Organic light-emitting element

Abstract

The present invention provides an organic light-emitting device.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2020 - 0098674 filed on August 6, 2020 and Korean Patent Application No. 10 - 2021 - 0098389 filed on July 27, 2021, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification. The present invention relates to an organic light - emitting device.

Background Art

[0002] Generally, the organic light - emitting phenomenon refers to the phenomenon of converting electrical energy into light energy using organic substances. Organic light - emitting devices using the organic light - emitting phenomenon have a wide viewing angle, excellent contrast, and fast response time, and many studies are being conducted due to their excellent luminance, driving voltage, and response speed characteristics.

[0003] An organic light - emitting device generally has a structure including a positive electrode, a negative electrode, and an organic layer between the positive electrode and the negative electrode. The organic layer often has a multi - layer structure composed of different substances in order to improve the efficiency and safety of the organic light - emitting device. For example, it may consist of a hole injection layer, a hole transport layer, a light - emitting layer, an electron transport layer, an electron injection layer, etc. In such a structure of an organic light - emitting device, when a voltage is applied between the two electrodes, holes are injected into the organic layer from the positive electrode and electrons are injected from the negative electrode. When the injected holes and electrons come into contact, an exciton is formed, and when this exciton falls back to the ground state again, light is emitted.

[0004] There has been a continuous demand for the development of new materials for the organic substances used in such organic light - emitting devices.

[0005] On the one hand, recently, in order to reduce process costs, organic light-emitting devices that use solution processes, particularly inkjet processes, instead of existing vapor deposition processes have been developed. In the early days, attempts were made to develop organic light-emitting devices by coating all organic light-emitting device layers using solution processes. However, there are limitations with current technology, and a hybrid process that performs only the HIL, HTL, and EML using solution processes and then utilizes the existing vapor deposition process for subsequent processes is under research.

[0006] Therefore, the present invention provides a novel material for an organic light-emitting device that is used in an organic light-emitting device and can be used in a solution process, and an organic light-emitting device using the same.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention is to provide an organic light-emitting device.

Means for Solving the Problems

[0009] To solve the above problems, the present invention provides an organic light-emitting device including a positive electrode, a negative electrode, a light-emitting layer between the positive electrode and the negative electrode, and a hole transport layer between the positive electrode and the light-emitting layer, wherein the hole transport layer includes a polymer including a repeating unit represented by the following Chemical Formula 1 and an ionic compound including an anion group represented by the following Chemical Formula 2:

Chemical Formula

[0010] The organic light-emitting device according to the present invention can manufacture a hole transport layer in a solution process, and can also improve the efficiency, lower driving voltage, and / or lifetime characteristics of the organic light-emitting device. [Brief Description of the Drawings]

[0011]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0012] Hereinafter, it will be described in more detail to assist in understanding the present invention.

[0013] (Definition of Terms) In this specification,

Chem.

Chem.

[0014] In this specification, the term "substituted or unsubstituted" means being substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium; a halogen group; a cyano group; a nitro group; a hydroxy group; a carbonyl group; an ester group; an imide group; an amino group; a phosphine oxide group; an alkoxy group; an aryloxy group; an alkylthioxy group; an arylthioxy group; an alkylsulfinyl group; an arylsulfinyl group; a silyl group; a boron group; an alkyl group; a cycloalkyl group; an alkenyl group; an aryl group; an aralkyl group; an aralkenyl group; an alkylaryl group; an alkylamine group; an aralkylamine group; a heteroarylamine group; an arylamine group; an arylphosphine group; or a heteroaryl containing one or more of N, O, and S atoms, or being substituted or unsubstituted with a substituent in which two or more of the exemplified substituents are linked. For example, the "substituent in which two or more substituents are linked" may be a biphenyl group. That is, the biphenyl group may be an aryl group and may also be interpreted as a substituent in which two phenyl groups are linked.

[0015] In this specification, the number of carbon atoms in the carbonyl group is not particularly limited, but it is preferably 1 to 40. Specifically, compounds having the following structures may be used, but are not limited thereto.

Chem.

[0016] In this specification, the oxygen atom of the ester group in 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, compounds having the following structural formulas may be used, but are not limited thereto.

Chem.

[0017] In this specification, the number of carbon atoms in the imide group is not particularly limited, but it is preferably 1 to 25. Specifically, compounds having the following structures may be used, but are not limited thereto.

Chem.

[0018] In this specification, specific examples of the silyl group include, but are not limited to, trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group, vinyldimethylsilyl group, propyldimethylsilyl group, triphenylsilyl group, diphenylsilyl group, phenylsilyl group, etc.

[0019] In this specification, specific examples of the boron group include, but are not limited to, trimethylboron group, triethylboron group, t-butyldimethylboron group, triphenylboron group, phenylboron group, etc.

[0020] In this specification, examples of the halogen group include fluorine, chlorine, bromine, or iodine.

[0021] In this 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 number of carbon atoms of the alkyl group is 1 to 20. According to yet another embodiment, the number of carbon atoms of the alkyl group is 1 to 10. According to yet another embodiment, the number of carbon atoms of the alkyl group is 1 to 6. 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 are not limited thereto.

[0022] In this 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 yet another embodiment, the number of carbon atoms of the alkenyl group is 2 to 10. According to yet another embodiment, the number of carbon atoms of the alkenyl group is 2 to 6. 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 are not limited thereto.

[0023] In this specification, the cycloalkyl group is not particularly limited, but the number of carbon atoms is preferably 3 to 60. According to one embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 30. According to yet another embodiment, the number of carbon atoms of the cycloalkyl group is 3 to 20. According to yet another 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, etc., but are not limited thereto.

[0024] In this 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 aryl group has 6 to 30 carbon atoms. According to one embodiment, the aryl group has 6 to 20 carbon atoms. Examples of the monocyclic aryl group may include, but are not limited to, a phenyl group, a biphenyl group, and a terphenyl group. Examples of the polycyclic aryl group may include, but are not limited to, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a perylenyl group, a chrysenyl group, and a fluorenyl group.

[0025] In this 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,

Chemical formula

[0026] As used herein, heteroaryl is heteroaryl containing one or more of O, N, Si, and S as heteroatoms, and the number of carbon atoms is not particularly limited, but is preferably 2 to 60. Examples of heteroaryl include xanthene, thioxanthene, thiophene group, furanyl group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, pyrimidinyl group, triazinyl group, acridinyl group, pyridazinyl group, pyrazinyl group, quinolinyl group, quinazolinyl group, quinoxalinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyrazinyl group, pyrazinopyrazinyl group, isoquinolyl group, indole group, carbazole group, benzoxazole group, benzimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline, isoxazolyl group, thiadiazolyl group, phenothiazinyl group, and dibenzofuranyl group, but is not limited thereto.

[0027] In this specification, for the aryl group in an aralkyl group, an aralkenyl group, an alkylaryl group, an arylamine group, and an arylsilyl group, the description of the aryl group mentioned above is applicable. In this specification, for the alkyl group in an aralkyl group, an alkylaryl group, and an alkylamine group, the description of the alkyl group mentioned above is applicable. In this specification, for the heteroaryl in a heteroarylamine group, the description of the heteroaryl mentioned above is applicable. In this specification, for the alkenyl group in an aralkenyl group, the description of the alkenyl group mentioned above is applicable. In this specification, for an arylene, except that it is a divalent group, the description of the aryl group mentioned above is applicable. In this specification, for a heteroarylene, except that it is a divalent group, the description of the heteroaryl mentioned above is applicable. In this specification, for a hydrocarbon ring, except that it is not a monovalent group and is formed by bonding two substituents, the description of the aryl group or cycloalkyl group mentioned above is applicable. In this specification, for a heterocyclic ring, except that it is not a monovalent group and is formed by bonding two substituents, the description of the heteroaryl mentioned above is applicable.

[0028] (Positive electrode and negative electrode) The organic light-emitting device according to the present invention includes a positive electrode and a negative electrode.

[0029] As the positive electrode material, a material having a large work function is generally preferred so that hole injection into the organic layer becomes smooth. Specific examples of the positive electrode 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; and conductive compounds such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but are not limited thereto.

[0030] As the negative electrode material, it is preferably a material with a small work function so that electron injection into the organic layer is facilitated. Specific examples of the negative electrode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; multilayer structured materials such as LiF / Al or LiO 2 / Al, etc., but are not limited thereto.

[0031] (Hole transport layer) The organic light-emitting device according to the present invention includes a hole transport layer between the positive electrode and the light-emitting layer, and the hole transport layer includes a polymer containing a repeating unit represented by the chemical formula 1 and an ionic compound containing an anion group represented by the chemical formula 2. The hole transport layer can be a hole injection layer, a hole transport layer, or a layer that simultaneously performs hole injection and transport.

[0032] Preferably, in the hole transport layer, the weight ratio of the polymer to the ionic compound is 99:1 to 50:50, 95:5 to 60:40, or 90:10 to 70:30.

[0033] Hereinafter, each substance will be described in detail.

[0034] (Polymer containing a repeating unit represented by chemical formula 1) In the chemical formula 1, preferably, L 1 is phenylene, biphenyldiyl, or binaphthyldiyl, and the L 1 is unsubstituted or substituted with one or two alkyl groups having 1 to 10 carbon atoms, or one or more deuteriums.

[0035] Preferably, L 1 is represented by any one of the following,

Chemical formula

[0036] Preferably, each R’ is independently methyl, propyl, butyl, pentyl, or hexyl.

[0037] L 2 is independently phenylene or biphenyldiyl, and the L 2 is unsubstituted or substituted with one or more deuteriums. More preferably, each L is independently 1,4-phenylene or 4,4’-biphenyldiyl, and the L 2 is unsubstituted or substituted with one or more deuteriums. Preferably, the L 2 are identical to each other.

[0038] Preferably, each Ar is independently phenyl or biphenylyl, and the Ar is unsubstituted or substituted with alkyl having 1 to 10 carbon atoms, N(aryl having 6 to 60 carbon atoms) 2 or one or more deuteriums. More preferably, Ar is biphenylyl, and the Ar is unsubstituted or substituted with propyl, isopropyl, butyl, isobutyl, N(phenyl) 2 or one or more deuteriums. Preferably, the Ar are identical to each other.

[0039] Preferably, each R is independently hydrogen, deuterium, or methyl.

[0040] Preferably, the chemical formula 1 is any one selected from the group consisting of the following:

Chemical formula

Chemical formula

Chemical formula

[0041] Also, the repeating unit represented by the chemical formula 1 is derived from the compound represented by the following chemical formula 1-1. [Chemical formula] In the above Chemical formula 1-1, the definitions of the remaining part excluding X are as described above, X is a halogen, and more preferably, it is bromine or chlorine.

[0042] The compound represented by the above Chemical formula 1-1 can be produced by a production method such as the following Reaction formula 1. [Chemical formula] In the above Reaction formula 1, the definitions of the remaining part excluding X are as described above, X is a halogen, and more preferably, it is bromine or chlorine.

[0043] Steps 1-1 and 1-2 in the above Reaction formula 1 are each an amine substitution reaction, which is a reaction carried out in the presence of a palladium catalyst and a base. The reaction groups for the amine substitution reaction can be changed by those known in the art. The above production method will be further embodied in the production examples described later.

[0044] The above polymer may further include a repeating unit represented by the following Chemical formula 1': [Chemical formula] In the above Chemical formula 1', L' are each independently a single bond; or a substituted or unsubstituted arylene having 6 to 60 carbon atoms, Z is C, Si, N, Si(phenyl), or an n-valent substituted or unsubstituted aromatic ring having 6 to 60 carbon atoms, n is 3 or 4, provided that when Z is C or Si, n is 4, and when Z is N or Si(phenyl), n is 3, * indicates the attachment point in the polymer.

[0045] The repeating unit represented by the above Chemical formula 1' is a branched repeating unit. When it is included in the polymer structure according to the present invention, the structure of the polymer can be made branched, and the solubility in a solvent can be improved.

[0046] Preferably, each L’ is independently a single bond; or phenylene.

[0047] Preferably, Z is C, N, Si, or trivalent benzene.

[0048] Preferably, the chemical formula 1’ is any one selected from the group consisting of the following:

Chemical formula

[0049] Also, the repeating unit represented by the chemical formula 1’ is derived from the compound represented by the following chemical formula 1’-1.

Chemical formula

[0050] The polymer may further contain a repeating unit represented by the following chemical formula 1’’:

Chemical formula

[0051] The end group represented by the chemical formula 1’’ is an aromatic cyclic end group, and when contained in the polymer structure according to the present invention, the solubility in a solvent can be improved.

[0052] Preferably, Ar’’ is phenyl or biphenylyl, and the Ar’’ is unsubstituted or substituted with an alkyl having 1 to 10 carbon atoms, a photocurable group, or a thermosetting group.

[0053] Preferably, the chemical formula 1'' is any one selected from the group consisting of the following: [Chemical formula] .

[0054] In addition, the repeating unit represented by the chemical formula 1'' is derived from a compound represented by the following chemical formula 1''-1. [Chemical formula] In the chemical formula 1''-1, the definitions of the rest except X'' are as described above, and X'' is a halogen, more preferably bromine or chlorine.

[0055] The polymer according to the present invention can be produced by polymerizing the monomer represented by the above-described chemical formula 1-1. Further, the polymer according to the present invention can be produced by polymerizing the monomer represented by the above-described chemical formula 1-1 and the monomer represented by the chemical formula 1'-1. Further, the polymer according to the present invention can be produced by polymerizing the monomer represented by the above-described chemical formula 1-1, the monomer represented by the chemical formula 1'-1, and the monomer represented by the chemical formula 1''-1. Preferably, the polymer according to the present invention is a random copolymer containing the repeating unit.

[0056] When the repeating unit of the chemical formula 1' is included in the polymer according to the present invention, preferably, 10 mol to 50 mol of the repeating unit of the chemical formula 1' is included with respect to 100 mol of the repeating unit represented by the chemical formula 1. More preferably, 15 mol or more, 20 mol or more, 25 mol or more, or 30 mol or more of the repeating unit of the chemical formula 1' is included with respect to 100 mol of the repeating unit represented by the chemical formula 1; and 45 mol or less, 40 mol or less, or 35 mol or less is included.

[0057] In the polymer according to the present invention, when the repeating unit of the chemical formula 1'' is included, preferably, the repeating unit of the chemical formula 1'' is included in an amount of 20 mol to 65 mol with respect to 100 mol of the repeating unit represented by the chemical formula 1. More preferably, the repeating unit of the chemical formula 1'' is included in an amount of 25 mol or more, 30 mol or more, 35 mol or more, or 40 mol or more with respect to 100 mol of the repeating unit represented by the chemical formula 1; and is included in an amount of 60 mol or less, or 55 mol or less.

[0058] In addition, the molar ratio of the polymer can be adjusted by adjusting the reaction molar ratio of the monomer represented by the above-described chemical formula 1-1, the monomer represented by the chemical formula 1'-1, and / or the monomer represented by the chemical formula 1''-1.

[0059] Preferably, the weight average molecular weight (Mw; g / mol) of the polymer is 3,000 to 1,000,000, more preferably 10,000 or more, 20,000 or more, 30,000 or more, 40,000 or more, 50,000 or more, 60,000 or more, 70,000 or more, or 80,000 or more; and is 500,000 or less, 400,000 or less, 300,000 or less, 200,000 or less, or 150,000 or less.

[0060] Preferably, the molecular weight distribution (PDI; Mw / Mn) of the polymer is 1 to 10, more preferably 1.5 or more, 2.0 or more, 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, or 2.5 or more; and is 9.0 or less, 8.0 or less, 7.0 or less, 6.0 or less, or 5.0 or less.

[0061] (Anionic group represented by Chemical Formula 2) In the chemical formula 2, preferably, the photocurable group or thermosetting group of R'' can apply the content of R defined in the chemical formula 1.

[0062] Preferably, R'' 1 is each independently hydrogen, fluorine, or CF 3 and is.

[0063] Preferably, Ar’’ 1 is any one selected from the group consisting of the following:

Chemical formula

[0064] Preferably, R’’ 2 are each independently hydrogen, fluorine, CF 3 , CF(CF 3 ), 2 , CF 2 CF 2 CF 2 CF 3 , a photocurable group, or a thermosetting group. At this time, the photocurable group; or the thermosetting group can apply the content of R defined in Chemical formula 1 above.

[0065] Preferably, Ar’’ 2 is any one selected from the group consisting of the following:

Chemical formula

[0066] Typical examples of the anionic group represented by Chemical formula 2 are as follows:

Chemical formula

Chemical formula

[0067] (Cationic group) In addition, the ionic compound according to the present invention may further contain a cationic group.

[0068] Preferably, the cationic group is selected from a monovalent cationic group, an onium compound, or the following structural formulas:

Chemical formula

[0069] Preferably, the cationic group is selected from the following structural formulas:

Chemical formula

[0070] Typical examples of the cationic group are as follows.

Chemical formula

[0071] On the other hand, the method for forming the hole transport layer according to the present invention will be described later.

[0072] (Light-emitting layer) The light-emitting layer can contain a host material and a dopant material. Examples of the host material include condensed aromatic ring derivatives or heterocyclic-containing compounds. Specifically, examples of the condensed aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, etc., and examples of the heterocyclic-containing compounds include carbazole derivatives, dibenzofuran derivatives, ladder-type furan compounds, pyrimidine derivatives, etc., but are not limited thereto.

[0073] Examples of the dopant material include aromatic amine derivatives, styrylamine compounds, boron complexes, fluoranthene compounds, metal complexes, etc. Specifically, examples of the aromatic amine derivatives include condensed aromatic ring derivatives having a substituted or unsubstituted arylamino group, such as pyrene, anthracene, chrysene, periflanthene having an arylamino group, etc., and examples of the styrylamine compounds are compounds in which at least one arylvinyl group is substituted on a substituted or unsubstituted arylamine, and the substituents are substituted or unsubstituted with one or more selected from the group consisting of an aryl group, a silyl group, an alkyl group, a cycloalkyl group, and an arylamino group. Specifically, there are styrylamine, styryldiamine, styryltriamine, styryltetraamine, etc., but are not limited thereto. Also, examples of the metal complexes include iridium complexes, platinum complexes, etc., but are not limited thereto.

[0074] (Electron transport layer) The organic light-emitting device according to the present invention can include an electron transport layer on the light-emitting layer.

[0075] 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 that can well receive electron injection from the negative electrode and transfer it to the light-emitting layer and has a high mobility for electrons is preferable. Specific examples include an Al complex of 8-hydroxyquinoline; Alq 3Complexes including; organic radical compounds; hydroxyflavone-metal complexes, etc., but not limited thereto. The electron transport layer can be used together with any desired cathode material as used in the prior art. In particular, examples of suitable cathode materials are ordinary materials having a low work function followed by an aluminum layer or a silver layer. Specifically, they are cesium, barium, calcium, ytterbium, and samarium, and in each case, an aluminum layer or a silver layer follows.

[0076] (Electron injection layer) The organic light-emitting device according to the present invention can include an electron injection layer between the electron transport layer (or the light-emitting layer) and the negative electrode, if necessary.

[0077] The electron injection layer is a layer that injects electrons from the electrode, has the ability to transport electrons, has an excellent electron injection effect on the electron injection effect from the negative electrode, the light-emitting layer or the light-emitting material, prevents the holes of the excitons generated in the light-emitting layer from moving to the hole injection layer, and a compound having excellent thin film forming ability is preferable. Specifically, there are fluorenone, anthraquinodimethane, diphenoquinone, thiopyrandioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenylidenemethane, anthrone, etc. and their derivatives, metal complex compounds, and nitrogen-containing 5-membered ring derivatives, etc., but not limited thereto.

[0078] Examples of the metal complex compound include, but are not limited to, lithium 8-hydroxyquinolinate, zinc bis(8-hydroxyquinolinate), copper bis(8-hydroxyquinolinate), manganese bis(8-hydroxyquinolinate), aluminum tris(8-hydroxyquinolinate), aluminum tris(2-methyl-8-hydroxyquinolinate), gallium tris(8-hydroxyquinolinate), beryllium bis(10-hydroxybenzo[h]quinolinate), zinc bis(10-hydroxybenzo[h]quinolinate), gallium bis(2-methyl-8-quinolinato)chloride, gallium bis(2-methyl-8-quinolinato)(o-cresolate), aluminum bis(2-methyl-8-quinolinato)(1-naphtholate), and gallium bis(2-methyl-8-quinolinato)(2-naphtholate).

[0079] In addition to the materials described above, the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer may further contain an inorganic compound such as a quantum dot or a polymer compound.

[0080] The quantum dots can be, for example, colloidal quantum dots, alloy quantum dots, core-shell quantum dots, or core quantum dots. The quantum dots can contain elements belonging to Group 2 and Group 16, elements belonging to Group 13 and Group 15, elements belonging to Group 13 and Group 17, elements belonging to Group 11 and Group 17, or elements belonging to Group 14 and Group 15, and quantum dots containing elements such as cadmium (Cd), selenium (Se), zinc (Zn), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium (Ga), and arsenic (As) can be used.

[0081] (Organic Light-Emitting Device) The organic light-emitting device according to the present invention can be an organic light-emitting device having a structure (normal type) in which a positive electrode, one or more organic layers, and a negative electrode are sequentially stacked on a substrate. Further, the organic light-emitting device according to the present invention can be an organic light-emitting device having an inverted structure (inverted type) in which a negative electrode, one or more organic layers, and a positive electrode are sequentially stacked on a substrate. For example, the structure of the organic light-emitting device according to an embodiment of the present invention is illustrated in FIGS. 1 and 2.

[0082] FIG. 1 is a diagram showing an example of an organic light-emitting device including a substrate 1, a positive electrode 2, a hole transport layer 3, a light-emitting layer 4, and a negative electrode 5. In this structure, the hole transport layer contains a polymer including a repeating unit represented by Chemical Formula 1 and an anionic compound represented by Chemical Formula 2.

[0083] FIG. 2 is a diagram showing an example of an organic light-emitting device including a substrate 1, a positive electrode 2, a hole transport layer 3, a light-emitting layer 4, an electron transport layer 6, an electron injection layer 7, and a negative electrode 5. In this structure, the hole transport layer contains a polymer including a repeating unit represented by Chemical Formula 1 and an anionic compound represented by Chemical Formula 2.

[0084] The organic light-emitting device according to the present invention can be manufactured by materials and methods known in the art, except that the above-described materials are used.

[0085] For example, the organic light-emitting device according to the present invention can be manufactured by sequentially stacking a positive electrode, an organic layer, and a negative electrode on a substrate. At this time, a positive electrode is formed by depositing a metal, a metal oxide having conductivity, or an alloy thereof on the substrate using a PVD (Physical Vapor Deposition) method such as a sputtering method or an e-beam evaporation method, and then a hole injection layer, a hole transport layer, a light-emitting layer, and an organic layer including an electron transport layer are formed thereon, and then a substance used as a negative electrode is deposited thereon for manufacturing.

[0086] In addition to this method, an organic light-emitting device can be manufactured by sequentially depositing an organic material layer and a positive electrode material on a substrate from a negative electrode material (WO2003 / 012890). However, the manufacturing method is not limited thereto.

[0087] The organic light-emitting device according to the present invention can be a front emission type, a rear emission type, or a double-sided emission type depending on the materials used.

[0088] (Coating composition) On the other hand, the hole transport layer according to the present invention can be formed in a solution process. Therefore, the present invention provides a coating composition for forming a hole transport layer containing a polymer containing a repeating unit represented by the above Chemical Formula 1 and an anionic compound represented by the above Chemical Formula 2.

[0089] The solvent is not particularly limited as long as it can dissolve or disperse the polymer and the compound according to the present invention. For example, chlorinated solvents such as chloroform, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, and o-dichlorobenzene; ether solvents such as tetrahydrofuran and dioxane; aromatic hydrocarbon solvents such as toluene, xylene, trimethylbenzene, and mesitylene; aliphatic hydrocarbon 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; polyhydric alcohols and their derivatives such as ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethoxyethane, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, and 1,2-hexanediol; alcohol solvents such as methanol, ethanol, propanol, isopropanol, and cyclohexanol; sulfoxide solvents such as dimethyl sulfoxide; amide solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide; benzoate solvents such as butyl benzoate and methyl-2-methoxybenzoate; tetralin; solvents such as 3-phenoxytoluene. In addition, the above-mentioned solvents can be used alone or in combination of two or more solvents.

[0090] In addition, the viscosity of the coating composition is preferably 1 cP or more. Also, considering the ease of coating of the coating composition, the viscosity of the coating composition is preferably 10 cP or less. Further, the concentration of the compound according to the present invention in the coating composition is preferably 0.1 wt / v% or more. Also, so that the coating composition is optimally coated, the concentration of the compound according to the present invention in the coating composition is preferably 20 wt / v% or less.

[0091] In addition, the coating composition may further contain one or more additives selected from the group consisting of a thermal polymerization initiator and a photoinitiator.

[0092] Examples of the thermal polymerization initiator include peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, acetylacetone peroxide, methyl cyclohexanone peroxide, cyclohexanone peroxide, isobutyryl peroxide, 2,4-dichlorobenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauryl peroxide, benzoyl peroxide, etc., or azo compounds such as azobisisobutyronitrile, azobisdimethylvaleronitrile, and azobiscyclohexylnitrile, but are not limited thereto.

[0093] Examples of the photoinitiator include acetophenone-based or ketal-based photoinitiators such as diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino(4-methylthiophenyl)propan-1-one, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime; benzoin ether-based photoinitiators such as benzoin, benzoin methyl ether, benzoin ethyl ether; benzophenone-based photoinitiators such as benzophenone, 4-hydroxybenzophenone, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether; thioxanthone-based photoinitiators such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone; and other photoinitiators such as ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, but are not limited thereto.

[0094] Those having a photo-polymerization promoting effect can be used alone or in combination with the photoinitiator. For example, but not limited thereto, there are triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino)ethyl benzoate, 4,4'-dimethylaminobenzophenone and the like.

[0095] The present invention also provides a method for forming a hole transport layer using the coating composition described above. Specifically, it includes coating the coating composition for forming the hole transport layer on the positive electrode in a solution process, and heat-treating or light-treating the coated coating composition.

[0096] The solution process uses the coating composition according to the present invention described above, and means spin coating, dip coating, doctor blading, inkjet printing, screen printing, spraying method, roll coating, etc., but is not limited thereto.

[0097] In the heat treatment step, the heat treatment temperature is preferably 150 to 230 °C. Also, the heat treatment time is 1 minute to 3 hours, more preferably 10 minutes to 1 hour. Further, the heat treatment is preferably performed in an inert gas atmosphere such as argon or nitrogen. Further, a step of evaporating the solvent may be further included between the coating step and the heat treatment or light treatment step.

[0098] Hereinafter, the manufacture of the organic light-emitting device according to the present invention will be specifically described with reference to examples. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited thereby.

Example

[0099] Production Example 1-1: Production of copolymer H1

Chemical formula

[0100] Compound M1 (0.765 mmol), compound B1 (0.158 mmol) and compound E1 (0.396 mmol) were added to a scintillation vial and dissolved in toluene (11 mL) to prepare a first solution.

[0101] A 50 mL Schlenk tube was charged with bis(1,5-cyclooctadiene)nickel(0) (2.42 mmol). 2,2'-Dipyridyl (2.42 mmol) and 1,5-cyclooctadiene (2.42 mmol) were weighed into a scintillation vial and dissolved in N,N'-dimethylformamide (5.5 mL) and toluene (11 mL) to prepare a second solution.

[0102] The second solution was added to the Schlenk tube and stirred at 50 °C for 30 minutes. The first solution was further added to the Schlenk tube and stirred at 50 °C for 180 minutes. Next, after cooling the Schlenk tube to room temperature, it was poured into HCl / methanol (5% v / v, concentrated HCl). After stirring for 45 minutes, the polymer was collected by vacuum filtration and dried under high vacuum. The polymer was dissolved in toluene (1% wt / v) and passed through a column containing basic aluminum oxide (6 g) layered on silica gel (6 g). The filtrate of the polymer / toluene was concentrated (2.5% wt / v toluene) and triturated with 3-pentanone. The toluene / 3-pentanone solution was decanted from the semi-solid polymer, dissolved in toluene (15 mL), and then poured into methanol under stirring conditions to obtain copolymer H1 in a 60% yield.

[0103] Production Example 1-2: Production of Copolymer H2

Chemical formula

[0104] Under an inert gas condition, compound M1 (0.207 mmol), compound B2 (0.092 mmol), Aliquat 336 (0.041 mmol), 1.24 mL of aqueous potassium carbonate solution (0.5 M), bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (0.1 μmol) and toluene (6.0 mL) were added to a scintillation vial equipped with a magnetic stir bar. The vial was sealed with a screw cap having a septum, inserted into an aluminum block, heated to an external temperature of 105 °C for 30 minutes, and stirred at that temperature under gentle reflux for 5 hours. Next, the reaction mixture was charged with bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (0.05 μmol), compound E2 (0.138 mmol) and toluene (0.9 ml). The reaction mixture was heated again at the above temperature for 1.5 hours. Next, iodobenzene (0.092 mmol) and toluene (0.6 mL) were added. The reaction mixture was heated for a further 1.5 hours and then cooled to room temperature. The aqueous layer was removed and the organic layer was washed twice with 20 mL portions of deionized water. The toluene layer was dried by passing it through 10 g of silica gel, and the silica was washed with toluene. The solvent was removed to obtain 250 mg of a crude product. The toluene solution was further purified by passing it through alumina, silica gel and Florisil®. After concentration, the product immersed in the solvent was diluted with about 14 mL of toluene and then added to ethyl acetate (150 mL) to obtain about 200 mg of a copolymer. The toluene solution of the product was reprecipitated in 3-pentanone to obtain 145 mg of the final copolymer H2.

[0105] Production Example 1-3: Production of Copolymer H3

Chemical formula

[0106] Copolymer H3 was produced in the same manner as the production method of the copolymer H1, except that compounds M2 and E3 were used instead of compounds M1 and E1, respectively.

[0107] Production Example 1-4: Production of Copolymer H4

Chem.

[0108] Copolymer H4 was produced in the same manner as the production method of Copolymer H2, except that Compounds M3, B3, and E3 were used instead of Compounds M1, B2, and E2, respectively.

[0109] Production Example 1-5: Production of Copolymer H5

Chem.

[0110] Copolymer H5 was produced in the same manner as the production method of Copolymer H1, except that Compounds M4 and E4 were used instead of Compounds M1 and E1, respectively.

[0111] Production Example 1-6: Production of Copolymer H6

Chem.

[0112] Copolymer H6 was produced in the same manner as the production method of Copolymer H1, except that Compounds M5 and E5 were used instead of Compounds M1 and E1, respectively.

[0113] Production Example 1-7: Production of Copolymer H7

Chem.

[0114] Copolymer H7 was produced in the same manner as the production method of Copolymer H2, except that Compounds M6, B3, and E4 were used instead of Compounds M1, B2, and E2, respectively.

[0115] The weight-average molecular weight (Mw) and molecular weight distribution (PDI, Mw / Mn) of the copolymer produced above were measured by GPC using a PS standard with an Agilent 1200 series, and the measurement was carried out using a solution prepared by dissolving the produced copolymer in THF at a concentration of 1 mg / 1 mL. The results are shown in Table 1 below.

[0116]

Table 1

[0117] Production Example 2-1: Production of Compound D1 Step 1) Production of Compound D1’

Chemical formula

[0118] Under a nitrogen atmosphere, Mg (193 mg, 7.92 mmol), I 2 (4 mg) and THF (10 mL) were placed in a 100 mL round-bottom flask and stirred for 30 minutes. 4-Bromostyrene (1.04 mL, 7.92 mmol) was added, and a 30°C water bath was placed under the round-bottom flask and stirred for 1 day. It was confirmed that the reaction solution turned black and Mg had dissolved. Ether (5 mL) was added to dilute the reaction solution.

[0119] Tris(pentafluorophenyl)borane (1 g, 3.96 mmol) was dissolved in ether (5 mL) and slowly added to the reaction solution over 30 minutes. The solution was stirred for 1 day. Na 2 CO 3 (0.1 M, 80 mL, 8.0 mmol) was slowly added to the reaction solution. Ethyl acetate (20 mL × 3) was used to extract the organic solvent, and the remaining water was removed with MgSO 4 . Furthermore, to remove the remaining water and impurities, it was distilled with benzene using a Dean-stock. When about 10 mL of the solvent remained, the solution was cooled and filtered to obtain Compound D1’ (1.6 g, yield 64%).

[0120] Production of Compound D1 in Step 2

Chemical formula

[0121] Compound D1’ (100 mg, 0.16 mmol), distilled water (10 mL) and Ph 2 ICl (60 mg, 0.19 mmol) were placed in a 25 mL round-bottom flask and stirred for 1 hour. Acetone (15 mL) was added to the reaction solution to cause precipitation, and the precipitate was filtered and dried to obtain Compound D1 (140 mg, yield 100%). MS: [M-H] - = 615 (negative mode) MS: [M+H] + = 281 (positive mode)

[0122] Production Example 2-2: Production of Compound D2 Step 1) Production of Compound D2’

Chemical formula

[0123] Methyltriphenylpotassium bromide (13.90 g, 38.91 mmol) and THF (100 mL) were placed in a 250 mL round-bottom flask and stirred at 0 °C for 30 minutes. n-BuLi (15.6 mL, 38.91 mmol, 2.5 M in Hexane) was slowly added to the reaction solution, and the mixture was stirred at 0 °C for 30 minutes. 4-Formyl-2,3,5,6-tetrafluoro-1-bromobenzene (5.0 g, 19.47 mmol, in 30 mL THF) was slowly added to the reaction solution at 0 °C. The reaction solution was slowly stirred while raising the temperature to room temperature. After 3 hours, ether (100 mL) and NH 4 Cl saturated solution (400 mL) were added. The organic solvent was extracted using ether (200 mL × 2), and the remaining water was removed with MgSO 4 Compound D2’ (1.29 g, yield 26%) was obtained using a column with ethyl acetate:hexane = 1:9 (v:v).

[0124] Step 2) Production of Compound D2’’

Chem.

[0125] Mg (95 mg, 3.92 mmol), THF (10 mL) and I 2 (4 mg) were placed in a 25 mL round-bottom flask and stirred. Compound D2’ (1.0 g, 3.92 mmol) was added to the reaction solution and stirred at room temperature. After 10 hours, it was confirmed that the solution was black and Mg had completely dissolved, and ether (10 mL) and BCl 3 (1.3 mL, 1.3 mmol, 1 M in hexane solution) was added over 30 minutes. After stirring the reaction solution for 1 day, Na 2 CO 3 (30 mL, 3.0 mmol, 0.1 M in H 2 O) was added. The synthetic substance was extracted with ethyl acetate (10 mL × 3), and the residual water was removed with MgSO 4 . After removing all the solvents, benzene was used to completely remove water by Dean-stock, and the solid was filtered to obtain Compound D2’’ (340 mg, yield 28%).

[0126] Step 3) Production of Compound D2

Chem.

[0127] Compound D2’’ (200 mg, 0.27 mmol), 1-(4-vinylbenzyl)pyridin-1-ium chloride (69 mg, 0.30 mmol), H 2 O (10 mL), and methylene chloride (10 mL) were placed in a 25 mL round-bottom flask and stirred vigorously for 30 minutes. The organic solvent was extracted using ether (10 mL × 3), and the residual water was removed with MgSO 4 . The solvent was removed and dried under vacuum to obtain Compound D2 (247 mg, yield 100%). MS: [M-H] - = 711 (negative mode) MS: [M+H] + =196 (positive mode)

[0128] Production Example 2-3: Production of Compound D3 Step 1) Production of Compound D3’

Chemical formula

[0129] 1-Bromo-2,3,5,6-tetrafluoro-4-(1,2,2-trifluorovinyl)benzene (2 g, 7.84 mmol) was placed in THF (20 mL) in a 50 mL round-bottom flask and stirred at -78 °C for 30 minutes. n-BuLi in hexane (3.45 mL, 8.63 mmol, 2.5 M) was slowly added to the solution, and the mixture was stirred at -78 °C for 30 minutes. BCl 3 (2.6 mL, 2.61 mmol, 1 M in hexane solution) was added dropwise at -78 °C over 15 minutes. The temperature was slowly raised to room temperature, and the reaction solution was stirred for 1 day, then water (30 mL) was added. The synthetic substance was extracted with ethyl acetate (10 mL × 3), and then all the solvents were removed. Water was completely removed by Dean-stock using benzene, and the solid was filtered to obtain Compound D3’ (800 mg, yield 43%).

[0130] Step 2) Production of Compound D3

Chemical formula

[0131] Compound D3’ (400 mg, 0.56 mmol), diphenyliodonium chloride (176 mg, 0.56 mmol), water (10 mL), and acetone (10 mL) were placed in a 25 mL round-bottom flask and stirred vigorously for 30 minutes. Extraction was carried out using dichloromethane (10 mL × 3) to remove the solvent, and after drying, Compound D3 (552 mg, yield 100%) was obtained. MS: [M-H] - =711 (negative mode) MS: [M+H] +=281 (positive mode)

[0132] Production Example 2-4: Production of Compound D4 Step 1) Production of Compound D4’ [Chemical formula]

[0133] Potassium carbonate (10.4 g, 75.3 mmol) was placed in a 500 mL round-bottom flask, and DMF (200 ml) was added. 2,3,5,6-Tetrafluorophenol (10.0 g, 60.22 mmol) was added to the flask, and the mixture was stirred at 60 °C for 30 minutes. 4-Vinylbenzyl chloride (7.66 g, 50.18 mmol) was slowly added to the reaction solution, and the mixture was stirred at 60 °C for 16 hours. Then, water (300 mL) and ethyl acetate (200 ml) were added. The organic layer was extracted using ethyl acetate (200 mL × 2), and the remaining water was removed with MgSO 4 . Compound D4’ (11.2 g, yield 79%) was obtained using a column with ethyl acetate:hexane = 1:9 (v:v).

[0134] Step 2) Production of Compound D4’’ [Chemical formula]

[0135] Compound D4’ (10 g, 35.43 mmol) was placed in a 250 ml round-bottom flask, and ether (130 ml) was added and stirred. The reaction solution was cooled to -78 °C and stirred for 30 minutes. n-BuLi (17 ml, 42.52 mmol, 2.5 M in Hexane) was slowly injected over 30 minutes. Then, the mixture was stirred for 1 hour. BCl 3(8.15 ml, 8.15 mmol, 1 M in Hexane) was slowly added over 30 minutes. The reaction solution was slowly warmed to room temperature. After stirring the reaction solution for 1 day, water (200 ml) was added. The synthetic substance was extracted with ether (100 mL × 3), and then all the solvents were removed. Thereafter, benzene was used to completely remove water by Dean-stock, and the solid was filtered to obtain compound D4’’ (6.2 g, yield 66%).

[0136] Step 3) Production of Compound D4

Chemical Structure

[0137] Compound D4’’ (6.2 g, 5.42 mmol), diphenyliodonium chloride (2.57 g, 8.13 mmol), water (50 mL), and acetone (10 mL) were placed in a 25 mL round-bottom flask and stirred vigorously for 30 minutes. The organic solvent was extracted using methylene chloride (20 mL × 3), and the solvent was removed. Compound D4 (5.0 g, yield 65%) was obtained using a column with methylene chloride:acetone = 9:1 (v:v). MS: [M-H] - = 1135 (negative mode) MS: [M+H] + = 281 (positive mode)

[0138] [Elemental Example] Example 1 A glass substrate with a 1500 Å-thick thin film of ITO deposited thereon was ultrasonically cleaned using an acetone solvent for 10 minutes. Thereafter, it was placed in distilled water with a dissolved detergent and ultrasonically cleaned for 10 minutes, and then ultrasonic cleaning with distilled water was repeated twice for 10 minutes each. After the distilled water cleaning was completed, ultrasonic cleaning was performed with an isopropyl alcohol solvent for 10 minutes and then dried. Thereafter, the substrate was transported to a glove box.

[0139] Onto the thus-prepared ITO transparent electrode, a 2 wt% cyclohexanone solution containing the copolymer H1 and the compound D1 prepared above in a weight ratio of 8:2 was spin-coated and heat-treated at 230 °C for 30 minutes to form a hole injection layer with a thickness of 600 Å. Onto the hole injection layer, a toluene solution containing 0.8 wt% of the following polymer HTL (weight average molecular weight: 83,661; measured by GPC using a PS standard with an Agilent 1200 series) was spin-coated to form a hole transport layer with a thickness of 140 nm. [Chemical formula]

[0140] Thereafter, on the hole transport layer, the following compound A and the following compound B were made into a 1.3 wt% solution in cyclohexanone at a weight ratio of 9:1, and then a light-emitting layer with a thickness of 550 Å was formed by a solution process. Onto the light-emitting layer, the following compound C was vacuum-deposited to form an electron injection and transport layer with a thickness of 400 Å. Onto the electron injection and transport layer, a 5 Å thick LiF and a 1000 Å thick aluminum were sequentially deposited to form a cathode. [Chemical formula]

[0141] In the above process, the deposition rate of the organic matter was maintained at 0.4 - 1.0 Å / sec, the deposition rate of LiF was 0.3 Å / sec, the deposition rate of aluminum was 2 Å / sec, and the vacuum degree during deposition was maintained at 2×10 -8 ~5×10 -6 torr.

[0142] Examples 2 - 12 Organic light-emitting devices were fabricated in the same manner as in Example 1, except that the compounds listed in Table 2 below were used instead of the copolymer H1 and / or the compound D1 during the fabrication of the hole injection layer.

[0143] Comparative Examples 1 and 2 An organic light-emitting device was manufactured in the same manner as in Example 1, except that the compounds described in Table 2 below were used instead of copolymer H1 and / or compound D1 during the production of the positive hole injection layer. Comparative compound 1 described in Table 2 below is as follows. [Chemical formula]

[0144] In the organic light-emitting devices manufactured in the above Examples and Comparative Examples, the driving voltage, external quantum efficiency (EQE), and lifetime at a current density of 10 mA / cm 2 were measured and are shown in Table 2 below. The external quantum efficiency is obtained from (number of photons emitted) / (number of charge carriers injected), and the lifetime (T95) means the time until the initial luminance decreases to 95%.

[0145] [Table 2]

[0146] As shown in Table 2 above, it was confirmed that when a polymer containing a repeating unit represented by Chemical Formula 1 according to the present invention and an ionic compound containing an anion group represented by Chemical Formula 2 are used in the hole transport layer, they are excellent in external quantum efficiency and lifetime.

[0147] On the other hand, in Comparative Example 1 where the ionic compound containing an anion group represented by Chemical Formula 2 according to the present invention is not used in the hole transport layer, the lifetime is extremely short, so it cannot be substantially used in an organic light-emitting device. Also, different from the ionic compound containing an anion group represented by Chemical Formula 2 according to the present invention, in Comparative Example 2 where Comparative Compound 1 having no photocurable group or thermosetting group is used as a dopant in the hole transport layer, it was confirmed that the external quantum efficiency and lifetime are significantly reduced.

[0148] [Measurement of curing conversion rate] A 2 wt% cyclohexanone solution of the copolymer produced above alone, or a 2 wt% cyclohexanone solution containing the copolymer produced above and a dopant compound in a weight ratio of 80:20 was prepared. Then, each of them was spin-coated and heat-treated at 230 °C for 30 minutes to obtain a thin film. The absorption spectrum of the thin film was measured by UV-vis, and the extinction coefficient (a1) at the point where the maximum absorption appeared was measured. Then, the thin film was immersed in cyclohexanone for 10 minutes, taken out, and the absorption spectrum was measured by UV-vis, and the extinction coefficient (a2) at the point where the maximum absorption appeared was measured. The curing conversion rate was calculated from the two measured values as shown in the following formula (1). [Formula (1)] Curing conversion rate (%) = (a2 / a1) × 100

[0149]

Table 3

[0150] As shown in Table 3 above, when used with a dopant as compared to the case of the copolymer alone, the curing conversion rate increased significantly. Although not limited by theory, it was confirmed from the above results that this was due to the more successful progress of curing by the photocurable group or thermosettable group of the ionic compound containing the anion group represented by Chemical Formula 2 according to the present invention.

Explanation of Symbols

[0151] 1 ··· Substrate 2 ··· Anode 3 ··· Hole transport layer 4 ··· Light-emitting layer 5 ··· Cathode 6 ··· Electron transport layer 7 ··· Electron injection layer

Claims

1. a positive electrode, a negative electrode, a light-emitting layer between the positive electrode and the negative electrode, and a hole transport layer between the positive electrode and the light-emitting layer An organic light-emitting device comprising: The hole transport layer contains a polymer and an ionic compound, The polymer is a copolymer represented by any one selected from the following Chemical Formula 1-H1 to Chemical Formula 1-H7. In Chemical Formula 1-H1 to Chemical Formula 1-H7, b1 is 10 to 50 with respect to the total of 100 of a1, b1, and e1, 【Chemical 14】 【Chemical Formula 15】 【Chemical 16】 【Chemical 17】 【Chemical Formula 18】 【Chemical Formula 19】 【Chemical 20】 The ionic compound contains an anion group represented by any one selected from the group consisting of the following, an organic light-emitting device 【Chemical 13】 。

2. The ionic compound contains a cation group, and the cation group is selected from a monovalent cation group, an onium compound, or the following structural formula. The organic light-emitting device according to Claim 1: 【Chemical 10】 In the structural formula, X １ to X ７６ are each independently hydrogen; cyano; nitro; halogen; -COOR １０４ ; substituted or unsubstituted alkyl having 1 to 60 carbon atoms; substituted or unsubstituted alkoxy having 1 to 60 carbon atoms; substituted or unsubstituted cycloalkyl having 3 to 60 carbon atoms; substituted or unsubstituted fluoroalkyl having 1 to 60 carbon atoms; or substituted or unsubstituted aryl having 6 to 60 carbon atoms; or a curable group, R １０４ is hydrogen; deuterium; or substituted or unsubstituted alkyl having 1 to 60 carbon atoms, p is an integer from 0 to 10, a is 1 or 2, b is 0 or 1, and a + b = 2.

3. The cation group is any one selected from the group consisting of the following structural formulas. The organic light-emitting device according to Claim 2: 【Chemical Formula 11】 。

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