KR102158805B1 - Organic light emitting device - Google Patents

Abstract

The present invention provides an organic light emitting device.

Description

Organic light emitting device {ORGANIC LIGHT EMITTING DEVICE}

The present invention relates to an organic light emitting device.

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

The organic light emitting device generally has a structure including an anode and a cathode, and an organic material layer between the anode and the cathode. The organic material layer is often made of a multi-layered structure made of different materials in order to increase the efficiency and stability of the organic light-emitting device.For example, it may be formed of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. In the structure of such an organic light emitting device, when a voltage is applied between the two electrodes, holes are injected from the anode and electrons from the cathode are injected into the organic material layer, and excitons are formed when the injected holes and electrons meet. It glows when it falls back to the ground.

Development of new materials for organic materials used in organic light emitting devices as described above is continuously required.

Korean Patent Publication No. 10-2000-0051826

The present invention provides an organic light emitting device.

The present invention is a positive electrode; A cathode provided to face the anode; And one or more organic material layers provided between the anode and the cathode, wherein the organic material layer includes an emission layer, and includes a compound represented by the following Formula 1 between the anode and the emission layer, and It provides an organic light emitting device including a compound represented by the following formula (2) between the light emitting layers.

[Formula 1]

[Formula 2]

In Formula 1, Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, or a heteroaryl having 2 to 60 carbon atoms including at least one of substituted or unsubstituted O and S And

L ¹ to L ³ are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 60 carbon atoms,

In Formula 2, X ¹ to X ³ are each independently N or CH, but at least one selected from X ¹ to X ³ is N,

Ar ³ is a substituted or unsubstituted arene having 6 to 60 carbon atoms, or a polyvalent residue derived from a heteroarene having 2 to 60 carbon atoms including at least one of substituted or unsubstituted O, N, Si and S,

Ar ⁴ and Ar ⁵ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, or a substituted or unsubstituted hetero containing at least one of O, N, Si and S 2 to 60 carbon atoms Is an aryl group,

L ⁴ and L ⁵ are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 60 carbon atoms,

n is an integer of 1 to 4.

The compound represented by Chemical Formula 1 is used as a material for the organic material layer between the anode and the emission layer, and the compound represented by Chemical Formula 2 is used as the material for the organic material layer between the cathode and the emission layer. Or it can improve the life characteristics and efficiency.

1 shows an example of an organic light-emitting device comprising a substrate 1, an anode 2, a hole injection layer 5, a hole transport layer 6, a light-emitting layer 7, an electron transport layer 8, and a cathode 4 I did it.

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

The present invention provides an organic light-emitting device using the compound represented by Formula 1 as the material of the organic material layer between the anode and the emission layer, and the compound represented by Formula 2 as the material of the organic material layer between the cathode and the emission layer. .

In the present specification, a single bond refers to a case in which a separate atom does not exist in the portion represented by L ¹ to L ⁵ . For example, if L ^{1 in} Formula 1 is a single bond, N may be directly connected to triphenylene.

In this specification the term "substituted or unsubstituted" may be substituted or means a unsubstituted by R ^a, R ^a is heavy hydrogen, a halogen, a cyano group, a nitro group, an amino group, an alkyl group having 1 to 40 carbon atoms, A haloalkyl group of 1 to 40, a heteroalkyl group having 1 to 40 carbon atoms including at least one of substituted or unsubstituted O, N, Si and S, at least one of substituted or unsubstituted O, N, Si and S It may be a C 1 to C 40 heterohaloalkyl group, or a C 2 to C 40 alkenyl group including.

In the present specification, halogen may be fluorine, chlorine, bromine or iodine.

In the present specification, the alkyl group having 1 to 40 carbon atoms may be a linear, branched or cyclic alkyl group. Specifically, the alkyl group having 1 to 40 carbon atoms is a linear alkyl group having 1 to 40 carbon atoms; A linear alkyl group having 1 to 20 carbon atoms; A linear alkyl group having 1 to 10 carbon atoms; A branched or cyclic alkyl group having 3 to 40 carbon atoms; A branched or cyclic alkyl group having 3 to 20 carbon atoms; Or it may be a branched chain or cyclic alkyl group having 3 to 10 carbon atoms. More specifically, the alkyl group having 1 to 40 carbon atoms is a methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, t-butyl group, n-pentyl group, iso-pentyl group, It may be a neo-pentyl group or a cyclohexyl group. However, it is not limited thereto.

In the present specification, the heteroalkyl group having 1 to 40 carbon atoms may be one in which one or more carbons of the alkyl group are each independently substituted with O, N, Si, or S. For example, as an example of a straight-chain alkyl group, the heteroalkyl group in which carbon 1 of the n-butyl group is substituted with O is an n-propoxy group, the heteroalkyl group substituted with N is an n-propylamino group, and the heteroalkyl group substituted with Si is n -Propylsilyl group, and the heteroalkyl group substituted with S is an n-propylthio group. And, as an example of a branched chain alkyl group, the heteroalkyl group in which carbon 1 of the neo-pentyl group is substituted with O is a t-butoxy group, the heteroalkyl group substituted with N is a t-butylamino group, and the heteroalkyl group substituted with Si is t -Butylsilyl group, and the heteroalkyl group substituted with S is a t-butylthio group. In addition, as an example of a cyclic alkyl group, the heteroalkyl group in which carbon 2 of the cyclohexyl group is substituted with O is a 2-tetrahydropyranyl group, and the heteroalkyl group substituted with N is a 2-piperidinyl group, The heteroalkyl group substituted with Si is a 1-sila-cyclohexyl group, and the heteroalkyl group substituted with S is a 2-tetrahydrothiopyranyl group. Specifically, the C1-C40 heteroalkyl group is a C1-C40 linear, branched or cyclic hydroxyalkyl group; A linear, branched or cyclic alkoxy group having 1 to 40 carbon atoms; A straight chain, branched chain or cyclic alkoxyalkyl group having 2 to 40 carbon atoms; A linear, branched or cyclic aminoalkyl group having 1 to 40 carbon atoms; A linear, branched or cyclic alkylamino group having 1 to 40 carbon atoms; A linear, branched or cyclic alkylaminoalkyl group having 1 to 40 carbon atoms; A linear, branched or cyclic silylalkyl (oxy) group having 1 to 40 carbon atoms; A linear, branched or cyclic alkyl (oxy)silyl group having 1 to 40 carbon atoms; A linear, branched or cyclic alkyl (oxy) silyl alkyl (oxy) group having 1 to 40 carbon atoms; A straight chain, branched chain or cyclic mercaptoalkyl group having 1 to 40 carbon atoms; A linear, branched or cyclic alkylthio group having 1 to 40 carbon atoms; Or it may be a C2-C40 linear, branched or cyclic alkylthioalkyl group. More specifically, the heteroalkyl group having 1 to 40 carbon atoms is a hydroxymethyl group, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, a t-butoxy group, a cyclohexanoxy group, a methoxymethyl group, iso-pro Foxymethyl group, cyclohectoxymethyl group, 2-tetrahydropyranyl group, aminomethyl group, methylamino group, n-propylamino group, t-butylamino group, methylaminopropyl group, 2-piperidinyl group, n- Propylsilyl group, trimethylsilyl group, dimethylmethoxysilyl group, t-butylsilyl group, 1-sila-cyclohexyl group, n-propylthio group, t-butylthio group or 2-tetra Hydrothiopyranyl (2-tetrahydrothiopyranyl) group, etc. are mentioned. However, it is not limited thereto.

In the present specification, the alkenyl group having 2 to 40 carbon atoms may be a linear, branched or cyclic alkenyl group. Specifically, the alkenyl group having 2 to 40 carbon atoms is a linear alkenyl group having 2 to 40 carbon atoms; A linear alkenyl group having 2 to 20 carbon atoms; A linear alkenyl group having 2 to 10 carbon atoms; A branched alkenyl group having 3 to 40 carbon atoms; A branched alkenyl group having 3 to 20 carbon atoms; A branched alkenyl group having 3 to 10 carbon atoms; A cyclic alkenyl group having 5 to 40 carbon atoms; A cyclic alkenyl group having 5 to 20 carbon atoms; Or it may be a cyclic alkenyl group having 5 to 10 carbon atoms. More specifically, the alkenyl group having 2 to 40 carbon atoms may be an ethenyl group, a propenyl group, a butenyl group, a pentenyl group, or a cyclohexenyl group. However, it is not limited thereto.

In the present specification, the aryl group having 6 to 60 carbon atoms may be a monocyclic aryl group or a polycyclic aryl group. Specifically, the aryl group having 6 to 60 carbon atoms is a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms; Or it may be a monocyclic or polycyclic aryl group having 6 to 20 carbon atoms. More specifically, the aryl group having 6 to 60 carbon atoms may be a phenyl group, a biphenyl group, or a terphenyl group as a monocyclic aryl group, and a naphthyl group, anthracenyl group, phenanthryl group, triphenylenyl group, pyrethyl group as a polycyclic aryl group It may be a nil group, a perylenyl group, a chrysenyl group, or a fluorenyl group.

In addition, the aryl group having 6 to 60 carbon atoms may have a structure in which two or more selected from the group consisting of a monocyclic aryl group and a polycyclic aryl group are connected to each other. Specifically, the aryl group having 6 to 60 carbon atoms may have a structure in which a polycyclic aryl group and/or a monocyclic aryl group is connected to a polycyclic aryl group. More specifically, the aryl group having 6 to 60 carbon atoms is a naphthylphenyl group, anthracenylphenyl group, phenanthrylphenyl group, triphenylenylphenyl group, pyrenylphenyl group, perylenylphenyl group, chrysenylphenyl group, fluorenylphenyl group, phenylnaphthyl group, It may be a phenylanthracenyl group or a phenylnaphthylphenyl group. However, it is not limited thereto.

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

Etc. However, it is not limited thereto.

In the present specification, the heteroaryl group having 2 to 60 carbon atoms may be one in which one or more carbons of the aryl group are each independently substituted with O, N, Si, or S. For example, a heteroaryl group in which carbon 9 of a fluorenyl group is substituted with O is a dibenzofuranyl group, a heteroaryl group substituted with N is a carbazoli group, and a heteroaryl group substituted with Si is a 9-sila-fluororenyl group The heteroaryl group substituted with S is a dibenzothiophenyl group. Specifically, the heteroaryl group having 2 to 60 carbon atoms is a heteroaryl group having 2 to 30 carbon atoms; Or it may be a C2 to C20 heteroaryl group. More specifically, the heteroaryl group having 2 to 60 carbon atoms is a thiophene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridyl group, a bipyridyl group, a pyrimidyl group, Triazine group, acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, Isoquinoline group, indole group, carbazole group, benzoxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, iso There are oxazolyl group, thiadiazolyl group, phenothiazinyl group, and dibenzofuranyl group, but are not limited thereto.

In the present specification, the arylene group refers to a divalent organic group from which any one hydrogen radical of the aryl group is removed, and the heteroarylene group refers to a divalent organic group from which any one hydrogen radical of the above-described heteroaryl group is removed. .

In Formula 1, Ar ¹ and Ar ² are each independently benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, 9,9-dimethylfluorene, 9,9-diphenylfluorene, spiro[flu Orene-9,9'-fluorene], dibenzofuran and dibenzothiophene may be a monovalent residue derived from arene or heteroarene selected from the group consisting of.

In Formula 1, L ¹ to L ³ are each independently a single bond or a phenylene group, or 9,9-dimethylfluorene, 9,9-diphenylfluorene and spiro[fluorene-9,9'-fluorene ] It may be a divalent residue derived from arene selected from the group consisting of.

Specifically, L ¹ may be a single bond, a phenylene group, or a divalent residue derived from 9,9-dimethylfluorene. And, L ² and L ³ may each independently be a single bond or a phenylene group.

More specifically, L ¹ is a single bond or a phenylene group, Ar ¹ is a 9,9-dimethylfluorenyl group, a biphenyl group or a terphenyl group, and Ar ² is benzene, biphenyl, terphenyl, 9,9-dimethylflu It may be a monovalent residue derived from an arene or heteroarene selected from the group consisting of orene, 9,9-diphenylfluorene, dibenzofuran and dibenzothiophene.

The compound represented by Formula 1 may be selected from the group consisting of the following compounds.

At least one of X ¹ to X ³ in Formula 2 may be N.

In Formula 2, L ⁴ may be a single bond or a divalent residue derived from arene selected from the group consisting of benzene, biphenyl, naphthalene, anthracene and phenanthrene.

Specifically, L ⁴ may be a single bond or a phenylene group.

In Formula 2, Ar ³ is a polyvalent residue derived from a substituted or unsubstituted arene having 6 to 60 carbon atoms, or a heteroarene having 2 to 60 carbon atoms including at least one of substituted or unsubstituted O, N, Si and S to be. Be a combination of Ar ³ is a value one greater than the number (n) of a cyano group (CN) that is substituted at the Ar ^3. Specifically, in Formula 2, when n is 1, Ar ³ is a divalent residue of the above-described arene or hetero arene, and when n is 2, Ar ³ is a trivalent residue of the above-described arene or hetero arene, and n is 3 In the case of, Ar ³ is a tetravalent residue of the above-described arene or hetero arene, and when n is 4, Ar ³ is a pentavalent residue of the above-described arene or hetero arene.

In Formula 2, n may be an integer of 1 to 4, an integer of 1 to 3, or an integer of 1 or 2.

Ar ³ in Formula 2 is benzene, biphenyl, terphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, 9,9-dimethylfluorene, 9,9-diphenylfluorene, and spiro[fluorene-9. ,9'-fluorene] may be a polyvalent residue derived from arene selected from the group consisting of.

Specifically, Ar ³ may be a polyvalent residue derived from benzene or biphenyl.

In Formula 2, Ar ⁴ and Ar ⁵ may each independently be hydrogen, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, or a pyridinyl group.

Specifically, Ar ⁴ and Ar ⁵ may be a phenyl group, a biphenyl group, or a terphenyl group.

In Formula 2, L ⁵ may be a divalent residue derived from arene selected from the group consisting of benzene, biphenyl, naphthalene, anthracene and phenanthrene.

In Formula 2, L ⁴ and L ⁵ are 1 and 2 of naphthalene, respectively; 1 and 4; 1 and 5; 1 and 6; 1 and 7; 1 and 8; 2 and 3; 2 and 6; Or it can be bonded to carbons 2 and 7.

Typically, naphthalene is numbered as shown in Formula 4.

[Formula 4]

Therefore, in Formula 2, the structure in which L ⁴ and L ⁵ are bonded to carbon 1 and 4 of naphthalene, respectively, is represented as in Formula 5, and the structure bonded to carbon 2 and 7 of naphthalene is as shown in Formula 6 below. Can be displayed.

[Formula 5]

[Formula 6]

가 나프탈렌의 1번 혹은 2번 탄소에 직접 결합할 수 있다. At this time, if L ⁴ is a single bond,

Can be directly bonded to carbon 1 or 2 of naphthalene.

The compound represented by Formula 2 may be selected from the group consisting of the following compounds.

The organic light-emitting device of the present invention includes an anode; A cathode provided to face the anode; And at least one organic material layer provided between the anode and the cathode. The organic material layer has a multilayer structure in which three or more organic material layers are stacked. For example, the organic light emitting device of the present invention may have a structure including a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, and the like as an organic material layer. However, the structure of the organic light-emitting device is not limited thereto, and may include a smaller number of organic material layers.

The organic light-emitting device according to the present invention may be a normal type organic light-emitting device in which an anode, one or more organic material layers, and a cathode are sequentially stacked on a substrate. In addition, the organic light emitting device according to the present invention may be an inverted type organic light emitting device in which a cathode, one or more organic material layers, and an anode are sequentially stacked on a substrate. For example, the structure of an organic light-emitting device according to an embodiment of the present invention is illustrated in FIG. 1.

1 shows an example of an organic light-emitting device comprising a substrate 1, an anode 2, a hole injection layer 5, a hole transport layer 6, a light-emitting layer 7, an electron transport layer 8 and a cathode 4 I did it. In such a structure, the compound represented by Formula 1 is included in the hole injection layer 5 and/or the hole transport layer 6, which is an organic material layer between the anode 2 and the emission layer 7, and represented by Formula 2 The resulting compound is included in the electron transport layer 8, which is an organic material layer between the cathode 4 and the light emitting layer 7, so that a low driving voltage and/or lifetime characteristics can be improved.

Specifically, the organic light-emitting device may include an electron blocking layer (not shown in FIG. 1) between the anode and the emission layer, and the electron blocking layer may include a compound represented by Formula 1 above. The electron blocking layer may be referred to as an electron blocking layer or an electron blocking layer, but in this specification, the electron blocking layer is unified and described.

The organic light-emitting device may include a hole transport layer between the anode and the emission layer, and the hole transport layer may include a compound represented by Formula 1 above.

The organic light-emitting device may include an electron injection layer, an electron transport layer, or an electron injection and transport layer between the cathode and the emission layer, and the electron injection layer, the electron transport layer, or the electron injection and transport layer may include a compound represented by Formula 2 above. have.

The organic light-emitting device according to the present invention includes the compound represented by Formula 1 in the organic material layer between the anode and the emission layer, and the compound represented by Formula 2 is included in the organic material layer between the cathode and the emission layer. It can be made with materials and methods known in the art. In addition, the plurality of organic material layers may be formed of the same material or different materials.

For example, an organic light-emitting device according to the present invention includes an electrode of any one of an anode and a cathode on a substrate; Organic layer; And one of the anode and the cathode may be sequentially stacked. At this time, using a PVD (physical vapor deposition) method such as sputtering or e-beam evaporation, the anode is formed by depositing a metal or a conductive metal oxide or an alloy thereof on the substrate. And, after forming an organic material layer including a hole injection layer, a hole transport layer, a light emitting layer and an electron transport layer thereon, it can be prepared by depositing a material that can be used as a cathode thereon. In addition to such a method, an organic light emitting device may be manufactured by sequentially depositing a cathode material, an organic material layer, and an anode material on a substrate (WO 2003/012890). However, the manufacturing method is not limited thereto.

In addition, the compound represented by Formula 1 and the compound represented by Formula 2 may be formed as an organic material layer by a solution coating method as well as a vacuum deposition method when manufacturing an organic light emitting device. Here, the solution coating method refers to spin coating, dip coating, doctor blading, inkjet printing, screen printing, spray method, roll coating, and the like, but is not limited thereto.

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

It is preferable that the cathode material is a material having a small work function to facilitate electron injection into the organic material layer. 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; There are multi-layered materials such as LiF/Al or LiO ₂ /Al, but are not limited thereto.

The hole injection layer is a layer into which holes are injected from an electrode, and a compound represented by Formula 1 may be used as a material for forming the hole injection layer. Since the compound represented by Chemical Formula 1 has been described in detail above, a detailed description thereof will be omitted.

The compound represented by Formula 1 has the ability to transport holes, and thus has a hole injection effect at the anode, an excellent hole injection effect for the light emitting layer or the light emitting material, and excitons generated in the light emitting layer are transferred to the electron injection layer or the electron injection material. It can prevent movement. In addition, the compound of Formula 1 has excellent thin film formation ability.

If the compound represented by Formula 1 is used as a material for forming another organic layer between the anode and the light emitting layer, the hole injection layer may be formed of a hole injection material known in the art in addition to the compound of Formula 1 above. have. As such a hole injection material, it is preferable that the HOMO (highest occupied molecular orbital) is between the work function of the positive electrode material and the HOMO of the surrounding organic material layer. Specific examples of such hole injection materials include metal porphyrin, oligothiophene, arylamine-based organics, hexanitrile hexaazatriphenylene-based organics, quinacridone-based organics, and perylene. There are a series of organic substances, anthraquinone, and polyaniline and a polythiophene series of conductive polymers, but are not limited thereto.

The hole transport layer is a layer that receives holes from the hole injection layer and transports holes to the emission layer, and the compound represented by Formula 1 may be used as a material for forming the hole transport layer.

The compound represented by Chemical Formula 1 is suitable for transporting holes from the anode or the hole injection layer and transferring them to the light emitting layer because of its high mobility for holes.

If the compound represented by Formula 1 is used as a material for forming another organic layer between the anode and the emission layer, the hole transport layer may be formed of a hole transport material known in the art in addition to the compound of Formula 1 . Specific examples of the hole transport material include, but are not limited to, an arylamine-based organic material, a conductive polymer, and a block copolymer having a conjugated portion and a non-conjugated portion.

An electron blocking layer may be formed between the hole transport layer and the emission layer to prevent electrons transferred to the emission layer from moving toward the anode. As a material for forming such an electron blocking layer, a compound represented by Formula 1 may be used. In particular, when the electron blocking layer is formed of the compound represented by Formula 1, the driving voltage of the organic light-emitting device may be lowered and luminance may be improved.

The emission layer is a layer capable of emitting light in a visible light region by transporting and bonding holes and electrons respectively from the hole transport layer and the electron transport layer, and the emission layer may include a host material and a dopant material.

As the host material, a condensed aromatic ring derivative or a heterocyclic-containing compound may be used. Specifically, condensed aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, and fluoranthene compounds, and heterocycle-containing compounds include carbazole derivatives, dibenzofuran derivatives, ladder type Furan compounds, pyrimidine derivatives, and the like, but are not limited thereto.

Specifically, the emission layer may include a compound represented by Formula 3 below as the host material.

[Formula 3]

In Formula 3, Ar ⁷ and Ar ⁸ are each independently a substituted or unsubstituted aryl group having 6 to 60 carbon atoms.

In Formula 3, Ar ⁷ and Ar ⁸ are each independently benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, 9,9-dimethylfluorene, 9,9-diphenylfluorene, spiro[ Fluorene-9,9'-fluorene], phenylnaphthalene, phenylanthracene, phenylphenanthrin and phenyltriphenylene may be a monovalent residue derived from arene selected from the group consisting of.

The compound represented by Formula 3 may be selected from the group consisting of the following compounds.

Dopant materials include aromatic amine derivatives, strylamine compounds, boron complexes, fluoranthene compounds, and metal complexes. Specifically, the aromatic amine derivative is a condensed aromatic ring derivative having a substituted or unsubstituted arylamino group, and includes pyrene, anthracene, chrysene, and periflanthene having an arylamino group, and the styrylamine compound is substituted or unsubstituted A compound in which at least one arylvinyl group is substituted on the arylamine, and one or two or more substituents selected from the group consisting of aryl group, silyl group, alkyl group, cycloalkyl group and arylamino group are substituted or unsubstituted. Specifically, there are styrylamine, styryldiamine, styryltriamine, styryltetraamine, and the like, but are not limited thereto. In addition, the metal complex includes an iridium complex, a platinum complex, and the like, but is not limited thereto.

The electron injection and transport layer is a layer that receives electrons from the cathode and transports electrons to the emission layer, and a compound represented by Formula 2 may be used as a material for forming the electron injection and transport layer. Since the compound represented by Chemical Formula 2 has been described in detail above, detailed descriptions are omitted here.

The compound represented by Formula 2 has a structure in which a substituent group substituted with a cyano group is connected at the terminal to a triazine-substituted naphthalene core, and has excellent thermal stability, and has high mobility for electrons, so electrons are well injected from the cathode to the light emitting layer. It is suitable for transfer.

Meanwhile, the electron injection and transport layer may be replaced by an electron injection layer or an electron transport layer, and may have an electron injection layer and an electron transport layer separately. In the case of an organic light-emitting device having both an electron injection layer and an electron transport layer, if the compound represented by Formula 2 is used as a material for forming another organic material layer between the cathode and the emission layer, the electron transport layer is It may be formed of an electron transport material known in the art to which the present invention belongs. Specific examples of such an electron transport material include Al complex of 8-hydroxyquinoline; Complexes containing Alq ₃ ; Organic radical compounds; Hydroxyflavone-metal complexes and the like, but are not limited thereto.

The electron injection layer is a layer into which electrons are injected from an electrode, and a compound represented by Formula 2 may be used as a material for forming the electron injection layer. The compound represented by Formula 2 has an ability to transport electrons, has an electron injection effect from the cathode, and an excellent electron injection effect to the light emitting layer or the light emitting material.

If the compound represented by Chemical Formula 2 is used as a material for forming another organic layer between the cathode and the emission layer, the electron injection layer may be formed of an electron injection material known in the art in addition to the compound of Chemical Formula 2. have. Specific examples of such electron injection materials include fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, preorenylidene methane, anthrone And their derivatives, metal complex compounds, and nitrogen-containing 5-membered ring derivatives, but are not limited thereto.

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

The organic light emitting device according to the present invention includes the compound represented by Formula 1 in the organic material layer between the anode and the emission layer, and includes the compound represented by Formula 2 in the organic material layer between the cathode and the emission layer. Or it can show life characteristics. In particular, the effect can be maximized by including the compound represented by Formula 1 in the hole transport layer or the electron blocking layer, and including the compound represented by Formula 2 in the electron injection layer, the electron transport layer, or the electron injection and transport layer.

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

The fabrication of the organic light emitting device described above will be described in detail in the following examples. However, the following examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1: Fabrication of an organic light emitting device

A glass substrate coated with ITO (indium tin oxide) to a thickness of 1000 Å was put in distilled water dissolved in a detergent and washed with ultrasonic waves. In this case, Fischer Co. product was used as a detergent, and distilled water secondarily filtered using a filter made by Millipore Co. was used as distilled water. After washing the ITO substrate for 30 minutes, ultrasonic cleaning was performed for 10 minutes by repeating twice with distilled water. After washing with distilled water, the ITO substrate was ultrasonically washed with a solvent of isopropyl alcohol, acetone, and methanol, dried, and then transported to a plasma cleaner. Then, the ITO substrate was cleaned for 5 minutes using oxygen plasma and then transported to a vacuum evaporator.

The following compound HAT was thermally vacuum deposited to a thickness of 100 Å on the prepared ITO electrode to form a hole injection layer. The following compound HT-1 was vacuum deposited on the hole injection layer to a thickness of 1150 Å to form a hole transport layer. Subsequently, the following Compound 1-1 was vacuum deposited on the hole transport layer to a thickness of 100 Å to form an electron blocking layer. The following compound BH and the following compound BD were vacuum-deposited at a weight ratio of 25:1 on the electron blocking layer to form a light emitting layer with a thickness of 200 Å. On the light emitting layer, the following compound 2-1 and LiQ (Lithium Quinolate) were vacuum-deposited at a weight ratio of 1:1 to form an electron injection and transport layer with a thickness of 350 Å. Lithium fluoride (LiF) having a thickness of 12 Å and aluminum having a thickness of 2000 Å were sequentially deposited on the electron injection and transport layer to form a negative electrode.

In the above process, the deposition rate of the organic material was maintained at 0.4 to 0.7 Å/sec, the deposition rate of lithium fluoride at the negative electrode was 0.3 Å/sec, and the deposition rate of aluminum 2 Å/sec. ^An organic light emitting device was manufactured by maintaining ^-7 to 5 X 10 ^-6 torr.

Example 2 to 16 and Comparative example 1 to 12: Fabrication of an organic light emitting device

An organic light-emitting device was manufactured in the same manner as in Example 1, except that the compound for forming the electron blocking layer and/or the electron injection and transport layer was changed as shown in Table 1 below.

Test example 1: Performance evaluation of organic light emitting device

At a current density of 10 mA/cm ² , voltage, luminous efficiency and lifetime of the organic light emitting devices manufactured according to Examples 1 to 16 and Comparative Examples 1 to 12 were measured, and the results are shown in Table 1. The lifetime (T95) is defined as the time required to decrease to 95% of the initial luminance (6000 nit), and was measured at a current density of 20 mA/cm ² .

Electron injection and transport layer Electron blocking layer Voltage(V) Efficiency (cd/A) T95(hr) Example 1 2-1 1-1 3.56 6.43 330 Example 2 2-2 1-1 3.57 6.44 350 Example 3 2-3 1-1 3.54 6.42 345 Example 4 2-4 1-1 3.58 6.43 330 Example 5 2-1 1-2 3.59 6.46 345 Example 6 2-2 1-2 3.51 6.38 360 Example 7 2-3 1-2 3.50 6.35 345 Example 8 2-4 1-2 3.56 6.3 325 Example 9 2-1 1-4 3.77 6.58 320 Example 10 2-2 1-4 3.78 6.57 385 Example 11 2-3 1-4 3.79 6.59 345 Example 12 2-4 1-4 3.74 6.58 335 Example 13 2-1 1-5 3.65 6.57 355 Example 14 2-2 1-5 3.66 6.56 385 Example 15 2-3 1-5 3.61 6.55 365 Example 16 2-4 1-5 3.62 6.54 375 Comparative Example 1 ET-1 EB-1 4.16 5.96 255 Comparative Example 2 ET-2 EB-2 4.04 6.13 250 Comparative Example 3 ET-3 EB-3 4.67 5.85 290 Comparative Example 4 ET-4 EB-4 5.05 5.21 185 Comparative Example 5 ET-1 1-1 4.09 6.17 270 Comparative Example 6 ET-1 1-2 3.98 6.23 275 Comparative Example 7 ET-1 1-4 4.01 6.13 265 Comparative Example 8 ET-1 1-5 4.06 6.18 260 Comparative Example 9 2-1 EB-1 4.03 6.12 295 Comparative Example 10 2-2 EB-1 4.02 6.15 305 Comparative Example 11 2-3 EB-1 4.05 6.07 290 Comparative Example 12 2-4 EB-1 3.94 6.27 285

The organic light-emitting device of Comparative Example 1 is a material widely used in a blue organic light-emitting device, and includes an electron blocking layer formed of compound EB-1 and an electron injection and transport layer formed of compound ET-1.

In Table 1, an organic light-emitting device (Comparative Examples 1 to 4) formed from existing compounds including Comparative Example 1, a compound represented by Formula 1 as an electron blocking layer material, is used, but an existing compound as an electron injection and transport layer material An organic light emitting device using (Comparative Examples 5 to 8) and an organic light emitting device using a compound represented by Formula 2 as the electron injection and transport layer material, but using an existing compound as an electron blocking layer material (Comparative Examples 9 to 8) The basic characteristics of 12) are shown.

Comparing Examples and Comparative Examples, when the compounds represented by Formulas 1 and 2 are used as materials for the electron blocking layer and the electron injection and transport layer, respectively, compared to the conventional organic light emitting device, a low driving voltage, high efficiency and long It is confirmed to indicate life. In particular, when the compound 1-1 or 1-2 was used as the electron blocking layer material, the driving voltage was the lowest, and when the compound 1-4 or 1-5 was used as the electron blocking layer material, the luminance was highest, When the compound 2-2 was used as an electron injection and transport layer material, the lifespan was the longest.

On the other hand, when comparing Comparative Examples 1 to 4, in Comparative Example 2 using the compound (ET-2) having a structure similar to that of Chemical Formula 2, lifespan characteristics were not improved, and Ar ¹ of Chemical Formula ¹ was a carbazole group ( In Comparative Example 3 using EB-3), the driving voltage tended to increase, and a compound (EB-4) in which a substituent other than an arylamine group was bonded to triphenylene as an electron blocking layer material was used, and the electron injection and transport layer In Comparative Example 4 in which the compound (ET-4) which does not contain a cyano group at the terminal was used as a material, the hole electron balance was broken, and the characteristics of the organic light emitting device were generally deteriorated. The reason for the increase in the driving voltage in Comparative Example 3 is that the HOMO value of the electron blocking layer is too deep to increase the barrier with the hole transport layer, so that holes are not smoothly injected into the emission layer.

Accordingly, it is confirmed that a low driving voltage, high luminance, and long life can be achieved only when the compounds represented by Formulas 1 and 2 are used as materials for the electron blocking layer and the electron injection and transport layer, respectively.

Example 17 to 32 and Comparative example 13 to 20: Fabrication of an organic light emitting device

An organic light-emitting device was prepared in the same manner as in Example 1, except that the electron blocking layer was formed with the compound EB-1, and the compound for forming the hole transport layer and/or the electron injection and transport layer was changed as shown in Table 2 below. Was produced.

Test example 2: Evaluation of the performance of the organic light emitting device

The characteristics of the organic light-emitting devices manufactured according to Examples 17 to 32 and Comparative Examples 13 to 20 were measured in the same manner as in Test Example 1, and the results are shown in Table 2.

Electron injection and transport layer Hole transport layer Voltage(V) Efficiency (cd/A) T95(hr) Comparative Example 1 ET-1 HT-1 4.16 5.96 255 Comparative Example 13 ET-1 1-1 3.72 6.38 300 Comparative Example 14 ET-1 1-3 3.85 6.47 310 Comparative Example 15 ET-1 1-5 3.74 6.36 305 Comparative Example 16 ET-1 1-6 3.98 6.50 320 Comparative Example 17 2-1 EB-1 3.82 6.52 315 Comparative Example 18 2-2 EB-1 3.78 6.51 310 Comparative Example 19 2-5 EB-1 3.93 6.49 310 Comparative Example 20 2-6 EB-1 3.85 6.43 325 Example 17 2-1 1-1 3.42 6.84 360 Example 18 2-2 1-1 3.44 6.82 370 Example 19 2-5 1-1 3.45 6.85 370 Example 20 2-6 1-1 3.40 6.84 360 Example 21 2-1 1-3 3.52 6.90 375 Example 22 2-2 1-3 3.51 6.94 375 Example 23 2-5 1-3 3.50 6.93 370 Example 24 2-6 1-3 3.52 6.95 350 Example 25 2-1 1-5 3.61 6.68 395 Example 26 2-2 1-5 3.68 6.66 405 Example 27 2-5 1-5 3.67 6.65 395 Example 28 2-6 1-5 3.64 6.74 390 Example 29 2-1 1-6 3.56 6.80 345 Example 30 2-2 1-6 3.54 6.76 365 Example 31 2-5 1-6 3.53 6.78 350 Example 32 2-6 1-6 3.51 6.75 355

The organic light-emitting device of Comparative Example 1 is a material widely used in a blue organic light-emitting device, and includes a hole transport layer formed of compound HT-1 and an electron injection and transport layer formed of compound ET-1.

In Table 1, the compound represented by Formula 1 is used as a material for the hole transport layer, including Comparative Example 1, but an organic light emitting device (Comparative Examples 13 to 16) using a conventional compound as a material for electron injection and transport layer, and electron injection and The basic characteristics of organic light-emitting devices (Comparative Examples 17 to 20) using the compound represented by Formula 2 as the material for the transport layer, but using the conventional compound as the material for the hole transport layer are shown.

Comparing Examples and Comparative Examples, when the compounds represented by Formulas 1 and 2 are used as materials for the hole transport layer and the electron injection and transport layer, respectively, lower driving voltage, higher efficiency, and longer life than the conventional organic light emitting device. It is confirmed to represent. In particular, when the compound 1-1 was used as the hole transport layer material, the driving voltage was the lowest, and the luminance was highest when the compound 1-3 was used as the hole transport layer material, and the compound 1-5 was used as the hole transport layer material. When used, it has the longest life.

Accordingly, it is confirmed that a low driving voltage, high luminance, and long life can be achieved only when the compounds represented by Formulas 1 and 2 are used as a hole transport layer and an electron injection and transport layer material, respectively.

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

Claims (16)

anode; A cathode provided to face the anode; And as an organic light emitting device comprising at least one organic material layer provided between the anode and the cathode,
The organic material layer includes a light emitting layer,
Including a compound represented by the following formula (1) between the anode and the light emitting layer,
Comprising a compound represented by the following formula (2) between the cathode and the light emitting layer,
Organic light emitting element:
[Formula 1]

[Formula 2]

In Formula 1,
Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms including at least one of O and S,
L ¹ to L ³ are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 60 carbon atoms,
In Chemical Formula 2,
X ¹ to X ³ are each independently N or CH, but at least one selected from X ¹ to X ³ is N,
Ar ³ is a substituted or unsubstituted arene having 6 to 60 carbon atoms, or a polyvalent residue derived from a heteroarene having 2 to 60 carbon atoms including at least one of substituted or unsubstituted O, N, Si and S,
Ar ⁴ and Ar ⁵ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, or a substituted or unsubstituted hetero containing at least one of O, N, Si and S 2 to 60 carbon atoms Is an aryl group,
L ⁴ and L ⁵ are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 60 carbon atoms,
n is an integer of 1 to 4.
The method of claim 1, wherein Ar ¹ and Ar ² are each independently benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, 9,9-dimethylfluorene, 9,9-diphenylfluorene, spiro An organic light-emitting device, which is a monovalent residue derived from arene or heteroarene selected from the group consisting of [fluorene-9,9'-fluorene], dibenzofuran and dibenzothiophene.
The method of claim 1, wherein L ¹ to L ³ are each independently a single bond or a phenylene group, or 9,9-dimethylfluorene, 9,9-diphenylfluorene and spiro[fluorene-9,9'- Fluorene], an organic light-emitting device which is a divalent residue derived from arene selected from the group consisting of.
The organic light-emitting device according to claim 1, wherein L ⁴ is a single bond or a divalent residue derived from arene selected from the group consisting of benzene, biphenyl, naphthalene, anthracene and phenanthrene.
The method of claim 1, wherein Ar ³ is benzene, biphenyl, terphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, 9,9-dimethylfluorene, 9,9-diphenylfluorene and spiro[fluorene -9,9'-fluorene] is a polyvalent residue derived from arene selected from the group consisting of, an organic light-emitting device.
The organic light-emitting device according to claim 1, wherein Ar ⁴ and Ar ⁵ are each independently hydrogen, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, or a pyridinyl group.
The organic light-emitting device of claim 1, wherein L ⁵ is a divalent residue derived from arene selected from the group consisting of benzene, biphenyl, naphthalene, anthracene and phenanthrene.
The method according to claim 1, wherein L ⁴ and L ⁵ are 1 and 2 of naphthalene, respectively; 1 and 4; 1 and 5; 1 and 6; 1 and 7; 1 and 8; 2 and 3; 2 and 6; Or an organic light-emitting device that binds to carbons 2 and 7.
The organic light-emitting device of claim 1, wherein the compound represented by Formula 1 is selected from the group consisting of the following compounds:

.
The organic light-emitting device of claim 1, wherein the compound represented by Formula 2 is selected from the group consisting of the following compounds:

.
The organic light-emitting device of claim 1, comprising an electron blocking layer between the anode and the emission layer, and wherein the electron blocking layer includes a compound represented by Chemical Formula 1.
The organic light-emitting device of claim 1, comprising a hole transport layer between the anode and the emission layer, and the hole transport layer comprises a compound represented by Formula 1 above.
The method of claim 1, comprising an electron injection layer, an electron transport layer, or an electron injection and transport layer between the cathode and the emission layer, and the electron injection layer, the electron transport layer, or the electron injection and transport layer comprises a compound represented by Formula 2 , Organic light emitting device.
The organic light-emitting device of claim 1, wherein the emission layer comprises a compound represented by the following formula (3):
[Formula 3]

In Formula 3, Ar ⁷ and Ar ⁸ are each independently a substituted or unsubstituted aryl group having 6 to 60 carbon atoms.
The method of claim 14, wherein Ar ⁷ and Ar ⁸ are each independently benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, 9,9-dimethylfluorene, 9,9-diphenylfluorene, spiro [Fluorene-9,9'-fluorene], phenylnaphthalene, phenylanthracene, phenylphenanthrin, and a monovalent residue derived from arene selected from the group consisting of phenyltriphenylene, an organic light-emitting device.
The organic light-emitting device of claim 14, wherein the compound represented by Formula 3 is selected from the group consisting of the following compounds:

.

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