CN111512458A

CN111512458A - Organic light emitting device

Info

Publication number: CN111512458A
Application number: CN201980006391.9A
Authority: CN
Inventors: 尹正民; 金公谦; 千民承; 具己洞; 金永锡; 李敏宇; 吴重锡
Original assignee: LG Chem Ltd
Current assignee: LG Chem Ltd
Priority date: 2018-08-28
Filing date: 2019-08-27
Publication date: 2020-08-07
Anticipated expiration: 2039-08-27
Also published as: KR20200024720A; KR102214384B1; CN111512458B

Abstract

The present invention provides an organic light emitting device, comprising: an anode, a cathode, a light emitting layer between the anode and the cathode, and an electron transport layer between the cathode and the light emitting layer, the electron transport layer including a compound represented by formula 1, thereby showing a current density of 0.1mA/cm in a current density-efficiency graph of the organic light emitting device²To 10mA/cm²Maximum efficiency value (Eff) of_max) And minimum efficiency value (Eff)_min) Has a ratio of 1.5 or less。

Description

Organic light emitting device

Technical Field

Cross reference to related applications

The present application claims priority based on korean patent application No. 10-2018-0101609 at 28.8.2018 and korean patent application No. 10-2019-0103965 at 23.8.2019, the entire contents of which are incorporated herein by reference.

The present invention relates to an organic light emitting device having a low driving voltage, a high light emitting efficiency, and an excellent lifetime.

Background

In general, the organic light emitting phenomenon refers to a phenomenon of converting electric energy into light energy using an organic substance. An organic light emitting device using an organic light emitting phenomenon has a wide viewing angle, excellent contrast, a fast response time, and excellent luminance, driving voltage, and response speed characteristics, and thus a great deal of research is being conducted.

An organic light emitting device generally has a structure including an anode and a cathode, and an organic layer between the anode and the cathode. In order to improve the efficiency and stability of the organic light emitting device, the organic layer is often formed of a multilayer structure formed of different materials, and may be formed of, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, or the like. In the structure of such an organic light emitting device, if a voltage is applied between both electrodes, holes are injected from the anode into the organic layer, electrons are injected from the cathode into the organic layer, and when the injected holes and electrons meet, excitons (exiton) are formed, which emit light when they transition to the ground state again.

For organic materials used for the organic light emitting devices as described above, development of new materials is continuously demanded.

Documents of the prior art

Patent document

(patent document 0001) Korean patent laid-open publication No. 10-2000-0051826

Disclosure of Invention

Technical subject

Means for solving the problems

In order to solve the above problems, the present invention provides the following organic light emitting device.

An organic light emitting device according to the present invention comprises:

an anode,

A cathode, a cathode,

A light-emitting layer between the anode and the cathode, and

an electron transport layer between the cathode and the light emitting layer,

in the current density-efficiency chart of the above organic light emitting device, at a current density of 0.1mA/cm²To 10mA/cm²Maximum efficiency value (Eff) of_max) And minimum efficiency value (Eff)_min) Satisfies the following mathematical formula 1,

the electron transport layer includes a compound represented by the following chemical formula 1:

[ mathematical formula 1]

Eff_max/Eff_min≤1.5

[ chemical formula 1]

In the above-described chemical formula 1,

L₁to L₃Each independently is a single bond, or substituted or unsubstituted C_6-60An arylene group, a cyclic or cyclic alkylene group,

Ar₁and Ar₂Each independently is substituted or unsubstituted C_6-60An aryl group; or substituted or unsubstituted C containing 1 to 3 heteroatoms selected from N, O and S_2-60(ii) a heteroaryl group, wherein,

a is represented by the following

chemical formula

2 or 3,

[ chemical formula 2]

[ chemical formula 3]

In the above

chemical formula

2 or 3,

w is O, S, CR₉R₁₀Or SiR₁₁R₁₂，

T is a benzene, naphthalene, or phenanthrene ring fused to an adjacent five-membered ring,

R₁to R₈Each independently hydrogen, deuterium, or cyano, or adjacent R₆And R₇Can be combined with each other to form a spiro structure,

R₉to R₁₂Each independently is hydrogen; deuterium; a cyano group; substituted or unsubstituted C_6-60An aryl group; or substituted or unsubstituted C containing 1 to 3 heteroatoms selected from N, O and S_2-60(ii) a heteroaryl group, wherein,

a1 is an integer of 0 to 3,

a 2-a 6 and a8 are each independently integers from 0 to 4,

a7 is an integer of 0 to 5,

a1 to a8 are each 2 or more, the structures in parentheses of 2 or more are the same as or different from each other,

l corresponding to the above chemical formula 1₃The position of the connection is such that,

however, L₁To L₃、Ar₁、Ar₂And at least one of A is substituted with cyano. Effects of the invention

In the organic light emitting device, since the compound represented by chemical formula 1, which will be described later, is used as a material of the electron transport layer, the change in efficiency due to the change in current density is small, and the change in color tone due to the driving environment is small, the fraction defective of the panel to which the compound is applied can be significantly reduced. In addition, the organic light emitting device may exhibit characteristics of low voltage, high efficiency, and long life.

Drawings

Fig. 1 illustrates an example of an organic light-emitting device composed of a substrate 1, an anode 2, a light-emitting layer 3, an electron transport layer 4, and a cathode 5.

Fig. 2 illustrates an example of an organic light-emitting device composed of a substrate 1, an anode 2, a hole injection layer 6, a hole transport layer 7, a light-emitting layer 3, an electron transport layer 4, an electron injection layer 8, and a cathode 5.

Fig. 3 is a graph showing a comparison of efficiency graphs of current densities of the organic light emitting devices according to example 16 and comparative example 7.

Detailed Description

Hereinafter, the present invention will be described in more detail to assist understanding thereof.

In the context of the present specification,

refers to a bond with another substituent, and a single bond refers to a bond at L₁To L₃The portion represented is absent other atoms.

In the present specification, the term "substituted or unsubstituted" means substituted with a substituent selected from deuterium; a halogen group; a cyano group; a nitro group; a hydroxyl group; a carbonyl group; an ester group; an imide group; an amino group; a phosphine oxide group; an alkoxy group; an aryloxy group; alkylthio radicals (A), (B), (C), (D), (

Alkyl thioxy); arylthio radicals (A), (B), (C

Aryl thio xy); alkylsulfonyl (

Alkyl sulfo xy); arylsulfonyl (

Aryl sulfoxy); a silyl group; a boron group; an alkyl group; a cycloalkyl group; an alkenyl group; an aryl group; aralkyl group; an aralkenyl group; an alkylaryl group; an alkylamino group; an aralkylamino group; a heteroaryl amino group; an arylamine group; an aryl phosphine group; or 1 or more substituents of 1 or more heteroaryl groups containing N, O and S atoms, or substituents formed by connecting 2 or more substituents of the above-exemplified substituents. For example, "a substituent in which 2 or more substituents are linked" may be a biphenyl group. That is, the biphenyl group may be an aryl group or may be interpreted as a substituent in which 2 phenyl groups are linked.

In the present specification, the number of carbon atoms of the carbonyl group is not particularly limited, but is preferably 1 to 40. Specifically, the compound may have the following structure, but is not limited thereto.

In the present specification, in the ester group, the oxygen of the ester group may be substituted with a linear, branched or cyclic alkyl group having 1 to 25 carbon atoms, or an aryl group having 6 to 25 carbon atoms. Specifically, the compound may be a compound of the following structural formula, but is not limited thereto.

In the present specification, the number of carbon atoms in the imide group is not particularly limited, but is preferably 1 to 25. Specifically, the compound may have the following structure, but is not limited thereto.

In the present specification, specific examples of the silyl group include, but are not limited to, a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, and a phenylsilyl group.

In the present specification, the boron group specifically includes a trimethylboron group, a triethylboron group, a t-butyldimethylboron group, a triphenylboron group, a phenylboron group, and the like, but is not limited thereto.

In the present specification, as examples of the halogen group, there are fluorine, chlorine, bromine or iodine.

In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 40. According to one embodiment, the alkyl group has 1 to 20 carbon atoms. According to another embodiment, the alkyl group has 1 to 10 carbon atoms. According to another embodiment, the alkyl group has 1 to 6 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an n-propyl group, an isopropyl group, a butyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a sec-butyl group, a 1-methylbutyl group, a 1-ethylbutyl group, a pentyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, a n-hexyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 4-methyl-2-pentyl group, a3, 3-dimethylbutyl group, a 2-ethylbutyl group, a heptyl group, a n-heptyl group, a 1-methylhexyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, an octyl group, a n-octyl group, a tert-octyl group, a 1-methylheptyl group, a 2-ethylhexyl group, a 2-propylpentyl group, 4-methylhexyl, 5-methylhexyl, and the like, but are not limited thereto.

In the present specification, the alkenyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 40. According to one embodiment, the number of carbon atoms of the alkenyl group is 2 to 20. According to another embodiment, the number of carbon atoms of the alkenyl group is 2 to 10. According to another embodiment, the number of carbon atoms of the above alkenyl group is 2 to 6. Specific examples thereof include, but are not limited to, vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-methyl-1-butenyl, 1, 3-butadienyl, allyl, 1-phenylethen-1-yl, 2-diphenylethen-1-yl, 2-phenyl-2- (naphthalen-1-yl) ethen-1-yl, 2-bis (biphenyl-1-yl) ethen-1-yl, stilbenyl, and styryl.

In the present specification, the cycloalkyl group is not particularly limited, but is preferably a cycloalkyl group having 3 to 60 carbon atoms. According to one embodiment, the cycloalkyl group has 3 to 30 carbon atoms. According to another embodiment, the cycloalkyl group has 3 to 20 carbon atoms. According to another embodiment, the number of carbon atoms of the above cycloalkyl group is 3 to 6. Specifically, there may be mentioned, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2, 3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2, 3-dimethylcyclohexyl, 3,4, 5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl and the like.

In the present specification, the aryl group is not particularly limited, but is preferably an aryl group having 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the aryl group has 6 to 30 carbon atoms. According to one embodiment, the aryl group has 6 to 20 carbon atoms. The aryl group may be a monocyclic aryl group such as a phenyl group, a biphenyl group, or a terphenyl group, but is not limited thereto. The polycyclic aromatic group may be a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a perylene group,

And a fluorenyl group, but is not limited thereto.

In the present specification, the fluorenyl group may be substituted, and 2 substituents may be combined with each other to formForming a spiral structure. When the fluorenyl group is substituted, the compound may be

And the like. But is not limited thereto.

In the present specification, the heteroaryl group is a heteroaryl group containing 1 or more of O, N, Si and S as a heteroatom, and the number of carbon atoms is not particularly limited, but preferably the number of carbon atoms is 2 to 60. Examples of heteroaryl groups include thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, thienyl,

Azolyl group,

Oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, benzobenzoxazinyl

Azolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, benzofuranyl, phenanthrolinyl (phenanthroline), isoquinoyl

Oxazolyl, thiadiazolyl, phenothiazinyl, dibenzofuranyl, and the like, but is not limited thereto.

In the present specification, the aryl group in the aralkyl group, aralkenyl group, alkylaryl group, arylamine group is the same as the above-mentioned examples of the aryl group. In the present specification, the alkyl group in the aralkyl group, the alkylaryl group, and the alkylamino group is the same as the above-mentioned examples of the alkyl group. In the present specification, the heteroaryl group in the heteroarylamine can be applied to the above description about the heteroaryl group. In the present specification, the alkenyl group in the aralkenyl group is the same as the above-mentioned examples of the alkenyl group. In the present specification, the arylene group is a 2-valent group, and in addition thereto, the above description about the aryl group can be applied. In the present specification, a heteroarylene group is a 2-valent group, and in addition to this, the above description about a heteroaryl group can be applied. In the present specification, the hydrocarbon ring is not a 1-valent group but is formed by combining 2 substituents, and in addition to this, the above description about the aryl group or the cycloalkyl group can be applied. In the present specification, the heterocyclic ring is not a 1-valent group but is formed by combining 2 substituents, and in addition to this, the description about the above-mentioned heteroaryl group can be applied.

On the other hand, the organic light emitting device according to the present invention has a current density (mA/cm) in the x-axis²) And the y-axis is efficiency (cd/A), in a current density-efficiency graph representing the change in efficiency based on current density, at a current density of 0.1mA/cm²To 10mA/cm²Of the efficiency values measured in the range, the maximum efficiency value (Eff)_max) And minimum efficiency value (Eff)_min) The ratio of (A) to (B) is 1.5 or less.

In the organic light emitting device satisfying the above equation 1, even if the current density is increased, the efficiency is relatively constant, and the color change according to the driving environment is small, whereby the panel defect rate can be remarkably reduced. In contrast, in the organic light emitting device that does not satisfy the above range, the efficiency change due to the current density change is large, and thus a panel defect may occur. In addition, since the change in efficiency based on the change in current density is small, the above organic light emitting device can also exhibit characteristics of low driving voltage, high efficiency, and long life.

Such an organic light emitting device satisfying the above formula 1 can be realized by using a compound having a specific structure substituted with one or more cyano groups as a material of an electron transport layer of the organic light emitting device, which will be described in detail below.

An anode and a cathode

The anode material is preferably a material having a large work function in order to smoothly inject holes into the organic layer. Specific examples of the anode material include metals such as vanadium, chromium, copper, zinc, and gold, and alloys thereof; metal oxides such as zinc oxide, Indium Tin Oxide (ITO), and Indium Zinc Oxide (IZO);ZnO-Al or SnO₂A combination of a metal such as Sb and an oxide; poly (3-methylthiophene), poly [3,4- (ethylene-1, 2-dioxy) thiophene]Conductive polymers such as (PEDOT), polypyrrole, and polyaniline, but the present invention is not limited thereto.

Specific examples of the cathode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof, or L iO₂And a multilayer structure material such as Al, but not limited thereto.

In addition, the anode may further include a hole injection layer. The hole injection layer is made of a hole injection material, and the following compounds are preferable as the hole injection material: a compound having an ability to transport holes, having an effect of injecting holes from an anode, having an excellent hole injection effect with respect to a light-emitting layer or a light-emitting material, preventing excitons generated in the light-emitting layer from migrating to an electron-injecting layer or an electron-injecting material, and having an excellent thin-film-forming ability.

Preferably, the HOMO (highest occupied molecular orbital) of the hole injecting substance is between the work function of the anode substance and the HOMO of the surrounding organic layer. Specific examples of the hole injecting substance include, but are not limited to, metalloporphyrin (porphyrin), oligothiophene, arylamine-based organic substances, hexanitrile-hexaazatriphenylene-based organic substances, quinacridone-based organic substances, perylene-based organic substances, anthraquinone, polyaniline, and polythiophene-based conductive polymers.

Hole transport layer

The hole transport layer used in the present invention is a layer which receives holes from the anode or a hole injection layer formed on the anode and transports the holes to the light-emitting layer, and the hole transport substance is a substance which can receive holes from the anode or the hole injection layer and transport them to the light-emitting layer, and is preferably a substance having a high mobility to holes.

Specific examples thereof include, but are not limited to, arylamine-based organic materials, conductive polymers, and block copolymers in which a conjugated portion and a non-conjugated portion are present simultaneously.

Luminescent layer

The light-emitting substance included in the light-emitting layer is a substance that can receive holes and electrons from the hole-transporting layer and the electron-transporting layer, respectively, and combine them to emit light in the visible light region, and a substance having a high quantum efficiency with respect to fluorescence or phosphorescence is preferable. As an example, there is an 8-hydroxyquinoline aluminum complex (Alq)₃) (ii) a A carbazole-based compound; dimeric styryl (dimerized styryl) compounds; BAlq; 10-hydroxybenzoquinoline-metal compounds; benzo (b) is

Azole, benzothiazole and benzimidazole-based compounds; poly (p-phenylene vinylene) (PPV) polymers; spiro (spiroo) compounds; polyfluorene, rubrene, and the like, but are not limited thereto.

The light emitting layer may include a host material and a dopant material. The host material includes aromatic fused ring derivatives, heterocyclic compounds, and the like. Specifically, the aromatic condensed ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, and the like, and the heterocyclic ring-containing compounds include carbazole derivatives, dibenzofuran derivatives, and ladder-type furan compounds

Pyrimidine derivatives, etc., but are not limited thereto.

As the dopant material, there are an aromatic amine derivative, a styryl amine compound, a boron complex, a fluoranthene compound, a metal complex, and the like. Specifically, the aromatic amine derivative is an aromatic fused ring derivative having a substituted or unsubstituted arylamino group, and includes pyrene, anthracene, or the like having an arylamino group,

Diindenopyrene, and the like, the styrylamine compound is a compound substituted with at least one arylvinyl group on a substituted or unsubstituted arylamine, and is selected from aryl and silyl1 or 2 or more substituents of the alkyl group, the cycloalkyl group and the arylamino group are substituted or unsubstituted. Specific examples thereof include, but are not limited to, styrylamine, styryldiamine, styryltrimethylamine, and styryltretramine. The metal complex includes, but is not limited to, iridium complexes and platinum complexes.

Electron transport layer

The organic light emitting device according to the present invention may include an electron transport layer between the above light emitting layer and the electron injection layer. The electron transporting layer is a layer that receives electrons from the electron injecting layer and transports the electrons to the light emitting layer, and the electron transporting substance is a substance that can favorably receive electrons from the cathode and transfer the electrons to the light emitting layer, and is preferably a substance having a high mobility to electrons.

In particular, in the present invention, a compound represented by the following chemical formula 1 is used as a material of the electron transport layer:

[ chemical formula 1]

In the above-described chemical formula 1,

a is represented by the following

chemical formula

2 or 3,

[ chemical formula 2]

[ chemical formula 3]

In the

above chemical formula

2 or 3,

w is O, S, CR₉R₁₀Or SiR₁₁R₁₂，

a1 is an integer of 0 to 3,

a 2-a 6 and a8 are each independently integers from 0 to 4,

a7 is an integer of 0 to 5,

however, L₁To L₃、Ar₁、Ar₂And at least one of A is substituted with cyano.

At this time, "L" of the above chemical formula 1₁To L₃、Ar₁、Ar₂And at least one of A is substituted by cyano "means L₁L a substituent group₂L a substituent group₃Substituent of (A), Ar₁Substituent of (A), Ar₂And a substituent (R) of A₁To R₁₂) Is cyano, in this case, L₁To L₃By cyano-substituted is meant L₁To L₃Is C_6-60In the case of arylene.

By including such a compound represented by the above chemical formula 1 having a cyano group in the electron transport layer, an organic light emitting device satisfying the above mathematical formula 1 can be realized.

Specifically, L of the above chemical formula 1₁L a substituent group₂L a substituent group₃Substituent of (A), Ar₁Substituent of (A), Ar₂And a substituent (R) of A₁To R₁₂) 1 to 3 of which may be cyano.

Preferably L₁To L₃、Ar₁、Ar₂And one of A is substituted with cyano, in other words, L of the above chemical formula 1₁L a substituent group₂L a substituent group₃Substituent of (A), Ar₁Substituent of (A), Ar₂And a substituent (R) of A₁To R₁₂) 1 or 2 of may be cyano.

In addition, in the present specification, the term "substituted with cyano group" in the definition of the substituent means that 1 or more hydrogen, preferably 1 or 2 hydrogen, of the hydrogens contained in the substituent is substituted with cyano group.

The compound represented by the above chemical formula 1 may be represented by the following chemical formula 1A, 1B or 1C:

[ chemical formula 1A ]

In the above-described chemical formula 1A,

L₁to L₃Each independently is a single bond; or C unsubstituted or substituted by cyano_6-20An arylene group, a cyclic or cyclic alkylene group,

Ar₁and Ar₂Each independently being C unsubstituted or substituted by methyl or cyano_6-20An aryl group, a heteroaryl group,

w is O or S, and W is O or S,

R₁to R₄Each independently hydrogen, deuterium, or cyano,

however, L₁To L₃At least one of which is C substituted by cyano_6-20An arylene group; or

Ar₁And Ar₂At least one of which is C substituted by cyano_6-20An aryl group; orA

R₁To R₄At least one of which is a cyano group,

[ chemical formula 1B ]

In the above-described chemical formula 1B,

R₅to R₈Each independently hydrogen, deuterium, or cyano,

Ar₁And Ar₂At least one of which is C substituted by cyano_6-20An aryl group; or

R₁To R₄At least one of which is a cyano group,

[ chemical formula 1C ]

In the above-described chemical formula 1C,

R₅to R₈、R₆' and R₇' are each independently hydrogen, deuterium, or cyano,

R₅To R₈、R₆' and R₇At least one of' is cyano.

In addition, in the present specification, in the definition of the substituent group, "C unsubstituted or substituted with methyl or cyano_6-20The term "aryl" refers to unsubstituted C_6-20Aryl, C substituted by 1 or more methyl groups_6-20Aryl, C substituted by 1 or more cyano groups_6-20Aryl, or C substituted by 1 or more cyano groups and 1 or more methyl groups_6-20And (4) an aryl group.

In addition, L₁To L₃May each independently be a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, or a substituted or unsubstituted naphthylene group.

For example, L₁To L₃May each independently be a single bond, a phenylene group unsubstituted or substituted with a cyano group, or a biphenylene group unsubstituted or substituted with a cyano group.

Specifically, for example, L₁To L₃May each independently be a single bond, a phenylene group unsubstituted or substituted with a cyano group, a biphenylene group unsubstituted or substituted with a cyano group, or a terphenylene group unsubstituted or substituted with a cyano group.

In addition, Ar₁And Ar₂C which may each independently be unsubstituted or substituted by methyl or cyano_6-20And (4) an aryl group.

For example, Ar₁And Ar₂May each independently be phenyl unsubstituted or substituted by cyano, biphenyl unsubstituted or substituted by cyano, terphenyl unsubstituted or substituted by cyano, or 9, 9-dimethylfluorene unsubstituted or substituted by cyano.

Specifically, for example, Ar₁And Ar₂Each independently is not takenPhenyl which is substituted by 1 or 2 cyano groups, biphenyl which is unsubstituted or substituted by 1 or 2 cyano groups, terphenyl which is unsubstituted or substituted by 1 or 2 cyano groups, or 9, 9-dimethylfluorene which is unsubstituted or substituted by 1 or 2 cyano groups.

In chemical formula 2, W may be O or S.

In the

above chemical formula

2 or 3, R₁To R₈May each independently be hydrogen or cyano. Furthermore, R₉To R₁₂May each independently be hydrogen; deuterium; a cyano group; c unsubstituted or substituted by cyano_6-20An aryl group; or C comprising 1 to 3 heteroatoms selected from N, O and S, unsubstituted or substituted with cyano_2-60A heteroaryl group. For example, R₉To R₁₂May each independently be hydrogen or cyano.

In this case, a1 to a8 each represents R₁To R₈When the number of (a) s, a1 to a8, is 2 or more, 2 or more R₁To R₈May be the same as or different from each other. For example, a 1-a 8 may each independently be 0 or 1.

In addition, A represented by the above chemical formula 3 may be represented by the following chemical formulas 3-1 to 3-10 according to T. In the case where T is a benzene ring, it may be represented by the following chemical formula 3-1; in the case where T is a naphthalene ring, it may be represented by the following chemical formulae 3-2 to 3-4; in the case where T is a phenanthrene ring, it can be represented by the following chemical formulae 3-5 to 3-10.

In the above chemical formulae 3-1 to 3-10, R₅To R₈And a5 to a8 are as defined in the above chemical formula 3, and represent L of the above chemical formula 1₃The location of the connection.

In addition, in adjacent R₆And R₇In the case where a spiro structure is formed by bonding to each other, a represented by the above chemical formula 3 may have a structure in which a bond is formed with one carbon atom as a junction with another compound structure. Specifically, adjacent R of the above chemical formula 3₆And R₇May be combined with each other to form a spiro structure connected to the fluorene structure with one carbon atom as a junction, which may be represented by the following chemical formulae 3 to 11.

In the above chemical formula 3-11, R₅To R₈And a5 to a8 are as defined in the above chemical formula 3, R₆'、R₇', a6' and a7' refer to the pairs R, respectively₆、R₇The descriptions of a6 and a7, respectively, represent L of the same chemical formula 1₃The location of the connection.

Specifically, a may be any one selected from the following chemical formulas 4a to 4 e:

in the above chemical formulas 4a to 4e,

w is O or S, and W is O or S,

R₁to R₈As defined in the

above chemical formulas

2 and 3,

R₆' and R₇' respective reference to R₆And R₇In the description of (1) the specification,

l corresponding to the above chemical formula 1₃The location of the connection.

More specifically, in the above chemical formulas 4a to 4e, R₁To R₈、R₆' and R₇' may each independently be hydrogen or cyano.

For example, in the above chemical formula 4a, R₁To R₄Is hydrogen, or R₁To R₄One of them is cyano and the others are hydrogen,

in the above chemical formulas 4b to 4d, R₅To R₈Is hydrogen, or R₅To R₈One of them is cyano and the others are hydrogen,

in the above chemical formula 4e, R₅To R₈、R₆' and R₇' may be hydrogen, or R₅To R₈、R₆' and R₇One of' may be cyano and the remainder hydrogen.

On the other hand, the compound represented by the above chemical formula 1 may be any one selected from the following chemical formulas 1-1 to 1-9:

[ chemical formula 1-1]

[ chemical formulas 1-2]

[ chemical formulas 1-3]

[ chemical formulas 1 to 4]

[ chemical formulas 1 to 5]

[ chemical formulas 1 to 6]

[ chemical formulas 1 to 7]

[ chemical formulas 1 to 8]

[ chemical formulas 1 to 9]

In the above chemical formulas 1-1 to 1-9,

w is O or S, and W is O or S,

L₁to L₃、Ar₁、Ar₂And R₁To R₈R is as defined in the above chemical formulae 1 to 3₆' and R₇' respective reference to R₆And R₇And (4) description.

Specifically, the compound represented by the above chemical formula 1 may be any one selected from the following structures:

on the other hand, as an example, the compound represented by the above chemical formula 1 may be produced by a production method as shown in the following reaction formula 1.

[ reaction formula 1]

In the above reaction scheme 1, p-L₁To L₃、Ar₁、Ar₂And A is as defined in the above chemical formula 1, and X is halogen, preferably bromine or chlorine. The above reaction is a suzuki coupling reaction, and is preferably carried out in the presence of a palladium catalyst, and the reactive group used in the suzuki coupling reaction may be changed as known in the art. The above-described manufacturing method can be further embodied in the manufacturing examples described later.

The electron transporting layer may further contain a known substance as a general electron transporting substance, and specific examples thereof include an Al complex of 8-hydroxyquinoline and Alq-containing substance₃Organic radical compounds, hydroxyl brass-metal complexes, etc., but are not limited thereto. The electron transport layer may be used with any desired cathode material as used in the art. Examples of suitable cathode substances are, in particular, the customary substances having a low work function and accompanied by an aluminum or silver layer. In particular cesium, barium, calcium, ytterbium and samarium,in each case with an aluminum or silver layer.

Electron injection layer

The electron injection layer is a layer for injecting electrons from the electrode, and is preferably a compound of: a compound having an ability to transport electrons, having an effect of injecting electrons from a cathode, having an excellent electron injection effect for a light-emitting layer or a light-emitting material, and having an excellent thin film-forming ability. In addition, the electron injection layer may also function as the electron transport layer.

Specific examples of the electron-injecting substance include L iF, NaCl, CsF, L i₂O, BaO, fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide,

Azole,

Oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidene methane, anthrone, and the like, and derivatives thereof, metal complex compounds, nitrogen-containing five-membered ring derivatives, and the like, but are not limited thereto.

Organic light emitting device

Fig. 1 illustrates a structure of an organic light emitting device according to the present invention. Fig. 1 illustrates an example of an organic light-emitting device composed of a substrate 1, an anode 2, a light-emitting layer 3, an electron transport layer 4, and a cathode 5. In the structure as described above, the compound represented by the above chemical formula 1 may be contained in the above electron transport layer.

Fig. 2 illustrates an example of an organic light-emitting device composed of a substrate 1, an anode 2, a hole injection layer 6, a hole transport layer 7, a light-emitting layer 3, an electron transport layer 4, an electron injection layer 8, and a cathode 5. In the structure as described above, the compound represented by the above chemical formula 1 may be contained in the above electron transport layer. In this case, the electron transport layer and the electron injection layer may be provided as one layer as in the electron injection and transport layer.

The organic light emitting device according to the present invention may be manufactured by sequentially stacking the above-described structures. In this case, the following production can be performed: the anode is formed by depositing a metal, a conductive metal oxide, or an alloy thereof on a substrate by a PVD (physical Vapor Deposition) method such as a sputtering method or an electron beam evaporation method, the layers are formed on the anode, and a substance that can be used as a cathode is deposited on the layers. In addition to this method, a cathode material, an organic layer, and an anode material may be sequentially deposited on a substrate to manufacture an organic light-emitting device. The light-emitting layer can be formed using a host and a dopant, and can be formed by a vacuum evaporation method or a solution coating method. Here, the solution coating method refers to spin coating, dip coating, blade coating, inkjet printing, screen printing, spraying, roll coating, and the like, but is not limited thereto.

In addition to these methods, an organic light-emitting device may be manufactured by depositing a cathode material, an organic layer, and an anode material on a substrate in this order (WO 2003/012890). However, the production method is not limited thereto.

On the other hand, the organic light emitting device according to the present invention may be a top emission type, a bottom emission type, or a bi-directional emission type, depending on the material used.

The fabrication of the above-described organic light emitting device is specifically described in the following examples. However, the following examples are provided to illustrate the present invention, and the scope of the present invention is not limited thereto.

Production example 1: production of Compound 1

The above-mentioned compound A1(10g, 25.2mmol) and the above-mentioned compound B1(11.6g, 25.2mmol) were put in tetrahydrofuran (150M L), and 2M K was put in₂CO₃(100m L), tris (dibenzylideneacetone) dipalladium (0) (Pd (dba)₂0.6g), and tetracyclohexylphosphine (PCy)₃0.6g), stirred and refluxed for 5 hours. Cooling to room temperature, filtering, and recrystallizing the solid with chloroform and ethanol to obtain the final productCompound 1(13.4g, yield 82%).

MS:[M+H]⁺＝651

Production example 2: production of Compound 2

The above-mentioned compound A2(10g, 21.2mmol) and the above-mentioned compound B2(9.2g, 21.2mmol) were put in tetrahydrofuran (150M L), and 2M K was put in₂CO₃(100mL)、Pd(dba)₂(0.5g) and PCy₃(0.5g), stirred and refluxed for 5 hours. After cooling to room temperature, filtration was performed, and the resulting solid was recrystallized from chloroform and ethanol, whereby the above-mentioned compound 2(10.5g, yield 71%) was produced.

MS:[M+H]⁺＝701

Production example 3: production of Compound 3

The above-mentioned compound A3(10g, 24.3mmol) and the above-mentioned compound B3(11.2g, 24.3mmol) were put in tetrahydrofuran (150M L), and 2M K was put in₂CO₃(100mL)、Pd(dba)₂(0.6g) and PCy₃(0.6g), stirred and refluxed for 5 hours. After cooling to room temperature, the reaction mixture was filtered, and the resulting solid was recrystallized from chloroform and ethanol, whereby the above-mentioned compound 3(12.6g, yield 78%) was produced.

MS:[M+H]⁺＝665

Production example 4: production of Compound 4

The above Compound A4(10g, 22.9mmol) and the above Compound B2(10g, 22.9mmol) were charged in tetrahydrofuran (150M L), 2M K was added₂CO₃(100mL)、Pd(dba)₂(0.6g) and PCy₃(0.6g), stirred and refluxed for 5 hours. Cooling to normal temperatureAfter warming, filtration was performed, and the resulting solid was recrystallized from chloroform and ethanol, thereby producing the above-mentioned compound 4(10.4g, yield 68%).

MS:[M+H]⁺＝665

Production example 5: production of Compound 5

The above-mentioned compound A5(10g, 17.9mmol) and the above-mentioned compound B4(9.6g, 17.9mmol) were put in tetrahydrofuran (150M L), and 2M K was put in₂CO₃(100mL)、Pd(dba)₂(0.5g) and PCy₃(0.5g), stirred and refluxed for 5 hours. After cooling to room temperature, the reaction mixture was filtered, and the resulting solid was recrystallized from chloroform and ethanol, whereby the above-mentioned compound 5(9.9g, yield 62%) was produced.

MS:[M+H]⁺＝890

Production example 6: production of Compound 6

The above-mentioned compound A3(10g, 24.3mmol) and the above-mentioned compound B5(11.2g, 24.3mmol) were put in tetrahydrofuran (150M L), and 2M K was put in₂CO₃(100mL)、Pd(dba)₂(0.6g) and PCy₃(0.6g), stirred and refluxed for 5 hours. After cooling to room temperature, filtration was performed, and the resulting solid was recrystallized from chloroform and ethanol, whereby the above-mentioned compound 6(12.9g, yield 80%) was produced.

MS:[M+H]⁺＝665

Production example 7: production of Compound 7

Compound 7 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound a6 was used in place of compound a1, and the above-mentioned compound B6 was used in place of compound B1.

MS:[M+H]⁺＝651

Production example 8: production of Compound 8

Compound 8 was produced by the same method as in production example 1, except that compound B7 was used instead of compound B1 in production example 1.

MS:[M+H]⁺＝727

Production example 9: production of Compound 9

Compound 9 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound a7 was used in place of compound a1, and the above-mentioned compound B8 was used in place of compound B1.

MS:[M+H]⁺＝777

Production example 10: production of Compound 10

Compound 10 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound a4 was used in place of compound a1, and the above-mentioned compound B9 was used in place of compound B1.

MS:[M+H]⁺＝589

Production example 11: production of Compound 11

Compound 11 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound A3 was used in place of compound a1, and the above-mentioned compound B10 was used in place of compound B1.

MS:[M+H]⁺＝741

Production example 12: production of Compound 12

Compound 12 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound A3 was used in place of compound a1, and the above-mentioned compound B11 was used in place of compound B1.

MS:[M+H]⁺＝893

Production example 13: production of Compound 13

Compound 13 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound a5 was used in place of compound a1, and the above-mentioned compound B9 was used in place of compound B1.

MS:[M+H]⁺＝737

Production example 14: production of Compound 14

Compound 14 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound A8 was used in place of compound a1, and the above-mentioned compound B12 was used in place of compound B1.

MS:[M+H]⁺＝751

Production example 15: production of Compound 15

Compound 15 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound A3 was used in place of compound a1, and the above-mentioned compound B13 was used in place of compound B1.

MS:[M+H]⁺＝665

Production example 16: production of Compound 16

Compound 16 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound A3 was used in place of compound a1, and the above-mentioned compound B14 was used in place of compound B1.

MS:[M+H]⁺＝664

Production example 17: production of Compound 17

Compound 17 was produced by the same method as in production example 1, except that in production example 1, the above-mentioned compound A3 was used in place of compound a1, and the above-mentioned compound B12 was used in place of compound B1.

MS:[M+H]⁺＝665

Example 1

ITO (indium tin oxide) is added

The glass substrate (corning 7059 glass) coated with a thin film was put in distilled water in which a dispersant was dissolved, and washed with ultrasonic waves. The detergent used was a product of fisher corporation (Fischer Co.) and the distilled water used was distilled water filtered twice with a Filter (Filter) manufactured by Millipore Co. After washing ITO for 30 minutes, ultrasonic washing was performed for 10 minutes by repeating twice with distilled water. After the completion of the distilled water washing, ultrasonic washing was performed in the order of solvents of isopropyl alcohol, acetone, and methanol, and then dried.

On the ITO transparent electrode thus prepared, hexanitrile Hexaazatriphenylene (HATCN) was added

The hole injection layer is formed by thermal vacuum deposition. HT1 as a substance for transporting holes is formed on the hole injection layer

Vacuum evaporation is performed to form a hole transport layer.

On the above hole transport layer, a host H1 and a dopant D1 are compounded

The thickness of (2) is vacuum-evaporated to form a light-emitting layer.

On the light-emitting layer, compound 1 produced in production example 1 and L iQ (8-quinolinolatum lithium, L ithiumQuinolate) were vacuum-evaporated at a weight ratio of 1:1 to obtain a light-emitting layer

The thickness of (2) forms an electron transport layer.

On the electron transport layer, lithium fluoride (L iF) was sequentially added

Thickness of aluminum and

the electron injection layer and the cathode are formed by vapor deposition to produce an organic light-emitting device.

In the above process, the evaporation speed of the organic material is maintained

Lithium fluoride maintenance of cathode

Deposition rate of (3), aluminum maintenance

The deposition rate of (2), vacuum depositionDegree maintenance of 2 × 10^-7～5×10^-6And supporting to thereby fabricate an organic light emitting device.

The compounds used in example 1 above are shown below.

Examples 2 to 17 and comparative examples 1 to 10

An organic light-emitting device was produced in the same manner as in example 1, except that in example 1, compounds shown in table 1 below were used instead of compound 1 as the electron transporting layer material.

The compounds used in the above examples were arranged as follows.

The compounds used in the above comparative examples were arranged as follows.

Examples of the experiments

The organic light emitting devices manufactured in the above examples and comparative examples were measured at 10mA/cm²A driving voltage and luminous efficiency at a current density of 20mA/cm²The time required for the initial luminance to reach 98% at the current density of (2) (L T98) is shown in table 1 below.

In addition, after obtaining current density-efficiency graphs of the organic light emitting devices manufactured in the above examples and comparative examples, respectively, the current density of 0.1mA/cm was obtained in the graphs²To 10mA/cm²Minimum efficiency value (Eff) of_min) And maximum efficiency value (Eff)_max) Then, Eff is calculated_max/Eff_minThe results are shown in table 1 below. In addition, current density-efficiency graphs of the organic light emitting devices of example 16 and comparative example 7 were compared and shown in fig. 3.

[ TABLE 1]

As shown in table 1 and fig. 3, it is understood that the organic light emitting device using the compound represented by chemical formula 1 as the substance of the electron transport layer is different from the organic light emitting device of the comparative example in Eff_max/Eff_minThe value of (A) is 1.5 or less. Further, the organic light emitting device using the compound represented by the above chemical formula 1 as a substance of an electron transport layer can be confirmed to show superior characteristics in terms of driving voltage, light emitting efficiency, and lifetime, as compared to the organic light emitting device of the comparative example.

This is judged because the organic light emitting device using the compound represented by the above chemical formula 1 as an electron transport layer material has a small change in efficiency and a small change in color tone depending on the driving environment even though the current density is increased, as compared with the organic light emitting device of the comparative example, and thus the driving voltage, efficiency and lifetime are improved. Therefore, in consideration of the point that the light emission efficiency and the life time characteristics of the organic light emitting device generally have such a Trade-off relationship with each other, it is known that the organic light emitting device using the compound of the present invention shows significantly improved device characteristics as compared with the device of the comparative example.

[ notation ] to show

1: substrate 2: anode

3: light-emitting layer 4: electron transport layer

5: and (3) cathode 6: hole injection layer

7: hole transport layer 8: an electron injection layer.

Claims

1. An organic light emitting device, comprising:

an anode,

A cathode, a cathode,

A light-emitting layer between the anode and the cathode, and

an electron transport layer between the cathode and the light emitting layer,

in a current density-efficiency chart of the organic light emitting device, at a current density of 0.1mA/cm²To 10mA/cm²Maximum efficiency Eff_maxAnd minimum efficiency Eff_minSatisfies the following mathematical formula 1,

mathematical formula 1

Eff_max/Eff_min≤1.5

Chemical formula 1

In the chemical formula 1, the first and second organic solvents,

a is represented by the following chemical formula 2 or 3,

chemical formula 2

Chemical formula 3

In the chemical formula 2 or 3,

w is O, S, CR₉R₁₀Or SiR₁₁R₁₂，

a1 is an integer of 0 to 3,

a 2-a 6 and a8 are each independently integers from 0 to 4,

a7 is an integer of 0 to 5,

l of chemical formula 1₃The position of the connection is such that,

2. The organic light emitting device according to claim 1, wherein the compound represented by the chemical formula 1 is represented by the following chemical formula 1A, 1B or 1C:

chemical formula 1A

In the chemical formula 1A, the metal oxide,

w is O or S, and W is O or S,

R₁to R₄Each independently hydrogen, deuterium, or cyano,

R₁To R₄At least one of which is a cyano group,

chemical formula 1B

In the chemical formula 1B, the metal oxide,

R₅to R₈Each independently hydrogen, deuterium, or cyano,

R₁To R₄At least one of which is a cyano group,

chemical formula 1C

In the chemical formula 1C, the metal oxide,

R₅To R₈、R₆' and R₇At least one of' is cyano.

3. The organic light emitting device of claim 1, wherein L₁To L₃Each independently a single bond, phenylene unsubstituted or substituted with a cyano group, biphenylene unsubstituted or substituted with a cyano group, or terphenylene unsubstituted or substituted with a cyano group.

4. The organic light emitting device of claim 1, wherein Ar₁And Ar₂Each independently is phenyl unsubstituted or substituted by cyano, biphenyl unsubstituted or substituted by cyano, terphenyl unsubstituted or substituted by cyano, or 9, 9-dimethylfluorene unsubstituted or substituted by cyano.

5. The organic light emitting device according to claim 1, wherein a is any one selected from the following chemical formulae 4a to 4 e:

in the chemical formulas 4a to 4e,

w is O or S, and W is O or S,

R₁to R₈As defined in claim 1, in the same way,

l of chemical formula 1₃The location of the connection.

6. The organic light emitting device of claim 5, wherein R₁To R₈、R₆' and R₇' are each independently hydrogen or cyano.

7. The organic light emitting device of claim 5,

in the chemical formula 4a, the first and second groups,

R₁to R₄Is hydrogen, or R₁To R₄One of them is cyano and the others are hydrogen,

in the chemical formulas 4b to 4d,

R₅to R₈Is hydrogen, or R₅To R₈One of them is cyano and the others are hydrogen,

in the chemical formula 4e, the first and second compounds,

R₅to R₈、R₆' and R₇' is hydrogen, or R₅To R₈、R₆' and R₇One of' is cyano and the remainder are hydrogen.

8. The organic light emitting device according to claim 1, wherein the compound represented by the chemical formula 1 is any one selected from the following chemical formulae 1-1 to 1-9:

chemical formula 1-1