KR102576153B1 - Novel copolymer and organic light emitting device comprising the same - Google Patents

Abstract

The present invention provides a novel copolymer and an organic light emitting device using the same.

Description

Novel copolymer and organic light emitting device comprising the same {Novel copolymer and organic light emitting device comprising the same}

The present invention relates to a novel copolymer and an organic light emitting device including the same.

In general, the organic light emitting phenomenon refers to a phenomenon in which electrical energy is converted into light energy using an organic material. An organic light emitting device using an organic light emitting phenomenon has a wide viewing angle, excellent contrast, and a fast response time, and has excellent luminance, driving voltage, and response speed characteristics, and thus many studies are being conducted.

An organic light emitting device generally has a structure including an anode, a cathode, and an organic material layer between the anode and the cathode. In order to increase the efficiency and stability of the organic light emitting device, the organic material layer is often composed of a multi-layered structure composed of different materials, and may include, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. In the structure of this organic light emitting device, when a voltage is applied between the two electrodes, holes are injected from the anode and electrons from the cathode are injected into the organic material layer, and when the injected holes and electrons meet, excitons are formed. When it falls back to the ground state, it glows.

The development of new materials for organic materials used in the organic light emitting device as described above is continuously required.

Meanwhile, in recent years, an organic light emitting device using a solution process, particularly an inkjet process, instead of a conventional deposition process has been developed to reduce process costs. In the early days, an attempt was made to develop an organic light emitting device by coating all organic light emitting device layers with a solution process, but the current technology has limitations, so only HIL, HTL, and EML in the form of a regular structure are carried out as a solution process, and the subsequent process is the existing deposition process A hybrid process that utilizes is being studied.

Accordingly, the present invention provides a novel material for an organic light emitting device that can be used for an organic light emitting device and can be deposited in a solution process at the same time.

Korean Patent Publication No. 10-2000-0051826

The present invention relates to a novel copolymer and an organic light emitting device including the same.

The present invention provides a copolymer comprising a repeating unit represented by Formula 1 below and a repeating unit represented by Formula 2 below:

[Formula 1]

In Formula 1,

R ₁ to R ₃ are each independently hydrogen or C _1-10 alkyl;

L ₁ is a single bond; Substituted or unsubstituted C _6-60 arylene; Or a C _2-60 heteroarylene containing at least one selected from the group consisting of substituted or unsubstituted N, O and S,

Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted C _6-60 aryl; Or a C _2-60 heteroaryl containing at least one selected from the group consisting of substituted or unsubstituted N, O and S, provided that Ar ₁ and Ar ₂ are different from each other,

[Formula 2]

In Formula 2,

R ₄ to R ₆ are each independently hydrogen or C _1-10 alkyl;

L ₂ is a substituted or unsubstituted C _6-60 arylene; Or a C _2-60 heteroarylene containing at least one selected from the group consisting of substituted or unsubstituted N, O and S,

x and y are each independently an integer from 1 to 100;

In addition, the present invention is a positive electrode; a cathode provided to face the anode; a light emitting layer provided between the anode and the cathode; and a hole transport layer provided between the anode and the light emitting layer, wherein the hole transport layer includes the copolymer.

The copolymer according to the present invention can be used as a material for a hole transport layer of an organic light emitting device, can be deposited by a solution process, and can improve efficiency, low driving voltage and/or lifetime characteristics in an organic light emitting device. .

1 shows an example of an organic light emitting device including a substrate 1, an anode 2, a hole transport layer 3, a light emitting layer 4, and a cathode 5.
2 is composed of a substrate (1), an anode (2), a hole injection layer (6), a hole transport layer (3), a light emitting layer (4), an electron transport layer (7), an electron injection layer (8) and a cathode (5). An example of an organic light emitting device is shown.
3 shows NMR data of a copolymer according to an embodiment of the present invention.
4 shows GPC data of a copolymer according to an embodiment of the present invention.
5 shows solvent resistance of a copolymer according to an embodiment of the present invention. The left two data of FIG. 5A are the data of the copolymer of Example 1, and the right two data are the data of the copolymer of Example 2. The left two of FIG. 5B are the data of the copolymer of Example 3, and the right two are the data of the copolymer of Example 4.

Hereinafter, in order to aid understanding of the present invention, it will be described in more detail.

또는

는 다른 치환기에 연결되는 결합을 의미한다. In this specification,

or

means a bond connected to another substituent.

In this specification, the term "substituted or unsubstituted" means deuterium; halogen group; nitrile group; nitro group; hydroxy group; carbonyl group; ester group; imide group; amino group; phosphine oxide group; alkoxy group; aryloxy group; Alkyl thioxy group; Arylthioxy group; an alkyl sulfoxy group; aryl sulfoxy groups; silyl group; boron group; an alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; Aralkenyl group; Alkyl aryl group; Alkylamine group; Aralkylamine group; heteroarylamine group; Arylamine group; Arylphosphine group; Or substituted or unsubstituted with one or more substituents selected from the group consisting of a heterocyclic group containing at least one of N, O, and S atoms, or substituted or unsubstituted with two or more substituents linked to each other among the substituents exemplified above. . For example, "a substituent in which two or more substituents are connected" may be a biphenyl group. That is, the biphenyl group may be an aryl group, and may be interpreted as a substituent in which two phenyl groups are connected.

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

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

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

In the present specification, the silyl group is specifically a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, and the like. but not limited to

In the present specification, the boron group specifically includes a trimethyl boron group, a triethyl boron group, a t-butyldimethyl boron group, a triphenyl boron group, a phenyl boron group, but is not limited thereto.

In this specification, examples of the halogen group include fluorine, chlorine, bromine or iodine.

In the present specification, the alkyl group may be straight-chain or branched-chain, and the number of carbon atoms is not particularly limited, but is preferably 1 to 40. According to one embodiment, the number of carbon atoms of the alkyl group is 1 to 20. According to another exemplary embodiment, the number of carbon atoms of the alkyl group is 1 to 10. According to another exemplary embodiment, the alkyl group has 1 to 6 carbon atoms. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n -pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl , n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2 -Dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, etc., but is 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 alkenyl group has 2 to 20 carbon atoms. According to another exemplary embodiment, the alkenyl group has 2 to 10 carbon atoms. According to another exemplary embodiment, the alkenyl group has 2 to 6 carbon atoms. Specific examples include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1- Butenyl, 1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-( naphthyl-1-yl)vinyl-1-yl, 2,2-bis(diphenyl-1-yl)vinyl-1-yl, stilbenyl group, styrenyl group, etc., but is not limited thereto.

In the present specification, the cycloalkyl group is not particularly limited, but preferably has 3 to 60 carbon atoms, and according to an exemplary embodiment, the cycloalkyl group has 3 to 30 carbon atoms. According to another exemplary embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 20. According to another exemplary embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 6. Specifically, 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, but are not limited thereto.

In the present specification, the aryl group is not particularly limited, but preferably has 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the number of carbon atoms of the aryl group is 6 to 30. According to one embodiment, the number of carbon atoms of the aryl group is 6 to 20. The aryl group may be a phenyl group, a biphenyl group, a terphenyl group, etc. as a monocyclic aryl group, but is not limited thereto. The polycyclic aryl group may be a naphthyl group, anthracenyl group, phenanthryl group, pyrenyl group, perylenyl group, chrysenyl group, fluorenyl group, and the like, but is not limited thereto.

등이 될 수 있다. 다만, 이에 한정되는 것은 아니다.In the present specification, the fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spiro structure. When the fluorenyl group is substituted,

etc. However, it is not limited thereto.

In the present specification, the heterocyclic group is a heterocyclic group containing at least one of O, N, Si, and S as heterogeneous elements, and the number of carbon atoms is not particularly limited, but preferably has 2 to 60 carbon atoms. Examples of the heterocyclic group include a thiophene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazine group, and an acridyl group. , pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyrazinyl group, pyrazinopyrazinyl group, isoquinoline group, indole group , carbazole group, benzoxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, isoxazolyl group, thiadia A zolyl group, a phenothiazinyl group, and a dibenzofuranyl group, but are not limited thereto.

In the present specification, an aralkyl group, an aralkenyl group, an alkylaryl group, and an aryl group among arylamine groups are the same as the examples of the aryl group described above. In the present specification, the alkyl group among the aralkyl group, the alkylaryl group, and the alkylamine group is the same as the examples of the above-mentioned alkyl group. In the present specification, the description of the heterocyclic group described above may be applied to the heteroaryl of the heteroarylamine. In the present specification, the alkenyl group among the aralkenyl groups is the same as the examples of the alkenyl group described above. In the present specification, the description of the aryl group described above may be applied except that the arylene is a divalent group. In the present specification, the description of the heterocyclic group described above may be applied except that the heteroarylene is a divalent group. In the present specification, the hydrocarbon ring is not a monovalent group, and the description of the aryl group or cycloalkyl group described above may be applied, except that the hydrocarbon ring is formed by combining two substituents. In the present specification, the heterocyclic group is not a monovalent group, and the description of the above-described heterocyclic group may be applied, except that it is formed by combining two substituents.

The present invention provides a copolymer including a repeating unit represented by Chemical Formula 1 and a repeating unit represented by Chemical Formula 2 above.

A conventionally used material for solution deposition has a problem in that, even if it has solubility in a solvent, the material is dissolved in a solvent used for deposition of the next layer, and the layer is mixed to deteriorate device performance.

However, as will be described in detail below, the copolymer according to the present invention has excellent hole transport properties by the repeating unit represented by Chemical Formula 1 and solvent orthogonality by curing the repeating unit represented by Chemical Formula 2 after deposition. ), which has the characteristic of suppressing interlayer mixing.

In the present specification, the 'first repeating unit' is a repeating unit represented by Chemical Formula 1 included in the copolymer according to the present invention, and has excellent hole transport properties.

Preferably, R ₁ to R ₃ are each independently hydrogen or methyl, more preferably all are hydrogen.

이다. Preferably, L ₁ is a single bond, or

am.

Preferably, Ar ₁ and Ar ₂ are each independently phenyl, biphenylyl, or dimethylfluorenyl.

Preferably, Ar ₁ is biphenylyl and Ar ₂ is dimethylfluorenyl.

Preferably, Formula 1 is a repeating unit represented by any one of the following:

Meanwhile, the compound represented by Formula 1 is derived from a monomer represented by Formula 1-1 below:

[Formula 1-1]

In Formula 1-1, R ₁ to R ₃ , L ₁ , Ar ₁ and Ar ₂ are as defined in Formula 1 above.

In the present specification, the 'second repeating unit' is a repeating unit represented by Chemical Formula 2 included in the copolymer according to the present invention, and includes a curable reactive group. By depositing and then curing the copolymer according to the present invention to make the deposited copolymer have solvent resistance, it can be applied to an organic light emitting device through a solution process.

Preferably, R ₄ to R ₆ are each independently hydrogen or methyl, more preferably all hydrogen.

Preferably, L ₂ is biphenyldiyl, more preferably biphenylyl-4,4'-diyl.

Preferably, Formula 2 is represented by

Meanwhile, the compound represented by Formula 2 is derived from a monomer represented by Formula 2-1 below:

[Formula 2-1]

In Formula 2-1, R ₄ to R ₆ , and L ₂ are as defined in Formula 2 above.

(copolymer)

The copolymer according to the present invention may be prepared by polymerizing the monomer represented by Chemical Formula 1-1 and the monomer represented by Chemical Formula 2-1. Preferably, the copolymer according to the present invention is a random copolymer including the repeating unit.

In the polymer according to the present invention, x and y are the molar ratios of the repeating unit of Formula 1 and the repeating unit of Formula 2 in the copolymer, the monomer represented by Formula 1-1, and the repeating unit of Formula 2-1 By adjusting the reaction molar ratio of the monomers to be, it is possible to control the molar ratio of the polymer. Preferably, the ratio of x:y is 70 to 90:1 to 30.

Preferably, the copolymer has a weight average molecular weight of 5,000 to 100,000.

(coating composition)

The copolymer according to the present invention can form an organic material layer, particularly a hole transport layer, of an organic light emitting device through a solution process. To this end, the present invention provides a coating composition comprising the above-described copolymer and a solvent according to the present invention.

The solvent is not particularly limited as long as it can dissolve or disperse the copolymer according to the present invention, and examples thereof include chloroform, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, chlorine-based solvents such as o-dichlorobenzene; ether solvents such as tetrahydrofuran and dioxane; aromatic hydrocarbon solvents such as toluene, xylene, trimethylbenzene, and mesitylene; aliphatic hydrocarbon-based solvents such as cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; Ketone solvents, such as acetone, methyl ethyl ketone, and cyclohexanone; Ester solvents, such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate; Ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethoxyethane, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, 1,2-hexanediol, etc. alcohol and its derivatives; alcohol solvents such as methanol, ethanol, propanol, isopropanol, and cyclohexanol; sulfoxide solvents such as dimethyl sulfoxide; and amide solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide; benzoate solvents such as butyl benzoate and methyl-2-methoxy benzoate; tetralin; and solvents such as 3-phenoxy-toluene. In addition, the above-mentioned solvent may be used alone or in combination of two or more solvents.

In addition, the viscosity of the coating composition is preferably 1 cP to 10 cP, and coating is easy within the above range. In addition, the concentration of the copolymer according to the present invention in the coating composition is preferably 0.1 wt / v% to 20 wt / v%.

In addition, the present invention provides a method of forming a hole transport layer using the coating composition described above. Specifically, coating the coating composition according to the present invention described above by a solution process on the anode or on the hole injection layer formed on the anode; and heat-treating the coated coating composition.

The solution process uses the above-described coating composition according to the present invention, and includes spin coating, dip coating, doctor blading, inkjet printing, screen printing, spraying, roll coating, etc., but is not limited thereto.

In the heat treatment step, the heat treatment temperature is preferably 150 to 230 °C. In addition, the heat treatment time is 1 minute to 3 hours, more preferably 10 minutes to 1 hour. In addition, the heat treatment is preferably performed in an inert gas atmosphere such as argon or nitrogen. In addition, a step of evaporating a solvent may be further included between the coating step and the heat treatment or light treatment step.

(organic light emitting element)

In addition, the present invention provides an organic light emitting device comprising the copolymer according to the present invention described above. Specifically, the present invention is a positive electrode; a cathode provided to face the anode; a light emitting layer provided between the anode and the cathode; and a hole transport layer provided between the anode and the light emitting layer, wherein the hole transport layer includes the copolymer according to the present invention.

The structure of an organic light emitting device according to an embodiment of the present invention is illustrated in FIGS. 1 and 2 .

1 shows an example of an organic light emitting device including a substrate 1, an anode 2, a hole transport layer 3, a light emitting layer 4, and a cathode 5. 2 is composed of a substrate (1), an anode (2), a hole injection layer (6), a hole transport layer (3), a light emitting layer (4), an electron transport layer (7), an electron injection layer (8) and a cathode (5). An example of an organic light emitting device is shown.

The organic light emitting device according to the present invention may be manufactured using materials and methods known in the art, except that the hole transport layer includes the copolymer according to the present invention and is manufactured as described above.

For example, the organic light emitting device according to the present invention may be manufactured by sequentially stacking an anode, an organic material layer, and a cathode on a substrate. At this time, using a physical vapor deposition (PVD) method such as sputtering or e-beam evaporation, depositing a metal or a metal oxide having conductivity or an alloy thereof on the substrate to form an anode After forming an organic material layer including a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer thereon, and depositing a material that can be used as a cathode thereon, it can be prepared.

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

As the anode material, a material having a high work function is generally preferred so that holes can be smoothly injected into the organic layer. Specific examples of the cathode material include metals such as vanadium, chromium, copper, zinc, and gold or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SNO ₂ :Sb; Conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but are not limited thereto.

The cathode material is preferably a material having a small work function so as to easily inject electrons into the organic material layer. Specific examples of the anode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; There are multi-layered materials such as LiF/Al or LiO ₂ /Al, but are not limited thereto.

The hole injection layer is a layer for injecting holes from the electrode, and the hole injection material has the ability to transport holes and has a hole injection effect at the anode, an excellent hole injection effect for the light emitting layer or the light emitting material, and generated in the light emitting layer A compound that prevents migration of excitons to the electron injecting layer or electron injecting material and has excellent thin film formation ability is preferred. It is preferable that the highest occupied molecular orbital (HOMO) of the hole injection material is between the work function of the anode material and the HOMO of the surrounding organic layer. Specific examples of the hole injection material include metal porphyrins, oligothiophenes, arylamine-based organic materials, hexanitrilehexaazatriphenylene-based organic materials, quinacridone-based organic materials, and perylene-based organic materials. of organic matter, anthraquinone, and polyaniline and polythiophene-based conductive polymers, but are not limited thereto.

The light emitting material is a material capable of emitting light in the visible ray region by receiving and combining holes and electrons from the hole transport layer and the electron transport layer, respectively, and a material having good quantum efficiency for fluorescence or phosphorescence is preferable. Specific examples include 8-hydroxy-quinoline aluminum complex (Alq ₃ ); carbazole-based compounds; dimerized styryl compounds; BAlq; 10-hydroxybenzoquinoline-metal compounds; compounds of the benzoxazole, benzthiazole and benzimidazole series; poly(p-phenylenevinylene) (PPV)-based polymers; spiro compounds; Polyfluorene, rubrene, etc., but are not limited thereto.

The light emitting layer may include a host material and a dopant material. The host material includes a condensed aromatic ring derivative or a compound containing a hetero ring. Specifically, condensed aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, etc., and heterocyclic-containing compounds include carbazole derivatives, dibenzofuran derivatives, ladder type furan compounds, pyrimidine derivatives, etc., but are not limited thereto.

Dopant materials include aromatic amine derivatives, strylamine compounds, boron complexes, fluoranthene compounds, metal complexes, and the like. Specifically, aromatic amine derivatives are condensed aromatic ring derivatives having a substituted or unsubstituted arylamino group, such as pyrene, anthracene, chrysene, periplanthene, etc. having an arylamino group, and styrylamine compounds include substituted or unsubstituted arylamine is substituted with at least one arylvinyl group, wherein one or two or more substituents selected from the group consisting of an aryl group, a silyl group, an alkyl group, a cycloalkyl group, and an arylamino group are substituted or unsubstituted. Specifically, there are styrylamine, styryldiamine, styryltriamine, styryltetraamine, etc., but is not limited thereto. In addition, metal complexes include, but are not limited to, iridium complexes and platinum complexes.

The electron transport layer is a layer that receives electrons from the electron injection layer and transports electrons to the light emitting layer. As the electron transport material, a material capable of receiving electrons from the cathode and transferring them to the light emitting layer is suitable. do. Specific examples include Al complexes of 8-hydroxyquinoline; Complexes containing Alq ₃ ; organic radical compounds; hydroxyflavone-metal complexes and the like, but are not limited thereto. The electron transport layer can be used with any desired cathode material as used according to the prior art. In particular, examples of suitable cathode materials are conventional materials having a low work function followed by a layer of aluminum or silver. Specifically cesium, barium, calcium, ytterbium and samarium, followed in each case by a layer of aluminum or silver.

The electron injection layer is a layer for injecting electrons from an electrode, has the ability to transport electrons, has an excellent electron injection effect from a cathode, an excellent electron injection effect for a light emitting layer or a light emitting material, and injects holes of excitons generated in the light emitting layer. A compound that prevents migration to a layer and has excellent thin film forming ability is preferred. Specifically, fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, preonylidene methane, anthrone, etc. and their derivatives, metals complex compounds and nitrogen-containing 5-membered ring derivatives, but are not limited thereto.

Examples of the metal complex compound include 8-hydroxyquinolinato lithium, bis(8-hydroxyquinolinato)zinc, bis(8-hydroxyquinolinato)copper, bis(8-hydroxyquinolinato)manganese, Tris(8-hydroxyquinolinato) aluminum, tris(2-methyl-8-hydroxyquinolinato) aluminum, tris(8-hydroxyquinolinato) gallium, bis(10-hydroxybenzo[h] Quinolinato) beryllium, bis(10-hydroxybenzo[h]quinolinato)zinc, bis(2-methyl-8-quinolinato)chlorogallium, bis(2-methyl-8-quinolinato)( There are o-cresolato) gallium, bis(2-methyl-8-quinolinato)(1-naphtolato)aluminum, and bis(2-methyl-8-quinolinato)(2-naphtolato)gallium. Not limited to this.

The organic light emitting device according to the present invention may be a top emission type, a bottom emission type, or a double side emission type depending on the material used.

In addition, the copolymer according to the present invention may be included in an organic solar cell or an organic transistor in addition to an organic light emitting device.

Preparation of the copolymer and the organic light emitting device including the copolymer according to the present invention will be described in detail in the following examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

Example One

Compound 1-1 (0.5 g, 0.93 mmol), compound 1-2 (0.2 g, 0.72 mmol), and AIBN (5.0 mg, 0.03 mmol) were put in a schlenk flask, dissolved in THF (1.5 ml), and freeze-evacuated. -thaw was repeated 3 times and stirred at 60 °C for 17 hours. After completion of the reaction, the solution was poured into methanol to precipitate and a copolymer was obtained. The copolymer obtained by filtration was stored overnight in a vacuum oven. After dissolving the obtained copolymer in THF (10 ml) at 0° C., TBAF (5 ml) was added and stirred for 3 hours, then water was added to terminate the reaction and precipitated in methanol. After removing the remaining monomers with an adsorption column (Hex:MC=8:2), evaporation of the obtained copolymer solution by flowing THF, precipitating in methanol, filtration, and drying in a vacuum oven to obtain a copolymer. Through 1H NMR and GPC analysis, whether the copolymer was polymerized, the block ratio of the copolymer, molecular weight and molecular weight distribution were confirmed.

Example 2

It was prepared in the same manner as in Example 1, but using 0.05 g of Compound 1-2 to obtain a copolymer.

Example 3

It was prepared in the same manner as in Example 1, but using 0.5 g of Compound 3-1 instead of Compound 1-1 and 0.05 g of Compound 1-2 to obtain a copolymer.

Example 4

It was prepared in the same manner as in Example 3, but using 0.2 g of Compound 1-2 to obtain a copolymer.

[ Experimental example ]

Experimental example One

Through 1H NMR and GPC analysis of the previously prepared copolymer, whether the copolymer was polymerized, the block ratio of the copolymer, molecular weight and molecular weight distribution were confirmed. Specifically, 1H NMR is shown in FIG. 3, and GPC analysis results are shown in FIG. In addition, based on the integration value of the ethynyl proton peak, the wt% of the block containing the ethynyl group in each copolymer was calculated and shown in Table 1 below.

Mn Mw Mw/Mn m:n (mol %) m:n (wt%) Example 1 22,000 47,000 2.17 57:43 78:22 Example 2 23,000 43,000 1.85 84:16 93:7 Example 3 26,000 47,000 1.80 75:25 92:8 Example 4 28,000 62,000 2.24 48:52 78:22

Experimental example 2

Solvent resistance of the prepared copolymer was evaluated using toluene and cyclohexanone.

Specifically, after preparing a solution in which the prepared copolymer was dissolved in toluene at 2 wt%, it was coated on a quartz substrate to a thickness of 100 nm by spin coating. Thereafter, after heat treatment at 190 to 200 ° C. for 1 hour in a nitrogen atmosphere, UV-Vis absorption spectrum was measured. Subsequently, the same sample was immersed in toluene or cyclohexanone for 10 minutes, then taken out, and the UV-Vis absorption spectrum was measured again after the solvent was dried.

The measurement results are shown in FIG. 5 . As shown in FIG. 5, the film retention rate was 100% for all cyclohexanone, and the film retention rate was also high for toluene.

Experimental example 3

A glass substrate coated with indium tin oxide (ITO) to a thickness of 1,500 Å was put in distilled water in which detergent was dissolved and washed with ultrasonic waves. At this time, a product of Fischer Co. was used as a detergent, and distilled water filtered through a second filter of a product of Millipore Co. was used as distilled water. After washing the ITO for 30 minutes, ultrasonic cleaning was performed twice with distilled water for 10 minutes. After washing with distilled water, ultrasonic cleaning was performed with solvents such as isopropyl and acetone, and after drying, the substrate was cleaned for 5 minutes and transported to a glove box.

A coating composition was prepared by dissolving the following VNBP compound as a host of the hole injection layer and the following IB compound as a dopant of the hole injection layer in a solvent (cyclohexanone). The ratio of the host and the dopant of the hole injection layer was mixed at a weight ratio of 8:2. The prepared hole injection layer mixture was spin-coated to a thickness of 400 Å on the previously prepared ITO substrate and cured at 230° C. for 30 minutes under an Ar atmosphere to form a hole injection layer. Thereafter, as shown in Table 1 below, on the hole injection layer, the copolymer prepared in the previous example was dissolved in toluene at 1.0 wt/v% and spin-coated to form a film with a thickness of 200 Å and heated at 200 ° C. for 1 hour under a nitrogen atmosphere. A hole transport layer was formed. Subsequently, a toluene solution containing the following HOST compound and a DOPANT compound in a weight ratio of 94:6 was spin-coated to 200 Å on the hole transport layer, and heated at 120° C. for 10 minutes under a nitrogen atmosphere to form a light emitting layer. An electron injection and transport layer was formed by vacuum depositing the following ETL compound on the light emitting layer to a thickness of 200 Å. A cathode was formed by sequentially depositing LiF to a thickness of 10 Å and aluminum to a thickness of 1000 Å on the electron injection and transport layer.

In the above process, the deposition rate of the organic material was maintained at 0.4 to 0.7 Å/sec, the deposition rate of LiF of the cathode was 0.3 Å/sec, and the deposition rate of aluminum was 2 Å/sec, and the vacuum degree during deposition was 2×10 ^-7 to 5×10 ^-8 torr was maintained. Thereafter, sealing was performed by bonding the sealing glass and the glass substrate to the glass using a photocurable epoxy resin, thereby producing an organic light emitting element having a multilayer structure. Subsequent operations were performed in the air at room temperature (25°C).

Driving voltage, efficiency, QE, and color coordinates of the prepared organic light emitting device were measured at a current density of 10 mA/cm ² and are shown in Table 2 below.

hole
transport layer Voltage
(V) efficiency
(Cd/A) lm/W QE
(%) Cd/ ^m2 CIEx CIEy Example 1 5.39 0.67 0.37 0.59 67.01 0.174 0.169 Example 2 4.75 2.25 1.49 2.59 224.77 0.146 0.109 Example 3 4.31 3.83 2.79 4.95 382.68 0.140 0.094 Example 4 5.19 1.06 0.64 1.15 106.16 0.152 0.119

1: substrate 2: anode
3: hole transport layer 4: light emitting layer
5: cathode 6: hole injection layer
7: electron transport layer 8: electron injection layer

Claims (9)

A copolymer comprising a repeating unit represented by Formula 1 below and a repeating unit represented by Formula 2 below:
[Formula 1]

In Formula 1,
R ₁ to R ₃ are each independently hydrogen or C _1-10 alkyl;
L ₁ is ego,
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted C _6-60 aryl; Or a C _2-60 heteroaryl containing at least one selected from the group consisting of substituted or unsubstituted N, O and S, provided that Ar ₁ and Ar ₂ are different from each other,
[Formula 2]

In Formula 2,
R ₄ to R ₆ are each independently hydrogen or C _1-10 alkyl;
L ₂ is a substituted or unsubstituted C _6-60 arylene; Or a C _2-60 heteroarylene containing at least one selected from the group consisting of substituted or unsubstituted N, O and S,
x and y are each independently an integer from 1 to 100;
delete According to claim 1,
Ar ₁ and Ar ₂ are each independently phenyl, biphenylyl, or dimethylfluorenyl;
copolymer.
According to claim 1,
Ar ₁ is biphenylyl;
Ar ₂ is dimethylfluorenyl;
copolymer.
According to claim 1,
Formula 1 is represented by
Copolymer:

According to claim 1,
L ₂ is biphenyldiyl;
copolymer.
According to claim 1,
Formula 2 is represented by
Copolymer:

According to claim 1,
The weight average molecular weight of the copolymer is 5,000 to 100,000,
copolymer.
anode; a cathode provided to face the anode; a light emitting layer provided between the anode and the cathode; and a hole transport layer provided between the anode and the light emitting layer, wherein the hole transport layer includes the copolymer according to any one of claims 1 and 3 to 8.