be done.
Specifically, examples of materials for the hole transport layer include N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α- NPD), N4,N4′-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4′-diphenylbiphenyl-4,4′-diamine (DBTPB), polyarylamines, fluorene-arylamine co- Polymer, fluorene-bithiophene copolymer, poly(N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylene vinylene), polytinylene vinylene, pyrene formaldehyde resin , ethylcarbazole formaldehyde resins or derivatives thereof. These materials for the hole transport layer 7 can also be used as mixtures with other compounds. An example of a mixture containing polythiophene used as a material for the hole transport layer 7 is poly(3,4-ethylenedioxythiophene/styrenesulfonic acid) (PEDOT/PSS).

Although the average thickness of the hole transport layer is not particularly limited, it is preferably 10 to 150 nm, more preferably 20 to 100 nm.
The average thickness of the hole transport layer can be measured by, for example, a stylus profilometer or spectroscopic ellipsometry.

"Luminous layer"
In the organic electroluminescence device of the present invention, as the material for forming the light-emitting layer, any material that can be normally used as a material for the light-emitting layer may be used, or a mixture of these materials may be used. Specifically, for example, bis[2-(2-benzothiazolyl)phenolato]zinc(II) (Zn(BTZ) ₂ ) and tris[1-phenylisoquinoline]iridium(III) (Ir(piq ) and ₃ ).
Moreover, the material forming the light-emitting layer may be a low-molecular-weight compound or a high-molecular-weight compound. In the present invention, a low-molecular-weight material means a material that is not a polymeric material (polymer), and does not necessarily mean an organic compound with a low molecular weight.

Examples of the polymer material forming the light-emitting layer include polyacetylene-based compounds such as trans-polyacetylene, cis-polyacetylene, poly(di-phenylacetylene) (PDPA), and poly(alkylphenylacetylene) (PAPA); (para-phenvinylene) (PPV), poly(2,5-dialkoxy-para-phenylenevinylene) (RO-PPV), cyano-substituted-poly(para-phenvinylene) (CN-PPV), poly(2 -Dimethyloctylsilyl-para-phenylene vinylene) (DMOS-PPV), poly(2-methoxy,5-(2'-ethylhexoxy)-para-phenylene vinylene) (MEH-PPV) poly-paraphenylene vinylene compounds poly(3-alkylthiophene) (PAT), polythiophene compounds such as poly(oxypropylene) triol (POPT); poly(9,9-dialkylfluorene) (PDAF), poly(dioctylfluorene-alto-benzothiadiazole ) (F8BT), α,ω-bis[N,N′-di(methylphenyl)aminophenyl]-poly[9,9-bis(2-ethylhexyl)fluorene-2,7-dyl] (PF2/6am4) , polyfluorene compounds such as poly(9,9-dioctyl-2,7-divinylenefluorenyl-ortho-co(anthracene-9,10-diyl); poly(para-phenylene) (PPP), poly Polyparaphenylene compounds such as (1,5-dialkoxy-para-phenylene) (RO-PPP); polycarbazole compounds such as poly(N-vinylcarbazole) (PVK); poly(methylphenylsilane) Polysilane compounds such as (PMPS), poly (naphthylphenylsilane) (PNPS), poly (biphenylylphenylsilane) (PBPS); A compound polymer material and the like can be mentioned.

Examples of low-molecular-weight materials forming the light-emitting layer include factoris (2-phenylpyridine), a three-coordinate iridium complex having 2,2'-bipyridine-4,4'-dicarboxylic acid as a ligand. iridium (Ir(ppy) ₃ ), 8-hydroxyquinoline aluminum (Alq ₃ ), tris(4-methyl-8quinolinoleate) aluminum (III) (Almq ₃ ), 8-hydroxyquinoline zinc (Znq ₂ ), (1, 10-phenanthroline)-tris-(4,4,4-trifluoro-1-(2-thienyl)-butane-1,3-dionate) europium (III) (Eu(TTA) ₃ (phen)), 2, Various metal complexes such as 3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(II); benzenes such as distyrylbenzene (DSB), diaminodistyrylbenzene (DADSB) naphthalene, naphthalene compounds such as Nile Red; phenanthrene compounds such as phenanthrene; chrysene, chrysene compounds such as 6-nitrochrysene; perylene, N,N'-bis(2,5-di- perylene compounds such as t-butylphenyl)-3,4,9,10-perylene-di-carboximide (BPPC); coronene compounds such as coronene; anthracene compounds such as anthracene and bisstyrylanthracene; Pyrene-based compounds such as pyrene; Pyran-based compounds such as 4-(di-cyanomethylene)-2-methyl-6-(para-dimethylaminostyryl)-4H-pyran (DCM); Acridine-based compounds such as acridine compounds; stilbene-based compounds such as stilbene; thiophene-based compounds such as 2,5-dibenzoxazole thiophene; benzoxazole-based compounds such as benzoxazole; benzimidazole-based compounds such as benzimidazole; benzothiazole compounds such as para-phenylenedivinylene)-bisbenzothiazole; butadiene compounds such as bistyryl (1,4-diphenyl-1,3-butadiene) and tetraphenylbutadiene; naphthalimides such as naphthalimide coumarin-based compounds such as coumarin; perinone-based compounds such as perinone; oxadiazole-based compounds such as oxadiazole; aldazine-based compounds; 1,2,3,4,5-pentaphenyl- cyclopentadiene compounds such as 1,3-cyclopentadiene (PPCP); quinacridone compounds such as quinacridone and quinacridone red; pyridine compounds such as pyrrolopyridine and thiadiazolopyridine; Spiro compounds such as '-tetraphenyl-9,9'-spirobifluorene; metal or metal-free phthalocyanine compounds such as phthalocyanine (H ₂ Pc) and copper phthalocyanine; Examples thereof include boron compound materials described in JP-A-2011-184430 and Japanese Patent Application No. 2011-6458.

Although the average thickness of the light-emitting layer is not particularly limited, it is preferably 10 to 150 nm, more preferably 20 to 100 nm.
The average thickness of the light emitting layer may be measured with a stylus profilometer, or may be measured at the time of film formation of the light emitting layer with a crystal oscillator film thickness meter.

"Electron transport layer"
In the organic electroluminescence device of the present invention, any material that can be commonly used as a material for an electron transport layer may be used as the material for the electron transport layer.
Specific examples of materials that can be commonly used as electron-transporting layer materials include phosphine oxide derivatives such as phenyl-dipyrenylphosphine oxide (POPy ₂ ), tris-1,3,5-(3′-(pyridine -3″-yl)phenyl)benzene (TmPhPyB), quinoline derivatives such as (2-(3-(9-carbazolyl)phenyl)quinoline (mCQ)), 2-phenyl-4,6 - pyrimidine derivatives such as bis(3,5-dipyridylphenyl)pyrimidine (BPyPPM), pyrazine derivatives, phenanthroline derivatives such as bathophenanthroline (BPhen), 2,4-bis(4-biphenyl)-6-(4' -(2-pyridinyl)-4-biphenyl)-[1,3,5]triazine (MPT), 3-phenyl-4-(1′-naphthyl)-5-phenyl-1,2, Triazole derivatives such as 4-triazole (TAZ), oxazole derivatives, oxa such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl-1,3,4-oxadiazole) (PBD) Diazole derivatives, imidazole derivatives such as 2,2′,2″-(1,3,5-benzotriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBI), naphthalene, perylene, etc. various metal complexes represented by aromatic ring tetracarboxylic acid anhydride, bis[2-(2-hydroxyphenyl)benzothiazolato]zinc (Zn(BTZ) ₂ ), tris(8-hydroxyquinolinato)aluminum (Alq3), 2,5-bis(6′-(2′,2″-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy) and other silole derivatives; Application 2012-228460, Japanese Patent Application 2015-503053, Japanese Patent Application 2015-053872, Japanese Patent Application 2015-081108 and Japanese Patent Application 2015-081109 include boron-containing compounds and the like, and using one or more of these can be done.
Among these electron transport layer materials, it is particularly preferable to use phosphine oxide derivatives such as _POPy2 , metal complexes such as Alq3 _, and pyridine derivatives such as TmPhPyB.

The average thickness of the electron transport layer is not particularly limited, but is preferably 10 to 150 nm, more preferably 20 to 100 nm.
The average thickness of the electron transport layer can be measured by a stylus profilometer or spectroscopic ellipsometry.

"Electron injection layer"
In the organic electroluminescent device of the present invention, the electron injection layer is a layer that improves the speed of injection of electrons from the cathode to the light emitting layer and the electron transport property. It is a layer containing a group-containing compound.
The average thickness of the electron injection layer is preferably 5 to 100 nm, more preferably 10 to 50 nm. When the electron injection layer has an average thickness of 100 nm or less, it is possible to sufficiently suppress an increase in the driving voltage of the organic electroluminescence device due to the provision of the electron injection layer.
The average thickness of the electron injection layer can be measured by a stylus profilometer and spectroscopic ellipsometry.

The organic electroluminescence device of the present invention uses the layer containing the amino group-containing compound represented by the general formula (1) as an electron injection layer, for example, the electron injection layer is an unstable material in the air. Excellent durability can be obtained as compared with the case of using an alkali metal.

"cathode"
In the organic electroluminescence device of the present invention, it is not essential to use an alkali metal or an alkaline earth metal as a cathode material, unlike a general cathode material. Medium work function metals such as Al and even more inert high work function gold can be used by themselves.

Although the average thickness of the cathode is not particularly limited, it is preferably 10 to 500 nm, more preferably 100 to 200 nm.
The average thickness of the cathode can be measured by a stylus profilometer and spectroscopic ellipsometry.

"sealing"
The organic electroluminescence device of the present invention may be sealed if necessary.
The sealing method is not particularly limited. good. Alternatively, the organic electroluminescence element may be housed in a sealing container and sealed by filling with a sealing material such as an ultraviolet (UV) curable resin. A sealing member comprising a plate member arranged on the cathode and a frame member arranged along the edge of the plate member facing the cathode; and the substrate may be sealed using an adhesive.

When the organic electroluminescence element is sealed using the sealing container or the sealing member, a desiccant that absorbs moisture may be placed inside the sealing container or the sealing member. Also, a material that absorbs moisture may be used as the sealed container or the sealing member. Further, a space may be formed inside the sealed container or inside the sealing member.

A resin material, a glass material, or the like can be used as a material for the sealing container or the sealing member used for sealing the organic electroluminescence element. As the resin material and the glass material used for the sealed container or the sealing member, the same materials as those used for the substrate can be used.

In the organic electroluminescence device of the present invention, the method for forming the layer formed from the organic compound is not particularly limited, and various methods can be appropriately used according to the properties of the material. Spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, slit coating method, dip coating method, spray coating method, screen printing method, flexographic printing method, offset A film can be formed using various coating methods such as a printing method and an inkjet printing method. Among these methods, the spin coating method and the slit coating method are preferable because the film thickness can be more easily controlled. Sputtering method, vacuum deposition method, sol-gel method, spray pyrolysis (SPD) method, atomic layer deposition (ALD) method, vapor phase deposition method, liquid phase deposition method, ESDUS when not coated or solvent solubility is low (Evaporative Spray Deposition from Ultra-dilute Solution) method or the like can be used.

When forming a layer formed from an organic compound including an amino group-containing compound represented by the general formula (1) by applying an organic compound solution, the solvent used for dissolving the organic compound includes, for example, , nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, inorganic solvents such as ethylene carbonate, methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone ( MIPK), ketone solvents such as cyclohexanone, methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol (DEG), alcohol solvents such as glycerin, diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4 -Ether solvents such as dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl ether (carbitol), cellosolve solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, hexane , pentane, heptane, cyclohexane, and other aliphatic hydrocarbon solvents; toluene, xylene, benzene, and other aromatic hydrocarbon solvents; pyridine, pyrazine, furan, pyrrole, thiophene, methylpyrrolidone, and other aromatic heterocyclic compound solvents , N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA) and other amide solvents, chlorobenzene, dichloromethane, chloroform, 1,2-dichloroethane and other halogen compound solvents, ethyl acetate, methyl acetate, Ester solvents such as ethyl formate, sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane, nitrile solvents such as acetonitrile, propionitrile and acrylonitrile, organic acid solvents such as formic acid, acetic acid, trichloroacetic acid and trifluoroacetic acid. Examples include various organic solvents such as solvents, or mixed solvents containing these.
Among these, nonpolar solvents are suitable as the solvent. Examples include aromatic heterocyclic compound solvents such as pyrrole, thiophene and methylpyrrolidone, and aliphatic hydrocarbon solvents such as hexane, pentane, heptane and cyclohexane, and these can be used alone or in combination.

The cathode and anode are formed by a sputtering method, a vacuum deposition method, a sol-gel method, a spray pyrolysis (SPD) method, an atomic layer deposition (ALD) method, a vapor deposition method, a liquid deposition method, or the like. can be done. Bonding of metal foils can also be used to form the anode and cathode. These methods are preferably selected according to the characteristics of the material of each layer, and the manufacturing method may be different for each layer. When the metal oxide layer is formed on the organic compound layer, it is more preferable to use the vapor deposition method among these methods. According to the vapor-phase film forming method, the organic compound layer can be formed cleanly and in good contact with adjacent layers without damaging the surface of the organic compound layer.

3. Method for Producing Organic Electroluminescent Device As described above, in the forward-structured organic electroluminescent device, a solution containing an amino group-containing compound having a structure represented by the general formula (1) is applied to form a layer. , an organic electroluminescence device having excellent electron injection properties can be obtained.
A method for producing such an organic electroluminescent device, that is, a method for producing an organic electroluminescent device having a structure in which a plurality of organic compound layers are laminated between a cathode and an anode formed on a substrate, The production method is the following general formula (1);
(X)-[(L)-(NR ¹ R ² )] _n (1)
(In the formula, X represents an n-valent group derived from an electron-transporting compound. L represents a linking group or a direct bond that links X and the amino group represented by NR ¹ R ² . R ¹ and R ² is the same or different and represents a hydrocarbon group optionally having a substituent.n represents a number from 1 to 8.) A solution containing an amino group-containing compound having a structure represented by and a step of forming a cathode adjacent to the layer containing the amino group-containing compound. is one.

In the method for producing an organic electroluminescent device of the present invention, the solvent used for preparing the solution containing the amino group-containing compound represented by the general formula (1) and the method for forming a coating film layer of the solution include: Those mentioned above can be used.

The method for producing an organic electroluminescent device of the present invention includes the step of applying a solution containing an amino group-containing compound having a structure represented by the general formula (1) to form a layer, and a layer containing the amino group-containing compound. Other steps may be included as long as the step of forming a cathode adjacent to is included. Other steps include a step of forming a layer other than the layer of the coating film of the solution containing the amino group-containing compound, a step of sealing the element, and the like.

In the organic electroluminescence device of the present invention, the color of emitted light can be changed by appropriately selecting the material of the organic compound layer, and a desired color of emitted light can be obtained by using a color filter or the like in combination. Therefore, it can be suitably used as a light-emitting part of a display device or a lighting device. In particular, when the organic electroluminescence element is an element with an inverted structure, a display device combined with an oxide TFT is suitable due to the characteristics of the inverted structure.
Such a display device comprising the organic electroluminescent device of the present invention and a lighting device comprising the organic electroluminescent device of the present invention are also included in the present invention.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited only to these examples. Unless otherwise specified, "part" means "part by weight" and "%" means "% by mass".

¹ H-NMR measurement of the compounds synthesized in Synthesis Examples was carried out as follows.
( ¹ H-NMR measurement)
A sample was dissolved in heavy chloroform containing tetramethylsilane and measured with a nuclear magnetic resonance apparatus (Varian 600 MHz).

(Synthesis example 1)
Synthesis of Organic Compound A An organic compound A represented by the following formula (i) was synthesized by reactions 1 to 5 shown below.

(Reaction 1) The following compound 1 was synthesized by the following reaction.

3-allyl-5-bromopyridine (7.6 g, 38.4 mmol) synthesized according to the literature (Angewandte Chemie International Edition, 2004, 43, p.3333) and THF ( 200 mL) was added, and boron trifluoride diethyl ether complex (BF ₃ OEt ₂ (4.8 mL, 38.2 mmol) was slowly added while stirring at 0° C. 9-borabicyclo[3,3,1]nonane. After dropping (9-BBN) (1.0 M THF solution, 100 mL, 100 mmol), the temperature was raised to room temperature and the mixture was stirred for 24 hours and then at 50° C. for 20 hours. N′,N′-Tetramethylethylenediamine (TMEDA) (2.9 mL, 19.2 mmol) was added, stirred at room temperature for 2 hours, cooled to 0° C. again, and dissolved in an aqueous sodium hydroxide solution (9.3 g in 93 mL of water). 35% aqueous hydrogen peroxide (93 mL) was added, and the mixture was stirred at room temperature for 3 hours.The reaction solution was transferred to a separatory funnel, extracted with ethyl acetate, and the organic layer was washed with saturated sodium chloride. The residue was washed with water, dried over sodium sulfate, filtered, and the residue was purified by silica gel column chromatography to obtain 7.9 g of compound 1 (36.6 mmol, 95%).

(Reaction 2) Compound 2 was synthesized from compound 1 by the following reaction.

Compound 1 (13.0 g, 60.2 mmol), THF (170 mL), and triethylamine (12.5 mL, 90.2 mmol) were placed in a 300 mL eggplant flask under a nitrogen atmosphere, and methanesulfonyl chloride (7 .0 mL, 90.4 mmol) was added slowly. After stirring overnight at room temperature, water was added and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over magnesium sulfate, and filtered. Silica gel column chromatography refine|purified the residue obtained by concentrating a filtrate, and 14.4g of compounds 2 were obtained. (48.9mmol, 81%)

(Reaction 3) Compound 3 was synthesized from compound 2 by the following reaction.

Compound 2 (14.4 g, 48.9 mmol) and THF (100 mL) were placed in a 300 mL flask, and a 50% dimethylamine aqueous solution was added while stirring at room temperature. After stirring overnight, the mixture was concentrated, water was added to the residue, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over magnesium sulfate, filtered, the filtrate was concentrated, and the residue was purified by silica gel column chromatography to obtain 11.5 g of compound 3. (47.3mmol, 97%)

(Reaction 4) Compound 4 was synthesized from Compound 3 by the following reaction.

Compound 3 (11.5 g, 47.3 mmol) and diethyl ether (300 mL) were placed in a 500 mL three-necked flask and cooled to -78°C. To this, n-butyllithium (1.63M, 33 mL, 52 mmol) was slowly added dropwise, and after stirring for 1 hour, tributyltin chloride (14.1 mL, 52 mmol) was slowly added. After stirring overnight at room temperature, saturated aqueous ammonium chloride solution was added, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over magnesium sulfate, filtered, the filtrate was concentrated, and the obtained residue was purified by silica gel column chromatography to obtain 18.4 g of Compound 4. (40.6mmol, 86%)

(Reaction 5) Compound 5 (organic compound A) was synthesized from compound 4 by the following reaction.

Compound 4 (10.8 g, 24 mmol), tris(3-bromophenyl)-1,3,5-triazine (3.0 g, 5.5 mmol), toluene (60 mL) were placed in a 200 mL two-necked flask under a nitrogen atmosphere. I put Tetrakis(triphenylphosphine)palladium (Pd(PPh ₃ ) ₄ ) (800 mg, 0.69 mmol) was added thereto, and the mixture was stirred at 110°C for 24 hours, then dioxane (60 mL) was added and further stirred for 17 hours. After allowing to cool to room temperature, water was added and the mixture was extracted with ethyl acetate. The organic layer was dried over magnesium sulfate and filtered. The filtrate was concentrated and purified by silica gel column chromatography to obtain a crude product. This was suspended in acetone, the insoluble compound was collected by filtration, washed with ethyl acetate, and the resulting white solid was recrystallized from toluene to obtain 1.13 g of compound 5 (organic compound A). (1.42mmol, 26%)
¹ H-NMR measurement results of the obtained organic compound A are as follows.
¹ H-NMR (600 MHz, CDCl ₃ ) δ = 8.99 (s, 1H), 8.91-8.78 (m, 2H), 8.57-8.49 (m, 1H), 7.84 (s, 1H), 7.85 (d, J = 7.7Hz, 2H), 7.73 (t, J = 7.8Hz, 1H), 2.79 (t, J = 7.8Hz, 2H) , 2.36 (t, J=7.2 Hz, 2H), 2.25 (s, 6H), 1.89 (quin, J=7.5 Hz, 2H).

(Preparation of organic electroluminescent element)
(Example 1)
[1] A commercially available transparent glass substrate with an ITO electrode layer having an average thickness of 0.7 mm was prepared. At this time, the ITO electrode (anode) of the substrate used was patterned to have a width of 2 mm. This substrate was subjected to ultrasonic cleaning in acetone and isopropanol for 10 minutes each, followed by vapor cleaning in isopropanol for 5 minutes. This substrate was dried by nitrogen blowing and UV ozone cleaning was performed for 20 minutes.
[2] This substrate was set on a spin coater, and an aqueous dispersion of poly(3,4-ethylenedioxythiophene/styrenesulfonic acid) (PEDOT/PSS) (manufactured by Heraeus, CH8000) was added dropwise. It was rotated for 60 seconds and dried on a hot plate at 130° C. for 10 minutes to form a hole injection layer made of PEDOT/PSS on the anode. The average thickness of the hole injection layer was 50 nm. The average thickness of the hole injection layer was measured with a stylus profilometer.
[3] A 2% xylene solution of poly(dioctylfluorene-alto-benzothiadiazole) (F8BT) (molecular weight 54000) was prepared. The substrate prepared in the above step [2] was set on a spin coater. An F8BT-xylene solution was dropped onto the hole injection layer formed in step [2] above, and rotated at 2,000 rpm for 60 seconds to form a light-emitting layer of F8BT on the interlayer layer. The average thickness of the light-emitting layer was 50 nm. The average thickness of the light-emitting layer was measured with a stylus profilometer.
[4] The substrate prepared in the above step [3] was set on a spin coater. An ethanol solution (0.5 wt%) of the organic compound A synthesized in Synthesis Example 1 was dropped onto the light-emitting layer formed in the above step [3], rotated at 2000 rpm for 60 seconds, and placed on the light-emitting layer. An electron injection layer was formed. The average thickness of the electron injection layer was 10 nm. The average thickness of the electron injection layer was measured with a stylus profilometer.
[5] The substrate prepared in the above step [4] was fixed to a substrate holder of a vacuum vapor deposition apparatus. An aluminum wire (Al) was placed in an alumina crucible and set to a vapor deposition source. The pressure inside the vacuum deposition apparatus was reduced to about 1×10 ⁻⁴ Pa, and Al (cathode) was deposited on the electron injection layer to an average thickness of 100 nm to fabricate an organic electroluminescence device. The average thickness of the cathode was measured during film formation with a crystal oscillator film thickness gauge.

(Comparative example 1)
An organic electroluminescence device was produced in the same manner as in Example 1, except that step [4] of Example 1 was changed to the following step [4-1].
[4-1] The substrate prepared in the above step [3] was fixed to a substrate holder of a vacuum vapor deposition apparatus. At the same time, the organic compound A synthesized in Synthesis Example 1 was placed in a crucible and set as a vapor deposition source. The pressure inside the vacuum deposition apparatus was reduced to about 1×10 ⁻⁴ Pa, and the organic compound A was deposited as an electron injection layer on the light-emitting layer formed in step [3] so as to have an average thickness of 10 nm. The average thickness of the electron injection layer was measured at the time of film formation with a crystal oscillator film thickness gauge.

(Measurement of luminous properties of organic electroluminescent device)
For the organic electroluminescence elements produced in Example 1 and Comparative Example 1, voltage application and current measurement to the elements were performed using a "2400 type source meter" manufactured by Keithley. In addition, luminescence luminance was measured using “BM-7” manufactured by Topcon Corporation. Measurements were performed under an argon atmosphere. The results are shown in Figures 2 and 3.
The organic electroluminescence element of Example 1 having the coating film of the organic compound A started to emit light at an applied voltage of about 2.8 V, whereas the organic electroluminescence element of Comparative Example 1 in which the organic compound A was formed by vapor deposition. However, light was not emitted unless a voltage of around 3.5 V was applied. Furthermore, when the luminance at an applied voltage of 6 V was compared, the organic electroluminescence device of Example 1 was about 10 times higher than the organic electroluminescence device of Comparative Example 1. From these results, it was confirmed that by forming a coating film layer of organic compound A, an element having excellent electron injection properties can be obtained.

1: Substrate 2: Anode 3: Hole injection layer 4: Hole transport layer 5: Light emitting layer 6: Electron transport layer 7: Electron injection layer 8: Cathode

Claims (5)

An organic electroluminescence device having a structure in which a plurality of organic compound layers are laminated between a cathode (excluding those made of oxide) and an anode formed on a substrate,
Among the organic compound layers, the layer adjacent to the cathode is
the following general formula (1);
(X)-[(L)-(NR ¹ R ² )] _n (1)
(In the formula, X represents an n-valent group derived from an electron-transporting compound. L represents a linking group or a direct bond that links X and the amino group represented by NR ¹ R ² . R ¹ and R ² is the same or different and represents an optionally substituted alkyl group n represents a number from 2 to 8.) of a solution containing an amino group-containing compound having a structure represented by An organic electroluminescence device characterized by being a layer of a coating film. 2. The organic compound according to claim 1, wherein in the general formula (1), the electron-transporting compound-derived n-valent group represented by X has a structure of a pyridine ring at the terminal portion that bonds to L. Electroluminescence device. A display device comprising the organic electroluminescence device according to claim 1 . A lighting device comprising the organic electroluminescence device according to claim 1 . A method for producing an organic electroluminescence device having a structure in which a plurality of organic compound layers are laminated between a cathode (excluding those made of oxide) and an anode formed on a substrate,
The production method comprises the following general formula (1);
(X)-[(L)-(NR ¹ R ² )] _n (1)
(In the formula, X represents an n-valent group derived from an electron-transporting compound. L represents a linking group or a direct bond that links X and the amino group represented by NR ¹ R ² . R ¹ and R ² is the same or different and represents an optionally substituted alkyl group, n represents a number from 2 to 8.) a solution containing an amino group-containing compound having a structure represented by applying to form a layer;
and forming a cathode adjacent to the layer containing the amino group-containing compound.

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