KR102022414B1 - New organic electroluminescent compound and organic electroluminescent device comprising the same - Google Patents

Abstract

The present invention relates to a novel organic light emitting compound and an organic light emitting device including the same. When the compound according to the present invention is employed as a host material in a phosphorescent light emitting layer, an organic light emitting device having excellent light emitting characteristics such as driving voltage, brightness, and long life is provided. Can be implemented.

Description

New organic electroluminescent compound and organic electroluminescent device comprising the same

The present invention relates to an organic light emitting compound which is a novel phosphorescent host compound and an organic light emitting device including the same.

An organic light emitting device is a device that emits light by dissipating electrons and holes after pairing when an electric charge is injected into an organic film formed between an electron injection electrode (cathode) and a hole injection electrode (anode). The device can be formed on a flexible transparent substrate such as plastic, and can be driven at a lower voltage (less than 10V) compared to a plasma display panel or an inorganic EL display, and also consumes power. It is relatively small and has the advantage of excellent color.

A general organic light emitting device includes a substrate, an anode, a hole injection layer that receives holes from an anode, a hole transport layer that transports holes, a light emitting layer that combines holes and electrons to emit light, an electron transport layer that receives electrons from a cathode and delivers them to the light emitting layer, And a cathode. In some cases, a light emitting layer may be formed by doping a small amount of fluorescent or phosphorescent dye into an electron transporting layer or a hole transporting layer without a separate light emitting layer, and in the case of using a polymer, it generally serves as a hole transporting layer, a light emitting layer, and an electron transporting layer. The polymer can be carried out simultaneously. The organic thin film layers between the two electrodes are formed by vacuum deposition or spin coating, inkjet printing, roll coating, or the like, and a separate electron injection layer may be inserted to efficiently inject electrons from the cathode.

The most important factor for determining the luminous efficiency in the organic light emitting device is the light emitting material. Fluorescent materials are widely used as light emitting materials, but development of phosphorescent materials is one of the best ways to improve luminous efficiency theoretically up to 4 times. To date, iridium (III) complexes are widely known as phosphorescent materials, and for each RGB, materials such as (acac) Ir (btp) ₂ , Ir (ppy) _3, and Firpic are known. CBP is the most widely known phosphorescent light emitting host material to date, and highly efficient OLEDs using a hole blocking layer such as BCP and BAlq are known. In Japan, Pioneer has developed a high-performance OLED using BAlq derivatives as a host. There is a bar.

However, the organic electroluminescent device using the conventional phosphorescent material has a significantly higher current efficiency (cd / A) than the device using the fluorescent material, but when using a material such as BAlq, CBP as a host of the phosphorescent material, the fluorescent material The driving voltage is higher than the device using the device, and there is no big advantage in terms of power efficiency (lm / w), and the device is not satisfactory in terms of the lifetime of the device. Therefore, development of a more stable and high-performance host material is required. .

Accordingly, the present inventors have repeatedly studied the light emitting host material in consideration of the problems of the prior art, and as a result, an organic light emitting compound which is a novel phosphorescent host compound which can greatly improve luminous efficiency, stability and device life, and organic light emitting light using the same The present invention has been completed to provide a device.

KR 10-2016-0017055 A

An object of the present invention is to provide an organic light emitting compound which is a novel phosphorescent host compound.

In addition, the present invention provides an organic light emitting device that uses the organic light emitting compound as a phosphorescent host material and not only has excellent light emission characteristics but also enhances a driving voltage, thereby inducing an increase in power efficiency and quantum efficiency, thereby improving power consumption. There is another purpose.

The present invention relates to a novel organic light emitting compound and an organic light emitting device comprising the same, and more particularly, 2,3,3-trisubstituted with a fused carbazole skeleton and 1-substituted in the benzene ring of the carbazole moiety. The present invention relates to an organic light emitting compound having a novel structure capable of being deposited or in solution, and an organic light emitting device including the same.

The present invention provides an organic light emitting compound represented by the following formula (1).

[Formula 1]

In Chemical Formula 1,

R, R 'and R' 'are each independently hydrogen, deuterium, (C1-C30) alkyl, (C3-C30) cycloalkyl;

R ₁ and R ₂ are each independently hydrogen, deuterium, halogen, (C1-C30) alkyl, (C3-C30) cycloalkyl, (C6-C30) aryl or (C3-C30) heteroaryl;

Q is NR ₃ , O, S, CR ₄ R ₅ or CR ₆ R ₇ CR ₈ R ₉ ;

R ₃ to R ₉ are each independently hydrogen, deuterium, halogen, (C1-C30) alkyl, (C3-C30) cycloalkyl, (C6-C30) aryl or (C3-C30) heteroaryl;

Alkyl, cycloalkyl, aryl or heteroaryl of R ₁ to R ₉ may be selected from (C1-C30) alkyl, halo (C1-C30) alkyl, halogen, cyano, (C3-C30) cycloalkyl, (C3-C30) Heterocycloalkyl, (C1-C30) alkoxy, (C6-C30) aryloxy, (C6-C30) ar (C1-C30) alkyl, (C6-C30) aryl, (C3-C30) heteroaryl, mono or di (C1-C30) alkylamino, mono or di (C6-C30) arylamino, tri (C1-C30) alkylsilyl, di (C1-C30) alkyl (C6-C30) arylsilyl, tri (C6-C30) aryl May be further substituted with one or more selected from the group consisting of silyl, nitro and hydroxy;

The heteroaryl includes one or more heteroatoms selected from B, N, O, S, P (= 0), Si and P.

In addition, the present invention provides an organic light emitting device including the organic light emitting compound represented by the formula (1).

The compound according to the present invention has a fused carbazole skeleton and a new structure capable of deposition or solution process, in which a 1-substituted-2,3,3-trisubstituted indolinyl group is bonded to a benzene ring of a carbazole moiety. When the compound is included in the light emitting layer of the organic light emitting device as a host material, the light emitting efficiency, the global efficiency, the quantum efficiency and the device life are better than the conventional materials, and the appropriate color coordinates are shown.

In addition, the organic light emitting compound according to the present invention is excellent in interfacial properties with the electrode due to the improved solubility and heat resistance of various organic solvents, it is possible to the solution process when manufacturing the organic light emitting device.

In addition, the organic light emitting compound according to the present invention has high electron transfer efficiency, which not only prevents crystallization during device fabrication but also has good layer formation, thereby improving current characteristics of the device, thereby intensifying driving voltage, thereby inducing an increase in power efficiency. There is an advantage that can be produced an organic light emitting device with improved power.

1 is a graph showing efficiency (cd / A) vs. luminance (cd / m 2) of organic light emitting diodes manufactured in Examples 3 to 4 and Comparative Example 1. FIG.
2 is a graph showing power efficiency (PE; lm / W) vs. brightness (cd / m 2) of the organic light emitting diodes manufactured in Examples 3 to 4 and Comparative Example 1. FIG.
3 is a graph showing quantum efficiency (QE;%) vs. luminance (cd / m 2) of the organic light emitting diodes manufactured in Examples 3 to 4 and Comparative Example 1. FIG.

An organic light emitting compound, which is a novel phosphorescent host compound according to the present invention, and an organic light emitting device using the same are described below. However, unless there is another definition in technical terms and scientific terms used at this time, common knowledge in the technical field to which the present invention belongs. The person having the ordinary meaning has a meaning commonly understood, and a description of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted in the following description.

The novel phosphorescent host compound according to the present invention may be represented by the following Chemical Formula 1.

[Formula 1]

In Chemical Formula 1,

R, R 'and R' 'are each independently hydrogen, deuterium, (C1-C30) alkyl, (C3-C30) cycloalkyl;

R ₁ and R ₂ are each independently hydrogen, deuterium, halogen, (C1-C30) alkyl, (C3-C30) cycloalkyl, (C6-C30) aryl or (C3-C30) heteroaryl;

Q is NR ₃ , O, S, CR ₄ R ₅ or CR ₆ R ₇ CR ₈ R ₉ ;

R ₃ to R ₉ are each independently hydrogen, deuterium, halogen, (C1-C30) alkyl, (C3-C30) cycloalkyl, (C6-C30) aryl or (C3-C30) heteroaryl;

Alkyl, cycloalkyl, aryl or heteroaryl of R ₁ to R ₉ may be selected from (C1-C30) alkyl, halo (C1-C30) alkyl, halogen, cyano, (C3-C30) cycloalkyl, (C3-C30) Heterocycloalkyl, (C1-C30) alkoxy, (C6-C30) aryloxy, (C6-C30) ar (C1-C30) alkyl, (C6-C30) aryl, (C3-C30) heteroaryl, mono or di (C1-C30) alkylamino, mono or di (C6-C30) arylamino, tri (C1-C30) alkylsilyl, di (C1-C30) alkyl (C6-C30) arylsilyl, tri (C6-C30) aryl May be further substituted with one or more selected from the group consisting of silyl, nitro and hydroxy;

The heteroaryl includes one or more heteroatoms selected from B, N, O, S, P (= 0), Si and P.

Substituents comprising the "alkyl", "alkoxy" and other "alkyl" moieties described herein include both straight and pulverized forms. In addition, the substituent including the alkyl, alkoxy and other alkyl moieties according to the present invention is a substituent having a short chain of 1 to 7 carbon atoms, but a substituent of 8 or more long chain is also an aspect of the present invention.

In addition, “aryl” described in the present invention is an organic radical derived from an aromatic hydrocarbon by one hydrogen removal, and is a single or fused ring containing 4 to 7, preferably 5 or 6 ring atoms, suitably in each ring. It includes a ring system, a form in which a plurality of aryl is connected by a single bond. Specific examples include phenyl, naphthyl, biphenyl, terphenyl, anthryl, indenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, peryleneyl, chrysenyl, naphthacenyl, fluoranthenyl, and the like. It is not limited to this.

The "heteroaryl" described in the present invention includes 1 to 4 heteroatoms selected from B, N, O, S. P (= O), Si and P as aromatic ring skeleton atoms, and the remaining aromatic ring skeleton atoms are carbon. It means an aryl group which is a 5-6 membered monocyclic heteroaryl, and polycyclic heteroaryl condensed with one or more benzene rings, and may be partially saturated. In addition, heteroaryl in the present invention also includes a form in which one or more heteroaryl is connected by a single bond. Specific examples include furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, isoxazolyl, oxazolyl, triazinyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, and the like. Monocyclic heteroaryl; Benzofuranyl, benzothiophenyl, isobenzofuranyl, benzoimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzooxazolyl, isoindolinyl, indolyl, indazolyl, quinolyl, iso Polycyclic heteroaryl such as quinolyl; And the like, but are not limited thereto.

In addition, "cycloalkyl" described herein refers to a fully saturated and partially unsaturated hydrocarbon ring of 3 to 9 carbon atoms, including those in which aryl or heteroaryl is fused.

The organic light emitting compound of Chemical Formula 1 according to an embodiment of the present invention is 1,3-dihydroindeno [2,1-b] carbazole, 6,8-dihydro-5H-naphtho [2,1- b] carbazole, indolo [2,3-b] carbazole, 7H-benzofuro [2,3-b] carbazole or 7H-benzothieno [2,3-b] carbazole skeleton 1-substituted -2,3,3-trisubstituted indolinyl group bonded to the benzene ring of the part, chemically stable, has a high electron density and high luminous efficiency. In addition, since the organic light emitting compound according to the present invention can be easily dissolved in organic solvents such as halogenated solvents and environmentally friendly halogen-free solvents, it is possible not only to maintain a large light emitting area but also to improve heat resistance and interface characteristics with electrodes. This is very excellent.

The organic light emitting compound according to an embodiment of the present invention preferably in terms of achieving excellent luminous efficiency and improved driving life, the Q may be NR ₃ or CR ₄ R ₅ , R ₃ to R ₅ are each Independently hydrogen, deuterium, (C1-C30) alkyl, (C6-C30) aryl (C1-C30) alkyl, (C3-C30) cycloalkyl, (C6-C30) aryl, (C1-C30) alkyl (C6- C30) aryl or (C3-C30) heteroaryl.

The organic light emitting compound according to an embodiment of the present invention may be specifically represented by the following formula (2) or (3).

[Formula 2]

[Formula 3]

In Chemical Formulas 2 and 3,

R, R 'and R' 'are each independently (C1-C30) alkyl;

R ₁ and R ₂ are each independently hydrogen, deuterium, (C1-C30) alkyl, (C3-C30) cycloalkyl, (C6-C30) aryl or (C3-C30) heteroaryl;

R ₃ to R ₅ are each independently hydrogen, deuterium, (C1-C30) alkyl, (C6-C30) aryl (C1-C30) alkyl, (C3-C30) cycloalkyl, (C6-C30) aryl, (C1 -C30) alkyl (C6-C30) aryl or (C3-C30) heteroaryl;

Alkyl, cycloalkyl, aryl or heteroaryl of R ₁ and R ₂ may be selected from (C1-C30) alkyl, halo (C1-C30) alkyl, halogen, cyano, (C3-C30) cycloalkyl, (C3-C30) Heterocycloalkyl, (C1-C30) alkoxy, (C6-C30) aryloxy, (C6-C30) ar (C1-C30) alkyl, (C6-C30) aryl, (C3-C30) heteroaryl, mono or di (C1-C30) alkylamino, mono or di (C6-C30) arylamino, tri (C1-C30) alkylsilyl, di (C1-C30) alkyl (C6-C30) arylsilyl, tri (C6-C30) aryl It may be further substituted with one or more selected from the group consisting of silyl, nitro and hydroxy.

More preferably, the organic light emitting compound according to the embodiment of the present invention, wherein R, R 'and R''are each independently (C1-C30) alkyl; R ₁ and R ₂ are each independently hydrogen, (C 1 -C 30) alkyl, (C 6 -C 30) aryl or (C 3 -C 30) heteroaryl, wherein the alkyl, aryl or heteroaryl of R ₁ and R ₂ is (C 1 -C30) alkyl, (C6-C30) aryl and (C3-C30) heteroaryl, which may be further substituted with one or more selected from the group consisting of; R ₃ to R ₅ may each independently be hydrogen, (C 1 -C 30) alkyl or (C 6 -C 30) aryl.

The organic light emitting compound according to an embodiment of the present invention is more preferably 1,3-dihydro of Chemical Formula 3 in terms of achieving excellent chemical and electrical stability, luminous efficiency, power efficiency, quantum efficiency and improved driving life It may be an indeno [2,1-b] carbazole compound.

In the organic light emitting compound represented by Formula 2 or Formula 3 according to an embodiment of the present invention, R, R 'and R''are each independently (C1-C10) alkyl; R ₁ is (C6-C12) aryl or (C3-C10) heteroaryl, R ₂ is (C1-C10) alkyl or (C6-C12) aryl, and the aryl or heteroaryl of R ₁ is (C1-C10) ) Alkyl, (C6-C12) aryl and (C3-C10) heteroaryl; and may be further substituted with one or more selected from the group consisting of; R ₃ to R ₅ may each independently be (C 1 -C 10) alkyl or (C 6 -C 12) aryl.

The organic light emitting compound according to an embodiment of the present invention may be used in the organic material layer of the organic light emitting device due to its structural specificity, and more specifically, may be used as a host compound in the light emitting layer in the organic material layer.

The organic light emitting compound according to an embodiment of the present invention may be more specifically exemplified by compounds having the following structure, but is not limited thereto.

The compound according to the present invention may be prepared as shown in the following scheme, but is not limited thereto and may be prepared through known organic reactions.

Scheme 1

In Scheme 1, R, R ', R'', R ₁ , R ₂ and Q are the same as defined in Formula 1; Hal is halogen.

In addition, the present invention provides an organic light emitting device comprising the compound of Formula 1.

An organic light emitting diode according to an embodiment of the present invention includes a first electrode; Second electrode; And one or more organic material layers interposed between the first electrode and the second electrode, and the organic material layer may be a single layer structure consisting of one layer or a multi-layered structure including two or more layers including a light emitting layer. When the organic material layer of the organic light emitting device has a multi-layer structure, for example, it may be a structure in which a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and the like are stacked. 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 material layer may include an emission layer including the compound of Formula 1, and the compound of Formula 1 may be included as a phosphorescent host material in the emission layer. When the compound of Formula 1 is included as a host material in the light emitting layer, the light emitting layer may include one or more dopants.

The first electrode may be an anode layer and is an electrode for injecting holes into the hole injection layer. Therefore, the material for forming the anode layer is not limited as long as the property is imparted to the anode layer. Specific examples of the material for forming the anode layer include metals such as vanadium, chromium, copper, zinc and gold or alloys thereof, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), and the like. Combinations of metals and oxides such as metal oxides, ZnO: Al or SnO2: Sb, poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDT) Conductive polymers such as polypyrrole and polyaniline, but are not limited thereto. In addition, the anode layer may be formed of only one type of the above materials, or may be formed of a mixture of a plurality of materials, and a multi-layer structure composed of a plurality of layers of the same composition or different compositions may be formed.

The organic material layer according to an embodiment of the present invention may include a hole injection layer (HIL), a hole blocking layer (HBL), a hole transport layer (HTL), a light emitting layer, an electron transport layer (ETL), an electron injection layer (EIL), etc. And may be omitted as necessary.

The hole injection layer HIL may be formed on the first electrode by using various methods such as vacuum deposition, spin coating, cast, LB, and the like, and the material of the hole injection layer that may be used is CuPc ( copper phthalocyanine), NPD (N, N'-dinaphthyl-N, N'-phenyl- (1,1'-biphenyl) -4,4'-diamine), m-MTDATA (4,4 ', 4 "-tris (3-Methylphenylphenylamino) triphenylamine), 1-TNATA (4,4 ', 4' '-tris [1-naphthyl (phenyl) amino] triphenyl amine), 2-TNATA (4,4', 4 ''-tris [ Aromatic amines such as 2-naphthyl (phenyl) amino] triphenyl amine), p-DPA-TDAB (1,3,5-tris [N- (4-diphenylaminophenyl) phenylamino] benzene), and polythiophene derivatives as conductive polymers. poly (3,4-ethylenedioxythiophene) -poly (styrnesulfonate) (PEDOT: PSS) may be used, etc. In the embodiment of the present invention, PEDOT: PSS is used as the hole injection layer, and the hole injection layer is 10 to 60 nm. The thickness may be coated on the upper portion of the first electrode.

In addition, the hole transport layer (HTL) is deposited on top of the hole injection layer so as to stably supply the holes introduced through the hole injection layer to the light emitting layer. As a material for the hole transport layer that can be used, a material commonly used may be used. Preferably, NPB (N, N′-bis (naphthalen-1-yl) -N, N′-bis (phenyl) -benzidine) , NPD (N, N′-bis (naphthalen-1-yl) -N, N′-bis (phenyl) -2,2′-dimethylbenzidine), TPD (N, N′-Bis (3-methylphenyl) -N , N′-diphenylbenzidine), TTB (N, N, N ', N'-tetrakis (4-methylphenyl)-(1,1'-biphenyl) -4,4-diamine), TTP (N1, N4-diphenyl- N1, N4-dim-tolylbenzene-1,4-diamine), ETPD (N, N'-bis (4-methylphenyl) -N, N'-bis (4-ethylphenyl)-[1,1 '-(3, 3'-dimethyl) biphenyl] -4,4'-diamine), VNPB (N4, N4'-di (naphthalen-1-yl) -N4, N4'-bis (4-vinylphenyl) biphenyl-4,4'- diamine), ONPB (N4, N4′-bis (4- (6-((3-ethyloxetan-3-yl) methoxy) hexyl) phenyl) -N4, N4′-diphenylbiphenyl-4,4′-diamine), OTPD Low molecular hole transport materials such as (N4, N4′-bis (4- (6-((3-ethyloxetan-3-yl) methoxy) hexyl) phenyl) -N4, N4′-diphenylbiphenyl-4,4′-diamine) and; Polymeric hole transport materials such as poly-N-vinylcarbazole (PVK), polyaniline, (phenylmenyl) polysilane and the like can be used. Preferably NPD, mCP or PVK can be used, in the embodiment of the present invention used PVK as a hole transport layer, the hole transport layer may be stacked on top of the light emitting layer to a thickness of 10 to 60 nm.

The light emitting layer according to an embodiment of the present invention may be a light emitting layer exhibiting phosphorescence, and by including the compound of Formula 1 according to the present invention, it is possible to implement an organic light emitting device having high brightness and long life characteristics. In the light emitting layer of the organic light emitting device of the present invention, the film thickness of the light emitting layer is not limited, but from the viewpoint of homogeneity of the film and prevention of unnecessary high voltage at the time of light emission and improvement of the stability of the light emission color with respect to the driving current, It is preferable to adjust to the range of nm-5 micrometers, More preferably, it adjusts to the range of 5-50 nm, Especially preferably, it is the range of 10-40 nm.

In addition, the light emitting layer may use a phosphorescent dopant together to obtain a high luminance color with higher efficiency. At this time, the dopant to be used is not limited, and known dopants may be selected and used according to needs. The phosphorescent dopant is a compound capable of emitting light from triplet excitons, and is not particularly limited as long as it emits light from triplet excitons, and includes at least one metal selected from the group consisting of Ir, Ru, Pd, Pt, Os, and Re, and the like. It is preferable that it is a metal complex, and especially a porphyrin metal complex or an ortho metallized metal complex is preferable. As a porphyrin metal complex, a porphyrin platinum complex is preferable. There are various ligands for forming the ortho metallized metal complex of the phosphorescent dopant, but preferred ligands include 2-phenylpyridine derivative, 7,8-benzoquinoline derivative, 2- (2-thienyl) pyridine derivative and 2- (1 -Naphthyl) pyridine derivative, 2-phenylquinoline derivative, etc. are mentioned. These derivatives may have a substituent as needed. As an auxiliary ligand, it may further have ligands other than the above ligands such as acetylacetonato and picric acid. Specific examples include bisthienylpyridine acetylacetonate Iridium, bis (benzothienylpyridine) acetylacetonate Iridium {bis (benzothienylpyridine) acetylacetonate Iridium}, bis (2-phenylbenzothiazole) acetylacetonate Iridium {Bis (2-phenylbenzothiazole) acetylacetonate Iridium}, bis (1-phenylisoquinoline) iridium acetylacetonate {bis (1-phenylisoquinoline) Iridium acetylacetonate}, tris (1-phenylisoquinoline) iridium {tris (1-phenylisoquinoline ) Iridium}, tris (phenylpyridine) Iridium}, tris (2-biphenylpyridine) Iridium}, tris (3-biphenylpyridine) iridium {tris (3 -biphenylpyridine) Iridium}, tris (4-biphenylpyridine) Iridium} and the like, but is not limited thereto. The amount of the dopant included in the light emitting layer is not limited, but is preferably included in the range of 2 to 20 parts by weight relative to 100 parts by weight of the host material, the total dopant content of the total weight of the light emitting layer is in the range of 0.5 to 35% by weight. good.

In this case, the hole blocking layer HBL may be formed to prevent the triplet excitons or holes from diffusing into the electron transport layer. In the case of forming the hole blocking layer by vacuum deposition and spin coating, the conditions vary depending on the compound used, but can generally be within the same condition range as the formation of the hole injection layer. Known hole blocking materials can also be used, and examples thereof include oxadiazole derivatives, triazole derivatives, and phenanthroline derivatives. For example, the following BCP etc. can be used as a hole-blocking layer material.

The electron transport layer (ETL) is mainly composed of a material containing a chemical component that attracts electrons, which requires high electron mobility and stably supplies electrons to the light emitting layer through smooth electron transport. As the material of the electron transport layer that can be used according to the present invention, a material commonly used may be used. Preferably, TSPO1 (diphenyl-4-triphenylsilylphenylphosphine oxide), TPBI (1,3,5-tris (N-phenylbenzimiazole-) 2-yl) benzene); Alq ₃ (Tris (8-hydroxyquinolinato) aluminum); BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline); PBD (2- (4-biphenyl) -5- (4-tert-butyl) -1,3,4-oxadizole), TAZ (3- (4-biphenyl) -4-phenyl-5- (4-tert- azole compounds such as butyl) -1,2,4-triazole), OXD-7 (1,3-bis [2- (4-tert-butylphenyl) -1,3,4-oxadiazo-5-yl] benzene) ; phenylquinozaline; TmPyPB (3,3 '-[5'-[3- (3-Pyridinyl) phenyl] [1,1 ': 3', 1 ''-terphenyl] -3,3 ''-diyl] bispyridine) But it is not limited thereto. Preferably, TSPO1, TPBi or Alq3 may be used. In an embodiment of the present invention, TSPO1 and TPBi are used as the electron transport layer, and the electron transport layer may be stacked on the light emitting layer with a thickness of 5 to 150 nm.

In addition, the electron injection layer may be deposited with a thickness of 1 to 50 nm using LIF or Liq (lithium quinolate), but is not limited thereto.

In addition, the second electrode may be a cathode layer, and metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead or alloys thereof, LiF / Al or LiO 2 / A metal having a low work function may be used, such as a multilayered structure material such as Al, and Al is preferable.

The organic light emitting device according to the present invention exhibits an efficient host-dopant energy transfer mechanism, and can express light emission characteristics of high efficiency based on an improvement in electron density distribution. In addition, it is possible to secure high-performance light emission characteristics having high efficiency and long life in each color by overcoming the initial efficiency deterioration characteristics and low life characteristics of the existing materials.

The above-described organic light emitting device according to the present invention may be applied to a display device, the display device may be a display device using a backlight unit, the organic light emitting device may be used as a light source and a single light source of the backlight unit, The display device may be an organic electroluminescent display (OLED) or the like, but is not limited thereto.

Hereinafter, the organic light emitting compound according to the present invention, a method for preparing the same and the light emitting characteristics of the device are described for a detailed understanding of the present invention, and the following examples are provided for purposes of illustration of the present invention. It is not intended to limit the scope of protection of the present invention.

Example 1 Preparation of Compound 1

Preparation of Compound 1-a

2-bromo-7,7-dimethyl-5-phenyl-5,7-dihydroindeno [2,1-b] carbazole (50 g, 114 mmol), bis ( Pinacolato) diboron (31.8 g, 125 mmol), 1,1'-bis (diphenylphosphino) ferrocene-palladium (II) dichloride dichloromethane complex (1.86 g, 2.3 mmol) and potassium acetate (22.4 g, 228 mmol) was added to 1,4-dioxane (750 mL) and heated to reflux for 8 hours. When the reaction was completed, the reaction was cooled to room temperature, extracted with water (800 mL) and ethyl acetate (1000 mL). The organic layer was dried over anhydrous magnesium sulfate, treated with activated carbon, and filtered through Celite. The obtained filtrate was concentrated under reduced pressure, the obtained solid was suspended in n-hexane, filtered and washed with n-hexane to give a white solid compound 1-a (32.8 g, yield: 65%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 7.86 (d, 1H), 7.77 (d, 1H), 7.72 (m, 2H), 7.65 (d, 3H), 7.53 (d, 1H), 7.47 (t , 1H), 7.41 (t, 1H), 7.30 (m, 2H), 1.76 (s, 6H), 1.42 (s, 12H)

Preparation of Compound 1

In a 1000 mL three-necked bottom flask, compound 1-a (20 g, 41.2 mmol), 5-bromo-2,3,3-trimethyl-1-phenylindolin (13.1 g, 41.6 mmol) and toluene (400 mL) was added. Tetrakis (triphenylphosphine) palladium (0) (0.48 g, 0.4 mmol) was added, 1M aqueous potassium carbonate solution (200 mL) was added and heated to reflux. After the reaction for 12 hours, the reaction was cooled to room temperature. The mixture was extracted with water and ethyl acetate, dried over anhydrous magnesium sulfate, treated with activated carbon, filtered through Celite, and concentrated under reduced pressure. After concentration, the mixture was separated by a silica gel column (hexane: methylene chloride = 3: 1) to obtain a white solid compound 1 (13.4 g, yield: 55%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 8.24 (s, 1H) 8.14 (s, 1H) 8.04 (d, 1H) 7.78 (d, 1H) 7.74 (s, 1H) 7.69 (s, 1H) 7.62 ( m, 4H) 7.51 (m, 2H) 7.45 (m, 3H) 7.28 (t, 1H) 7.22 (t, 3H) 7.07 (d, 2H) 6.90 (t, 1H) 3.43 (q, 1H) 1.71 (s, 6H) 1.38 (s, 6H) 1.21 (d, 3H)

Example 2 Preparation of Compound 2

Preparation of Compound 2-a

2-bromo-5- (4,6-diphenyl-1,3,5-triazin-2-yl) -7,7-dimethyl-5,7-dihydro into a 2000 mL three-neck round flask Indeno [2,1-b] carbazole (40 g, 91.2 mmol), bis (pinacolato) diboron (25.5 g, 100 mmol), 1,1'-bis (diphenylphosphino) ferrocene-palladium ( II) Dichloride dichloromethane complex (1.49 g, 1.8 mmol) and potassium acetate (18 g, 182 mmol) were added to 1,4-dioxane (600 mL) and heated to reflux for 8 hours. When the reaction was completed, the reaction was cooled to room temperature, extracted with water (800mL) and ethyl acetate (1000mL). The organic layer was dried over anhydrous magnesium sulfate, treated with activated carbon, and filtered through Celite. The obtained filtrate was concentrated under reduced pressure, and the obtained solid was recrystallized under ethyl acetate and n-hexane. The mixture was filtered and washed with n-hexane to obtain an ivory-colored solid compound 2-a (28.8 g, yield: 65%).

H NMR (400 MHz, CDCl ₃ , ppm) δ 8.14 (s, 1H) 8.05 (d, 2H) 7.92 (s, 1H) 7.80 (m, 5H) 7.63 (d, 1H) 7.56 (t, 1H) 7.50 (m , 4H) 7.42 (m, 4H) 1.74 (s, 6H) 1.41 (s, 12H)

Preparation of Compound 2

In a 1000 mL three-necked bottom flask, compound 2-a (25 g, 39 mmol), 5-bromo-1-hexyl-2,3,3-trimethylindoline (12.8 g, 39 mmol) and toluene (400 mL) was added. Tetrakis (triphenylphosphine) palladium (0) (0.45 g, 0.4 mmol) was added, 1 M aqueous potassium carbonate solution (200 mL) was added and heated to reflux. After the reaction for 12 hours, the reaction was cooled to room temperature. The mixture was extracted with water and ethyl acetate, dried over anhydrous magnesium sulfate, treated with activated carbon, filtered through Celite, and concentrated under reduced pressure. After concentration, the mixture was separated by a silica gel column (hexane: methylene chloride = 5: 1) to obtain a white solid compound 2 (14.9 g, yield: 50%).

¹ H NMR (400 MHz, CDCl ₃ , ppm) δ 8.24 (s, 1H) 8.18 (s, 1H) 8.08 (d, 1H) 8.05 (d, 1H) 7.92 (s, 1H) 7.81 (d, 4H) 7.65 ( q, 2H) 7.57-7.51 (m, 6H) 7.43 (m, 3H) 7.33 (d, 1H) 6.72 (d, 1H) 3.46 (t, 1H) 3.43 (t, 1H) 3.27 (t, 1H) 1.74 ( s, 6H) 1.60 (m, 2H) 1.38 (m, 12H) 1.21 (d, 3H) 0.99 (t, 3H)

Example 3 Fabrication of Organic Light-Emitting Device Using Compound 1 According to the Present Invention

A 25 mm × 25 mm × 0.7 mm sized glass substrate having an ITO (indium tin oxide) transparent electrode line having a thin film thickness of 150 nm was ultrasonically cleaned in distilled water containing detergent for 20 minutes, and isopropyl alcohol was Washed once for 10 minutes. After isopropyl alcohol cleaning, the substrate was again ultrasonically washed twice with 10 minutes using distilled water and dried. Subsequently, the oxygen / nitrogen plasma was treated for 2 minutes in the vacuum deposition equipment.

After plasma processing of the substrate, the substrate is vacuum-adsorbed to spin coater equipment to manufacture a device for solution process, and then PEDOT: PSS, a conductive polythiophene derivative, is a conductive polymer to cover the transparent electrode on the surface where the transparent electrode line is formed. Poly (3,4-ethylenedioxythiophene) -poly (styrenesulfonate)) was diluted with isopropyl alcohol, spin coated at 2000 rpm for 1 minute, dried on a hot plate at 130 ° C for 30 minutes to form a thin film with a thickness of 50 nm. Used as injection layer. Next, PVK (poly-N-vinylcarbazole) was diluted in toluene or chlorobenzene on the hole injection layer and spin-coated at 2000 rpm for 30 seconds, followed by baking for 30 minutes on a hotplate at 130 ° C., followed by a hole transport layer of 15 nm. Formed. Next, mixed with toluene or chlorobenzene at a concentration of 5% by weight to the organic light emitting compound 1 (Example 1) according to the present invention, the host AYPD as a dopant on the hole transport layer and spin-coated at 2000rpm for 30 seconds. Thereafter, baking was performed for 30 minutes on a hot plate at 80 ° C to form a light emitting layer having a thickness of 30 nm.

Subsequently, TSPO1 (diphenyl-4-triphenylsilylphenylphosphine oxide) and TPBi (1,3,5-tris (N-phenylbenzimiazole-2-yl) benzene) were deposited on the light emitting layer with an electron transport layer having a thickness of 25 nm, and then Liq (lithium) was formed thereon. quinolate) was deposited to form an electron injection layer having a thickness of 1 nm. Metal aluminum was deposited on the Liq film to form a metal cathode, thereby producing an organic light emitting device.

The light emission test was performed by applying a voltage of 0 to 15V to the organic light emitting device manufactured as described above. Table 1 shows the results of the electroluminescent properties and the basic physical properties. In addition, FIG. 1 illustrates the efficiency (cd / A) versus luminance (cd / m 2) of the organic light emitting device manufactured as described above, and FIG. 2 illustrates the power efficiency (PE; lm / W) versus brightness (cd / m 2). 3 shows quantum efficiency (QE;%) versus brightness (cd / m 2).

Example 4 Fabrication of Organic Light-Emitting Device Using Compound 2 According to the Present Invention

An organic light-emitting device was manufactured in the same process as in Example 3, except that Compound 2 was used instead of Compound 1 as a host material in Example 3, and the electroluminescent properties and basis shown in Table 1 and FIGS. Physical property measurement results are shown.

Comparative Example 1 Fabrication of Organic Light-Emitting Device Using Compound CBP

An organic light emitting device was manufactured in the same manner as in Example 3, except that Compound CBP having the following structure was used instead of Compound 1 as the host material in Example 3, and the electroluminescence shown in Table 1 and FIGS. The results of measurement of properties and basic properties are shown.

efficiency
(cd / A) Power efficiency
(lm / W) Quantum Efficiency (%) Color coordinates (x, y) Example 3 43.01 19.99 13.63 (0.453, 0.534) Example 4 37.28 18.91 12.31 (0.452, 0.534) Comparative Example 1 31.88 16.47 9.91 (0.453, 0.534)

As shown in Table 1, the organic light emitting device including the compound according to the present invention in the light emitting layer as a light emitting host material has excellent light emission characteristics in efficiency, power efficiency and quantum efficiency compared to conventional CBP. It was confirmed (FIGS. 1-3).

That is, when the compound having the characteristic structure according to the present invention is used as the light emitting host material in the light emitting layer, the driving voltage is further lowered, and the exciton in the light emitting layer is effectively confined to dramatically increase efficiency, power efficiency and quantum efficiency, and at high current density. By suppressing the roll-off phenomenon it is possible to implement a more excellent durability can have a long life characteristics.

Although described in detail with respect to embodiments of the present invention as described above, those of ordinary skill in the art, without departing from the spirit and scope of the invention as defined in the appended claims Various modifications may be made to the invention. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

Claims (7)

delete An organic light emitting compound represented by the following formula (3).
[Formula 3]

In Chemical Formula 3,
R, R 'and R''are each independently (C1-C30) alkyl;
R ₁ is (C6-C30) aryl or (C3-C30) heteroaryl;
R ₂ is (C1-C30) alkyl or (C6-C30) aryl;
R ₄ and R ₅ are each independently (C 1 -C 30) alkyl;
The heteroaryl of R ₁ may be further substituted with (C6-C30) aryl.
delete The method of claim 2,
An organic light emitting compound selected from the following compounds.

An organic light emitting device comprising the organic light emitting compound according to any one of claims 2 and 4. The method of claim 5,
The organic light emitting diode includes a first electrode; Second electrode; And at least one organic material layer interposed between the first electrode and the second electrode, wherein the organic material layer comprises a light emitting layer containing the organic light emitting compound. The method of claim 6,
The organic light emitting compound is to be included as a host of the light emitting layer, the organic light emitting device.

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