CN116041276A - Organic compound, light-emitting element, and light-emitting element material - Google Patents

Abstract

The invention provides a compound for improving electron transport efficiency of an organic light-emitting element, an organic light-emitting element material containing the compound, an organic light-emitting element electron transport layer, a hole blocking layer, a cover layer material and an organic light-emitting element. The compound provided by the invention has a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure or a pyrrole structure on one hand, and contains a series of aryl and heteroaryl structures on the other hand. The organic light-emitting element provided by the invention can realize high light-emitting efficiency, low driving voltage and long durability, and can be used for light sources, marking plates, marking lamps and the like of backlights of organic EL displays and liquid crystal displays, illumination, meters and the like. The invention provides an organic light-emitting element which can greatly improve the light-emitting efficiency and has a longer service life.

Description

Organic compound, light-emitting element, and light-emitting element material

Technical Field

The present invention relates to an organic compound for a light-emitting element, an electron transport material, a hole blocking layer material, a capping layer material, and a light-emitting element each containing the compound, which can greatly improve light-emitting efficiency.

Background

The organic light emitting device is a self-luminous display device and has the characteristics of light weight, wide viewing angle, low power consumption, high contrast, wide color gamut and the like. With the development of technology, the organic light emitting element can also be flexible, and bending or folding operation is performed in use, so that the product is more portable, or can be applied in more various scenes.

The light-emitting principle of the organic light-emitting element is that holes and electrons are generated on electrodes at both ends by applying a voltage to the element, and the holes and electrons are combined in the light-emitting layer to generate excitons by conduction of each functional layer, so that the light-emitting material is excited, and the light-emitting material returns to a ground state through the excited state, and finally light is generated. Such a light-emitting element has a light-thin structure, can emit light with high luminance at a low driving voltage, and can emit light with multiple colors by selecting a light-emitting material, and is attracting attention.

Since kodak c.w.tang et al revealed that an organic thin film element can emit light with high luminance, many studies have been made on the application of the organic thin film light emitting element. The organic thin film light-emitting element is widely applied to the fields of mobile phone display screens, television display screens, intelligent watches, VR/AR equipment and the like at present, and practical progress is made in the aspect of practicality. However, there are many technical problems, and there is a need to solve the problems for a long time, such as improving the light emitting efficiency of the light emitting element and reducing the power consumption of the light emitting element.

In the prior art, an organic light emitting device generally comprises a Hole Injection Layer (HIL), a Hole Blocking Layer (HBL), a Hole Transport Layer (HTL), an Electron Injection Layer (EIL), an Electron Blocking Layer (EBL), an Electron Transport Layer (ETL), and an emission layer (EML), i.e., other auxiliary layers. In the top emission device, there is also generally a cover layer (CPL) or the like for improving light extraction efficiency.

Among them, an Electron Transport Layer (ETL) is widely used in various organic light emitting elements, and a substance having a large electron affinity and electron mobility is generally selected. The electron transport layer material used in the conventional organic light emitting element is 8-hydroxyquinoline aluminum (i.e., alq ₃ ) But its electron mobility is low. Meanwhile, a part of electron transport layer materials having a strong hole blocking property are also used for a Hole Blocking Layer (HBL). With the widespread development and application of organic light emitting elements, the demand for electron transport materials and hole blocking materials having higher performance is also increasing with the demand for improved device efficiency.

Disclosure of Invention

In order to solve the technical problems, the invention provides an organic compound with higher electron transport efficiency. The organic compound provided by the invention is characterized in that the organic compound contains a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure or a pyrrole structure, and contains an aryl group, a heteroaryl group, a condensed ring aryl group and a condensed ring heteroaryl group simultaneously, so that the organic compound has high electron affinity and electron mobility, and meanwhile, the organic compound has excellent charge transmission capability, and the efficiency and performance of an organic light-emitting element can be effectively improved. Meanwhile, the material also has higher hole blocking performance, and can be applied to hole blocking layer materials.

An aspect of the present invention provides an organic compound having a structure represented by the following formula 1:

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wherein a, b, c, d, e is an integer of 0 or more but not 0 at the same time;

ar1, ar2 and Ar3 are the same or different and are selected from one or more of aryl or heteroaryl;

L ₁ and L ₂ And may be the same or different, and represents a structure represented by the following general formula 2:

x is selected from sulfur atom, oxygen atom, N-R ₁ Or C (R) ₂ )(R ₃ ) One or more of the following; wherein R is ₁ 、R ₂ 、R ₃ Independently selected from one or more of a hydrogen atom, a hydroxyl group, an alkyl group, a cycloalkyl group, a heterocyclic group, a cycloalkenyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, an acyl group, a carboxylic acid group, an acyloxy group, a silane group, an alkylamino group, or an arylamine group;

A ₁ is a nitrogen atom or CR ₄ ；

A ₂ Is a nitrogen atom or CR ₅ ；

R ₄ And R is ₅ And may be the same or different and is selected from one or more of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, a cycloalkenyl group, an aryl group, or a heteroaryl group.

X is preferably a sulfur atom or an oxygen atom from the viewpoint of high electron affinity and electron mobility.

Ar from the viewpoint of high electron affinity and electron mobility ₁ 、Ar ₂ 、Ar ₃ May be the same or different, and is preferably phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, fluoranthracenyl, perylenyl, phenanthryl, benzene One or more of a phenanthryl, pyrenyl, carbazolyl, thiazolyl, thiadiazolyl, oxazolyl, oxadiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzopyrimidinyl, triazinyl, quinoxalinyl, quinolinyl, isoquinolinyl, phenanthroline, phenothiazinyl, phenoxazinyl, acridone, benzotriazolyl, benzimidazolyl, indolyl, benzothiazolyl, benzoxazolyl, benzothienyl, benzofuranyl, dibenzothiophenyl, or dibenzofuranyl group.

Another aspect of the present invention provides a light-emitting element material containing the above-described organic compound.

Another aspect of the present invention provides a light-emitting device, including a substrate, a first electrode, a second electrode, and a cover layer; the first electrode comprises more than three film layers including a light-emitting layer, an electron transport layer and a hole blocking layer; the light-emitting element contains the light-emitting element material.

Another aspect of the present invention provides a light-emitting element electron transport layer material containing the above organic compound.

Another aspect of the present invention provides a hole blocking layer material for a light emitting element, which contains the above organic compound.

Another aspect of the present invention provides a light-emitting element cover material containing the above organic compound.

The organic compound provided by the invention has higher electron transmission performance and hole blocking performance, can be applied to a cover layer, and can obviously improve the luminous efficiency of a luminous element.

Detailed Description

The following describes specific embodiments of the present invention in detail.

First, the organic compound having the structure of formula 1 provided by the present invention will be described.

Wherein a, b, c, d, e is an integer of 0 or more but not 0 at the same time;

ar1, ar2 and Ar3 are the same or different and are selected from one or more of aryl or heteroaryl;

L ₁ and L ₂ And may be the same or different, and represents a structure represented by the following general formula 2:

x is selected from sulfur atom, oxygen atom, N-R ₁ Or C (R) ₂ )(R ₃ ) One or more of the following; wherein R is ₁ 、R ₂ 、R ₃ Independently selected from one or more of a hydrogen atom, a hydroxyl group, an alkyl group, a cycloalkyl group, a heterocyclic group, a cycloalkenyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, an acyl group, a carboxylic acid group, an acyloxy group, a silane group, an alkylamino group, or an arylamine group;

A ₁ is a nitrogen atom or CR ₄ ；

A ₂ Is a nitrogen atom or CR ₅ ；

R ₄ And R is ₅ And may be the same or different and is selected from one or more of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, a cycloalkenyl group, an aryl group, or a heteroaryl group.

The above alkyl group is preferably a C1-C20 alkyl group, more preferably a C1-C10 alkyl group, still more preferably a C1-C6 alkyl group; further preferred is one or more of saturated aliphatic hydrocarbon groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and tert-butyl.

The cycloalkyl group is preferably a C3-C20 cycloalkyl group, more preferably a C3-C12 cycloalkyl group, and still more preferably a C3-C10 cycloalkyl group; further preferred is one or more of saturated alicyclic hydrocarbon groups such as cyclopropyl, cyclohexyl, norbornyl, and adamantyl.

The above heterocyclic group is preferably a C2-C20 heterocyclic group, more preferably a C2-C10 heterocyclic group, still more preferably a C2-C6 heterocyclic group; further, one or more kinds of aliphatic rings having an atom other than carbon in the ring such as a pyran ring, a piperidine ring, or a cyclic amide are preferable.

The cycloalkenyl group is preferably a C3-C20 cycloalkenyl group, more preferably a C3-C12 cycloalkenyl group, and still more preferably a C3-C10 cycloalkenyl group; further preferred is one or more of unsaturated alicyclic hydrocarbon groups containing a double bond such as cyclopentenyl, cyclopentadienyl, or cyclohexenyl.

The above alkenyl group is preferably a C2-C20 alkenyl group, more preferably a C2-C10 alkenyl group, still more preferably a C2-C6 alkenyl group; further preferred is one or more of unsaturated aliphatic hydrocarbon groups containing a double bond such as vinyl group.

The above alkynyl group is preferably a C2-C20 alkynyl group, more preferably a C2-C10 alkynyl group, and still more preferably a C2-C6 alkynyl group; further preferred is one or more of unsaturated aliphatic hydrocarbon groups containing a triple bond such as an acetylene group.

The above alkoxy group is preferably a C1-C20 alkoxy group, more preferably a C1-C10 alkoxy group, still more preferably a C1-C6 alkoxy group; more preferably, one or more of functional groups such as methoxy, ethoxy, and propoxy, each of which is bonded to an aliphatic hydrocarbon group via an ether bond.

The alkylthio group is a group in which an oxygen atom of an alkoxy group is replaced with a sulfur atom. The above-mentioned alkoxy group is preferably one or more of C1-C20 alkylthio groups (more preferably C1-C10 alkylthio groups, still more preferably C1-C6 alkylthio groups).

The above-mentioned aryl ether group is preferably a C6-C40 aryl ether group, more preferably a C6-C20 aryl ether group, still more preferably a C6-C10 aryl ether group; more preferably, one or more of functional groups such as phenoxy groups and the like are bonded to an aromatic hydrocarbon group via an ether bond.

The above-mentioned aryl sulfide group is a group in which an oxygen atom of an ether bond of an aryl ether group is replaced with a sulfur atom. Preferably a C6-C60 aryl sulfide group (more preferably a C6-C40 aryl sulfide group, and still more preferably a C6-C20 aryl sulfide group).

The above aryl group is preferably a C6-C60 aryl group, more preferably a C6-C40 aryl group, still more preferably a C6-C20 aryl group; more preferably, the aromatic hydrocarbon group is one or more of phenyl, naphthyl, biphenyl, phenanthryl, benzoterphenyl, pyrenyl, and the like.

The heteroaryl group is preferably a C4-C60 aromatic heterocyclic group, more preferably a C4-C40 aromatic heterocyclic group, and still more preferably a C4-C20 aromatic heterocyclic group; further preferred is one or more of furyl, thienyl, pyrrole, benzofuryl, benzothienyl, dibenzofuryl, dibenzothienyl, pyridyl or quinolinyl and the like.

The above acyl group is preferably a C2-C20 acyl group, more preferably a C2-C12 acyl group, still more preferably a C2-C8 acyl group; further preferred is one or more of acetyl, benzenesulfonyl and the like.

The carboxylic acid group is preferably a C2-C20 carboxylic acid group, more preferably a C2-C10 carboxylic acid group, and still more preferably a C2-C6 carboxylic acid group; further preferred is one or more of an acetic acid group, a propionic acid group, a butyric acid group and the like.

The above-mentioned acyloxy group is preferably a C2-C20 acyloxy group, more preferably a C2-C10 acyloxy group, still more preferably a C2-C8 acyloxy group; further preferred is one or more of an acetoxy group, propionyloxy group, phenylacyloxy group and the like.

The silane group is represented by a functional group having a bond to a silicon atom, such as a trimethylsilyl group, a triethylsilyl group, a dimethyl-t-butylsilyl group, or a triphenylsilyl group. The number of carbons of the silane group is not particularly limited, and may be generally in the range of 1 to 40, more preferably 1 to 20, and still more preferably 1 to 10.

The above-mentioned alkylamino is preferably a C1-C20 alkylamino, more preferably a C1-C10 alkylamino, still more preferably a C1-C6 alkylamino; more preferably, one or more of methylamino, dimethylamino, methylethylamino, diethylamino and the like.

The arylamine group is preferably a C6-C60 arylamine group, more preferably a C6-C40 arylamine group, and still more preferably a C6-C20 arylamine group; further preferred is one or more of a phenylamino group, a naphthylamino group and the like.

Here, the terms "alkyl", "cycloalkyl", "heterocyclyl", "cycloalkenyl", "alkenyl", "alkynyl", "alkoxy", "alkylthio", "aryl ether", "aryl thioether", "aryl", "heteroaryl", "acyl", "carboxylic acid", "acyloxy", "silane", "alkylamino", "arylamino" include unsubstituted and substituted cases, and the term "substituted case" means that the above-mentioned groups may have substituents without affecting the effect of the present invention.

The substituent is selected from one or more of halogen, C1-C15 alkyl, C3-C15 cycloalkyl, C3-C15 heterocyclic, C2-C15 alkenyl, C4-C15 cycloalkenyl, C2-C15 alkynyl, C1-C55 alkoxy, C1-C55 alkylthio, C6-C55 aryl ether, C6-C55 aryl thioether, C6-C55 aryl, C4-C55 aromatic heterocyclic, acyl, carboxyl, acyloxy or C3-C15 silane with silicon number of 1-5.

Preferably, X in the general formula 2 is a sulfur atom or an oxygen atom. The compound containing a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure or a pyrrole structure, especially the compound containing a thiophene structure, a furan structure or a pyrrole structure, has higher glass transition temperature (Tg) and a steric hindrance effect, and therefore, the compound has excellent stability in a film form. Meanwhile, in the thiophene structure, thiazole structure, thiadiazole structure, furan structure, oxazole structure, oxadiazole structure or pyrrole structure, especially in the thiophene structure, thiazole structure, thiadiazole structure, oxazole structure and oxadiazole structure, due to the introduction of hetero atoms, the electron affinity of molecules can be effectively improved, so that the molecules can more easily receive electrons from a cathode, thereby reducing the driving voltage of a light-emitting element, increasing the electron supply to a light-emitting layer, increasing the probability of combining electrons and holes in the light-emitting layer, and finally improving the light-emitting efficiency.

Therefore, from the viewpoint of obtaining higher electron transport performance, L ₁ Preferred are thienyl, thiazolyl, thiadiazolyl, furyl, oxazolyl, oxadiazolyl, pyrrolyl, and the like.

L ₂ Preferred are thienyl, thiazolyl, thiadiazolyl, furyl, oxazolyl, oxadiazolyl, pyrrolyl, and the like.

The Ar is as follows ₁ 、Ar ₂ 、Ar ₃ The selected aryl and heteroaryl can provide a wider range of conjugated systems, and the introduction of the condensed ring aryl and condensed ring heteroaryl can further improve the glass transition temperature (Tg) of molecules, increase the stability of materials, introduce hetero atoms on the basis, further reduce the driving voltage, improve the electron transmission capability, improve the luminous efficiency of devices and prolong the service life. The hetero atom described in the present application has the same meaning as commonly known in the art, and for example, refers to an atom other than carbon in a ring constituting a cyclic group.

Therefore, from the viewpoint of improving electron transport ability, ar ₁ Preferably phenyl, biphenyl, terphenyl, naphthyl, anthryl, fluoranthryl, perylenyl, phenanthryl, benzophenanthryl, pyrenyl, carbazolyl, thiazolyl, thiadiazolyl, oxazolyl, oxadiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzopyrimidinyl, triazinyl, quinoxalinyl, quinolinyl, isoquinolinyl, phenanthroline, phenothiazinyl, phenoxazinyl, acridone, benzotriazolyl, benzimidazolyl, indolyl, benzothiazolyl, benzoxazolyl, benzothienyl, benzofuranyl, dibenzothiophenyl, dibenzofuranyl or dibenzofuranyl and the like. Ar (Ar) ₁ The linking position of (a) may be any two positions, for example, in the case of furyl, any one of 2, 5-furyl, 2, 3-furyl, 2, 4-furyl and 3, 4-furyl is possible.

Ar ₂ Preferably phenyl, biphenyl, terphenyl, naphthyl, anthryl, fluoranthryl, perylenyl, phenanthryl, benzophenanthryl, pyrenyl, carbazolyl, thiazolyl, thiadiazolyl, oxazolyl, oxadiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzopyrimidinyl, triazinyl, quinoxalinyl, quinolinyl, isoquinolinyl, phenanthroline, phenothiazinyl, phenoxazinyl, acridone, benzotriazolyl, benzimidazolyl, indolyl, benzothiazolyl, benzoxazolyl benzothienyl, benzofuranyl, dibenzothiophenyl, dibenzofuranyl, and the like. Ar (Ar) ₂ The linking position of (a) may be any position, for example, in the case of a thiazolyl group, any of a 2-thiazolyl group, a 4-thiazolyl group, and a 5-thiazolyl group is possible.

Ar ₃ Preferably phenyl, biphenyl, terphenyl, naphthyl, anthryl, fluoranthryl, perylenyl, phenanthryl, benzophenanthryl, pyrenyl, carbazolyl, thiazolyl, thiadiazolyl, oxazolyl, oxadiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzopyrimidinyl, triazinyl, quinoxalinyl, quinolinyl, isoquinolinyl, phenanthroline, phenothiazinyl, phenoxazinyl, acridone, benzotriazolyl, benzimidazolyl, indolyl, benzothiazolyl, benzoxazolyl, benzothienyl, benzofuranyl, dibenzothiophenyl, dibenzofuranyl or dibenzofuranyl and the like. Ar (Ar) ₃ The linking position of (a) may be any position, and for example, in the case of a pyridyl group, any of a 2-pyridyl group, a 3-pyridyl group and a 4-pyridyl group is acceptable.

In view of convenience of raw materials and synthesis, a is preferably 0, 1 or 2, and b, c, d and e are preferably 1 or 2.

The terms "phenyl", "biphenyl", "terphenyl", "naphthyl", "anthryl", "fluoranthenyl", "perylene", "phenanthryl", "benzophenanthryl", "pyrenyl", "carbazolyl", "thiazolyl", "thiadiazolyl", "oxazolyl", "oxadiazolyl", "pyridyl", "pyrazinyl", "pyrimidinyl", "benzopyrimidinyl", "triazinyl", "quinoxalinyl", "quinolinyl", "isoquinolinyl", "phenanthroline", "phenothiazinyl", "phenoxazinyl", "acridone", "benzotriazolyl", "benzimidazolyl", "indolyl", "benzothiazolyl", "benzoxazolyl", "benzothienyl", "benzofuranyl", "dibenzothiophenyl" and "dibenzofuranyl" include the case where they are unsubstituted and the case where they are substituted, and the case where they are "substituted" means that the above-mentioned groups may have substituents without affecting the effect of the present invention.

The above substituent may be selected from one or more of halogen, C1-C15 alkyl, C3-C15 cycloalkyl, C3-C15 heterocyclyl, C2-C15 alkenyl, C4-C15 cycloalkenyl, C2-C15 alkynyl, C1-C55 alkoxy, C1-C55 alkylthio, C6-C55 aryl ether, C6-C55 aryl thioether, C6-C55 aryl, C4-C55 aromatic heterocyclyl, acyl, carboxyl, acyloxy or C3-C15 silyl having 1 to 5 silicon atoms.

The compound of the present invention is not particularly limited as long as it satisfies the above structure, and the following examples are preferred:

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the compound of the general formula 1 in the present invention may be used alone, may be used in combination of 2 or more kinds or may be used in layered lamination, or may be used in combination with other materials or may be used in layered lamination in an organic light-emitting element.

The above description of the compounds of the invention is detailed, and the mechanism of the invention is considered as follows (but without limiting the invention in any way): the compound provided by the invention has higher glass transition temperature (Tg) and steric hindrance effect because the compound contains a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure or a pyrrole structure, especially the compound containing the thiophene structure, the furan structure or the pyrrole structure has excellent stability in a film form. Meanwhile, the introduction of the hetero atoms can effectively improve the electron cloud density of the groups, so that the electron transport capacity of the whole molecule is improved.

Therefore, the use of the compound of the present invention in an electron transport layer material can give a high electron transport efficiency, thereby giving an organic light-emitting element having a greatly improved light extraction efficiency.

Embodiments of the organic light-emitting element material, the organic light-emitting element, the electron transport layer, the hole transport layer, and the capping layer material provided by the present invention will be described in detail below.

The invention also provides an organic light-emitting element material, which contains the compound. The organic light-emitting element of the present invention comprises: a substrate, a first electrode, a second electrode and a cover layer; the first electrode comprises more than three film layers including a light-emitting layer, an electron transport layer and a hole blocking layer; the organic light-emitting element contains the organic light-emitting element material described above.

Embodiments of the organic light emitting element of the present invention are specifically described below. The organic light-emitting device of the present invention is an organic light-emitting device comprising the compound of the present invention, and comprises, in order, a substrate, a first electrode, a second electrode, and a cover layer, wherein the first electrode comprises three or more layers including a light-emitting layer, an electron transport layer, and a hole blocking layer, and the second electrode transmits light emitted from the light-emitting layer, and the light extraction efficiency improving layer (i.e., the cover layer) is configured such that the light-emitting layer emits light by electric energy.

In the light-emitting element of the present invention, the substrate used is preferably a glass substrate such as soda glass or alkali-free glass. The thickness of the glass substrate may be 0.5mm or more, as long as it is sufficient to maintain mechanical strength. As the material of the glass, alkali-free glass is preferable because the smaller the amount of ions eluted from the glass, the better. In addition, commercially available SiO-coated ₂ Glass with protective coatings may also be used. In addition, if the first electrode stably functions, the substrate does not necessarily have to be glass, and for example, it may be formed on a plastic substrateAnd an anode.

The material used for the first electrode is preferably a metal such as gold, silver, or aluminum having a high refractive index characteristic, or a metal alloy such as an APC-based alloy. These metals or metal alloys may be laminated in a multilayer structure. Further, a transparent conductive metal oxide such as tin oxide, indium Tin Oxide (ITO), indium Zinc Oxide (IZO) or the like may be laminated on and/or under the metal, metal alloy or laminate thereof.

The material used for the second electrode is preferably a material which can form a translucent or transparent film which can transmit light. For example, silver, magnesium, aluminum, calcium, or an alloy of these metals, transparent conductive metal oxides such as tin oxide, indium Tin Oxide (ITO), and Indium Zinc Oxide (IZO). These metals, alloys, or metal oxides may be laminated in a multilayer structure.

The method for forming the electrode may be resistance heating vapor deposition, electron beam vapor deposition, sputtering, ion plating, or paste coating method, and is not particularly limited. In addition, the first electrode and the second electrode function as an anode with respect to the organic film layer and as a cathode, respectively, depending on the work function of the materials used.

The organic layer may be a stacked structure of 1) a structure formed by stacking a hole transporting layer/a light emitting layer/an electron transporting layer, 2) a structure formed by stacking a hole injecting layer/a hole transporting layer/a light emitting layer/an electron transporting layer, 3) a structure formed by stacking a hole injecting layer/a hole transporting layer/a light emitting layer/an electron transporting layer/an electron injecting layer, or the like. Further, each of the above layers may be a single layer structure or a multilayer structure, respectively. Preferably, when any one of the structures 1) to 3) is adopted, the anode-side electrode is bonded to the hole injection layer or the hole transport layer, and the cathode-side electrode is bonded to the electron injection layer or the electron transport layer.

The hole transporting layer may be formed by a method of laminating or mixing one or more of hole transporting materials, or by a method of using a mixture of a hole transporting material and a polymer binder. Since a hole transport material is required to transport holes from the positive electrode with high efficiency between electrodes to which an electric field is applied, it is desirable that the hole transport material has high hole injection efficiency and can transport injected holes with high efficiency. Therefore, a hole transport material is required to have an appropriate ion potential, a large hole mobility, and excellent stability, and impurities that become traps are not easily generated during production and use. The substance satisfying such conditions is not particularly limited, and may be, for example, benzidine such as 4,4' -bis (N- (3-methylphenyl) -N-phenylamino) biphenyl (TPD), 4' -bis (N- (1-naphthyl) -N-phenylamino) biphenyl (also known as N, N ' -diphenyl-N, N ' -bis (1-naphthyl) -1,1' -biphenyl-4, 4' -diamine, abbreviated as NPD), 4' -bis (N, N-bis (4-biphenylyl) amino) biphenyl (also known as N, N, N ', N ' -tetrakis (4-biphenylene) diaminobiphenylene, abbreviated as TBDB), bis (N, N-diphenyl-4-phenylamino) -N, N-diphenyl-4, 4' -diamino-1, 1' -biphenyl (TPD 232), materials having a carbazole skeleton, such as 4,4' -tris (3-methylphenyl (phenyl) amino) triphenylamine (m-MTDATA), 4' -tris (1-naphthyl (phenyl) amino) triphenylamine (1-TNATA), and the like, are referred to as star-shaped triarylamines, and among them, carbazole-based polymers are preferable, and specifically, dicarbazole derivatives such as bis (N-arylcarbazole) and bis (N-alkylcarbazole), tricarbazole derivatives, tetracarbazole derivatives, triphenyl compounds, pyrazoline derivatives, stilbene compounds, hydrazine compounds, benzofuran derivatives, and the like are preferable, in the polymer system, a heterocyclic compound such as a thiophene derivative, an oxadiazole derivative, a phthalocyanine derivative, or a porphyrin derivative, or a fullerene derivative, and a polycarbonate or a styrene derivative, a polythiophene, a polyaniline, a polyfluorene, a polyvinylcarbazole, or a polysilane, each of which has the above-described monomer in a side chain, are preferable. In addition, inorganic compounds such as P-type Si and P-type SiC can be used.

A hole injection layer may be disposed between the anode and the hole transport layer. By providing the hole injection layer, the organic light emitting element can realize low driving voltage and improve durability. It is generally preferable to use a material having a lower ion potential than the hole transport layer material. Specifically, for example, a benzidine derivative such as TPD232 and a star-shaped triarylamine material group may be used, and a phthalocyanine derivative or the like may be used. It is also preferable that the hole injection layer is composed of an acceptor compound alone or that the acceptor compound is doped in another hole transport layer. Examples of the acceptor compound include metal chlorides such as iron (III) trichloride, aluminum chloride, gallium chloride, indium chloride, and antimony chloride, metal oxides such as molybdenum oxide, vanadium oxide, tungsten oxide, and ruthenium oxide, and charge transfer ligands such as ammonium tris (4-bromophenyl) hexachloroantimonate (TBPAH). In addition, an organic compound having a nitro group, a cyano group, a halogen group, or a trifluoromethyl group in the molecule, a quinone compound, an acid anhydride compound, a fullerene, or the like may be used.

In the present invention, the light-emitting layer may have a single-layer structure or a multilayer structure, and each layer may be formed of a light-emitting material (host material or dopant material), and may be a mixture of the host material and the dopant material, or may be the host material alone, or may be any of them. That is, in each light-emitting layer of the light-emitting element of the present invention, only the host material or only the dopant material may emit light, or the host material and the dopant material may emit light together. In view of efficient use of electric energy and high color purity of light emission, the light-emitting layer is preferably formed by mixing a host material and a dopant material. The host material and the dopant material may be either one or a combination of two or more kinds. The doping material may be added to the entire host material or a part of the host material, or may be added in any case. The doping material may be laminated or dispersed, and may be any one of them. The doping material can control the luminescence color. When the amount of the dopant is too large, concentration extinction occurs, and therefore, the amount thereof is preferably 20% by weight or less, more preferably 10% by weight or less, relative to the host material. The doping method may be a method of co-evaporation with the host material, or may be a method of simultaneous evaporation after previously mixing with the host material.

As the light-emitting material, specifically, condensed ring derivatives such as anthracene and pyrene, metal chelate type hydroxyquinoline compounds such as tris (8-hydroxyquinoline) aluminum, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polythiophene derivatives, and the like, which have been known as light-emitting materials, can be used, and the like in the polymer are not particularly limited.

The host material to be contained in the light-emitting material is not particularly limited, and compounds having a condensed aromatic ring such as anthracene, phenanthrene, pyrene, benzophenanthrene, naphthacene, perylene, benzo [9, 10] phenanthrene, fluoranthene, fluorene, indene and the like or derivatives thereof, aromatic amine derivatives such as N, N '-dinaphthyl-N, N' -diphenyl-4, 4 '-diphenyl-1, 1' -diamine and the like, metal chelate hydroxyquinoline compounds such as tris (8-hydroxyquinoline) aluminum and the like, pyrrolopyrrole derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives and the like can be used, and polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives and the like can be used in the polymer.

The doping material is not particularly limited, and examples thereof include compounds having a condensed aromatic ring such as naphthalene, anthracene, phenanthrene, pyrene, benzophenanthrene, perylene, benzo [9, 10] phenanthrene, fluoranthene, fluorene, indene, and the like, or derivatives thereof (for example, 2- (benzothiazol-2-yl) -9, 10-diphenylanthracene, and the like), furan, pyrrole, thiophene, silole, 9-silafluorene, 9' -spirodisilazafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene, and the like, and derivatives thereof, borane derivatives, stilbene derivatives, aminostyryl derivatives, pyrrolmethine derivatives, diketopyrrolo [3,4-c ] pyrrole derivatives, coumarin derivatives, imidazole, thiazole, thiadiazole, carbazole, oxazole derivatives, oxadiazole, triazole, and the like, aromatic amine derivatives, and the like.

In addition, the light-emitting layer may be doped with a phosphorescent light-emitting material. The phosphorescent material is a material which can also phosphorescence at room temperature. When a phosphorescent light-emitting material is used as a dopant, it is preferable that the phosphorescent light-emitting material is capable of phosphorescence at room temperature, but not particularly limited, and an organometallic complex compound containing at least one metal selected from indium, ruthenium, rhodium, palladium, platinum, osmium, and rhenium is preferable. The organometallic complex having indium or platinum is more preferable in view of having high phosphorescence emission efficiency at room temperature. As the host material used in combination with the phosphorescent dopant, indole derivatives, carbazole derivatives, indolocarbazole derivatives, nitrogen-containing aromatic compound derivatives having pyridine, pyrimidine, and triazine skeletons, aromatic hydrocarbon compound derivatives such as polyarylbenzene derivatives, spirofluorene derivatives, indane, benzo [9, 10] phenanthrene, and the like, compounds containing an oxygen group element such as dibenzofuran derivatives, dibenzothiophene, and organometallic complexes such as hydroxyquinoline beryllium complexes can be used favorably, but basically, the host material is not particularly limited as long as the triplet state of the dopant used is larger, and electrons and holes can be smoothly injected or transported from the respective layer transport layers. In addition, 2 or more triplet light emitting dopants may be contained, or 2 or more host materials may be contained. Further, one or more triplet light emitting dopants and one or more fluorescent light emitting dopants may be contained.

In the present invention, the electron transport layer is a layer in which electrons are injected from a cathode and then transported. The electron transport layer preferably has high electron injection efficiency and can efficiently transport the injected electrons. Therefore, the electron transport layer is preferably composed of a substance which has high electron affinity and electron mobility and is excellent in stability, and which is less likely to cause impurities that become traps when manufactured and used. However, when considering the balance of hole and electron transport, if the electron transport layer mainly plays a role of preventing holes from the anode from being combined and flowing to the cathode side with high efficiency, the effect of improving the light emission efficiency is comparable to the case of a material having high electron transport ability even if the material is composed of a material having not so high electron transport ability. Thus, in the electron transport layer in the present invention, a hole blocking layer that can efficiently block the migration of holes is also included as an equivalent.

The electron transport layer according to the present invention may comprise the above-described compound having a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure, or a pyrrole structure. The heteroaromatic ring has high electrophilicity, and the electron transport material containing the structure easily receives electrons from the cathode with high electrophilicity, so that the driving voltage of the light emitting element can be reduced. Further, since the electron supply to the light-emitting layer increases and the probability of combining electrons and holes in the light-emitting layer increases, the light-emitting efficiency increases.

Examples of the compound having a heteroaromatic ring structure include thienyl, thiazolyl, thiadiazolyl, furyl, oxazolyl, oxadiazolyl, pyridyl, pyrazinyl, triazinyl, quinoxalinyl, quinolinyl, isoquinolinyl, phenanthroline, phenothiazinyl, phenoxazinyl, acridone, benzotriazolyl, benzimidazolyl, indolyl, benzothiazolyl, benzoxazolyl, benzothienyl, benzofuranyl, dibenzothiophenyl, and dibenzofuranyl. When the derivative has a condensed aromatic ring skeleton, the glass transition temperature is increased and the electron mobility is increased, whereby the effect of reducing the driving voltage of the light-emitting element is increased, which is preferable.

The electron transport materials may be used alone, or two or more of the electron transport materials may be used in combination, or one or more other electron transport materials may be used in combination with the electron transport materials. In addition, donor compounds may also be added. The donor compound is a compound that improves electron injection energy barrier, thereby facilitating electron injection from the cathode or the electron injection layer to the electron transport layer, and further improving electrical conductivity of the electron transport layer. Preferable examples of the donor compound of the present invention include: alkali metal, inorganic salt containing alkali metal, complex of alkali metal and organic substance, alkaline earth metal, inorganic salt containing alkaline earth metal, complex of alkaline earth metal and organic substance, etc. Preferred alkali metals and alkaline earth metals include alkali metals such as lithium, sodium and cesium, alkaline earth metals such as magnesium and calcium, which have a low work function and a high effect of improving electron transport ability.

In the present invention, an electron injection layer may be provided between the cathode and the electron transport layer. In general, the electron injection layer is inserted for the purpose of assisting electron injection from the cathode to the electron transport layer, and in the case of insertion, a compound having a heteroaromatic ring structure containing electron-withdrawing nitrogen may be used, or a layer containing the above-mentioned donor compound may be used. In addition, an inorganic substance such as an insulator or a semiconductor may be used for the electron injection layer. The use of these materials is preferable because short-circuiting of the light-emitting element can be effectively prevented and electron injection properties can be improved. As these insulators, at least one metal compound selected from alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides is preferably used. In addition, complexes of organic substances and metals can also be used favorably.

The method for forming each layer constituting the light-emitting element is not particularly limited, and examples thereof include resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, and coating method.

The thickness of the organic layer is not particularly limited, but is preferably 1 to 1000nm, although it depends on the resistance value of the light-emitting substance. The film thickness of each of the light-emitting layer, the electron transport layer, and the hole transport layer is preferably 1nm to 200nm, more preferably 5nm to 100 nm.

The light extraction efficiency improving layer of the present invention may contain the above-described compound having a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure, or a pyrrole structure. In order to maximize the high luminous efficiency and realize color reproducibility, it is preferable that the above-mentioned compound having a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure or a pyrrole structure is laminated at a thickness of 20nm to 120 nm. More preferably, the thickness of the laminate is 40nm to 80nm. In addition, from the viewpoint of maximizing the luminous efficiency, the thickness of the light extraction efficiency improving layer is more preferably 50nm to 70nm.

The method for forming the light extraction efficiency improving layer is not particularly limited, and examples thereof include resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, coating, inkjet, doctor blading, laser transfer, and the like. Among them, the vapor deposition method is the most popular formation method. Substances that crystallize readily during this process can affect the overall performance of the device.

The light emitting element of the present invention has a function of converting electric energy into light. Here, as the electric energy, mainly dc current is used, and pulse current or ac current may be used. The current value and the voltage value are not particularly limited, but should be selected so that the maximum luminance can be obtained with the lowest possible energy in consideration of the power consumption and the lifetime of the element.

The light emitting element of the present invention can be favorably used as a flat display for displaying in, for example, a matrix and/or field manner.

The matrix system is a system in which pixels for display are arranged in two dimensions such as a square or a mosaic, and characters or images are displayed by a set of pixels. The shape and size of the pixels are dependent on the application. For example, in the case of a large display such as a display panel, pixels having a side length of a square shape of 300 μm or less are generally used for displaying images and characters on a computer, a monitor, and a television, and pixels having a side length of a mm are generally used. In the case of monochrome display, the pixels of the same color may be arranged, but in the case of color display, the red, green, and blue pixels are arranged to display. In this case, a triangular shape and a stripe shape are typical. Also, the driving method of the matrix may be any one of a line-by-line driving method and an active matrix. The line-by-line driving is simple in structure, but in consideration of the operation characteristics, an active matrix may be excellent, and thus, flexible use is required according to the application.

The field method in the present invention is a method of forming a pattern, and displaying predetermined information by emitting light from a region specified by the arrangement of the pattern. Examples include: time and temperature display in digital clock and thermometer, operation status display of sound equipment and electromagnetic oven, and panel display of automobile. Also, the matrix display and the field display may coexist in the same panel.

The light-emitting element of the present invention is preferably used as an illumination light source, and can provide a light source which is thinner and lighter than conventional light sources and can perform surface light emission.

Examples

The present invention will be described in more detail with reference to specific examples, but the following examples are only for the convenience of those skilled in the art to understand the concept of the present invention and are not intended to limit the scope of the present invention.

Synthesis examples and examples

The present invention will be described below by way of examples and examples, but the present invention is not limited to these examples and examples. The numerals of the compounds in the following synthesis examples and examples refer to the numerals of the compounds described above.

Synthesis example 1

Synthesis of Compound [003]

Under the nitrogen atmosphere, 10mmol of 2-bromo-5-chlorothiazole, 5mmol of 1, 4-phenyldiboronic acid, 22mmol of sodium carbonate, 0.1mmol of bis (triphenylphosphine) palladium dichloride, 35mL of ethylene glycol dimethyl ether and 15mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. Cooled to room temperature, filtered, the filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered, and dried in vacuo to give 4.4mmol of intermediate 1.

Under the nitrogen atmosphere, 4mmol of intermediate 1, (3, 5-diphenyl benzene) boric acid 8mmol, sodium carbonate 16mmol, bis (triphenylphosphine) palladium dichloride 0.08mmol, ethylene glycol dimethyl ether 30mL and water 10mL are added into a reactor, and stirring reflux reaction is carried out for 8h. Cooled to room temperature, filtered, the filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered, and dried under vacuum to give 3.5mmol of compound [003].

Synthesis example 2

Synthesis of Compound [047]

The synthesis steps are the same as those of the compound [003] except that 2-boric acid benzoxazole is substituted for (3, 5-diphenylbenzene) boric acid. 3.4mmol of compound [047] was obtained.

Synthesis example 3

Synthesis of Compound [069]

The synthesis procedure was followed except for the substitution of 2, 4-diphenyl-6- (4-boronic acid phenyl) -1,3, 5-triazine for (3, 5-diphenylbenzene) boronic acid to give compound [004]. 3.7mmol of compound [069] was obtained.

Synthesis example 4

Synthesis of Compound [113]

Under the nitrogen atmosphere, 10mmol of 2, 5-dibromothiazole, 20mmol of 2-thiophene borate, 22mmol of sodium carbonate, 0.1mmol of bis triphenylphosphine palladium dichloride, 75mL of ethylene glycol dimethyl ether and 25mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. The filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered and dried in vacuo to give 9.1mmol of intermediate 2.

9mmol of intermediate 2, NBS 20mmol and 100mL of tetrahydrofuran were added to the reactor under nitrogen atmosphere, and the mixture was stirred at room temperature for 8 hours. 100mL of water was added and the mixture was filtered, 200mL of water was washed twice, filtered, the filter cake was stirred twice with 100mL of methanol, filtered and dried under vacuum to give 8.2mmol of intermediate 3.

Under the nitrogen atmosphere, 8mmol of intermediate 3, 16mmol of 4- (benzoxazole-2-) phenylboric acid, 32mmol of sodium carbonate, 0.08mmol of bis (triphenylphosphine) palladium dichloride, 60mL of ethylene glycol dimethyl ether and 20mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. Cooled to room temperature, filtered, the filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered, and dried under vacuum to give 6.1mmol of compound [113].

Synthesis example 5

Synthesis of Compound [173]

The synthesis procedure was the same as that of compound [003] except that 2-bromo-5-chlorothiophene was substituted for 2-bromo-5-chlorothiazole and benzothiophene-2-boronic acid was substituted for (3, 5-diphenylbenzene) boronic acid. 3.3mmol of compound [173] was obtained.

Synthesis example 6

Synthesis of Compound [233]

The synthesis steps are the same as those of the compound [003] except that 1, 4-naphthalene diboronic acid is substituted for 1, 4-benzene diboronic acid and N-phenyl-3-carbazole boric acid is substituted for (3, 5-diphenyl benzene) boric acid. 3.1mmol of compound [233] was obtained.

Synthesis example 7

Synthesis of Compound [295]

Under the nitrogen atmosphere, 10mmol of 4,4' -biphenyl diboronic acid, 20mmol of 2-bromooxazole, 22mmol of sodium carbonate, 0.1mmol of bis triphenylphosphine palladium dichloride, 75mL of ethylene glycol dimethyl ether and 25mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. The filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered and dried in vacuo to give 9.3mmol of intermediate 4.

9mmol of intermediate 4, NBS 20mmol, and 100mL of tetrahydrofuran were added to the reactor under nitrogen atmosphere, and the mixture was stirred at room temperature for 8 hours. 100mL of water was added and the mixture was filtered, 200mL of water was washed twice, filtered, the filter cake was stirred twice with 100mL of methanol, filtered and dried under vacuum to give 8.3mmol of intermediate 5.

Under the nitrogen atmosphere, 8mmol of intermediate 5, 16mmol of 4- (benzothiazole-2-) phenylboric acid, 32mmol of sodium carbonate, 0.08mmol of bis (triphenylphosphine) palladium dichloride, 60mL of ethylene glycol dimethyl ether and 20mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. Cooled to room temperature, filtered, the filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered, and dried under vacuum to give 7.2mmol of compound [295].

Synthesis example 8

Synthesis of Compound [314]

The synthesis procedure was the same as that of compound [295] except that 2-bromofuran was substituted for 2-bromooxazole and 2-cyanopyrimidine-5-boronic acid pinacol ester was substituted for 4- (benzothiazole-2-) phenylboronic acid. 7.5mmol of compound [314] was obtained.

Synthesis example 9

Synthesis of Compound [381]

Under the nitrogen atmosphere, 10mmol of 5-bromo-2-chlorothiophene, 5mmol of 1, 4-phenyldiboronic acid, 22mmol of sodium carbonate, 0.1mmol of bis (triphenylphosphine) palladium dichloride, 35mL of ethylene glycol dimethyl ether and 15mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. Cooled to room temperature, filtered, the filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered, and dried in vacuo to give 4.5mmol of intermediate 6.

Under the nitrogen atmosphere, 4mmol of intermediate 6, 8mmol of bisboronic acid pinacol ester, 9mmol of sodium tert-butoxide, 0.08mmol of bis (dibenzylideneacetone) palladium, 0.16mmol of 2-dicyclohexylphosphine-2 ',4',6' -triisopropylbiphenyl and 40mL of dioxane are added into a reactor, and the mixture is stirred and refluxed for 8 hours. Cooled to room temperature, 40mL of water was added, filtration was carried out, the cake was washed twice with 100mL of water, filtration was carried out, the cake was stirred twice with 100mL of methanol, filtration was carried out, and vacuum drying was carried out, yielding 3.5mmol of intermediate 7.

Under the nitrogen atmosphere, 3mmol of intermediate 7, 6mmol of 2-bromo-5-phenyl-1, 3, 4-thiadiazole, 6mmol of sodium carbonate, 0.06mmol of bis triphenylphosphine palladium dichloride, 20mL of ethylene glycol dimethyl ether and 10mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. Cooled to room temperature, filtered, the filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered, and dried under vacuum to give 2.5mmol of compound [381].

Synthesis example 10

Synthesis of Compound [407]

Under the nitrogen atmosphere, 10mmol of 2-bromo-5- (4-chlorophenyl) -1,3, 4-oxadiazole, 5mmol of 1, 4-phenyldiboronic acid, 22mmol of sodium carbonate, 0.1mmol of bis triphenylphosphine palladium dichloride, 35mL of ethylene glycol dimethyl ether and 15mL of water are added into a reactor, and stirring reflux reaction is carried out for 8h. Cooled to room temperature, filtered, the filter cake was rinsed with 50ml of ethylene glycol dimethyl ether, washed twice with 100ml of water, filtered, the filter cake was stirred twice with 100ml of methanol, filtered, and dried in vacuo to give 4.3mmol of intermediate 8.

Under the nitrogen atmosphere, 4mmol of intermediate 8, 8mmol of carbazole, 9mmol of sodium tert-butoxide, 0.08mmol of bis (dibenzylideneacetone) palladium, 0.16mmol of 2-dicyclohexylphosphine-2 ',4',6' -triisopropylbiphenyl and 40mL of o-xylene are added into a reactor, and the mixture is stirred and refluxed for 8 hours. Cooled to room temperature, 40mL of methanol was added, filtration was performed, the cake was washed twice with 100mL of water, filtration was performed, the cake was stirred twice with 100mL of methanol, filtration was performed, and vacuum drying was performed to obtain 3.7mmol of compound [407].

The compounds in the above synthesis examples, including but not limited to, were all used in an amount of 1×10 using an oil diffusion pump ^-3 The sublimation purification under pressure Pa is performed to obtain a compound which can be used as a material for a light-emitting element.

In examples and comparative examples, the following substances were used:

HAT-CN ₆ (the structure is as follows)

HT-1 (Structure as follows)

/>

H-1 (structure is as follows)

D-1 (Structure is as follows)

E-1 (structure is as follows)

E-2 (structure is as follows)

E-3 (structure is as follows)

Example 1

A glass substrate (manufactured by GEOMATEC Co., ltd., 11. OMEGA/≡, sputtered) on which a 165nm ITO transparent conductive film was deposited was cut into pieces of 38X 46mm and etched. The obtained substrate was ultrasonically cleaned with "semiconductor Clean56" (trade name, manufactured by Furuuchi Chemical Corporation) for 15 minutes, and then cleaned with ultrapure water. The substrate was subjected to UV-ozone treatment for 1 hour immediately before element fabrication, and placed in a vacuum vapor deposition apparatus, and then the substrate was exhausted to the outside The vacuum degree in the container was 5×10 ^-4 Pa or below. Firstly, evaporating HAT-CN with the wavelength of 5nm by using a resistance heating method ₆ As a hole injection layer, 50nm of HT-1 was evaporated as a hole transport layer. Next, as the light-emitting layer, the host material H-1 and the dopant material D-1 were evaporated to a thickness of 20nm so that the doping concentration became 5 mass%. Next, as the 1 st electron transport layer, a compound [003]]Evaporated and laminated to a thickness of 25 nm. Further, as the 2 nd electron transport layer, the compound [003]]For electron transport materials, lithium is used as a guest material, so that a compound [003]]And lithium vapor deposition rate ratio of 20:1 to a thickness of 10 nm. Next, after 0.5nm of lithium fluoride was vapor-deposited, 1000nm of aluminum was vapor-deposited as a cathode to produce a square 5X 5mm element. The light-emitting element is at 1000cd/m ² The characteristic is a driving voltage of 4.6V and an external quantum efficiency of 5.5%. In addition, the initial luminance was set to 1000cd/m ² When driven with constant current, the brightness was reduced by 20% for 2100 hours.

Examples 2 to 20 and comparative examples 1, 2 and 3

Example 2

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [022 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 3

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [047 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 4

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [056 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 5

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [063 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 6

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [069 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 7

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [113 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 8

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [166 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 9

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [173 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 10

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [201 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 11

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [233 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 12

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [248 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 13

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [286 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 14

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [295 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 15

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [314 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 16

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [330 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 17

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [349 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 18

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [371 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 19

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [396 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Example 20

The procedure of example 1 was repeated except that the compound [003] was changed to the compound [415 ].

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Comparative example 1

The procedure of example 1 was repeated except that the compound [003] was changed to E-1.

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Comparative example 2

The procedure of example 1 was repeated except that the compound [003] was changed to E-2.

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

Comparative example 3

The procedure of example 1 was repeated except that the compound [003] was changed to E-3.

The obtained film sample was evaluated. The evaluation results are shown in Table 1.

[ Table 1 ]

As a result, the compounds of the present invention are suitable for use in organic light-emitting element materials, and have lower external quantum efficiency, higher driving voltage, and lower durability in examples 2 and 10 than the preferred compounds of Ar1, ar2, and Ar 3. But in general, the compound of the present invention can give a light-emitting element satisfying high quantum efficiency, low driving voltage and long durability at the same time, as compared with conventional light-emitting element materials.

Claims (8)

1. An organic compound having a structure represented by the following general formula 1:

wherein a, b, c, d, e is an integer of 0 or more but not 0 at the same time;

ar1, ar2 and Ar3 are the same or different and are selected from one or more of aryl or heteroaryl;

L ₁ and L ₂ And may be the same or different, and represents a structure represented by the following general formula 2:

x is selected from sulfur atom, oxygen atom, N-R ₁ Or C (R) ₂ )(R ₃ ) One or more of the following; wherein R is ₁ 、R ₂ 、R ₃ Independently selected from one or more of a hydrogen atom, a hydroxyl group, an alkyl group, a cycloalkyl group, a heterocyclic group, a cycloalkenyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, an acyl group, a carboxylic acid group, an acyloxy group, a silane group, an alkylamino group, or an arylamine group;

A ₁ Is a nitrogen atom or CR ₄ ；

A ₂ Is a nitrogen atom or CR ₅ ；

R ₄ And R is ₅ And may be the same or different and is selected from one or more of a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, a cycloalkenyl group, an aryl group, or a heteroaryl group.

2. The organic compound according to claim 1, wherein: x is a sulfur atom or an oxygen atom.

3. The organic compound according to claim 2, characterized in that: ar (Ar) ₁ 、Ar ₂ 、Ar ₃ And may be the same or different and is selected from one or more of phenyl, biphenyl, terphenyl, naphthyl, anthryl, fluoranthryl, perylenyl, phenanthryl, benzophenanthryl, pyrenyl, carbazolyl, thiazolyl, thiadiazolyl, oxazolyl, oxadiazolyl, pyridyl, pyrazinyl, pyrimidinyl, benzopyrimidinyl, triazinyl, quinoxalinyl, quinolinyl, isoquinolinyl, phenanthrolinyl, phenothiazinyl, phenoxazinyl, acridone, benzotriazolyl, benzimidazolyl, indolyl, benzothiazolyl, benzoxazolyl, benzothienyl, benzofuranyl, dibenzothiophenyl or dibenzofuranyl.

4. A light-emitting element material characterized by: the material comprising the organic compound according to any one of claims 1 to 3.

5. A light emitting element characterized in that: comprises a substrate, a first electrode, a second electrode and a covering layer; the first electrode comprises more than three film layers including a light-emitting layer, an electron transport layer and a hole blocking layer; the light-emitting element comprising the light-emitting element material according to claim 4.

6. An electron transport layer material for a light emitting element, characterized in that: the material comprising the organic compound according to any one of claims 1 to 3.

7. A light emitting device hole blocking layer material, characterized in that: the material comprising the organic compound according to any one of claims 1 to 3.

8. A light emitting element cover material characterized by: the material comprising the organic compound according to any one of claims 1 to 3.