KR101319275B1 - Composition for Organic Light Emitting Device and Organic Light Emitting Device using the same - Google Patents

Abstract

The present invention relates to a composition for an organic light emitting layer, and an organic light emitting device using the same, comprising a base polymer resin, a monomer having a photoreactor, a photoinitiator, a monomolecular emission pigment, and a solvent.

According to the present invention, a large area is possible, a photolithography process can be applied, and since monomolecular emission pigments are used, impurity purification is advantageous, thereby increasing the life of the device.

The organic light-

Description

Composition for Organic Light Emitting Device, and Organic Light Emitting Device Using the Same {Composition for Organic Light Emitting Device and Organic Light Emitting Device using the same}

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

<Explanation of symbols for the main parts of the drawings>

10 transparent substrate 20 anode

30: hole injection layer 40: hole transport layer

50: organic light emitting layer 60: electron transport layer

70 electron injection layer 80 cathode

The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting layer of an organic light emitting device.

The organic light emitting device has a structure in which a thin film organic light emitting layer having semiconductor characteristics is formed between an anode and a cathode, and when current is applied to the anode and the cathode, holes from electrons and anodes from the cathode are injected into the organic light emitting layer. An exciton is a device that emits light in the visible region as it transitions from an excited state to a ground state.

The organic light emitting device may use a single molecule material or a polymer material as the organic light emitting layer.

In the case where the monomolecular material is used as the organic light emitting layer, a thin film type organic light emitting layer is formed by using a vapor deposition method of the monomolecular material in powder form.

When the polymer material is used as the organic light emitting layer, the organic material is dissolved in a solvent to form a thin film organic light emitting layer using a spin coating method or an inkjet method.

When the monomolecular material is used as the organic light emitting layer, impurity purification is advantageous, and thus the lifetime of the device is increased. However, since a thin film is manufactured through a deposition method, uniformity is produced when manufacturing a large area device. Apart from the large area, there are disadvantages.

In the case where the polymer material is used as the organic light emitting layer, uniformity can be maintained and a large area can be obtained. However, impurity refining is disadvantageous and the lifetime of the device is shortened. In addition, when the polymer material is used as the organic light emitting layer, since the polymer material is dissolved and laminated in the solvent, when forming a plurality of layers, the lower layer may be dissolved in the solvent when the upper layer is formed, and thus it is difficult to apply the photolithography process to the plurality of layers. Pattern formation becomes impossible.

Due to such a problem, although it is disadvantageous for a large area device, an organic light emitting device using a single molecular material as an organic light emitting layer has been commercialized.

Therefore, the development of an organic light emitting layer material that can overcome all the disadvantages of the mono- and polymer materials in the organic light emitting device is required.

The present invention has been made to solve the above conventional problems,

A first object of the present invention is to provide an organic light emitting layer material which is advantageous in purifying impurity to increase the lifetime of the device and to increase the uniformity, so that it is applicable to large area devices and easy to form patterns on thin films.

It is a second object of the present invention to provide an organic light emitting device to which the organic light emitting layer material is applied.

In order to achieve the first object as described above, the present invention provides a composition for an organic light emitting layer, comprising a base polymer resin, a monomer having a photoreactor, a photoinitiator, a monomolecular emission pigment, and a solvent.

In order to achieve the second object as described above, the present invention comprises an anode, a cathode, and an organic light emitting layer formed between the anode and the cathode, the organic light emitting layer is the base polymer resin, a monomer having a photoreactor, a photoinitiator The present invention provides an organic light emitting device comprising a composition for an organic light emitting layer, the composition comprising a single molecule light emitting pigment and a solvent.

Hereinafter, a composition for an organic light emitting layer according to a preferred embodiment of the present invention will be described in detail.

The composition for an organic light emitting layer according to an embodiment of the present invention comprises a base polymer resin, a monomer having a photoreactor, a photoinitiator, a monomolecular emission pigment, and a solvent.

The base polymer resin, the monomer having the photoreactor, and the photoinitiator are dissolved in a solvent, and the single molecule light emitting pigment is dispersed in the solvent.

As such, since the composition for the organic light emitting layer according to the present invention is present in a solution state, when the organic light emitting layer is applied as an organic light emitting layer, the composition may be formed in a thin film form using a spin coating method or an ink jet method, thereby maintaining uniformity. The area can be increased.

In addition, the base polymer resin serves as a support, and the monomer having the photoreactive group is a photopolymerization reaction by the photoinitiator to form a crosslink, the composition is cured by the photopolymerization reaction of the monomer having the photoreactive group After the composition is configured in a thin film form, the photolithography process can be applied.

In addition, since the composition for an organic light emitting layer according to the present invention uses a monomolecular light emitting color as a light emitting color for emitting blue, green and red light, impurity purification is advantageous and the life of the device is increased.

Hereinafter, each composition component constituting the composition for an organic light emitting layer according to the present invention will be described in detail.

The base polymer resin serves as a support, preferably made of polyvinylcarbazole (PVK), and the content thereof is preferably included in an amount of 30-60 wt% based on the total composition.

The polyvinylcarbazole used as the base polymer resin is preferably a compound represented by the following Chemical Formula 1.

Formula 1

(Wherein n is an integer of 1 or more).

The monomer having the photoreactor is crosslinked by a photopolymerization reaction, preferably made of a carbazole monomer, the content of which is preferably contained in 5-20% by weight based on the total composition.

The carbazole monomer used as the monomer having the photoreactor is preferably composed of a carbazole monomer consisting of the following Chemical Formula 2, Chemical Formula 3, Chemical Formula 4, or Chemical Formula 5.

(2)

,

,

(3)

,

,

Formula 4

,

,

Formula 5

.

.

Formula 2 may be prepared by the following N-alkylation reaction (N-Alkylation).

Formula 3 may be prepared by dimethyl bromination as described below.

Formula 4 may be prepared by the alcoholation reaction as follows.

Formula 5 may be prepared by the following reaction.

The photoinitiator is to initiate a photopolymerization reaction of the acrylic monomer, it may be composed of a compound selected from the group consisting of triazine compound, acetophenone compound, xanthone compound, benzoin compound, and imidazole compound, the content of It is preferred to include 0.5-5% by weight based on the total composition.

Specific examples of the triazine-based compound include 2,4-bistrichloromethyl-6-p-methoxystyryl-s-triazine and 2-p-methoxystyryl-4,6-bistrichloromethyl-s -Triazine, 2,4-trichloromethyl-6-triazine, 2- (2-bromo-4-methylphenyl) -4,6-bis (trichloromethyl) -s-triazine and the like.

Specific examples of the acetophenone compound include benzophenone, p- (dimethylamino) benzophenone, 2,2-dichloro-4-phenoxycetophenone, 4,4-bisdiethylaminobenzophenone, 2,2- Diethoxyacetophenone, 2,2-dibutoxyacetophenone, 2-hydroxy-2-methylproriophenone, pt-butyltrichloroacetophenone, and the like.

Specific examples of the xanthone compound include xanthone, thioxanthone, 2-methyl thioxanthone, 2-isobutyl thioxanthone, 2-dodecyl thioxanthone, and 2,4-dimethyl thioxanthone.

Specific examples of the benzoin-based compound include compounds such as benzoin, benzoin ethyl ether, benzoin methyl ether, benzoyl propyl ether, t-butyl benzoyl ether and the like.

Specific examples of the imidazole compound include 2,2-bis-2-chlorophenyl-4,5,4,5-tetraphenyl-2-1,2-biimidazole, 2,2-bis (2,4 , 6-tricyanophenyl) -4,4,5,5-tetraphenyl-1,2-biimidazole.

The photoinitiator may be mixed with a sensitizer, a curing accelerator, and the like as necessary, and specific examples thereof include 4-dimethylamino benzophenone, isopropyl thioxanthone, methyl-o-benzoylbenzoate, and 4- (methylphenylthio)-. Compounds, such as phenyl- phenylmethane, 2, 4- diethyl thioxanthone, 2-chloro thioxanthone, benzophenone, and ethyl anthraquinone, can be used.

The monomolecular emission pigment is contained in 20-50% by weight based on the total composition, it may be made of a material represented by the formula (6) or the following formula (7). Formula 6 may be used as a single-molecule emitting color that emits green light, and Formula 7 may be used as a single-molecule emitting color that emits blue light.

6

,

,

Formula 7

.

.

In addition, the monomolecular emission pigment is a material selected from the group consisting of PtOEP (Octaethylporphine platinum (II)), rhodamine (rhodamine), rhodamine derivatives, perylene, quinacridone, rubrene, distyryl biphenyl and derivatives thereof Can be done. Rhodamine, rhodamine derivatives, and perylene are used as monomolecular luminescent dyes emitting red light, knacridon and rubrene are used as monomolecular luminescent dyes emitting green light, Distyrylbiphenyl and its derivatives are used as monomolecular luminescent pigments that emit blue light.

In the present invention, the monomer having the base polymer resin and the photoreactor constitutes a host material, and the monomolecular light emitting pigment constitutes a guest material.

The host material absorbs light in the UV region and emits light in the short wavelength region, and the guest material absorbs light in the region where the host material emits light and displays visible light (red, green, blue). It has the property of emitting light of the area. Luminous efficiency can be improved by combining a host material and a guest material having such properties.

The solvent is isopropyl alcohol (IPA), normal butanol, γ-butyrolactone, N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI) and derivatives thereof, carbitol Glycol ethers such as acetate and butyl carbitol acetate, toluene, xylene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, cyclohexylbenzene, mixtures thereof, and the like can be used.

The amount of the solvent is included in the remaining amount except for the other components.

On the other hand, the composition for the organic light emitting layer may further include additives such as a dispersant for improving the dispersibility of the composition or a coating agent for improving the coating properties, the content of these additives is used in 0.1 to 2% by weight based on the total composition It is desirable to.

Hereinafter, an organic light emitting diode according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

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

As can be seen in Figure 1, the organic light emitting device according to the present invention is the anode 20, the hole injection layer 30, the hole transport layer 40, the organic light emitting layer 50, the electron transport layer 60 on the transparent substrate 10 The electron injection layer 70 and the cathode 80 have a stacked structure formed sequentially.

The transparent substrate 1 may be glass or transparent plastic.

The anode 20 may be patterned using indium tin oxide (ITO), tin oxide, a composite oxide of indium oxide and zinc oxide, etc. using a photolithography process.

The hole injection layer 30 may use copper phthalocyanine (copper (II) Phthalocyanine).

The hole transport layer 40 may use a-NPD, TPD, N, N-di (naphthalen-1-yl) -N, N'-diphenylbenzidine, triazole derivatives, styrylamine compounds, and the like. have.

The organic light emitting layer 50 uses the above-described composition for organic light emitting layers.

The organic light emitting layer 50 is formed by using the organic light emitting layer composition comprising the base polymer resin, a monomer having a photoreactor, a photoinitiator, a monomolecular emission pigment, and a solvent.

In the process of forming the organic light emitting layer 50, the composition for forming the organic light emitting layer is formed into a thin film using a spin coating method or an inkjet method, and then irradiates with light to polymerize the monomer having the photoreactive group to cure the thin film. After being made, it may be made of a process of forming a pattern using a photolithography process.

Since each component constituting the organic light emitting layer composition is the same as the above-described embodiment, a detailed description thereof will be omitted.

As the electron transport layer, Alq3, PBD, nitride fluorenone derivatives, anthraquinodimethane derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanine, and the like can be used.

The electron injection layer may use an alkali metal derivative.

The cathode may be formed using a metal material such as Mg, Ag, Al, or Li.

According to the present invention as described above, the following effects can be obtained.

First, since the composition for the organic light emitting layer is present in a solution state, when the organic light emitting layer is applied to the organic light emitting layer, the composition may be formed in a thin film form using a spin coating method or an inkjet method, thereby maintaining uniformity and thus allowing a large area.

Second, since the composition is cured by a photopolymerization reaction of a monomer having a photoreactive group, it is possible to apply the photolithography process after configuring the composition in a thin film form.

Third, since the composition for the organic light emitting layer uses a monomolecular light emitting color as a light emitting color for emitting blue, green, and red light, impurity purification is advantageous and the life of the device is increased.

Claims (17)

A base polymer resin composed of polyvinylcarbazole (PVK), a carbazole monomer, and a monomer having a photoreactor, a photoinitiator, a monomolecular luminescent dye, and a solvent; The monomolecular luminescent dye is a substance represented by the following formula (6) or (7), or PtOEP (Octaethylporphine platinum (II)), rhodamine (rhodamine), rhodamine derivatives, perylene, quinacridone, rubrene, disti An organic light emitting layer composition comprising: a material selected from the group consisting of rylbiphenyl and derivatives thereof; 6

, Formula 7

. The method of claim 1, The base polymer resin is included in 30 to 60% by weight, Monomer having the photoreactor is included in 5 to 20% by weight, The photoinitiator is contained in 0.5 to 5% by weight, The monomolecular emission pigment is included in 20 to 50% by weight, The solvent is a residual amount of the organic light emitting layer composition. delete The method of claim 1, The base polymer resin is an organic light emitting layer composition, characterized in that consisting of polyvinylcarbazole represented by the following formula (1): Formula 1

(Wherein n is an integer of 1 or more). delete The method of claim 1, The monomer having a photoreactor is an organic light emitting layer composition comprising a carbazole monomer consisting of the following formula (2), (3), (4), or (5): (2)

, (3)

, Formula 4

, Formula 5

. The method of claim 1, The photoinitiator is an organic light emitting layer composition, characterized in that consisting of a material selected from the group consisting of triazine compound, acetophenone compound, xanthone compound, benzoin compound, and imidazole compound. delete delete The method of claim 1, The solvent is isopropyl alcohol (IPA), normal butanol, γ-butyrolactone, N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI) and derivatives thereof, carbitol Glycol ethers such as acetate and butyl carbitol acetate, toluene, xylene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene, and cyclohexylbenzene. The method of claim 1, An organic light emitting layer composition, characterized in that it further comprises an additive.  An anode, a cathode, and an organic light emitting layer formed between the anode and the cathode, wherein the organic light emitting layer is the first, second, fourth, sixth, seventh, tenth, and tenth terms. An organic light-emitting device, characterized in that formed using the composition for an organic light emitting layer according to any one of claims. The method of claim 12, The organic light emitting layer is formed in a thin film form using the spin coating method or an inkjet method of the organic light emitting layer composition, and then irradiated with light to polymerize the monomer having the photoreactive group to cure the thin film, and then subjected to a photolithography process An organic light emitting device, characterized in that formed through a process of forming a pattern using. The method of claim 12, The organic light emitting device of claim 1, further comprising a hole injection layer between the anode and the organic light emitting layer. The method of claim 12, An organic light emitting device, characterized in that it further comprises a hole transport layer between the anode and the organic light emitting layer. The method of claim 12, An organic light emitting device, characterized in that it further comprises an electron injection layer between the cathode and the organic light emitting layer. The method of claim 12, An organic light emitting device, characterized in that it further comprises an electron transport layer between the anode and the organic light emitting layer.

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