KR20200014877A - Organic light emitting device - Google Patents

Abstract

Provided is an organic light emitting device capable of improving the low driving voltage, life characteristics and efficiency thereof. The organic light emitting device comprises: an anode; a cathode provided opposite to the anode; and at least one organic material layer provided between the anode and the cathode.

Description

Organic light emitting element {ORGANIC LIGHT EMITTING DEVICE}

The present invention relates to an organic light emitting device.

In general, organic light emitting phenomenon refers to a phenomenon of converting electrical energy into light energy using an organic material. The organic light emitting device using the organic light emitting phenomenon has a wide viewing angle, excellent contrast, fast response time, excellent brightness, driving voltage and response speed characteristics, many studies have been conducted.

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

There is a continuous demand for the development of new materials for organic materials used in such organic light emitting devices.

Korean Patent Publication No. 10-2000-0051826

The present invention provides an organic light emitting device.

The present invention is an anode; A cathode provided to face the anode; And at least one organic layer provided between the anode and the cathode, wherein the organic layer includes a light emitting layer, and includes a compound represented by the following Chemical Formula 1 between the anode and the light emitting layer, It provides an organic light emitting device comprising a compound represented by the formula (2) between the light emitting layer.

[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 containing 2 to 60 carbon atoms containing at least one of O and S Gigi,

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, at least one selected from X ¹ to X ³ is N,

Ar ³ is a polyvalent moiety derived from a substituted or unsubstituted C6-C60 arylene or a C2-C60 heteroarylene containing one or more 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 heteroaryl having 2 to 60 carbon atoms containing at least one of substituted, unsubstituted O, N, Si, and S; 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 1-4.

The compound represented by Chemical Formula 1 may be used as an organic material layer between an anode and a light emitting layer, and the compound represented by Chemical Formula 2 may be used as a material of an organic material layer between a cathode and a light emitting layer to provide a low driving voltage and / or Alternatively, lifespan characteristics and efficiency can be improved.

1 shows an example of an organic light emitting element consisting of 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. It is.

Hereinafter, the present invention 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 a material of the organic layer between the anode and the light emitting layer, and using the compound represented by Formula 2 as a material of the organic layer between the cathode and the light emitting layer. .

In the present specification, a single bond means a case where no separate atom is present in a moiety represented by L ¹ to L ⁵ . For example, a ¹ L of formula N is coupled directly to the triphenylene is a single bond.

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, 1 to 40 haloalkyl groups, substituted or unsubstituted O, N, Si and S containing at least one heteroalkyl group containing 1 to 40 carbon atoms, substituted or unsubstituted O, N, Si and S at least one It may be a heterohaloalkyl group having 1 to 40 carbon atoms, or an alkenyl group having 2 to 40 carbon atoms.

Halogen herein may be fluorine, chlorine, bromine or iodine.

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

In the present specification, the heteroalkyl group having 1 to 40 carbon atoms may be 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 linear alkyl group, the heteroalkyl group in which carbon number 1 of the n-butyl group is substituted with O is n-propoxy group, the heteroalkyl group substituted with N is n-propylamino group, and the heteroalkyl group substituted with Si is n And a heteroalkyl group substituted with S is an n-propylthio group. As an example of the branched alkyl group, the heteroalkyl group in which carbon number 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 by S is a t-butylthio group. In addition, as an example of a cyclic alkyl group, a heteroalkyl group in which carbon number 2 of a cyclohexyl group is substituted with O is a 2-tetrahydropyranyl group, a 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 heteroalkyl group having 1 to 40 carbon atoms may be a straight, branched or cyclic hydroxyalkyl group having 1 to 40 carbon atoms; Linear, branched or cyclic alkoxy groups having 1 to 40 carbon atoms; Linear, branched or cyclic alkoxyalkyl groups having 2 to 40 carbon atoms; Linear, branched or cyclic aminoalkyl groups having 1 to 40 carbon atoms; Linear, branched or cyclic alkylamino groups having 1 to 40 carbon atoms; Linear, branched or cyclic alkylaminoalkyl groups having 1 to 40 carbon atoms; Linear, branched or cyclic silylalkyl (oxy) groups having 1 to 40 carbon atoms; Linear, branched or cyclic alkyl (oxy) silyl groups having 1 to 40 carbon atoms; Linear, branched or cyclic alkyl (oxy) silylalkyl (oxy) groups having 1 to 40 carbon atoms; Linear, branched or cyclic mercaptoalkyl groups having 1 to 40 carbon atoms; Linear, branched or cyclic alkylthio groups having 1 to 40 carbon atoms; Or a straight, branched or cyclic alkylthioalkyl group having 2 to 40 carbon atoms. More specifically, the heteroalkyl group having 1 to 40 carbon atoms has a hydroxymethyl group, methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, t-butoxy group, cyclohexoxy group, methoxymethyl group, iso-prop Foxymethyl group, cyclohexoxymethyl 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 Hydrotepyyranyl (2-tetrahydrothiopyranyl) group, etc. are mentioned. However, the present invention is not limited thereto.

In the present specification, the alkenyl group having 2 to 40 carbon atoms may be a straight chain, branched chain or cyclic alkenyl group. Specifically, the alkenyl group having 2 to 40 carbon atoms has a straight chain alkenyl group having 2 to 40 carbon atoms; Linear alkenyl groups having 2 to 20 carbon atoms; Linear alkenyl groups having 2 to 10 carbon atoms; Branched alkenyl groups having 3 to 40 carbon atoms; Branched alkenyl groups having 3 to 20 carbon atoms; Branched alkenyl groups having 3 to 10 carbon atoms; Cyclic alkenyl groups having 5 to 40 carbon atoms; Cyclic alkenyl groups having 5 to 20 carbon atoms; Or 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, propenyl group, butenyl group, pentenyl group or cyclohexenyl group. However, the present invention 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, an aryl group having 6 to 60 carbon atoms has a monocyclic or polycyclic aryl group having 6 to 30 carbon atoms; Or 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 as a polycyclic aryl group, a naphthyl group, anthracenyl group, phenanthryl group, triphenylenyl group, pyre Or a phenyl group, a perrylenyl 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 are linked to the polycyclic aryl group. More specifically, the aryl group having 6 to 60 carbon atoms is naphthylphenyl group, anthracenylphenyl group, phenanthrylphenyl group, triphenylenylphenyl group, pyrenylphenyl group, peryllenylphenyl group, chrysenylphenyl group, fluorenylphenyl group, phenylnaphthyl group, Or a phenylanthracenyl group or a phenylnaphthylphenyl group. However, the present invention is not limited thereto.

등이 될 수 있다. 다만, 이에 한정되는 것은 아니다.In the present specification, a 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,

And so on. However, the present invention is not limited thereto.

In the present specification, the heteroaryl group having 2 to 60 carbon atoms may be one or more carbons of the aryl group are each independently substituted with O, N, Si or S. For example, the heteroaryl group in which carbon number 9 of the fluorenyl group is substituted with O is a dibenzofuranyl group, the heteroaryl group substituted with N is a carbazolyl group, and the heteroaryl group substituted with Si is a 9-sila-fluoroenyl group The heteroaryl group substituted with S is a dibenzothiophenyl group. Specifically, a heteroaryl group having 2 to 60 carbon atoms is a heteroaryl group having 2 to 30 carbon atoms; Or a heteroaryl group having 2 to 20 carbon atoms. More specifically, the heteroaryl group having 2 to 60 carbon atoms has 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, acridil 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 (phenanthroline), iso An oxazolyl group, a thiadiazolyl group, a phenothiazinyl group, and a dibenzofuranyl group are mentioned, but it is not limited to these.

In the present specification, the arylene group refers to a divalent organic group in which any one hydrogen radical of the aryl group has been removed, and the heteroarylene group refers to a divalent organic group in which any one hydrogen radical of the aforementioned heteroaryl group has been 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, and a monovalent moiety derived from an 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 from the 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. In addition, L ² and L ³ may be each independently 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 Or a monovalent residue 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.

In Formula 2, at least one of X ¹ to X ³ 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.

Ar ³ in Formula 2 is a polyvalent moiety derived from a heteroarylene having 2 to 60 carbon atoms, including at least one of substituted or unsubstituted carbon atoms having 6 to 60 carbon atoms, or 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-mentioned arene or hetero arene, and when n is 2, Ar ³ is a trivalent residue of the above-mentioned arene or hetero arene, and n is 3 When Ar ³ is a tetravalent residue of the above-mentioned arene or hetero arene, and when n is 4, Ar ³ is a pentavalent residue of the above-mentioned 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 multivalent moiety derived from arene.

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

Ar ⁴ and Ar ⁵ in Formula 2 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, biphenyl group or 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.

L ⁴ and L ⁵ in Chemical Formula 2 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 carbon atoms 2 and 7.

Typically, naphthalene is numbered as in Formula 4 below.

[Formula 4]

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

[Formula 5]

[Formula 6]

가 나프탈렌의 1번 혹은 2번 탄소에 직접 결합할 수 있다. If L ⁴ is a single bond, then

It can be bonded directly to carbon 1 or 2 of the 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 is an anode; A cathode provided to face the anode; And one or more organic material layers 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 the organic 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 an organic light emitting device having a structure 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 diode according to the present invention may be an organic light emitting diode having an inverted type structure 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 diode according to an embodiment of the present invention is illustrated in FIG. 1.

1 shows an example of an organic light emitting element consisting of 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. It is. In such a structure, the compound represented by Chemical Formula 1 is included in the hole injection layer 5 and / or the hole transport layer 6, which is an organic layer between the anode 2 and the light emitting layer 7, and is represented by Chemical Formula 2 The compound may be included in the electron transport layer 8, which is an organic layer between the cathode 4 and the emission layer 7, to improve low driving voltage and / or life characteristics.

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

The organic light emitting diode may include a hole transport layer between the anode and the light emitting layer, and the hole transport layer may include a compound represented by Chemical Formula 1.

The organic light emitting diode may include an electron injection layer, an electron transport layer, or an electron injection and transport layer between the cathode and the light emitting 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 a compound represented by Chemical Formula 1 in the organic material layer between the anode and the light emitting layer, except that the compound represented by Chemical Formula 2 in the organic material layer between the cathode and the light emitting layer. It may be prepared by 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 it can be prepared by sequentially stacking the other electrode of the positive electrode and the negative electrode. At this time, by using a physical vapor deposition (PVD) method such as sputtering or e-beam evaporation, a metal or conductive metal oxide or an alloy thereof is deposited on the substrate to form an anode. In addition, an organic material layer including a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer may be formed thereon, and then a material that may be used as a cathode may be deposited thereon. In addition to the above 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 Chemical Formula 1 and the compound represented by Chemical Formula 2 may be formed as an organic layer by a solution coating method as well as a vacuum deposition method in the manufacture of the organic light emitting device. Here, the solution coating method means spin coating, dip coating, doctor blading, inkjet printing, screen printing, spray method, roll coating, etc., but is not limited thereto.

As the anode material, a material having a large work function is generally preferred to facilitate hole injection into the organic material layer. Specific examples of the positive electrode material include metals such as vanadium, chromium, copper, zinc and gold or alloys thereof; Metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO); Combinations of oxides with metals such as ZnO: Al or SNO ₂ : Sb; Conductive polymers such as poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDOT), polypyrrole and polyaniline, 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; Multilayer structure materials such as LiF / Al or LiO ₂ / Al, and the like, but are not limited thereto.

The hole injection layer is a layer in which holes are injected from an electrode, and the compound represented by Chemical 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 above in detail, a detailed description thereof will be omitted.

The compound represented by the formula (1) has the ability to transport holes, has a hole injection effect at the anode, excellent hole injection effect to the light emitting layer or light emitting material, and the excitons generated in the light emitting layer to the electron injection layer or electron injection material It can prevent movement. In addition, the compound of Formula 1 is excellent in the ability to form a thin film.

If the compound represented by Chemical 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 to which the present invention pertains, in addition to the compound of Chemical Formula 1 above. have. As the hole injection material, the highest occupied molecular orbital (HOMO) is preferably between the work function of the positive electrode material and the HOMO of the surrounding organic layer. Specific examples of the hole injection material include metal porphyrin, oligothiophene, arylamine-based organic material, hexanitrile hexaazatriphenylene-based organic material, quinacridone-based organic material, and perylene Organic, anthraquinone, and polyaniline and polythiophene-based 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 light emitting layer, and a compound represented by Chemical 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 an anode or a hole injection layer to a light emitting layer because of high mobility to holes.

If the compound represented by Chemical Formula 1 is used as a material for forming another organic layer between the anode and the light emitting layer, the hole transport layer may be formed of a hole transporting material known in the art, in addition to the compound of Chemical Formula 1 above. . Specific examples of such hole transport materials include, but are not limited to, arylamine-based organics, conductive polymers, and block copolymers having both conjugated and non-conjugated portions.

An electron blocking layer may be formed between the hole transport layer and the light emitting layer to prevent electrons transferred to the light emitting layer from moving toward the anode. As the material for forming the electron blocking layer, a compound represented by Chemical Formula 1 may be used. In particular, when the electron blocking layer is formed of the compound represented by Chemical 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 the visible region by transporting and combining holes and electrons from the hole transport layer and the electron transport layer, respectively, 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 compound may be used. Specifically, the condensed aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, and fluoranthene compounds, and the heterocyclic containing compounds include carbazole derivatives, dibenzofuran derivatives and ladder types. Furan compounds, pyrimidine derivatives, and the like, but are not limited thereto.

Specifically, the light emitting layer may include a compound represented by the following Chemical Formula 3 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, phenylphenanthrine and phenyltriphenylene.

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

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

The electron injection and transport layer is a layer that receives electrons from the cathode and transports electrons to the light emitting layer, and a compound represented by Chemical 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, a detailed description thereof will be omitted.

The compound represented by Formula 2 has a structure in which a substituent substituted with a cyano group at the end is connected to a triazine-substituted naphthalene core and has excellent thermal stability, and because of its high mobility to electrons, electrons are well injected from the cathode to the light emitting layer. Suitable for moving

Meanwhile, the electron injection and transport layer may be replaced with an electron injection layer or an electron transport layer, and may be provided separately from the electron injection layer and the electron transport layer. In the case of an organic light emitting device including both an electron injection layer and an electron transporting layer, if the compound represented by Chemical Formula 2 is used as a material for forming another organic material layer between the cathode and the light emitting layer, the electron transporting layer may be used in addition to the compound represented by Chemical Formula 2 above. It may be formed of an electron transporting material known in the art. Specific examples of such electron transport materials include Al complexes of 8-hydroxyquinoline; Complexes including Alq ₃ ; Organic radical compounds; Hydroxyflavone-metal complexes and the like, but are not limited thereto.

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

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

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

The organic light emitting device according to the present invention includes a compound represented by Chemical Formula 1 in the organic material layer between the anode and the light emitting layer, and a low driving voltage including the compound represented by Chemical Formula 2 in the organic material layer between the cathode and the light emitting layer. Or lifespan characteristics. In particular, the compound represented by Formula 1 may be included in the hole transport layer or the electron blocking layer, and the compound represented by Formula 2 may be maximized 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.

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

Example 1 Fabrication of Organic Light-Emitting Device

A glass substrate coated with a thickness of 1000 kPa of ITO (indium tin oxide) was placed in distilled water in which a detergent was dissolved and ultrasonically washed. At this time, Fischer Co. product was used as a detergent, and distilled water was filtered secondly using a filter of Millipore Co. product. After washing the ITO substrate for 30 minutes, the ultrasonic cleaning was performed twice with distilled water for 10 minutes. After the distilled water was washed, the ITO substrate was ultrasonically cleaned with a solvent of isopropyl alcohol, acetone and methanol, dried, and then transported to a plasma cleaner. 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 kPa on the prepared ITO electrode to form a hole injection layer. Compound HT-1 was vacuum deposited to a thickness of 1150 kPa on the hole injection layer to form a hole transport layer. Subsequently, the following compound 1-1 was vacuum deposited to a thickness of 100 kPa on the hole transport layer to form an electron blocking layer. The following compound BH and the following compound BD were vacuum deposited on the electron blocking layer in a weight ratio of 25: 1 to form a light emitting layer having a thickness of 200 kHz. Compound 2-1 and LiQ (Lithium Quinolate) were vacuum deposited on the emission layer at a weight ratio of 1: 1 to form an electron injection and transport layer at a thickness of 350 kPa. A cathode was formed by sequentially depositing 12 Å thick lithium fluoride (LiF) and 2000 Å thick aluminum on the electron injection and transport layer.

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

Examples 2-16 and Comparative Examples 1-12: Fabrication of 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 , voltages, luminous efficiencies, and lifetimes of the organic light emitting diodes 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 taken to reduce to 95% of the initial luminance (6000 nit) and measured at a current density of 20 mA / cm ² .

Electron injection and transport layer Electronic stop 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, the organic light-emitting device (Comparative Examples 1 to 4) formed from existing compounds including Comparative Example 1, and the compound represented by the formula (1) as the electron blocking layer material, but the conventional compound as the electron injection and transport layer material An organic light emitting device (Comparative Examples 5 to 8) using the compound and an organic light emitting device using a compound represented by the formula (2) as the electron injection and transport layer material, but using a conventional compound as the electron blocking layer material (Comparative Examples 9 to 8) 12) shows the basic characteristics.

Comparing the Examples and Comparative Examples, when using the compounds represented by Formula 1 and 2 as the material of the electron blocking layer and the electron injection and transport layer, respectively, lower driving voltage, higher efficiency and longer length than the conventional organic light emitting device. It is confirmed that the service life. Particularly, when the compound 1-1 or 1-2 was used as the electron blocking layer material, the driving voltage was the lowest, and the brightness was the highest when the compound 1-4 or 1-5 was used as the electron blocking layer material. When the compound 2-2 was used as the electron injection and transport layer material, the lifetime was longest.

On the other hand, when comparing Comparative Examples 1 to 4, in Comparative Example 2 using a compound (ET-2) having a structure similar to the formula (2) did not improve the life characteristics, the compound of Ar ¹ of Formula ¹ is a carbazole group ( In Comparative Example 3 using EB-3), the driving voltage tended to increase, and as the electron blocking layer material, a compound (EB-4) having a substituent other than an arylamine group bonded to triphenylene was used, and an electron injection and transport layer was used. In Comparative Example 4 using the compound (ET-4) containing no cyano group at the end of the material, the hole transport balance (hole electron balance) collapsed, the overall characteristics of the organic light emitting device showed a tendency. The reason why the driving voltage is increased in Comparative Example 3 is that the HOMO value of the electron blocking layer is so deep that the barrier with the hole transport layer becomes large, so that holes are not smoothly injected into the light emitting layer.

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

Examples 17 to 32 and Comparative Examples 13 to 20: Fabrication of Organic Light-Emitting Device

An organic light-emitting device was manufactured in the same manner as in Example 1, except that the electron blocking layer was formed of 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. Produced.

Test Example 2: Performance Evaluation of Organic Light-Emitting Device

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

Comparing the examples and comparative examples, when the compounds represented by the formulas (1) and (2) are used as the material for the hole transporting layer and the electron injection and transporting layer, respectively, lower driving voltage, higher efficiency, and longer lifetime than those of conventional organic light emitting devices. Is confirmed. In particular, when Compound 1-1 was used as the hole transport layer material, the driving voltage was the lowest, and when Compound 1-3 was used as the hole transport layer material, luminance was the highest, and Compound 1-5 was used as the hole transport layer material. The longest lifetime when used.

As a result, it is confirmed that low drive voltage, high brightness and long life can be achieved only when the compounds represented by the above formulas (1) and (2) are used as the hole transport layer and the 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 one or more organic material layers provided between the anode and the cathode.
The organic layer includes a light emitting layer,
It includes a compound represented by the formula (1) between the anode and the light emitting layer,
Including a compound represented by the formula (2) between the cathode and the light emitting layer,
Organic light emitting device:
[Formula 1]

In Chemical 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 containing 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,
[Formula 2]

In Chemical Formula 2,
X ¹ to X ³ are each independently N or CH, at least one selected from X ¹ to X ³ is N,
Ar ³ is a polyvalent moiety derived from a substituted or unsubstituted C6-C60 arylene or a C2-C60 heteroarylene containing one or more 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 heteroaryl having 2 to 60 carbon atoms containing at least one of substituted, unsubstituted O, N, Si, and S; 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 1-4.
The method of claim 1,
Ar ¹ and Ar ² are each independently benzene, biphenyl, terphenyl, naphthalene, phenanthrene, triphenylene, 9,9-dimethylfluorene, 9,9-diphenylfluorene, spiro [fluorene-9, 9'-fluorene], dibenzofuran and dibenzothiophene, a monovalent moiety derived from an arene or heteroarene selected from the group consisting of
Organic light emitting device.
The method of claim 1,
L ¹ to L ³ are each independently a single bond or a phenylene group, or a group consisting of 9,9-dimethylfluorene, 9,9-diphenylfluorene and spiro [fluorene-9,9'-fluorene] Is a divalent residue from arene selected from
Organic light emitting device.
The method of claim 1,
L ⁴ is a single bond or a divalent residue from an arene selected from the group consisting of benzene, biphenyl, naphthalene, anthracene and phenanthrene,
Organic light emitting device.
The method of claim 1,
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
Organic light emitting device.
The method of claim 1,
Ar ⁴ and Ar ⁵ are each independently hydrogen, phenyl group, biphenyl group, terphenyl group, naphthyl group or pyridinyl group,
Organic light emitting device.
The method of claim 1,
L ⁵ is a divalent residue derived from arene selected from the group consisting of benzene, biphenyl, naphthalene, anthracene and phenanthrene,
Organic light emitting device.
The method of claim 1,
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 bonds to carbon 2 and 7,
Organic light emitting device.
The method of claim 1,
The compound represented by Formula 1 is selected from the group consisting of the following compounds,
Organic light emitting device:

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

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

In Chemical 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,
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, phenylphenanthrine and phenyltriphenylene, which are monovalent residues derived from arene,
Organic light emitting device.
The method of claim 14,
The compound represented by Formula 3 is selected from the group consisting of
Organic light emitting device:

.

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