KR20170077774A - Polymer, organic light-emitting device material including the same, and organic light-emitting device including the same - Google Patents

Abstract

Polymers, organic light emitting device materials containing them, and organic light emitting devices comprising the same are described.

Description

[0001] The present invention relates to a polymer, an organic light-emitting device material containing the same, and an organic light-emitting device including the polymer, organic light-emitting device material including same, and organic light-

Polymer, a material for an organic light emitting diode including the same, and an organic light emitting device including the same.

BACKGROUND ART [0002] Recently, organic light-emitting device materials, organic light-emitting devices, and display devices and lighting devices have been actively developed.

In such an organic luminescent device, in order to manufacture a device having a large area at a lower cost, it has been studied to use a solution coating method instead of the vacuum vapor deposition. The solution coating method has a higher utilization efficiency of a material than a vacuum evaporation method and can be easily formed into a large area, and expensive vacuum evaporation becomes unnecessary, and thus it has been expected as a more efficient method of manufacturing an organic light emitting device.

An organic light emitting device material including a polymer having a novel structure capable of improving the light emitting efficiency and the light emission lifetime of the organic light emitting device, and an organic light emitting device using such an organic light emitting device material.

According to one aspect, there is provided a polymer comprising a repeating unit represented by the following formula (1): < EMI ID =

≪ Formula 1 >

In Formula 1,

R ₁ , R ₂ and R ₃ are, independently of each other, hydrogen, deuterium, fluorine; An alkylsilyl group having 1 to 10 carbon atoms; An arylsilyl group having 6 to 30 carbon atoms; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted C6 to C30 aryl; And a substituted or unsubstituted C1 to C30 heteroaryl group,

L is a single bond; A substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkylene group having 5 to 30 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms, provided that it is not a substituted or unsubstituted carbazolylene group,

A ₁ and A ₂ are, independently of each other, a single bond; Oxygen atom; Sulfur atom; A substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms,

A ₃ is a substituted or unsubstituted, tricyclic alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted tricyclic aryl group having 6 to 30 carbon atoms; And a substituted or unsubstituted trivalent heteroaryl group having 1 to 30 carbon atoms,

A ₄ and A ₅ independently represent a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms,

m is an integer of 1 to 10;

By this aspect, the luminous efficiency and the luminescent lifetime of the organic light emitting device can be improved.

In another aspect, the polymer may include a repeating unit represented by the following formula (2).

(2)

In Formula 2,

R ₁ , R ₂ , R ₃ , L, A ₁ , A ₂ and m are as defined in claim 1,

W ₁ to W ₁₁ are, independently of each other, N or CX,

X is hydrogen; heavy hydrogen; An alkylsilyl group having 1 to 10 carbon atoms; An arylsilyl group having 6 to 30 carbon atoms; An alkylamino group having 1 to 10 carbon atoms; An arylamino group having 6 to 60 carbon atoms; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted C6 to C30 aryl; And a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

By this aspect, the luminous efficiency and the luminescent lifetime of the organic light emitting device can be improved.

In one aspect, L is a single bond; A substituted or unsubstituted arylene group having 6 to 15 carbon atoms; And a substituted or unsubstituted heteroarylene group having 5 to 15 carbon atoms, and is not a substituted or unsubstituted carbazolylene group.

In another aspect, A ₁ and A ₂ independently of each other are a single bond; Oxygen atom; And sulfur atoms.

In one aspect, W ₁ to W ₁₁ may be CX, respectively.

In yet another aspect, X is independently from each other hydrogen; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted arylamino group having 6 to 30 carbon atoms; And a substituted or unsubstituted C6 to C15 aryl group.

By this aspect, the luminous efficiency and the luminescent lifetime of the organic light emitting device can be improved.

In one aspect, the polymer may further comprise a crosslinking group.

In another aspect, the crosslinker may be selected from the following structures.

Among these structures,

R ₄ to R ₁₀ are hydrogen; Or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms,

p is an integer of 1 to 10;

By this aspect, the luminous efficiency and the luminescent lifetime of the organic light emitting device can be improved.

Further, in another aspect for solving the above-mentioned problems, there is provided an organic light emitting device material comprising the above-described polymer and a solution.

According to another aspect, there is provided a liquid crystal display comprising: a first electrode; A second electrode; And an organic layer interposed between the first electrode and the second electrode;

Wherein the organic layer comprises the above-mentioned polymer.

The organic light emitting device including the polymer has improved luminous efficiency and luminescent lifetime.

FIG. 1 schematically shows an organic light emitting device according to one embodiment.

As an organic light emitting element material using a solution coating method, for example, a low molecular material and a high molecular material have been studied. Among them, the polymer material is highly developed because it has high coating uniformity and is easy to form a laminate. In particular, it can be used in displays and lighting devices, and the development of polymeric hole transport materials is expected.

For example, the following patent documents disclose an organic light-emitting device material in which a part of a low-molecular material is substituted with a vinyl group and polymerized to polymerize.

Japanese Patent Application Laid-Open No. 1995-090255

Japanese Patent Application Laid-Open No. 1996-054833

Japanese Patent Application Laid-Open No. 1996-269133

Japanese Patent Application Laid-Open No. 2001-098023

Japanese Patent Application Laid-Open No. 2002-110359

Japanese Patent Application Laid-Open No. 2003-313240

Japanese Patent Application Laid-Open No. 2004-059743

Japanese Patent Application Laid-Open No. 2006-237592

Japanese Patent Application Laid-Open No. 2008-198989

Japanese Patent Application Laid-Open No. 2008-218983

However, the organic light-emitting device manufactured by the solution coating method using the organic light-emitting element material described in the patent document has a problem that the light emission lifetime is not sufficient.

Accordingly, in view of the above problems, it is an object of the present invention to provide an organic light emitting device material including a polymer having a novel structure capable of improving the light emitting efficiency and the light emission lifetime of the organic light emitting device, and an organic light emitting device using such an organic light emitting device material. A polymer according to an embodiment, an organic light emitting device material including the same, and an organic light emitting device including the same will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

polymer

As a result of studying an organic light emitting device material capable of improving the luminous efficiency of an organic light emitting device due to a phenomenon that a light emitting efficiency of a conventional organic light emitting device is low, there is a phenomenon that an exciton leaks from the light emitting layer to a hole transporting layer. (T ₁ ) of the hole transport layer is increased by incorporating a polymer obtained by polymerizing a polymerizable monomer containing a specific condensed ring structure in the side chain of the hole transporting layer, for example, a hole transporting layer. By using such a polymer, it has been found that the exciton in the light emitting layer can be prevented from leaking to the hole transporting layer, and the exciton can be trapped in the light emitting layer, thereby improving the light emitting efficiency of the organic light emitting device and further improving the light emitting lifetime .

In one embodiment, there is provided a polymer obtained by polymerizing a polymerizable monomer containing a specific condensed ring structure in the side chain of the polymer. Such a polymer has high solubility and coating stability, and can improve the luminous efficiency and the luminescent lifetime of the organic light emitting device.

In one embodiment, the polymer compound formed by polymerizing the polymerizable monomer includes a repeating unit represented by the following formula (1).

≪ Formula 1 >

In Formula 1,

R ₁ , R ₂ and R ₃ are, independently of each other, hydrogen, deuterium, fluorine; An alkylsilyl group having 1 to 10 carbon atoms; An arylsilyl group having 6 to 30 carbon atoms; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted C6 to C30 aryl; And a substituted or unsubstituted C1 to C30 heteroaryl group,

L is a single bond; A substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkylene group having 5 to 30 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms,

A ₁ and A ₂ are, independently of each other, a single bond; Oxygen atom; Sulfur atom; A substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms,

A ₃ is a substituted or unsubstituted, tricyclic alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted tricyclic aryl group having 6 to 30 carbon atoms; And a substituted or unsubstituted C1 to C30 heteroaryl group,

A ₄ and A ₅ independently represent a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms,

m is an integer of 1 to 10;

The repeating unit represented by the formula (1) may be represented by the following formula (2).

(2)

In Formula 2,

R ₁ , R ₂ , R ₃ , L, A ₁ , A ₂ and m are as defined in claim 1,

W ₁ to W ₁₁ are, independently of each other, N or CX,

X is hydrogen; heavy hydrogen; An alkylsilyl group having 1 to 10 carbon atoms; An arylsilyl group having 6 to 30 carbon atoms; An alkylamino group having 1 to 10 carbon atoms; An arylamino group having 6 to 60 carbon atoms; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted C6 to C30 aryl; And a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

In one embodiment, the polymer comprises a first unit represented by Formula 1 and a second unit represented by Formula 1, and the structures of the first unit and the second unit may be different from each other. In one embodiment, L is a single bond; A substituted or unsubstituted arylene group having 6 to 15 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 15 carbon atoms, and is not a substituted or unsubstituted carbazolylene group.

In another embodiment, L may be selected from a single bond and a substituted or unsubstituted arylene group having 6 to 15 carbon atoms.

For example, L is a single bond; A substituted or unsubstituted phenylene group; A substituted or unsubstituted naphthylene group; A substituted or unsubstituted anthracenylene group; A substituted or unsubstituted biphenylene group; A substituted or unsubstituted terphenylene group; And a substituted or unsubstituted fluorenylene group.

In yet another embodiment, L is a single bond; A substituted or unsubstituted phenylene group; A substituted or unsubstituted naphthylene group; And a substituted or unsubstituted fluorenyl group.

For example, L is a single bond; A phenylene group; Naphthylene group; And a fluorenyl group substituted with an alkyl group.

In one embodiment, m may be 1, 2, or 3. For example, m may be 1 or 2.

In another embodiment, A ₁ and A ₂ are independently of each other a single bond; Oxygen atom; And sulfur atoms.

In one embodiment, W ₁ through W ₁₁ may each be CX. That is, W ₁ to W ₁₁ each may be a carbon atom substituted with X.

In one embodiment, X is a hydrogen atom; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted arylamino group having 6 to 30 carbon atoms; And a substituted or unsubstituted C6 to C15 aryl group. For example, X is a hydrogen atom; An arylamino group; A phenyl group; Naphthyl group; A phenanthryl group; A biphenylyl group; A terphenyl group; And a fluorenyl group.

In one embodiment, the repeating unit represented by the formula (1) or (2) is a nitrogen-containing condensed ring structure bonded to the side chain of the polymer through L, and may be selected from the following structures, It is not. The position at which the nitrogen-containing condensed ring structure is connected to the main chain of the polymer may be any bonding site.

Further, a plurality of nitrogen-containing condensed-ring structures may be connected to the side chain of the polymer via L. For example, two nitrogen-containing condensed ring structures may be connected as in the following structures, in which case m is 2, but is not limited thereto.

In another embodiment, the aforementioned nitrogen-containing condensed ring may be substituted with at least one or more substituents. For example, the repeating unit represented by the formula (1) may be selected from the following structures, but is not limited thereto.

In one embodiment, the polymer may further comprise a crosslinker. For example, the crosslinking group may be selected from the following structures, but is not limited thereto.

Among these structures,

R ₄ to R ₁₀ are hydrogen; Or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms,

p is an integer of 1 to 10;

In one embodiment, the polymerizable monomer comprising the unit represented by Chemical Formula 1 or Chemical Formula 2 and the crosslinking group may be selected from the following structures, but is not limited thereto.

In one embodiment, the polymer may be a polymer obtained by polymerizing a polymerizable monomer containing a repeating unit represented by the general formula (1) or (2) alone. In another embodiment, the polymer may be a copolymer obtained by copolymerizing a polymerizable monomer containing a repeating unit represented by the formula (1) or (2) and another polymerizable monomer. That is, in one embodiment, the polymer may contain repeating units represented by the above-described formula (1) or (2).

As described above, the polymer according to one embodiment includes a specific condensed ring structure in the side chain portion. Since the polymer having such a specific condensed ring structure has a high energy of the triplet excited state (T ₁ ), for example, it is used in the hole transporting layer to suppress leakage of the exciton in the light emitting layer into the hole transporting layer, The light emitting efficiency of the organic light emitting device can be improved, and the life of the light emitting device can be further improved.

In one embodiment, the number average molecular weight of the polymer can be, for example, from 10,000 to 100,000, or from 10,000 to 100,000. In another embodiment, the degree of dispersion of the polymer, i. E. The weight average molecular weight divided by the number average molecular weight, can be, for example, from 1.5 to 2.5, or from 1.5 to 2.5.

As described above, the polymer according to one embodiment can form a film by the solution coating method, and the luminous efficiency and the luminescent lifetime of the organic light emitting device can be improved. In addition, when the polymer according to one embodiment includes a crosslinking group, the coating stability can be improved by crosslinking after coating. Therefore, when the laminated structure of the organic light emitting device is formed using the polymer, the light emitting property and stability Can be improved.

In one embodiment, the polymer can be synthesized using known organic synthesis methods. In one embodiment, a specific synthesis method of the polymer can be easily understood and practiced by those skilled in the art with reference to the following embodiments.

"Alkyl group" includes, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a s-butyl group, an isobutyl group, N-octyl group.

The "cycloalkyl group" may be, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, or a 1-norbonyl group.

The "aryl group" may be, for example, a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a biphenylyl group, a terphenyl group, a tolyl group, a fluoranthenyl group or a fluorenyl group.

The "heteroaryl group" includes, for example, a pyrrolyl group, a pyridinyl group, a pyridinyl group, an indolyl group, an isoindolyl group, a furyl group, a benzofuranyl group, an isobenzofuranyl group, a quinolyl group, an isoquinolyl group, A phenanthridinyl group, a phenoxazinyl group, an oxazolyl group, an oxadiazolyl group, a furazanyl group, and a thienyl group.

Further, the alkylene group, cycloalkylene group, arylene group and heteroarylene group means a divalent group in which one hydrogen is removed from each of the above-exemplified alkyl group, aryl group, and heteroaryl group.

The "alkylsilyl group" means a monovalent to trivalent silicon (Si) atom substituted with the alkyl group, and the "arylsilyl group" has a monovalent to trivalent silicon (Si) atom substituted with the aryl group. The "alkylamino group" means a monovalent to trivalent nitrogen atom substituted with the alkyl group, and the "arylamino group" means a monovalent to trivalent nitrogen atom substituted with an aryl group.

Also, in the present specification, the meaning of "substituted" means that it is substituted with any substituent, and specifically means substituted with any of the above-mentioned alkyl group, aryl group, and heteroaryl group.

Organic light emitting device material

In one embodiment, there is provided an organic light emitting device material comprising the above polymer. The polymer is applicable as an organic light emitting device material. In addition, the polymer has hole transport and hole injection capability. Accordingly, the organic light emitting device material according to one embodiment can be used, for example, as a material for a hole transporting layer, a hole injecting layer, and a light emitting layer.

In another embodiment, the organic luminescent material may be the material of the luminescent layer, and the above-mentioned polymer may be used as the host material. In this case, the organic light emitting device material according to one embodiment may further include a compound having a hole transporting ability.

The compound having such a hole transporting ability is not particularly limited, and known hole injecting materials, hole transporting materials and host materials described later can be used.

In one embodiment, the organic luminescent material is a material of the luminescent layer, and the organic luminescent material may further include a luminescent material. As such a light emitting material, a light emitting material described later can be used.

In one embodiment, there is provided an organic light emitting device material comprising a polymer and a solvent as described above. In one embodiment, the organic light emitting device material may be used, for example, to form each layer of the organic light emitting device by a solution coating method.

As the solvent, those capable of dissolving the above-described organic light emitting element material may be used, but the present invention is not limited thereto.

In one embodiment, the solvent is selected from the group consisting of toluene, xylene, ethylbenzene, diethylbenzene, mesitylene, propylbenzene, cyclohexylbenzene, dimethoxybenzene, anisole, ethoxytoluene, phenoxy Aromatic solvents such as toluene, isopropyl biphenyl, dimethyl anisole, phenylacetate, phenyl propionate, methyl benzoate, and ethyl benzoate may be used, but are not limited thereto.

Organic light emitting device

Hereinafter, an organic light emitting device according to an embodiment of the present invention will be described with reference to FIG.

The organic light emitting device 100 includes a substrate 110, a first electrode 120 disposed on the substrate 110, a hole injection layer 130 disposed on the first electrode 120, a hole injection layer 130, A light emitting layer 150 disposed on the hole transporting layer 140, an electron transporting layer 160 disposed on the light emitting layer 150, an electron injection layer 160 disposed on the electron transporting layer 160, And a second electrode 180 disposed on the electron injection layer 170 and the electron injection layer 170.

The substrate 110 may be a substrate used as a typical organic light emitting device. For example, the substrate 110 may be a glass substrate, a silicon substrate, or a transparent plastic substrate.

The first electrode 120 may be formed on the substrate 110. The first electrode 12 is, for example, an anode and may be formed using a material having a high work function such as a metal, an alloy, or a conductive compound. For example, the first electrode 120 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO ₂ ), zinc oxide (ZnO) or the like having excellent transparency and conductivity. Also, the first electrode 120 may be formed as a reflective electrode using magnesium (Mg), aluminum (Al), or the like.

A hole injection layer 130 may be formed on the first electrode 120. The hole injection layer 130 is a layer having a function of facilitating the injection of holes from the first electrode 120 and is formed to have a thickness of, for example, about 10 nm to 1000 nm, or about 10 nm to 100 nm .

The hole injection layer 130 can be formed using a known hole injection material. For example, poly (ether ketone) -containing triphenylamine (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate (PPBI) , N, N'-diphenyl-N, N'-diphenyl-N, N'-bis- [4- (phenyl- m- tolyl-amino) -phenyl] -biphenyl-4,4'-diamine DNTPD), copper phthalocyanine, 4,4 ', 4 "-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), N, N'- (NPB), 4,4 ', 4 "-tris (N, N'-2-naphthylphenylamino) triphenylamine (2-TNATA), polyaniline / dodecylbenzenesulfonic acid, poly (3,4-ethylenedioxythiophene) / poly (4-styrenesulfonate)), or polyaniline / 10-camphorsulfonic acid.

On the hole injection layer 130, a hole transport layer 140 is formed. The hole transporting layer 140 is a layer including a hole transporting material having a function of transporting holes, and may be formed to a thickness of, for example, about 10 nm to about 150 nm. The hole transporting layer 140 can be formed by a solution coating method using a polymer according to one embodiment. According to the above method, it is possible to improve the light emission lifetime of the organic light emitting element 100, and it is easy to form a large area.

The light emitting layer 150 may be formed on the hole transport layer 140. The light-emitting layer 150 is a layer that emits light such as fluorescence or phosphorescence, and may be formed using a vacuum deposition method, a spin coating method, an ink-jet method, or the like. The light emitting layer 150 may be formed to a thickness of, for example, about 10 nm to 60 nm.

As the light emitting material of the light emitting layer 150, a known light emitting material can be used. In one embodiment, the light emitting material contained in the light emitting layer 150 may be a light emitting material capable of emitting light, that is, phosphorescence, from the triplet exciton. In this case, the light emitting lifetime of the organic light emitting element 100 can be improved.

As the host material of the light emitting layer 150, for example, tris (8-quinolinato) aluminum (Alq ₃ ), 4,4'-N, N'-dicarbazole-biphenyl (CBP) (PVK), 9,10-di (naphthalen-2-yl) anthracene) (ADN), 4,4 ', 4 "-tris (N-carbazole) triphenylene (TBPI), 3-tert-butyl-9,10-di (naphth-2-yl) anthracene (TBADN), distyrylarylene (DSA), 4.4'-bis (9-carbazole) -2,2'-dimethylbiphenyl (dmCBP), and the like.

Examples of the dopant material of the light emitting layer 150 include perylene and its derivatives, rubrene and its derivatives, coumarin and its derivatives, 4- (dicyanomethylene) -2-methyl-6- [p- (4-fluorophenyl) pyridinate] picolinate iridium (III) (FIrpic), bis (1- phenyl isoquinoline) (acetylacetonato) iridium (III) [Ir (piq) ₂ (acac)], tris (2-phenylpyridine) iridium (III) [Ir (ppy) 3] such as an iridium complex, an osmium (Os ) Complexes, platinum complexes.

The electron transport layer 160 may be formed on the light emitting layer 150. The electron transporting layer 160 may be formed using a vacuum evaporation method, a spin coating method, an inkjet method, or the like as a layer having a function of transporting electrons. The electron transporting layer 160 may be formed to a thickness of, for example, about 15 nm to about 50 nm.

As the electron transporting layer 160, a known electron transporting material can be used. As a known electron transporting material, for example, tris (8-quinolinato) aluminum (Alq ₃ ) and a compound containing a nitrogen-containing aromatic ring can be used. The nitrogen-containing aromatic ring compound may be, for example, a compound containing a pyridine ring such as (1,3,5-tri [(3-pyridyl) -phenyl-3-yl] benzene) (3 '- (pyridin-3-yl)) biphenyl-3-yl) -1,3,5-triazine), a compound containing a triazine ring such as 2- 1-yl-phenyl) -9,10-dinaphthylanthracene), and the like. Examples of commercially available products include KLET-01, KLET-02, KLET-03, KLET-10 and KLET-M1 (available from Chemipro Kasei) as electron transporting materials .

The electron injection layer 170 may be formed on the electron transport layer 160. The electron injection layer 170 is a layer having a function of facilitating injection of electrons from the second electrode 180, and may be formed on the electron transport layer 160 using a vacuum deposition method or the like.

The electron injection layer 170 may be formed to a thickness of about 0.3 nm to about 9 nm.

The electron injection layer 170 can be formed using a known electron injecting material. For example, it is possible to use (8-quinolinato) lithium (Liq) and lithium fluoride (LiF), sodium chloride (NaCl), cesium fluoride (CsF), lithium oxide (Li ₂ O), barium oxide .

A second electrode 180 may be formed on the electron injection layer 170. The second electrode 180 may be, for example, a cathode and may be formed using a metal, an alloy, or a conductive compound having a small work function. For example, lithium, magnesium, aluminum, calcium, aluminum-lithium, magnesium-indium, magnesium-silver, And the like. Further, it can be formed as a transparent electrode using indium tin oxide (ITO), indium zinc oxide (IZO) or the like.

An example of the structure of the organic light emitting diode 100 according to the embodiment of the present invention has been described above. The organic light emitting device 100 according to one embodiment can improve the light emission lifetime by incorporating the above-mentioned polymer into the organic layer.

The structure of the organic light emitting diode 100 according to an embodiment of the present invention is not limited to the above example. The organic light emitting device 100 according to an embodiment of the present invention may be formed using various structures of known organic light emitting devices. For example, the organic light emitting device 100 may not have one or more layers of the hole injection layer 130, the hole transport layer 140, the electron transport layer 160, and the electron injection layer 170. Each layer of the organic light emitting diode 100 may be formed as a single layer or a plurality of layers.

The organic light emitting diode 100 may include a hole blocking layer between the hole transport layer 140 and the light emitting layer 150 to prevent triplet excitons or holes from diffusing into the electron transport layer 160. The hole blocking layer can be formed, for example, by an oxadiazole derivative, a triazole derivative, a phenanthroline derivative or the like.

Hereinafter, polymers, organic light emitting device materials, compositions for preparing organic light emitting devices, and organic light emitting devices according to an embodiment of the present invention will be described in more detail with reference to the following Synthesis Examples and Examples, But is not limited to the examples.

[ Example ]

Synthesis of Polymer A

As a method of synthesizing the polymer according to one embodiment, the following synthesis method of the polymer A will be specifically described. In addition, the synthesis method described below is only an example, and the method of synthesizing the polymer is not limited to the following examples.

First, Compound 3 was synthesized according to Reaction Scheme 1 below.

<Reaction Scheme 1>

Under argon atmosphere, 2-iodoanisole (40.0 g, 192.3 mmol), 4-bromo-2,6-difluoroaniline (100.0 g, 427.3 mmol) and carbonic acid Potassium K ₂ CO ₃ (111.0 g, 803.2 mmol), copper (15.6 g, 246.0 mmol) and 520 ml of o-dichlorobenzene were added and the mixture was stirred at 180 ° C. for 80 hours. After the reaction was completed, the mixture was cooled to room temperature and impurities were separated using celite (R). After removing the solvent, the solution was washed three times with 300 ml of hexane to obtain Compound 1 as a white powder. (48.0 g, 114.2 mmol, yield 26.7%).

Then, Compound 1 (47.00 g, 111.84 mmol) and dehydrated dichloromethane (1800 mL) were added to a 3 L four-necked flask under an argon atmosphere, and the mixture was stirred at -75 캜 for 15 minutes. Then, 230 ml of a 1.0 M solution of tribromoboronic acid in dichloromethane) was added dropwise, the temperature was slowly raised to room temperature, and the mixture was stirred for 5 hours. Then, 1000 ml of water was added to the reaction solution and extracted three times with dichloromethane. The organic layer was concentrated, and purified by column chromatography to obtain Compound (2). (38.0 g, 96.9 mmol, 86.6% yield)

Subsequently, Compound 2 (37.0 g, 94.35 mmol), potassium carbonate (39.00 g, 283.00 mmol) and dimethylformamide (500 ml) were added to a 2 L four-necked flask under an argon atmosphere, and the mixture was stirred at 100 ° C for 10 hours. The mixture was cooled to room temperature and 1000 ml of water was added to extract the white solid. The resulting solid was purified by recrystallization using a mixed solvent of chloroform and hexane to obtain Compound (3). (26.3 g, 74.7 mmol, yield 79.1%).

Next, monomer A was synthesized according to the following Reaction Scheme 2.

<Reaction Scheme 2>

Compound (3) (2.00 g, 5.68 mmol), vinylphenylboronic acid (0.92 g, 6.25 mmol), tetrakis (triphenylphosphine) palladium (0.20 g, 0.17 mmol), 1,2 -Dimethoxyethane and 4.3 ml of a 2M aqueous solution of sodium carbonate (Na ₂ CO ₃ aq) were added, and the mixture was stirred at 80 ° C for 7 hours. The mixture was cooled to room temperature and extracted three times with toluene / water. The organic layer was concentrated and purified by column chromatography to obtain monomer A (1.97 g, yield 92.6%). The structure of monomer A was confirmed by liquid chromatography mass spectrometry (LC-MS).

Subsequently, monomer A (1.00 g, 2.66 mmol), azobisisobutyronitrile (AIBN) (0.005 g, 0.0305 mmol) and 10 ml of dehydrated toluene were added to a three-necked flask under an argon atmosphere, The mixture was stirred for 8 hours. After the mixture was cooled to room temperature, methanol was added to extract the extract, and the extract was filtered. The obtained solid was dissolved in tetrahydrofuran (THF) and refined by reprecipitation treatment using acetone to obtain 0.5 g of polymer A having the following structure. Further, the number-average molecular weight Mn and the weight-average molecular weight Mw of the polymer A were measured using GPC (gel permeation chromatography), and the Mn was 21200 and the Mw was 4840.

<Polymer A>

Manufacture of organic light emitting device

An organic light emitting device including the above-mentioned polymer was prepared by the following process.

First, PEDOT / PSS / poly (4-styrene sulfonate) (manufactured by Sigma-Aldrich) was dried on a striped ITO glass substrate as a first electrode (anode) To form a hole injection layer.

Next, the synthesized polymer A was dissolved in xylene at 1% by mass to prepare a positive hole transport layer coating liquid. On the hole injection layer, the hole transport layer coating liquid was applied by spin coating so as to have a film thickness of 30 nm after drying, and heated at 230 DEG C for 1 hour to form a hole transport layer.

Next, on the hole transporting layer, triphenylenylsilyl 3,6-biscarbazole benzene (SimCP) and 4,4'-bis (carbazol-9-yl) biphenyl (CBP) Tris (2- (3-xylyl) phenylpyridine iridium (III) (TEG) was co-deposited with a vacuum deposition apparatus to form a light emitting layer with a thickness of 30 nm.

The proportion of SimCP and CBP was set at a mass ratio of SimCP: CBP = 7: 3, and the doping amount of tris (2-3-xylyl) phenylpyridine iridium (III) was 10 mass%. In addition, tris (2- (3-p-xylyl) phenylpyridine iridium (III) is a luminescent material capable of emitting light from a triplet exciton, that is, phosphorescent light emission.

Next, (8-quinolinolato) lithium (Liq) and KLET-03 (manufactured by Chemipro Kasei) were co-deposited on the light emitting layer with a vacuum vapor deposition apparatus to form an electron transporting layer having a thickness of 50 nm. Further, lithium fluoride (LiF) was vapor deposited on the electron transporting layer using a vacuum deposition apparatus to form an electron injection layer with a thickness of 1 nm. On the electron injecting layer, aluminum was vapor-deposited by a vacuum evaporator to form a second electrode (cathode) of 100 nm. The organic light emitting device was fabricated by the above method.

Example  2 to 6 and Comparative Example  One

A device was manufactured and evaluated in the same manner as in Example 1 except that the hole transport layer was formed using the polymer shown in Table 1 below.

<Polymer B>

<Polymer C>

<Polymer D>

<Polymer E>

<Polymer F>

<Polymer a>

Evaluation of organic light emitting device

The current efficiency and the luminescent lifetime of the thus fabricated organic luminescent device were evaluated according to the following methods.

A predetermined voltage was applied to each of the organic light emitting elements using a DC constant voltage power source (source meter, manufactured by KEYENCE) to emit the organic light emitting element. While measuring the luminescence of the organic light emitting device by means of a luminance measuring device (SR-3, Topcom), the current density was slowly measured and the current was kept constant when the luminance was increased to 3000 cd / m ² . The current efficiency was calculated from the obtained current density.

Further, the time until the value of the luminance measured by the luminance measuring device gradually lowers to 80% of the initial luminance is called the luminescence lifetime.

The evaluation results are shown in Table 1 below. In Table 1, the current efficiency and the light emission luminance are represented by relative values when the measured value of Comparative Example 1 is taken as 100.

The results are shown in Table 1.

HTL Mn Mw n: m efficiency(%) Device life (%) Example 1 Polymer A 21,200 48,400 - 120 1,700 Example 2 Polymer B 20,600 44,600 - 128 1,500 Example 3 Polymer C 22,900 52,700 - 125 2,000 Example 4 Polymer D 27,000 70,200 9: 1 122 2,300 Example 5 Polymer E 5,380 18,000 9: 1 118 1,650 Example 6 Polymer F 10,900 43,400 9: 1 120 1,900 Comparative Example 1 Polymer a 23,900 64,100 9: 1 100 100

Referring to the results of Table 1, it can be seen that Examples 1 to 6 using the polymer according to one embodiment as a material of the hole transport layer have improved luminous efficiency and luminescence lifetime of the organic light emitting device as compared with Comparative Example 1.

As can be seen from the above results, the polymer according to one embodiment can be efficiently formed by the solution coating method, and the luminous efficiency and the luminescence lifetime of the organic light emitting device can be improved.

As described above, it is possible to provide a polymer in which a polymerizable monomer containing a specific condensed ring structure contains repeating repeating units. Such polymers are useful as hole injecting and transporting materials, and have excellent solubility, high thermal stability, and high film uniformity suitable for solution processing. When the organic layer is formed using the polymer according to one embodiment, it can be provided as a coating type organic light emitting device material which is excellent in light emitting efficiency, light emission life time, and device characteristics and can be laminated by a coating method.

Further, since the polymer according to one embodiment can be synthesized by radical polymerization, the polymer can be easily produced compared with the organic light emitting element material using condensation polymerization. Further, the application range of the polymer of the present invention is not limited to the field of organic light emitting devices, and can be used in a wide range of fields that can be used as a charge transport layer.

While the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the scope of the present invention is not limited to the above embodiments. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

100: Organic light emitting device
110: substrate
120: first electrode
130: Hole injection layer
140: hole transport layer
150: light emitting layer
160: electron transport layer
170: electron injection layer
180: second electrode

Claims (20)

1. A polymer comprising a repeating unit represented by the following formula (1): < EMI ID =
&Lt; Formula 1 &gt;

In Formula 1,
R ₁ , R ₂ and R ₃ are, independently of each other, hydrogen, deuterium, fluorine; An alkylsilyl group having 1 to 10 carbon atoms; An arylsilyl group having 6 to 30 carbon atoms; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted C6 to C30 aryl; And a substituted or unsubstituted C1 to C30 heteroaryl group,
L is a single bond; A substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted cycloalkylene group having 5 to 30 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms, provided that it is not a substituted or unsubstituted carbazolylene group,
A ₁ and A ₂ are, independently of each other, a single bond; Oxygen atom; Sulfur atom; A substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms,
A ₃ is a substituted or unsubstituted, tricyclic alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted tricyclic aryl group having 6 to 30 carbon atoms; And a substituted or unsubstituted trivalent heteroaryl group having 1 to 30 carbon atoms,
A ₄ and A ₅ independently represent a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; A substituted or unsubstituted arylene group having 6 to 30 carbon atoms; And a substituted or unsubstituted heteroarylene group having 1 to 30 carbon atoms,
m is an integer of 1 to 10; The polymer according to claim 1, wherein the repeating unit represented by the formula (1) is represented by the following formula (2):
(2)

In Formula 2,
R ₁ , R ₂ , R ₃ , L, A ₁ , A ₂ and m are as defined in claim 1,
W ₁ to W ₁₁ are, independently of each other, N or CX,
X is hydrogen; heavy hydrogen; An alkylsilyl group having 1 to 10 carbon atoms; An arylsilyl group having 6 to 30 carbon atoms; An alkylamino group having 1 to 10 carbon atoms; An arylamino group having 6 to 60 carbon atoms; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted C6 to C30 aryl; And a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms. The polymer of claim 1, wherein the polymer comprises a first unit represented by Formula 1 and a second unit represented by Formula 1,
Wherein the structure of the first unit and the structure of the second unit are different from each other. 2. The compound of claim 1, wherein L is a single bond; A substituted or unsubstituted arylene group having 6 to 15 carbon atoms; And a substituted or unsubstituted heteroarylene group having 5 to 15 carbon atoms, and is not a substituted or unsubstituted carbazolylene group. 2. The compound of claim 1, wherein L is a single bond; A substituted or unsubstituted phenylene group; A substituted or unsubstituted naphthylene group; And a substituted or unsubstituted fluorenyl group. 2. The polymer of claim 1, wherein A &lt; ₁ &gt; and A &lt; ₂ &gt; _2. A compound according to claim 1, wherein A &lt; ₁ &gt; and A &lt; ₂ &gt; Oxygen atom; And a sulfur atom. The polymer according to claim 1, wherein W ₁ to W ₁₁ are each CX. 2. The compound of claim 1, wherein X is independently from each other hydrogen; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted arylamino group having 6 to 30 carbon atoms; And a substituted or unsubstituted aryl group having 6 to 15 carbon atoms. 2. The compound according to claim 1, wherein X is Hydrogen; A substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; A substituted or unsubstituted phenyl group; A substituted or unsubstituted biphenyl group; A substituted or unsubstituted terphenyl group; A substituted or unsubstituted fluorenyl group; A substituted or unsubstituted spirobifluorenyl group; A substituted or unsubstituted arylamino group having 6 to 30 carbon atoms; And a substituted or unsubstituted triarylamino group having 6 to 30 carbon atoms. The polymer of claim 1, wherein m is 1, 2 or 3. The polymer of claim 1, wherein the polymer further comprises a crosslinker. 12. The polymer of claim 11, wherein the crosslinker is selected from the group consisting of:

Among these structures,
R ₄ to R ₁₀ are hydrogen; Or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms,
p is an integer of 1 to 10; The copolymer according to claim 1, wherein the number average molecular weight of the polymer is 10,000 to 100,000. The copolymer according to claim 1, wherein the polymer has a polydispersity index of 1.5 to 2.5. A first electrode; A second electrode; And an organic layer interposed between the first electrode and the second electrode;
Wherein the organic layer comprises the polymer of any one of claims 1 to 15. The organic light emitting device according to claim 16, wherein at least one of the organic layers is a hole transport layer containing the copolymer. The organic light emitting device according to claim 16, wherein at least one of the organic layers is a light emitting layer including a light emitting material capable of emitting triplet excitons. 15. An organic light emitting device material comprising a polymer according to any one of claims 1 to 15. 20. The organic electroluminescent device material according to claim 19, further comprising a solvent.

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