KR20180127905A - Novel single molecule thermal polymerization type hole transport material and organic light emitting diode using the same - Google Patents

Abstract

The present invention relates to a novel single molecule thermal polymerization type hole transport material capable of forming a multi-layer structure, and to a high-efficiency organic light emitting diode (OLED) for a solution process, and when a hole transport layer is formed of the novel single molecule thermally polymerizable hole transport material, since the interface of the hole transport layer is not dissolved in the solvent after thermal crosslinking, the OLED having the multi-layer structure is effectively manufactured, and since the thermal crosslinking is performed at a relatively low temperature of 50 to 150°C, the hole transport material can be used in a process of applying a plastic substrate having a low glass transition temperature in addition to a glass substrate.

Description

[0001] The present invention relates to a novel single-molecule heat polymerization type hole transport material and an organic light emitting diode using the same. [0002]

The present invention relates to a hole transporting layer made of a heat polymerization type hole transporting material and an organic light emitting diode using the same. More specifically, the present invention relates to a novel single molecule heat polymerization type hole transporting material capable of forming a multilayer structure, and a high- Lt; / RTI >

 Organic light emitting diodes (OLEDs) have a simple structure compared to conventional LCDs and PDP displays. They have a wide viewing angle with high image quality, high color purity, low power consumption and low voltage driving Has attracted attention as a next-generation display.

 A typical OLED has a structure in which an anode is formed on a substrate, a hole transporting layer and an electron transporting layer, which are organic layers, are formed on the anode, and a cathode is sequentially formed thereon. However, existing processes for fabricating OLEDs use vacuum deposition for all layers. Vacuum deposition has disadvantages in that it is not suitable for mass production in terms of time, cost, and quantity.

 Therefore, from this point of view, the vacuum deposition method needs to be improved, and a solution process is attracting attention as an alternative thereto. However, when the OLED is manufactured using a solution process, interlayer intermixing occurs in the process of laminating the organic layers, or the purity of the materials and deterioration of the other materials due to the heat treatment (crosslinking reaction, etc.) There is a disadvantage in that the characteristics are lower than those of the evaporation type device, and in particular, the lifetime is low. Therefore, research on various solution process materials and processes has been actively conducted, but the above problems have not yet been completely solved.

Generally, there are two ways of laminating organic materials by solution process. The first method is to select the type of solvent that dissolves the material to be laminated. For example, if the lower layer is formed by dissolving in water / alcohol and the upper layer is dissolved in a common organic solvent, then the interlayer intermixing phenomenon can be reduced. The second is a way of bridging downstairs. When crosslinked, the dissolution and melting properties are remarkably reduced, so that the interaction with the solvent in the upper layer can be reduced.

The currently developed organic light emitting diode materials using crosslinking are classified into siloxanes, styrenes, acrylates, trifluorovinyl ethers, and the like depending on the type of crosslinking agent. , Benzocyclo-butenes, cinnamates / chalcones, and oxetanes. However, when an organic light emitting diode is fabricated using materials including these crosslinking agents, a chemical structure that can act as a trap through a process temperature of 200 ° C or more or a long time, unreacted or side reaction may be made, There is a disadvantage that a material adversely affecting the characteristics remains. When an unnecessary structure or material is contained in an organic light emitting diode, the lifetime and efficiency characteristics are significantly deteriorated. Also, if the process temperature is too high, the selection of the substrate material may have a limited effect. Therefore, an organic light emitting diode material using crosslinking that solves such a problem will be required.

1. Korean Patent Publication No. 10-2014-0069568 2. Korean Patent Publication No. 10-2013-0074815

The first problem to be solved by the present invention is to provide a thermally polymerizable hole transport material having a novel molecular structure for improving the disadvantages and problems of the prior art as described above.

A second problem to be solved by the present invention is to provide a process for producing the heat polymerization type hole transport material.

Furthermore, a third problem to be solved by the present invention is to provide an organic light emitting diode including a hole transporting layer containing the heat polymerization type hole transporting material.

However, the problems to be solved by the present invention are not limited to those mentioned above, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the first object, the present invention provides a novel single molecule thermopolymerizable hole transport material represented by the following general formula (1).

[Chemical Formula 1]

(In the formula 1,

Ar ¹ to Ar ³ independently represent a substituted or unsubstituted C ₃ -C ₃₀ aryl, heteroaryl, arylalkyl or alkylaryl group,

R ¹ and R ² independently represent a substituted or unsubstituted C ₁ -C ₉ alkyl group, a substituted or unsubstituted C ₅ -C ₃₀ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, A substituted or unsubstituted C ₆ -C ₃₀ alkylaryl group, a substituted or unsubstituted C ₆ -C ₃₀ arylalkyl group, a substituted or unsubstituted C ₃ -C ₃₀ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group And a sulfone group,

m and n are each 1 to 5)

More preferably, Ar ¹ to Ar ³ independently represent a non-fused ring aromatic substituent consisting of benzene, pyridine, pyrrole, furan and thiophene; Hetero-fused-ring aromatic substituents; A fused ring aromatic substituent consisting of naphthalene, anthracene, triphenylene, pyrene and perylene; And dibenzoyl fused ring substituents consisting of carbazole, fluorene, dibenzofuran, dibenzothiophene and spirofluorene,

R ¹ and R ² independently represent a substituted or unsubstituted C ₁ -C ₄ alkyl group, a substituted or unsubstituted C ₅ -C ₁₂ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₁₂ aryl group, A substituted or unsubstituted C ₆ -C ₁₂ alkylaryl group, a substituted or unsubstituted C ₆ -C ₁₂ arylalkyl group, a substituted or unsubstituted C ₃ -C ₁₂ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group And a sulfone group,

m and n may be 1 to 5, respectively.

More preferably, the thermally polymerizable hole transport material can be selected from the following compounds 1-70.

More preferably, the compound of Formula 1 has at least one unit of an arylamine unit and a tertiary alcohol unit in the molecule, the reactive hydrogen is present at an ortho or para position of the benzene group of the arylamine, The alcohol unit may be in the form of sp3 carbon or three alkyl or aryl groups connected to the silicon.

More preferably, the number of reactive hydrogen atoms of the arylamine in the molecule of Formula 1 may be equal to or greater than the number of OH groups in the tertiary alcohol unit.

More preferably, the compound of Formula 1 may have a molecular weight of 2000 or less.

In order to achieve the second object, the present invention provides,

Reacting a halogen functional group in an allyl amine compound of formula (2) with an alkyl lithium or magnesium in an organic solvent to prepare an organometallic reagent of formula (3) containing allylamine (step 1); And

The compound of Chemical Formula 4 having at least one carbonyl functional group in the molecule is reacted with the organometallic reagent of Formula 3 containing the allylamine and then a hydrogen-supplying reagent is added to form a tertiary alcohol, (Step 2) of preparing a novel single-molecule heat-polymerizable hole-transporting material.

[Reaction Scheme 1]

(In the above Reaction Scheme 1, Ar ¹ to Ar ³ , R ¹ and R ² , n and m are as defined in Formula 1.)

In addition, the present invention relates to a process for producing a compound represented by the formula

The compound of formula (I) is prepared by treating a intermediate of formula (5) having at least one carbonyl functionality and an arylamine in the molecule simultaneously in an organic solvent with an aromatic lithium or aromatic Grignard reagent and a hydrogen-providing reagent to form a tertiary alcohol, And a method for producing the novel single-molecule heat polymerization type hole transporting material.

[Reaction Scheme 2]

(In the above Reaction Scheme 2,

Ar and Ar ⁴ to Ar ⁶ are non-fused ring aromatic substituents consisting of benzene, pyridine, pyrrole, furan and thiophene; Hetero-fused-ring aromatic substituents; A fused ring aromatic substituent consisting of naphthalene, anthracene, triphenylene, pyrene and perylene; And dibenzoyl fused ring substituents consisting of carbazole, fluorene, dibenzofuran, dibenzothiophene and spirofluorene,

R ³ and R ⁴ independently represent a substituted or unsubstituted C ₁ -C ₄ alkyl group, a substituted or unsubstituted C ₅ -C ₁₂ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₁₂ aryl group, A substituted or unsubstituted C ₆ -C ₁₂ alkylaryl group, a substituted or unsubstituted C ₆ -C ₁₂ arylalkyl group, a substituted or unsubstituted C ₃ -C ₁₂ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group And a sulfone group,

m and n are each 1 to 5,

Formula (Ia) is included in Formula (1) of Claim 1.

More preferably, the produced single molecule thermopolymerizable hole transporting material may further include high purity purification through a column, recrystallization, and finally sublimation purification.

Further, in order to achieve the third object, the present invention provides an organic light emitting diode including a hole transport layer including a novel single molecule thermopolymerization type hole transport material.

More preferably, the hole transporting layer may be formed through a solution process and then thermally crosslinked.

More preferably, the solution process may be selected from the group consisting of spin coating, ink jet coating and nozzle jet coating.

More preferably, the thermal crosslinking can be carried out at a low temperature of 50 to 150 ° C.

More preferably, the hole transporting layer is characterized in that the interface does not dissolve in the solvent after thermal crosslinking.

When the hole transport layer is formed of the novel single molecule thermopolymerization type hole transport material according to the present invention, since the interface is not dissolved in the solvent after the thermal crosslinking, the light emitting layer is laminated on the upper side using a solution process, The organic light emitting diode (OLED) having a multi-layer structure can be manufactured effectively. Therefore, instead of the OLED display process which is currently limited to the vacuum deposition method, a multi-layered OLED having more excellent stability can be realized by using an effective solution process in terms of time and cost.

The novel single molecule thermopolymerization type hole transport material according to the present invention is easy to improve the purity of the material in a low molecular form and can directly give advantages to the life and efficiency and the heat crosslinking is performed at a relatively low temperature of 50 to 150 ° C Can be used in a process of applying a plastic substrate having a low glass transition temperature in addition to a glass substrate. Further, since there are few residual by-products and additives after the film formation, they have an advantage of excellent lifetime and efficiency.

Although the present invention focuses on the hole transporting layer, it is possible to realize a crosslinked light emitting layer and an electron transporting layer through the change of the unit in the formula structure according to the present invention. Therefore, at present, it is a method of manufacturing an OLED using a solution process partly, but it is possible to implement an OLED by using the whole process as a solution process through future improvement.

The technical effects of the present invention are not limited to those mentioned above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the following description.

1 is a cross-sectional view illustrating an organic light emitting diode according to an exemplary embodiment of the present invention.
2 is an image of a glass substrate on which a thermally crosslinked thin film is formed through a novel single molecule thermal polymerization type hole transport material according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals designate like elements throughout the specification.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, such elements, components, regions, layers and / And should not be limited by these terms.

Unless otherwise specifically defined herein, the term "alkyl group" means an aliphatic hydrocarbon group. The alkyl group may be a "saturated alkyl group" which does not contain any double or triple bonds. Or the alkyl group may be an "unsaturated alkyl group" comprising at least one double bond or triple bond. The alkyl group, whether saturated or unsaturated, can be branched, straight chain or cyclic. The alkyl group may be a C ₁ to C ₃₀ alkyl group. More particularly the alkyl group may be a C ₁ ~ C ₁₀ alkyl group or a C ₁ ~ C ₆ alkyl group. For example, the C ₁ -C ₄ alkyl group can be selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl and t-butyl.

Also, unless otherwise defined in the present specification, the "cycloalkyl group" means a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Specifically, the cycloalkyl group includes a cycloalkyl group having 3 to 6 carbon atoms. Specific examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Also, unless otherwise defined herein, "aryl group (Ar)" means a carbocyclic aromatic radical having from 6 to 20 carbon atoms containing at least one ring, which rings are attached together by a pendant method Or fused. Specifically, the aryl group includes an aryl group having 6 to 20 carbon atoms, more specifically 6 to 12 carbon atoms. Specific examples of the aryl group include a phenyl group, a naphthyl group and a biphenyl group.

Unless otherwise defined in the present specification, "arylalkyl group" means a functional group (Ar-Ra-) in which a linear or branched alkyl group (Ra) is substituted with an aryl group (Ar) which is an aromatic hydrocarbon group. Specifically, the arylalkyl group includes an arylalkyl group having 7 to 20 carbon atoms, more specifically 7 to 12 carbon atoms. Specific examples of the arylalkyl group include a benzyl group and a phenethyl group.

The term "alkylaryl group" as used herein means a functional group (Ra-Ar-) in which an aromatic hydrocarbon group (Ar) is substituted with a linear or branched alkyl group (Ra) unless otherwise defined herein. Specifically, the alkylaryl group includes an alkylaryl group having 7 to 20 carbon atoms, more specifically 7 to 12 carbon atoms.

In addition, unless otherwise defined herein, "aryloxy group" means an aryl group (-OAr) bonded with oxygen, wherein the aryl group is as defined above. Specifically, the aryloxy group includes an aryloxy group having 6 to 20 carbon atoms, more specifically 6 to 12 carbon atoms. Specific examples of the aryloxy group include phenoxy and the like.

The term "arylamine group" as used herein means a functional group (Ar-NH ₂ -) in which an amine group (NH ₂ -) is substituted with an aryl group (Ar) which is an aromatic hydrocarbon group, unless otherwise defined herein. Specifically, the arylalkyl group includes an arylamine group having 6 to 20 carbon atoms, more specifically 6 to 12 carbon atoms.

Unless otherwise specifically defined herein, a "heteroaryl group" includes at least one heteroatom selected from the group consisting of N, O, S, Se, and P in at least one ring, Means a polycyclic aromatic compound consisting of a monocyclic aromatic compound or a fused aromatic ring which is a carbon, monocyclic aromatic compound, or a fused aromatic ring.

In the present specification, when "C _x -C _y " is described, the case where the number of carbon atoms corresponding to all the integers between the number of carbon atoms x and the number of carbon atoms y is also to be interpreted as described.

Heat polymerization type  Hole transport material

The present invention proposes a novel single molecule thermo-polymerizable hole transport material capable of forming a polymer or a crosslinked polymer through a cross-linking reaction before forming a thin film or forming a thin film in a low molecular form as a material constituting the hole layer .

The following formula 1 represents a compound according to one embodiment of the present invention.

In Formula 1,

Ar ¹ to Ar ³ independently represent a substituted or unsubstituted C ₃ -C ₃₀ aryl, heteroaryl, arylalkyl or alkylaryl group,

R ¹ and R ² independently represent a substituted or unsubstituted C ₁ -C ₉ alkyl group, a substituted or unsubstituted C ₅ -C ₃₀ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, A substituted or unsubstituted C ₆ -C ₃₀ alkylaryl group, a substituted or unsubstituted C ₆ -C ₃₀ arylalkyl group, a substituted or unsubstituted C ₃ -C ₃₀ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group Or a sulfonic group,

m and n are each 1 to 5.

Preferably,

Ar ¹ to Ar ³ are non-fused ring aromatic substituents consisting of benzene, pyridine, pyrrole, furan and thiophene; Hetero-fused-ring aromatic substituents; A fused ring aromatic substituent consisting of naphthalene, anthracene, triphenylene, pyrene and perylene; And dibenzoyl fused ring substituents consisting of carbazole, fluorene, dibenzofuran, dibenzothiophene and spirofluorene,

R ¹ and R ² independently represent a substituted or unsubstituted C ₁ -C ₄ alkyl group, a substituted or unsubstituted C ₅ -C ₁₂ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₁₂ aryl group, A substituted or unsubstituted C ₆ -C ₁₂ alkylaryl group, a substituted or unsubstituted C ₆ -C ₁₂ arylalkyl group, a substituted or unsubstituted C ₃ -C ₁₂ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group Or a sulfonic group,

m and n are each 1 to 5.

More preferably, the thermally polymerizable hole transport material according to the present invention can be selected from the following compounds 1-70.

The heat-polymerizable hole-transporting material of the present invention is characterized in that an aryl amine unit having a high hole-transporting ability is chemically reacted with the arylamine derivative in order to impart hole-transporting properties to hole injection and / or hole- And a tertiary alcohol unit which can be bound through the same molecule.

In the compound of formula (1) according to the present invention, the arylamine unit is a benzene-substituted form, and the reactive hydrogen is present at the ortho or para position of the benzene. Alkyl or aryl group is connected.

The compound containing both of the arylamine and the tertiary alcohol of the formula (1) is a low molecular weight substance having a molecular weight of 2000 or less which can improve the purity and can form a polymer or a crosslinked polymer through a crosslinking reaction before or after forming a thin film. have.

Specifically, when the compound of formula (1) containing both the arylamine and the tertiary alcohol is dissolved in an appropriate solvent and then Bronsted acid or Lewis acid is added, the aryl unit of the amine and the tertiary A dehydration condensation reaction takes place between the alcohols to form intermolecular or intramolecular bonds.

Therefore, in order to carry out such polymerization, at least one unit of an arylamine unit and a tertiary alcohol unit should be present in the compound, and in the case of an arylamine, a hydrogen capable of reacting with a reactive site (mainly a para position of nitrogen) Must be at least one. When two or more reactive hydrogen atoms are present and two or more tertiary alcohol units are present, a highly crosslinked polymer can be obtained.

Further, in order to completely remove the OH group which may act as a trap of charges after the reaction or affect the stability of the device, the number of reactive hydrogen atoms (para-position hydrogen of aromatic amine) in the molecule is preferably equal to or more than the number of OH groups Do.

Heat polymerization type  Method of manufacturing hole-transporting material

The thermally polymerizable hole transport material represented by the above formula (1) can be obtained by the reaction shown in the following reaction formula (1).

[Reaction Scheme 1]

(In the above Reaction Scheme 1, Ar ¹ to Ar ³ , R ¹ and R ² , n and m are as defined in Formula 1.)

Specifically, the process for preparing a thermally polymerizable hole transporting material of Formula 1 according to the present invention comprises reacting a halogen functional group in an allylamine compound of Formula 2 with an alkyllithium or magnesium in an organic solvent, Preparing an organometallic reagent of Formula 3 containing an amine (Step 1); And

The compound of Chemical Formula 4 having at least one carbonyl functional group in the molecule is reacted with the organometallic reagent of Formula 3 containing the allylamine and then a hydrogen-supplying reagent is added to form a tertiary alcohol, (Step 2).

At this time, the halogen functional group is preferably Br or I.

Examples of the organic solvent in step 1 include, but are not limited to, tetrahydrofuran, ethyl ether, and 1,4-dioxane.

The reaction temperature in step 1 is preferably -100 to -50 ° C. If the reaction temperature is below the freezing temperature, there is a problem in the progress of the reaction. If the reaction temperature is higher than room temperature, side reactions may occur.

In step 2, water, alcohols, sodium hydrogencarbonate, or the like may be used as the hydrogen-supplying reagent, but the present invention is not limited thereto.

In the step 2, the reaction temperature is preferably -100 to -50 ° C when the carbonyl derivative is added. If the reaction temperature is below the freezing temperature, there is a problem in the reaction progress. If the reaction temperature is higher than the normal temperature, There is a problem.

In addition, the reaction of adding hydrogen (protons, H ⁺ ) is generally preferably carried out at room temperature.

The thermally polymerizable hole transport material represented by the above formula (1) can be obtained by the reaction shown in the following reaction formula (2).

[Reaction Scheme 2]

(In the above Reaction Scheme 2,

Ar and Ar ⁴ to Ar ⁶ are non-fused ring aromatic substituents consisting of benzene, pyridine, pyrrole, furan and thiophene; Hetero-fused-ring aromatic substituents; A fused ring aromatic substituent consisting of naphthalene, anthracene, triphenylene, pyrene and perylene; And dibenzoyl fused ring substituents consisting of carbazole, fluorene, dibenzofuran, dibenzothiophene and spirofluorene,

R ³ and R ⁴ independently represent a substituted or unsubstituted C ₁ -C ₄ alkyl group, a substituted or unsubstituted C ₅ -C ₁₂ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₁₂ aryl group, A substituted or unsubstituted C ₆ -C ₁₂ alkylaryl group, a substituted or unsubstituted C ₆ -C ₁₂ arylalkyl group, a substituted or unsubstituted C ₃ -C ₁₂ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group Or a sulfonic group,

m and n are each 1 to 5,

Formula (Ia) is included in Formula (I).

Specifically, the process for preparing a thermally polymerizable hole transport material of Formula 1 according to the present invention is characterized in that an intermediate of Formula 5 having at least one carbonyl functional group and an arylamine in a molecule in an organic solvent, , An aromatic lithium or aromatic Grignard reagent and a hydrogen-supplying reagent to form a tertiary alcohol to prepare a compound of formula (I).

Examples of the organic solvent include, but are not limited to, tetrahydrofuran, ethyl ether, and 1,4-dioxane.

The reaction temperature in step 1 is preferably -100 to -50 ° C. If the reaction temperature is below the freezing temperature, there is a problem in the progress of the reaction. If the reaction temperature is higher than room temperature, side reactions may occur.

In step 2, water, alcohols, sodium hydrogencarbonate, or the like may be used as the hydrogen-supplying reagent, but the present invention is not limited thereto.

The compound of formula (1a) is included in the compound of formula (1).

The compound of formula (I) thus prepared may further be purified by high purity through a column, recrystallization, and finally sublimation purification. To this end, the compound of formula (I) of the present invention is not limited in molecular weight, but it is preferably synthesized in a low molecular weight form having a molecular weight of 2000 or less, and the lifetime and efficiency of the device can be improved through effective removal of impurities due to such molecular weight limitation .

Organic light emitting diode

1 is a cross-sectional view illustrating an organic light emitting diode according to an exemplary embodiment of the present invention.

1, an organic light emitting diode includes an anode 10 and a cathode 70, a light emitting layer 40 disposed between the two electrodes, a hole conduction layer 20 disposed between the anode 10 and the light emitting layer 40, And an electron conduction layer 50 disposed between the light emitting layer 40 and the cathode 70. The hole transport layer 20 may include a hole transport layer 25 for transporting holes and a hole injection layer 23 for facilitating injection of holes. In addition, the electron conduction layer 50 may include an electron transport layer 55 for transporting electrons and an electron injection layer 53 for facilitating injection of electrons. In addition, a hole blocking layer (not shown) may be disposed between the light emitting layer 40 and the electron transporting layer 55. Further, an electron blocking layer (not shown) may be disposed between the light emitting layer 40 and the hole transporting layer 25. However, the present invention is not limited thereto, and the electron transport layer 55 may serve as a hole blocking layer, or the hole transport layer 25 may serve as an electron blocking layer.

The anode 10 may be a conductive metal oxide, a metal, a metal alloy, or a carbon material. The conductive metal oxide is indium tin oxide (indium tin oxide: ITO), fluorine tin oxide (fluorine tin oxide: FTO), antimony tin oxide (antimony tin oxide, ATO), fluorine-doped tin oxide (FTO), SnO _2, ZnO , Or a combination thereof. The metal or metal alloy suitable as the anode 10 may be Au and CuI. The carbon material may be graphite, graphene, or carbon nanotubes.

When a forward bias is applied to the organic light emitting diode, holes are injected from the anode 10 into the light emitting layer 40, and electrons from the cathode 70 are injected into the light emitting layer 40. Electrons and holes injected into the light emitting layer 40 are combined with each other to form excitons, and light is emitted while the excitons transition to the ground state.

The light emitting layer 40 may be made of a single light emitting material or may include a light emitting host material and a light emitting dopant material.

On the other hand, the hole injection layer 23 and / or the hole transport layer 25 are layers having a HOMO level between the work function level of the anode 10 and the HOMO level of the light emitting layer 40, ) To enhance the injection or transport efficiency of holes. The electron injection layer 53 and / or the electron transport layer 55 are layers having a LUMO level between the work function level of the cathode 70 and the LUMO level of the light emitting layer 40, ) In order to increase the injection or transport efficiency of electrons.

The hole injecting layer 23 and / or the hole transporting layer 25 may be formed by applying a hole transporting material represented by the above-described formula (1) and performing polymerization or crosslinking reaction through heat treatment. The polymerized or crosslinked hole transport material proposed in the present invention may also serve as an electron blocking layer. In addition, the thin film made of the compound represented by the formula (1) of the present invention can be used as one layer of the hole injection layer (23) or the hole transport layer (25). In this case, The hole transporting layer 23 or the hole transporting layer 25 may be a commonly used hole transporting material.

Typical hole transport materials include, for example, mCP (N, N-dicarbazolyl-3,5-benzene); PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrenesulfonate); NPD (N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine); N, N'-diphenyl-N, N'-di (3-methylphenyl) -4,4'-diaminobiphenyl (TPD); N, N'-diphenyl-N, N'-dinaphthyl-4,4'-diaminobiphenyl; N, N, N'N'-tetra-p-tolyl-4,4'-diaminobiphenyl; N, N, N'N'-tetraphenyl-4,4'-diaminobiphenyl; Porphyrin compound derivatives such as copper (II) 1,10,15,20-tetraphenyl-21H, 23H-porphyrin and the like; TAPC (1,1-Bis [4- [N, N'-Di (p-tolyl) Amino] Phenyl] cyclohexane; Triarylamine derivatives such as N, N, N-tri (p-tolyl) amine and 4,4 ', 4'-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine; Carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole; Phthalocyanine derivatives such as nonmetal phthalocyanine and copper phthalocyanine; Starburst amine derivatives; Enamnstilbene derivatives; Derivatives of aromatic tertiary amines and styryl amine compounds; And polysilane.

The hole blocking layer serves to prevent triplet excitons or holes from diffusing toward the cathode 70, and may be selected arbitrarily from known hole blocking materials. For example, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, and the like can be used.

The electron transporting layer 55 may be formed of a material selected from the group consisting of diphenylphosphine oxide-4- (triphenylsilyl) phenyl, tris (8-quinolinolate) aluminum (Alq3), 2,5- diarylsilole derivative (PyPySPyPy), perfluorinated compound PF-6P), COTs (octasubstituted cyclooctatetraene), TAZ (see the following chemical formula), Bphen (4,7-diphenyl-1,10-phenanthroline) (See the following formula), or BAlq (see the following formula).

The electron injection layer 53 may be, for example, LiF, NaCl, CsF, Li 2 O, BaO, BaF 2, or Liq (lithium quinol rate).

The cathode 70 is a conductive film having a lower work function than the anode 70 and is made of a metal such as aluminum, magnesium, calcium, sodium, potassium, indium, yttrium, lithium, May be formed using a combination of two or more of them.

The anode 10 and the cathode 70 may be formed using a sputtering method, a vapor deposition method, or an ion beam deposition method. The hole injecting layer 23, the hole transporting layer 25, the light emitting layer 40, the hole blocking layer, the electron transporting layer 55 and the electron injecting layer 53 are formed by a vapor deposition method or a coating method, , Spin coating, dipping, printing, inkjet printing, nozzle jet printing, doctor blading, or electrophoresis.

In particular, the compound of Formula 1 of the present invention can be used as a hole transport layer material. The method of forming the hole transport layer of the organic light emitting diode using the compound of Formula 1 of the present invention may be a method of polymerizing or crosslinking after vacuum deposition, A solution may be prepared using a suitable solvent, and then a thin film may be formed using a solution process. Preferably, the compound of formula (I) of the present invention may be formed into a thin film by a solution process, and the solution process may be spin coating, ink jet coating, nozzle jet coating, or the like.

The basic reaction utilizes an electrophilic substitution reaction of an aromatic compound as shown in Reaction Scheme 3 below, and the reaction can be terminated within one hour at a temperature of from room temperature to 150 ° C using Bronsted acid or Lewis acid as a catalyst . Water (H ₂ O) as a by-product after the reaction is terminated and acid used as a catalyst may remain in the thin film, but can be removed by an additional heating process.

[Reaction Scheme 3]

At this time, the acid used in the reaction is a monovalent or divalent polyvalent acid, and may be a polyvalent acid such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, oxalic acid, benzoic acid ), Carbonic acid, fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, Organic acids such as trichloroacetic acid and isobutyric acid, and inorganic acids such as HF, HCl, HBr, HI, and sulfuric acid. Lewis acids such as trifluoroborane: THF may also be used. Such organic acids, inorganic acids, Lewis acids and the like are not particularly limited, but it is preferable to use an acid having a boiling point of 200 캜 or less in terms of device characteristics.

The organic light emitting diode may be disposed on a substrate (not shown), which may be disposed under the anode 10 or above the cathode 70. In other words, the anode 10 may be formed on the substrate before the cathode 70, or the cathode 70 may be formed before the anode 10.

The substrate may be a light-transmissive substrate as a flat plate member, in which case the substrate may be glass; Ceramics material; And may be made of a polymer material such as polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polypropylene (PP) However, the present invention is not limited to this, and the substrate may be a metal substrate capable of light reflection.

Hereinafter, preferred examples and examples of the present invention will be described in order to facilitate understanding of the present invention. However, the following Synthesis Examples and Experimental Examples are for the purpose of helping understanding the present invention, and the present invention is not limited by the following Synthesis Examples and Experimental Examples.

< Synthetic example  1: Preparation of compound 1 &gt;

Compound 1 as a hole transporting material was prepared in the following manner.

Specifically, 4-bromo-N, N-diphenyl aniline (1 eq.) Was dissolved in tetrahydrofuran in which water was removed in a nitrogen atmosphere, and the mixture was stirred at -78 ° C. Next, 1.6 M butyllithium solution (1.2 equivalents) was slowly added at -78 占 폚 and stirred for 2 hours. A solution of 9-fluorene (1.2 equivalents) in anhydrous tetrahydrofuran was slowly added at -78 ° C and stirred for 2 hours. The reaction solution was gradually warmed to room temperature and stirred for an additional 6 hours. Finally, the reaction was terminated by slow addition of water and tetrahydrofuran solution. The reaction mixture solution was extracted with methylene chloride, and purified by column chromatography using an ethyl acetate / hexane mixed solvent as a developing solvent. Subsequently, the obtained solid component was subjected to sublimation purification to obtain pure Compound 1.

Compound 1: Yield 71%, Mass Spectrum (FD) m / z 426 [(M + H) <^+> ].

^{1 H NMR: δ 2.51 (s} , 1H), δ 6.96 (t, 2H), δ 7.04 ~ 7.1 (m, 6H), δ 7.19 ~ 7.24 (t, 4H), δ 7.27 ~ 7.3 (d, 2H), ? 7.38-7.42 (d, 2H),? 7.45-7.5 (m, 4H),? 7.55-7.58 (d, 2H)

< Synthetic example  2: Preparation of Compound 9 &gt;

Synthesis of compound 9 was carried out by reacting 4-bromo-N, N-diphenyl aniline with N, N'-bis (4-bromophenyl) -N, N'-diphenylbenzene- ), 1.6 M butyllithium solution (2.3 equivalents) and 9-fluorenone (2.3 equivalents) were used.

Compound 9: Yield 65%, Mass Spec (FD) m / z 773 [(M + H) <^+> ].

^{1 H NMR: δ 2.56 (s} , 2H), δ 6.99 ~ 7.04 (m, 8H), 7.11 ~ 7.16 (m, 6H), δ 7.25 ~ 7.29 (m, 8H), 7.37 ~ 7.41 (d, 4H), 7.44-7.49 (m, 8H), [delta] 7.55-7.57 (d, 4H)

&Lt; Synthesis Example 3: Preparation of Compound 13 &gt;

Synthesis of compound 13 was carried out in the same manner as in the synthesis of compound 13 except that 4-bromo-N, N-diphenyl aniline was dissolved in N, N'-bis (3-bromophenyl) -N, N'- (2.3 eq.) And 9-fluorenone (2.3 eq.).

Compound 13: Yield 68%, mass spectroscopy (FD) m / z 849 [(M + H) <^+> ].

^{1 H NMR: δ 2.53 (s} , 2H), δ 7.02 ~ 7.06 (m, 4H), δ 7.11 ~ 7.17 (m, 12H), δ 7.26 ~ 7.30 (m, 6H), 7.38 ~ 7.42 (d, 4H) , [delta] 7.44 to 7.49 (m, 12H), [delta] 7.60 to 7.64 (d, 4H)

< Manufacturing example  1: Synthetic example  1 &lt; / RTI &gt; prepared in Example &lt; RTI ID = Hole transport layer  Formation>

A hole transport layer was formed by a solution process using Compound 1 which is a hole transport material in the following manner.

First, PEDOT: PSS was spin-coated on the ITO glass as a substrate, followed by heat treatment at 150 ° C to form a thin film. Next, a solution prepared by dissolving Compound 1 prepared in Synthesis Example 1 in toluene solvent at 0.5 wt% was spin-coated at 2000 rpm for 30 seconds to form a compound 1 thin film. Thereafter, heat treatment was performed at 100 占 폚 for 30 minutes to prepare thermally crosslinked thin films.

2 shows a glass substrate on which a hole transporting layer thin film formed using Compound 1 was formed. As shown in FIG. 2, it can be seen that a thin film of the hole transporting layer is well formed on the glass substrate.

< Experimental Example  One: Thermally crosslinked Hole transport layer  Thin-film In an organic solvent  Impact Assessment on>

In order to investigate the effect of the compound of formula (1) according to the present invention on the organic solvent, the following experiment was conducted.

The thermally crosslinked hole transporting layer thin film prepared using the compound 1 of FIG. 2 was subjected to a washing treatment with toluene in which the compound 1 was dissolved, and the thickness of the thin film was measured before and after the washing treatment.

The results are shown in Table 1 below.

Transfer of toluene wash After toluene washing Thin film thickness of Compound 1 18nm 18nm

As shown in Table 1, the thickness of the hole transporting layer thin film made of the compound of Formula 1 according to the present invention did not change even after washing with toluene solvent after thermal crosslinking, Transporting layer thin film is not dissolved by an organic solvent even when a light-emitting layer or the like is laminated, it is possible to prevent the phenomenon of intermixing due to the solution. Therefore, when the hole transport layer is formed of the compound of Formula 1 according to the present invention, a hole transport layer can be formed using a solution process, and the produced hole transport layer is not dissolved in an organic solvent after thermal crosslinking, It is possible to effectively produce an OLED because there is little intermixing between layers.

Therefore, when the compound of Formula 1 according to the present invention is used instead of the OLED display process which is currently limited to the vacuum evaporation method, even when an effective solution process is used in terms of time and cost, An OLED having an excellent multi-layer structure can be realized.

< Manufacturing example  2: Of an organic light emitting diode  Manufacturing>

(ITO / PEDOT: PSS / Compound 1 / mCP: Ir (ppy) ₃ / TSPO1 / TPBi / LiF / Al)

The glass substrate on which the anode ITO (150 nm) was deposited was cleaned with isopropyl alcohol as a solvent for 30 minutes under ultrasonic irradiation. The cleaned ITO substrate was surface-treated with ultraviolet rays of short wavelength, then PEDOT: PSS solution was spin-coated and then heat-treated at 150 ° C to form a hole injection layer. Next, a mixed solution of acetic acid and toluene (solvent ratio: 1: 1) in which the compound 1 prepared in Synthesis Example 1 was dissolved at 0.5 wt% was spin-coated at 2000 rpm for 30 seconds to form a hole transport layer. Thereafter, heat treatment was performed at 100 占 폚 for 30 minutes to prepare a thermally crosslinked hole transporting layer.

Then, the light-emitting layer mCP (N, N-dicarbazolyl- 3,5-benzene) and tris [2-phenyl-pyrido Dina sat -C2, N] iridium (III) (or less Ir (ppy) _3), each light-emitting host material and a phosphorescent And used as a dopant material. The light emitting layer was formed by quantifying mCP and Ir (ppy) ₃ at a weight ratio of 100: 10, dissolving in toluene, and spin coating to form a 25 nm light emitting layer.

Subsequent processes used deposition methods. TSPO1 (diphenylphosphine oxide-4- (triphenylsilyl) phenyl), which was used as a hole blocking layer, was deposited at a rate of 0.1 nm / s under a pressure of 1 × 10 ^-6 torr to form 5 nm, followed by TPBi Tris (N-phenylbenzimidazol-2-yl) benzene) was deposited at the same deposition rate to form an electron transport layer of 30 nm. Thereafter, LiF was deposited as an electron injecting material under a pressure of 1 × 10 ^-6 torr at a rate of 0.01 nm / s to form a 1 nm electron injecting layer. Thereafter, Al was vapor-deposited at a rate of 0.5 nm / sec under a pressure of 1 × 10 ^-6 torr to form a cathode of 120 nm to form an organic light-emitting diode. After the device was formed, the device was sealed using a CaO wetting agent and a glass cover glass. As a result, the device structure was ITO / PEDOT: PSS / Compound 1 / mCP: Ir (ppy) ₃ / TSPO1 / TPBi / LiF / Al.

The current efficiency and the power efficiency were 57.0 cd / A and 44.7 lm / W, respectively, and the x, y and z values of the organic light emitting diode prepared in Manufacturing Example 2 were 16.8% at a voltage of 4 V, 0.31 and y = 0.62, respectively.

< Manufacturing example  3: Of an organic light emitting diode  Manufacturing>

(ITO / PEDOT: PSS / Compound 9 / mCP: Ir (ppy) ₃ / TSPO1 / TPBi / LiF / Al)

In Production Example 3, a device was manufactured in the same manner except that Compound 1 used as the hole transport layer material in Production Example 2 was used as Compound 9.

The organic light emitting diode prepared in Example 3 had a quantum efficiency of 17.8% at a voltage of 4 V. The current efficiency and power efficiency were 60.5 cd / A and 47.5 lm / W, respectively, and x = 0.31 and y = 0.62, respectively.

< Manufacturing example  4: Of an organic light emitting diode  Manufacturing>

(ITO / PEDOT: PSS / Compound 13 / mCP: Ir (ppy) ₃ / TSPO1 / TPBi / LiF / Al)

In Production Example 4, a device was manufactured in the same manner as in Production Example 2, except that the compound 1 used as the hole transport layer material was used as the compound 13.

The current efficiency and power efficiency of the organic light emitting diode fabricated through Production Example 4 were 18.9% at a voltage of 4 V and 58.6 cd / A and 51.1 lm / W, respectively, 0.26, and y = 0.64, respectively.

< Manufacturing example  5: Of an organic light emitting diode  Manufacturing>

(ITO / PEDOT: PSS / Compound 1: Compound  13 / mCP: Ir (ppy) ₃ / TSPO1 / TPBi / LiF / Al)

In Production Example 5, the compound 1 and the compound 13 were used in a weight ratio of 1: 1 as the hole transport layer material. In the other front and back processes, the device was manufactured in the same manner as in Production Example 2.

The organic light emitting diode prepared in Example 5 had a quantum efficiency of 22.5% at a voltage of 4 V. The current efficiency and the power efficiency were 71.8 cd / A and 62.3 lm / W, respectively, and x = 0.30 and y = 0.63, respectively. Therefore, when the compound of the present invention is mixed and used, better device characteristics may be exhibited.

< Comparative Example  1: Conventional Of an organic light emitting diode  Manufacturing>

In Comparative Example 1, devices were manufactured in the same manner as in Production Example 2 except that the compound 1 used as the hole transport layer material was used as polyvinylcarbazole (molecular weight: 1,000,000).

The organic light emitting diode prepared in Comparative Example 1 had a quantum efficiency of 13.2% at a voltage of 4 V. The current efficiency and the power efficiency were 40.5 cd / A and 34.8 lm / W, respectively, and x = 0.27 and y = 0.64, respectively.

The characteristics of the organic light emitting diodes manufactured in Production Examples and Comparative Examples are summarized in Table 2 below.

Quantum efficiency (4V) (%) Current efficiency (cd / A) Power Efficiency (lm / W) CIE 1931 color coordinates Production Example 2 16.8 57.0 44.7 (0.31, 0.62) Production Example 3 17.8 60.5 47.5 (0.31, 0.62) Production Example 4 18.9 58.6 51.1 (0.26, 0.64) Production Example 5 22.5 71.8 62.3 (0.30, 0.63) Comparative Example 1 13.2 40.5 34.8 (0.27, 0.64)

As shown in Table 2, the organic light emitting diode including the hole transporting layer made of the novel single molecule thermally polymerizable hole transporting material of the present invention is superior to the organic light emitting diode made of the conventional hole transporting material in terms of quantum efficiency, And the efficiency is improved, so that it can be usefully used in organic light emitting diodes.

10: anode
20: hole conduction layer
23: Hole injection layer
25: hole transport layer
40: light emitting layer
50: electron conductive layer
53: electron injection layer
55: electron transport layer
70: cathode

Claims (14)

A novel single molecule thermopolymerizable hole transport material represented by the following formula (1).
[Chemical Formula 1]

(In the formula 1,
Ar ¹ to Ar ³ independently represent a substituted or unsubstituted C ₃ -C ₃₀ aryl, heteroaryl, arylalkyl or alkylaryl group,
R ¹ and R ² independently represent a substituted or unsubstituted C ₁ -C ₉ alkyl group, a substituted or unsubstituted C ₅ -C ₃₀ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, A substituted or unsubstituted C ₆ -C ₃₀ alkylaryl group, a substituted or unsubstituted C ₆ -C ₃₀ arylalkyl group, a substituted or unsubstituted C ₃ -C ₃₀ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group And a sulfone group,
m and n are each 1 to 5)
The method according to claim 1,
Ar ¹ to Ar ³ independently represent a non-fused ring aromatic substituent consisting of benzene, pyridine, pyrrole, furan and thiophene; Hetero-fused-ring aromatic substituents; A fused ring aromatic substituent consisting of naphthalene, anthracene, triphenylene, pyrene and perylene; And dibenzoyl fused ring substituents consisting of carbazole, fluorene, dibenzofuran, dibenzothiophene and spirofluorene,
R ¹ and R ² independently represent a substituted or unsubstituted C ₁ -C ₄ alkyl group, a substituted or unsubstituted C ₅ -C ₁₂ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₁₂ aryl group, A substituted or unsubstituted C ₆ -C ₁₂ alkylaryl group, a substituted or unsubstituted C ₆ -C ₁₂ arylalkyl group, a substituted or unsubstituted C ₃ -C ₁₂ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group And a sulfone group,
and m and n are each 1 to 5. 2. The hole-transporting material according to claim 1,
The method according to claim 1,
Wherein the heat-polymerizable hole-transporting material is selected from the following compounds 1-70.

The method according to claim 1,
Wherein the compound of Formula 1 has at least one arylamine unit and at least one tertiary alcohol unit in the molecule, reactive hydrogen is present at the ortho or para position of the benzene group of the arylamine, and the tertiary alcohol unit is a sp3 carbon Or a structure in which three alkyl or aryl groups are bonded to silicon.
5. The method of claim 4,
Wherein the number of reactive hydrogen atoms of the arylamine in the molecule is equal to or greater than the number of OH groups in the tertiary alcohol unit.
The method according to claim 1,
Wherein the compound of Formula 1 has a molecular weight of 2000 or less.
As shown in Scheme 1 below,
Reacting a halogen functional group in an allyl amine compound of formula (2) with an alkyl lithium or magnesium in an organic solvent to prepare an organometallic reagent of formula (3) containing allylamine (step 1); And
The compound of Chemical Formula 4 having at least one carbonyl functional group in the molecule is reacted with the organometallic reagent of Formula 3 containing the allylamine and then a hydrogen-supplying reagent is added to form a tertiary alcohol, (Step 2) of preparing the novel single-molecule heat-polymerizable hole-transporting material.
[Reaction Scheme 1]

(In the above Reaction Scheme 1, Ar ¹ to Ar ³ , R ¹ and R ² , n and m are as defined in Chemical Formula 1 of the above-mentioned 1)
As shown in Scheme 2 below,
The compound of formula (I) is prepared by treating a intermediate of formula (5) having at least one carbonyl functionality and an arylamine in the molecule simultaneously in an organic solvent with an aromatic lithium or aromatic Grignard reagent and a hydrogen-providing reagent to form a tertiary alcohol, The method for producing a novel single-molecule heat-polymerizable hole-transporting material according to claim 1, comprising the steps of:
[Reaction Scheme 2]

(In the above Reaction Scheme 2,
Ar and Ar ⁴ to Ar ⁶ are non-fused ring aromatic substituents consisting of benzene, pyridine, pyrrole, furan and thiophene; Hetero-fused-ring aromatic substituents; A fused ring aromatic substituent consisting of naphthalene, anthracene, triphenylene, pyrene and perylene; And dibenzoyl fused ring substituents consisting of carbazole, fluorene, dibenzofuran, dibenzothiophene and spirofluorene,
R ³ and R ⁴ independently represent a substituted or unsubstituted C ₁ -C ₄ alkyl group, a substituted or unsubstituted C ₅ -C ₁₂ cycloalkyl group, a substituted or unsubstituted C ₆ -C ₁₂ aryl group, A substituted or unsubstituted C ₆ -C ₁₂ alkylaryl group, a substituted or unsubstituted C ₆ -C ₁₂ arylalkyl group, a substituted or unsubstituted C ₃ -C ₁₂ heteroaryl group, a substituted or unsubstituted aryl Substituted or unsubstituted arylamine, a substituted or unsubstituted fused arylamine group, a substituted or unsubstituted phosphine or phosphine oxide group, a substituted or unsubstituted thiol group, a substituted or unsubstituted sulfoxide group And a sulfone group,
m and n are each 1 to 5,
Formula (Ia) is included in Formula (1) of Claim 1.
9. The method according to claim 7 or 8,
Wherein the produced single molecule thermally polymerizable hole transport material further comprises high purity purification through a column, recrystallization, and finally sublimation purification.
An organic light emitting diode comprising a hole transport layer comprising the novel single molecule thermopolymerizable hole transport material of claim 1.
The organic light emitting diode according to claim 10, wherein the hole transport layer is formed through a solution process and then thermally crosslinked.
12. The organic light emitting diode according to claim 11, wherein the solution process is selected from the group consisting of spin coating, ink jet coating and nozzle jet coating.
The organic light emitting diode according to claim 11, wherein the thermal crosslinking is performed at a low temperature of 50 to 150 占 폚.
The organic light emitting diode according to claim 11, wherein the hole transport layer does not dissolve the interface in the solvent after thermal crosslinking.

Images