KR102028940B1 - Material for luminescent element, and luminescent element - Google Patents

Abstract

By using the compound which is a carbazole dimer compound and has a substituent represented by specific Ar in a specific position, the organic thin film light emitting element which improved the luminous efficiency and durability life while maintaining a low drive voltage is provided.

Description

Light-Emitting Element Materials and Light-Emitting Element {MATERIAL FOR LUMINESCENT ELEMENT, AND LUMINESCENT ELEMENT}

The present invention relates to a light emitting device capable of converting electrical energy into light and a light emitting device material used therein. More specifically, the present invention relates to light emitting devices usable in fields such as display devices, flat panel displays, backlights, lighting, interiors, signs, signs, electronic cameras and optical signal generators, and light emitting device materials used therein.

Research into organic thin film light emitting devices that emit light when electrons injected from the cathode and holes injected from the anode recombine in an organic phosphor sandwiched between both poles has been actively conducted in recent years. This light emitting element is attracting attention because it is ultra-thin and is characterized by high luminance emission under low driving voltage and multicolor emission by selecting a fluorescent material.

Since this research has shown that organic thin film elements emit light with high brightness by Kodak's C.W.Tang et al., A number of practical studies have been conducted, and organic thin film light emitting elements have been reliably applied to main displays of mobile phones. Is going on. However, there are still many technical problems, and among them, both high efficiency and long life of the device are one of the major problems.

The drive voltage of the device is largely dependent on the carrier transport material for transporting carriers, such as holes and electrons, to the light emitting layer. Among these, the material which has a carbazole skeleton as a material (hole transport material, an electron transport material) which transports a hole and an electron is known (for example, refer patent documents 1-11).

Japanese Patent Laid-Open No. 8-3547 Korean Patent Publication No. 2010-0079458 Japanese Patent Laid-Open No. 9-249876 Korean Patent Publication No. 2009-0028943 International Publication No. 2009/61145 Japanese Patent Publication No. 2008-294161 International Publication No. 2010/41872 International Publication No. 2010/44342 Japanese Patent Publication No. 2008-135498 International Publication No.2012 / 108388 International Publication No. 2012/165256

However, in the prior art, it is difficult to sufficiently lower the driving voltage of the device, and even if the driving voltage can be lowered, the luminous efficiency and durability life of the device are insufficient. As such, a technique for achieving both low driving voltage, high luminous efficiency, and durability life has not been found.

SUMMARY OF THE INVENTION An object of the present invention is to solve such problems of the prior art and to provide an organic thin film light emitting device which has improved luminous efficiency and endurance life while maintaining a low driving voltage.

This invention contains the compound represented by following General formula (1), It is a light emitting element material characterized by the above-mentioned.

R ¹ to R ¹³ may be the same as or different from each other, and each hydrogen, alkyl group, cycloalkyl group, aryl group, heterocyclic group, heteroaryl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, arylether group, Arylthioether group, halogen, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, -P (= O) R ¹⁶ R ¹⁷ and silyl group. R ¹⁶ and R ¹⁷ are each an aryl group or a heteroaryl group. These substituents may further be substituted and the adjacent substituents may further form the ring. R ¹⁴ and R ¹⁵ may each be the same or different and are selected from the group consisting of an alkyl group, an aryl group (except fluorenyl group and fluoranthenyl group), an alkenyl group, an alkylthio group, an arylthio group, and a heterocyclic group. . Ar is a substituted or unsubstituted aryl group (except for fluoranthenyl group), and is composed of 6 to 18 carbon atoms including a substituent. However, in the case of a substituted aryl group, the case where it is substituted by an amino group is excluded. In addition, Ar and R <^3> are another group.

(Effects of the Invention)

Advantageous Effects of Invention The present invention can provide an organic electroluminescent device having a low driving voltage, high luminous efficiency, and also having a sufficient durability life.

The compound represented by General formula (1) in this invention is demonstrated in detail.

R ¹ to R ¹³ may be the same as or different from each other, and each hydrogen, alkyl group, cycloalkyl group, aryl group, heterocyclic group, heteroaryl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, arylether group, Arylthioether group, halogen, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, -P (= O) R ¹⁶ R ¹⁷ and silyl group. R ¹⁶ and R ¹⁷ are each an aryl group or a heteroaryl group. These substituents may further be substituted and the adjacent substituents may further form the ring. R ¹⁴ and R ¹⁵ may be the same or different and are selected from the group consisting of an alkyl group, an aryl group (except fluorenyl group and fluoranthenyl group), an alkenyl group, an alkylthio group, an arylthio group, and a heterocyclic group. . Ar is a substituted or unsubstituted aryl group (except for fluoranthenyl group), and is composed of 6 to 18 carbon atoms including a substituent. However, in the case of a substituted aryl group, the case where it is substituted by an amino group is excluded. In addition, Ar and R <^3> are another group.

Deuterium may be sufficient as hydrogen among these substituents. Moreover, an alkyl group shows saturated aliphatic hydrocarbon groups, such as a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and tert- butyl group, for example, and it does not have a substituent. You may be. There is no restriction | limiting in particular in the further substituent in the case of substitution, For example, an alkyl group, an aryl group, heteroaryl group, etc. are mentioned, This point is common also to the following description. In addition, although carbon number of an alkyl group is not specifically limited, Usually, 1 or more and 20 or less, More preferably, they are 1 or more and 8 or less from the point of the availability and cost.

The cycloalkyl group represents, for example, saturated alicyclic hydrocarbon groups such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, and may or may not have a substituent. Although carbon number of an alkyl-group part is not specifically limited, Usually, it is the range of 3-20.

An aryl group represents aromatic hydrocarbon groups, such as a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group, a phenanthryl group, anthracenyl group, a chrysenyl group, a triphenylenyl group, a terphenyl group, and a pyrenyl group, for example. The aryl group may or may not have a substituent. Although carbon number of an aryl group is not specifically limited, Usually, it is the range of 6-40.

The heterocyclic group represents, for example, an aliphatic ring having an atom other than carbon, such as a pyran ring, a piperidine ring, a cyclic amide, and may or may not have a substituent. Although carbon number of a heterocyclic group is not specifically limited, Usually, it is the range of 2-20.

Heteroaryl group is furanyl group, thiophenyl group, pyridyl group, quinolinyl group, pyrazinyl group, naphthyridyl group, benzofuranyl group, benzothiophenyl group, indolyl group, dibenzofuranyl group, dibenzothiophenyl group, carbazolyl group, etc. A cyclic aromatic group having one or a plurality of atoms other than carbon in a ring is shown, and this may be unsubstituted or substituted. Although carbon number of a heteroaryl group is not specifically limited, Usually, it is the range of 2-30.

An alkenyl group represents the unsaturated aliphatic hydrocarbon group containing double bonds, such as a vinyl group, an allyl group, butadienyl group, for example, and it may or may not have a substituent. Although carbon number of an alkenyl group is not specifically limited, Usually, it is the range of 2-20.

A cycloalkenyl group shows an unsaturated alicyclic hydrocarbon group containing double bonds, such as a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexenyl group, for example, and it may or may not have a substituent. Although carbon number of a cycloalkenyl group is not specifically limited, Usually, it is the range of 2-20.

An alkynyl group represents the unsaturated aliphatic hydrocarbon group containing triple bonds, such as an ethynyl group, for example, and it may or may not have a substituent. Although carbon number of an alkynyl group is not specifically limited, Usually, it is the range of 2-20.

An alkoxy group represents the functional group which the aliphatic hydrocarbon group couple | bonded through ether bonds, such as a methoxy group, an ethoxy group, a propoxy group, for example, and this aliphatic hydrocarbon group may have a substituent. Although carbon number of an alkoxy group is not specifically limited, Usually, it is the range of 1 or more and 20 or less.

An alkylthio group is one in which an oxygen atom of an ether bond of an alkoxy group is substituted with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. Although carbon number of an alkylthio group is not specifically limited, Usually, it is the range of 1 or more and 20 or less.

An aryl ether group may represent the functional group which the aromatic hydrocarbon group couple | bonded through ether bonds, such as a phenoxy group, for example, and the aromatic hydrocarbon group may have a substituent. Although carbon number of an arylether group is not specifically limited, Usually, it is the range of 6-40.

An arylthio ether group is an oxygen atom in which the ether atom of the arylether group is substituted with a sulfur atom. The aromatic hydrocarbon group in the arylether group may or may not have a substituent. Although carbon number of an arylether group is not specifically limited, Usually, it is the range of 6-40.

Halogen represents fluorine, chlorine, bromine and iodine.

The carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group may or may not have a substituent, for example, an alkyl group, a cycloalkyl group, an aryl group, etc. are mentioned, and these substituents may further substitute.

The silyl group represents, for example, a functional group having a bond to silicon atoms such as trimethylsilyl group, and may or may not have a substituent. Although carbon number of a silyl group is not specifically limited, Usually, it is the range of 3-20. Moreover, silicon number is the range of 1 or more and 6 or less normally.

The alkylene group represents a divalent group derived from an alkyl group, and examples thereof include methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, sec-butylene group, tert-butylene group and the like. These may or may not have a substituent. Although carbon number of an alkylene group is not specifically limited, Usually, it is the range of 1 or more and 20 or less.

Among the above, R ¹ to R ¹³ are preferably hydrogen, an alkyl group, a cycloalkyl group and an alkoxy group. This is because the alkyl group, the cycloalkyl group and the alkoxy group have a small effect on the mother skeleton like hydrogen, and thus the effect of increasing the ionization potential is small without lowering the triplet level of the compound represented by the general formula (1). These groups may be further substituted. In addition, in consideration of the availability of raw materials and the synthesis cost, R ¹ to R ¹³ are most preferably all hydrogen. In addition, although it is as above-mentioned, hydrogen here may also be deuterium.

In addition, in consideration of thermal stability and electrochemical stability of the material, R ¹⁴ and R ¹⁵ are preferably a substituted or unsubstituted aryl group (except fluorenyl group and fluoranthenyl group). Preferred substituents in the case where these groups are substituted include alkyl groups, alkoxy groups, aryl groups, heteroaryl groups and the like. R ¹⁴ and R ¹⁵ are preferably an aryl group having 6 to 30 nuclear carbon atoms, and more preferably an aryl group having 6 to 12 nuclear carbon atoms. If the molecular weight of R ¹⁴ and R ¹⁵ is too large, there is a fear of thermal decomposition during deposition. Among these, a phenyl group, a biphenyl group, a dibenzoprayl group, or a dibenzothiophenyl group is more preferable. Moreover, an unsubstituted phenyl group or an alkyl substituted phenyl group is more preferable from a viewpoint of not reducing a triplet level, and an unsubstituted phenyl group is especially preferable.

Ar is selected from substituted or unsubstituted aryl groups in consideration of thermal stability and electrochemical stability of the material (except fluoranthenyl group), and is different from R ³ in view of stability of film quality of the material. Ar is composed of 6 to 18 nuclear carbon atoms including substituents in consideration of thermal stability during sublimation purification. However, in the case of a substituted aryl group, the case where it is substituted by an amino group is excluded. This is because, when the amino group is substituted, the electrochemical stability is deficient and the stability at the time of driving the device is lowered.

Among them, Ar is substituted or unsubstituted 4-methylphenyl group, substituted or unsubstituted biphenyl group, substituted or unsubstituted 2 in order to improve hole mobility and to not lower the triplet level by broadening the airspace. It is preferable that they are a fluorenyl group, a substituted or unsubstituted terphenyl group, or a substituted or unsubstituted triphenylenyl group. Although it is preferable that a 4-methylphenyl group, a biphenyl group, and 2-fluorenyl group are unsubstituted, the methyl group which does not significantly affect the increase of molecular weight and does not reduce triplet level may be substituted. Moreover, in order to make ionization potential lower and to improve hole injection property, 2-fluorenyl group is more preferable. Among the 2-fluorenyl groups, the 9,9-dimethylfluorenyl group is most preferable because the ionization potential is lower and the hole injection property is improved. Terphenyl group and triphenyl group are most preferably unsubstituted from the viewpoint of synthesis phase and molecular weight.

Specific examples of the structure of Ar include the following skeletons.

Moreover, as a compound represented by such General formula (1), the following compounds are specifically mentioned. In addition, the example of the compound represented by General formula (1) is not limited to these.

The compound represented by General formula (1) can be manufactured by a well-known method. First, a carbazole dimer monobromo is synthesized by Suzuki coupling reaction of 3-iodine-6-bromomer of carbazole substituted with 9-position and 3-boric acid of carbazole substituted with 9-position. . On the other hand, the compound represented by General formula (1) by converting aryl boric acid, aryl boric acid ester, and bromo aryl into a boric acid or a boric acid ester body, and by Suzuki coupling reaction with the monobromo of the carbazole dimer mentioned above. This can be easily synthesized, but the production method is not limited to this.

The compound represented by General formula (1) in this invention is used as a light emitting element material. Herein, the light emitting element material in the present invention refers to a material used for any one layer of the light emitting element, and as described later, in addition to being a material used for the hole injection layer, the hole transport layer, the light emitting layer and / or the electron transport layer, The material used for the protective film of a cathode is also included. By using the compound represented by General formula (1) in this invention for either layer of a light emitting element, high luminous efficiency is obtained and the light emitting element excellent in durability is obtained.

Next, embodiment of the light emitting element of this invention is described in detail. The light emitting element of this invention has an organic layer interposed between an anode and a cathode, and these anode and a cathode, and the said organic layer emits light by electric energy.

In this light emitting device, the layer structure between the anode and the cathode is not only a light emitting layer but also includes a light emitting layer / electron transport layer, 2) hole transport layer / light emitting layer, 3) hole transport layer / light emitting layer / electron transport layer, and 4) hole injection layer /. The lamination | stacking structure of a hole transport layer / light emitting layer / electron transport layer, 5) hole transport layer / light emitting layer / electron transport layer / electron injection layer, 6) hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer is mentioned. Each of the above layers may be either a single layer or a plurality of layers, respectively.

The compound represented by the general formula (1) may be used in any one of the above layers in the light emitting device, but is particularly preferably used in the hole transport layer.

In the light emitting device of the present invention, the anode and the cathode have a role for supplying a sufficient current for light emission of the device, and at least one of the anode and the cathode is preferably transparent or translucent to extract light. Usually, the anode formed on a board | substrate is made into a transparent electrode.

The material used for the anode is a material capable of efficiently injecting holes into the organic layer, and if it is transparent or translucent to extract light, zinc oxide, tin oxide, indium oxide, tin indium oxide (ITO), zinc indium oxide (IZO) Conductive metal oxides such as metals), metals such as gold, silver and chromium, inorganic conductive materials such as copper iodide and copper sulfide, and conductive polymers such as polythiophene, polypyrrole, and polyaniline, but are not particularly limited, but are not limited to ITO glass or NESA. Particular preference is given to using glass. These electrode materials may be used alone, or a plurality of materials may be laminated or mixed. The resistance of the transparent electrode is not limited, as long as it can supply a sufficient current for light emission of the device, but is preferably low resistance from the viewpoint of power consumption of the device. For example, an ITO substrate of 300 Ω / □ or less functions as an element electrode, but since it is possible to supply a substrate of about 10 Ω / □, it is particularly preferable to use a low resistance substrate of 20 Ω / □ or less. . Although the thickness of ITO can be arbitrarily selected according to a resistance value, it is usually used between 50-300 nm.

Moreover, in order to maintain the mechanical strength of a light emitting element, it is preferable to form a light emitting element on a board | substrate. As a board | substrate, glass substrates, such as a soda glass and an alkali free glass, are used preferably. Since the thickness of a glass substrate should just be thickness enough to maintain mechanical strength, 0.5 mm or more is enough. As for the material of the glass, an alkali-free glass is preferable because it is better to have less elution ions from the glass. Alternatively, soda-lime glass coated with a barrier coating such as SiO _{2 is} also commercially available. In addition, as long as a 1st electrode functions stably, a board | substrate does not need to be glass, For example, you may form an anode on a plastic substrate. The method for forming an ITO film is not particularly limited such as an electron beam beam method, a sputtering method and a chemical reaction method.

The material used for the cathode is not particularly limited as long as it is a material capable of injecting electrons efficiently into the light emitting layer. Generally, metals such as platinum, gold, silver copper, iron, tin, aluminum, indium, or alloys of these metals with low work function metals such as lithium, sodium, potassium, calcium, and magnesium, or multilayer lamination are preferable. Do. Especially, as a main component, aluminum, silver, and magnesium are preferable from a viewpoint of electrical resistance value, the ease of film forming, stability of a film, luminous efficiency, etc. In particular, it is preferable to comprise magnesium and silver because electron injection into the electron transporting layer and the electron injection layer in the present invention can be facilitated and low-voltage driving can be performed.

In addition, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium or inorganic materials such as silica, titania, and silicon nitride, polyvinyl alcohol, polyvinyl chloride, hydrocarbons for cathodic protection It is enumerated as a preferable example to laminate an organic polymer compound such as a polymer compound on a cathode as a protective film layer. However, in the case of an element structure (top emission structure) for extracting light from the cathode side, the protective film layer is selected from a material having light transmission in the visible light region. The manufacturing method of these electrodes is not specifically limited, such as resistance heating, an electron beam, sputtering, ion plating, and coating.

The hole injection layer is a layer inserted between the anode and the hole transport layer. The hole injection layer may be one, or a plurality of layers may be laminated. The presence of the hole injection layer between the hole transport layer and the anode is preferable because it not only drives lower voltage and improves the endurance life, but also improves the carrier balance of the device and improves the luminous efficiency.

Although the material used for a hole injection layer is not specifically limited, For example, 4,4'-bis (N- (3-methylphenyl) -N-phenylamino) biphenyl (TPD), 4,4'-bis ( N- (1-naphthyl) -N-phenyl amino) biphenyl (NPD), 4,4'-bis (N, N-bis (4-biphenylyl) amino) biphenyl (TBDB), bis (N Benzine derivatives referred to as, N'-diphenyl-4-aminophenyl) -N, N-diphenyl-4,4'-diamino-1,1'-biphenyl (TPD232), 4,4 ', 4 " Stars such as -tris (3-methylphenyl (phenyl) amino) triphenylamine (m-MTDATA), 4,4 ', 4 "-tris (1-naphthyl (phenyl) amino) triphenylamine (1-TNATA) A group of materials called burst arylamines, biscarbazole derivatives such as bis (N-arylcarbazole) or bis (N-alkylcarbazole), pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives, thiophene Heterocyclic compounds of derivatives, oxadiazole derivatives, phthalocyanine derivatives, porphyrin derivatives, polymers described above The polycarbonates or styrene derivatives having a side chain bodies, such as polythiophene, polyaniline, polyfluorene, polyvinyl carbazole and polysilane may be used. Moreover, the compound represented by General formula (1) can also be used. Among them, a benzidine derivative and a starburst arylamine-based material group are more preferably used from the viewpoint of having a lower HOMO level than the compound represented by the general formula (1) and smoothly injecting and transporting holes from the anode to the hole transport layer.

These materials may be used alone or in combination of two or more materials. Alternatively, a plurality of materials may be laminated to form a hole injection layer. In addition, it is more preferable that the hole injection layer is composed of the acceptor compound alone, or when the acceptor compound is doped into the hole injection material as described above, the above-described effects are obtained more remarkably. An acceptor compound is a material which forms the hole-transporting layer which contact | connects when used as a single layer film, and the material which comprises a hole injection layer, when doped and uses, and a charge transfer complex. The use of such a material improves the conductivity of the hole injection layer, contributes to lowering the driving voltage of the device, and obtains an effect of improving luminous efficiency and improving durability life.

Examples of acceptor compounds include iron (III) chloride, aluminum chloride, gallium chloride, indium chloride, metal chlorides such as antimony chloride, metal oxides such as molybdenum oxide, vanadium oxide, tungsten oxide, ruthenium oxide, tris (4-bromophenyl Charge transfer complexes such as aluminum hexachloroantimonate (TBPAH) are listed. Moreover, organic compounds, quinone compounds, acid anhydride compounds, fullerenes and the like having a nitro group, cyano group, halogen or trifluoromethyl group in the molecule are also preferably used. Specific examples of these compounds include hexacyanobutadiene, hexacyanobenzene, tetracyanoethylene, tetracyanoquinodimethane (TCNQ), tetrafluorotetracyanoquinodimethane (F4-TCNQ), and p-fluoro Nyl, p-chloranyl, p-bromanyl, p-benzoquinone, 2,6-dichlorobenzoquinone, 2,5-dichlorobenzoquinone, tetramethylbenzoquinone, 1,2,4,5-tetracyano Benzene, o-dicyanobenzene, p-dicyanobenzene, 1,4-dicyanotetrafluorobenzene, 2,3-dichloro-5,6-dicyanobenzoquinone, p-dinitrobenzene, m-dinitro Benzene, o-dinitrobenzene, p-cyanonitrobenzene, m-cyanonitrobenzene, o-cyanonitrobenzene, 1,4-naphthoquinone, 2,3-dichloronaphthoquinone, 1-nitronaphthalene , 2-nitronaphthalene, 1,3-dinitronaphthalene, 1,5-dinitronaphthalene, 9-cyanoanthracene, 9-nitroanthracene, 9,10-anthraquinone, 1,3,6,8-tetranitro Carbazole, 2,4,7-tree The like Trojan-9-fluorenone, 2,3,5,6-dicyano pyridine, maleic anhydride, phthalic anhydride, C60 and C70 are listed.

Among these, since a metal oxide and a cyano group containing compound are easy to handle and also easy to deposit, since the above-mentioned effect is acquired easily, it is preferable. In either case where the hole injection layer is composed of the acceptor compound alone, or when the acceptor compound is doped in the hole injection layer, the hole injection layer may be one layer, and a plurality of layers are laminated. You may be.

The hole transport layer is a layer for transporting holes injected from the anode to the light emitting layer. The hole transport layer may be either a single layer or a plurality of layers laminated.

The compound represented by formula (1) has an ionization potential of 5.3 to 5.5 eV (measured by Riken Keiki Co., Ltd. of the deposition film), high triplet level, high hole transporting property and thin film stability. Therefore, it is preferable to use for the hole injection layer and the hole transport layer of a light emitting element. In addition, the compound represented by the general formula (1) has a large energy gap with respect to the hole transporting material having a conventional benzidine skeleton, and therefore has a high LUMO level and is excellent in electron blocking property. In addition, it is preferable to use the compound represented by General formula (1) as a hole transport material of the element which used triplet light emitting material. A hole transport material having a benzidine skeleton, which is a conventional material, has a low triplet level and is in direct contact with a light emitting layer containing a triplet luminescent dopant, resulting in leakage of triplet excitation energy and lowering of luminous efficiency. This is because the compound represented by the high triplet level does not cause such a problem.

In the case of a plurality of hole transport layers, the hole transport layer containing the compound represented by the general formula (1) is preferably in direct contact with the light emitting layer. It is because the compound represented by General formula (1) has high electron blocking property, and can prevent the invasion of the electron which flows out from a light emitting layer. Moreover, since the compound represented by General formula (1) has a high triplet level, it also has the effect of trapping the excitation energy of triplet luminescent material. Therefore, even when the triplet light emitting material is contained in the light emitting layer, the hole transport layer containing the compound represented by the general formula (1) is preferably in direct contact with the light emitting layer.

The hole transport layer may be comprised only of the compound represented by General formula (1), and the other material may be mixed in the range which does not impair the effect of this invention. In this case, as another material used, for example, 4,4'-bis (N- (3-methylphenyl) -N-phenylamino) biphenyl (TPD), 4,4'-bis (N- (1- Naphthyl) -N-phenylamino) biphenyl (NPD), 4,4'-bis (N, N-bis (4-biphenylyl) amino) biphenyl (TBDB), bis (N, N'-di Benzidine derivatives referred to as phenyl-4-aminophenyl) -N, N-diphenyl-4,4'-diamino-1,1'-biphenyl (TPD232), 4,4 ', 4 "-tris (3- Called starburst arylamines such as methylphenyl (phenyl) amino) triphenylamine (m-MTDATA), 4,4 ', 4 "-tris (1-naphthyl (phenyl) amino) triphenylamine (1-TNATA) Biscarbazole derivatives such as material group, bis (N-arylcarbazole) or bis (N-alkylcarbazole), pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazoles Heterocyclic compounds, such as derivatives, phthalocyanine derivatives, porphyrin derivatives, and polymers, The carbonate or styrene derivatives, polythiophene, polyaniline, such as polyfluorene, Poly-vinylcarbazole and polysilane are exemplified.

The light emitting layer may be either a single layer or a plurality of layers, and may be formed of a light emitting material (host material, dopant material), respectively, and this may be a mixture of a host material and a dopant material, or may be a host material alone. That is, in the light emitting device of the present invention, in each light emitting layer, only the host material or the dopant material may emit light, and the host material and the dopant material may emit light together. It is preferable that a light emitting layer consists of a mixture of a host material and a dopant material from a viewpoint of using electric energy efficiently and obtaining light emission of high color purity. In addition, the host material and the dopant material may be any one type or a plurality of combinations, respectively. The dopant material may be included in the whole of the host material or partially contained, or any kind thereof. The dopant material may be either laminated or dispersed. The dopant material can control the emission color. If the amount of the dopant material is too large, concentration quenching occurs, and therefore it is preferably used at 20% by weight or less with respect to the host material, more preferably 10% by weight or less. Although the doping method can be formed by the co-deposition method with a host material, you may vapor-deposit simultaneously after mixing with a host material previously.

The light emitting material is, in addition to the compound represented by the general formula (1), a metal chelated oxynoid compound, bis, including condensed ring derivatives such as anthracene and pyrene, tris (8-quinolinolate) aluminum, which have been known as light emitters before. Bisstyryl derivatives such as styryl anthracene derivatives and distyryl benzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives and oxadiazole derivatives , Thiadiazolopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, and polyphenylenevinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives may be used in the polymer system. It doesn't happen.

The host material contained in the luminescent material need not be limited to only one compound, and may be used by mixing a plurality of compounds of the present invention or by mixing one or more types of other host materials. Although it does not specifically limit as a host material which can be mixed, It has condensed aryl ring, such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, indene, etc. Aromatic amine derivatives, such as a compound and its derivative (s), N, N'- dinaphthyl-N, N'- diphenyl-4,4'- diphenyl- 1,1'- diamine, and tris (8-quinolinato) Bisstyryl derivatives, such as metal chelating oxynoid compounds, such as aluminum (III), and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, and cyclo Pentadiene derivatives, pyrrolopyrrole derivatives, thiadiazolopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, polyphenylenevinylene derivatives and polyparaphenyls in the polymer system Available derivatives, polyfluorene derivatives, polyvinyl carbazole derivative, polythiophene derivative, such as, but is not particularly limited. Among them, metal chelation oxynoid compounds, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives and the like are preferably used as the host used when the light emitting layer performs triplet emission (phosphorescence emission). .

It is preferable to contain the compound represented by General formula (2) in the said light emitting layer among the host materials in a triplet light emission system.

Z and R ¹⁸ to R ²² are hydrogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, arylether group, arylthioether group, aryl group, heteroaryl group , Halogen, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, silyl group, -P (= O) R ²³ R ^{24 It} is selected from the group consisting of. R ²³ and R ²⁴ are aryl groups or heteroaryl groups. R ¹⁸ to R ²² may form a ring between adjacent substituents. L ¹ is a single bond or a divalent linking group. X ^{1 to} X ⁵ represent a carbon atom or a nitrogen atom, and in the case of a nitrogen atom, R ¹⁸ to R ^{22, which} is a substituent on the nitrogen atom, do not exist. In X ^1- X ⁵ , the number of nitrogen atoms is 1-4. m and n are the integers of 1-5 each independently.

It is preferable to have a carbazole skeleton among the preferred substituents of Z because ionization potential is small and hole injection becomes easy. The carbazole skeleton is preferable because the hole transporting property is further improved by dimerization or condensation. In the case of condensation, the indolocarbazole skeleton or the dihydroindenocarbazole skeleton is more preferable from the viewpoint of synthesis. The direction of the ring is not particularly limited. In addition, in order to accelerate electron injection, the nitrogen atom may be contained in the indolocarbazole skeleton or the dihydroindolocarbazole skeleton.

It is preferable that L <^1> is a single bond unsubstituted arylene group or unsubstituted heteroarylene group from a molecular weight viewpoint.

It is preferable that it is two or more, and, as for the number of nitrogen atoms in X <^1> -X < ⁵ >, it is more preferable that it is three. Especially, when X <^1> , X <^3> and X <^5> are nitrogen atoms and X <^2> and X <^4> are carbon atoms, it becomes a triazine frame | skeleton, electron attraction property improves more, and electron injection becomes easy, and it is preferable.

It is preferable that m is 1-2 and n is 1 from a viewpoint of molecular weight in m and n.

As a compound represented by such General formula (2), the following compounds are specifically mentioned. In addition, the example of the compound represented by General formula (2) is not limited to these.

Further, the host material used in combination with the blue fluorescent dopant is preferably a compound having an anthracene skeleton or a pyrene skeleton, and specifically, WO2008 / 108256, WO2007 / 029798, WO2010 / 114266, WO2011 / 115378, WO2005 / 113531, Japan Although the compound described in Unexamined-Japanese-Patent No. 2011-204844, etc. are contained, It is not limited to these.

The triplet light emitting material used as the dopant material includes at least one metal selected from the group consisting of iridium (Ir), ruthenium (Ru), palladium (Pd), platinum (Pt), osmium (Os) and rhenium (Re). It is preferable that it is a containing metal complex compound. The ligand preferably has a nitrogen-containing aromatic heterocycle such as a phenylpyridine skeleton or a phenylquinoline skeleton. However, it is not limited to these, An appropriate complex is selected from the relationship with the light emission color, element performance, and a host compound which are required. Specifically, tris (2-phenylpyridyl) iridium complex, tris {2- (2-thiophenyl) pyridyl} iridium complex, tris {2- (2-benzothiophenyl) pyridyl} iridium complex, tris (2 -Phenylbenzothiazole) iridium complex, tris (2-phenylbenzooxazole) iridium complex, trisbenzoquinolinedidium complex, bis (2-phenylpyridyl) (acetylacetonato) iridium complex, bis {2- (2 -Thiophenyl) pyridyl} iridium complex, bis {2- (2-benzothiophenyl) pyridyl} (acetylacetonato) iridium complex, bis (2-phenylbenzothiazole) (acetylacetonato) iridium complex, bis (2-phenylbenzooxazole) (acetylacetonato) iridium complex, bisbenzoquinoline (acetylacetonato) iridium complex, bis {2- (2,4-difluorophenyl) pyridyl} (acetylacetonato) iridium Complex, tetraethylporphyrin platinum complex, {tris (cenoyltrifluoroacetone) mono (1,10-phenanthroline)} europium complex, {tris (ceno) Trifluoroacetone) mono (4,7-diphenyl-1,10-phenanthroline)} europium complex, {tris (1,3-diphenyl-1,3-propanedione) mono (1,10-phenan Trolline)} europium complexes, trisacetylacetone terbium complexes and the like. In addition, the phosphorescent dopant described in Japanese Patent Laid-Open No. 2009-130141 is also preferably used. Although not limited to these, since high efficiency light emission is easy to be obtained, an iridium complex or a platinum complex is used preferably.

The triplet luminescent material used as a dopant material may contain only 1 type, respectively, in a light emitting layer, and may mix and use 2 or more types. When using two kinds of triplet light emitting materials, it is preferable that the total weight of the dopant material is 20% by weight or less with respect to the host material.

The light emitting layer may further contain, in addition to the host material and the triplet light emitting material, a third component for adjusting the carrier balance in the light emitting layer and for stabilizing the layer structure of the light emitting layer. However, as a 3rd component, the material which does not produce interaction between the host material which consists of the compound which has the said carbazole skeleton, and the dopant material which consists of triplet light emitting material is selected.

Although it does not specifically limit as a preferable dopant in a triplet emission system, Specifically, the following examples are mentioned.

In the present invention, the electron transport layer is a layer in which electrons are injected from the cathode and transport electrons. The electron transporting layer has a high electron injection efficiency and is required to transport the injected electrons with high efficiency. For this reason, the electron transport layer is required to be a substance having a high electron affinity, a high electron mobility, excellent stability, and hardly generating impurities which are trapped during production and use. Particularly, when the film thickness is laminated thickly, a compound having a molecular weight of 400 or more that maintains a stable film quality is preferable because low molecular weight compounds tend to deteriorate due to crystallization. However, in consideration of the transport balance between the holes and the electrons, if the electron transport layer mainly plays a role of effectively preventing the holes from the anode from flowing back to the cathode side without recombination, the material having the electron transport ability is not so high. Even if it is comprised, the effect of improving luminous efficiency is equivalent to the case where it is comprised from the material with high electron transport ability. Therefore, the electron blocking layer in the present invention also includes a hole blocking layer that can effectively inhibit the movement of holes.

Examples of the electron transporting material used in the electron transporting layer include condensed polycyclic aromatic derivatives such as naphthalene and anthracene, styryl-based aromatic ring derivatives represented by 4,4'-bis (diphenylethenyl) biphenyl, anthraquinone and diphenoquinone, and the like. Quinoline derivatives, phosphorus oxide derivatives, quinolinol complexes such as tris (8-quinolinolate) aluminum (III), benzoquinolinol complexes, hydroxyazole complexes, azomethine complexes, tropolone metal complexes and flavonol metals Although various metal complexes, such as a complex, are enumerated, since a driving voltage is reduced and high efficiency light emission is obtained, the heteroaryl ring which consists of an element chosen from carbon, hydrogen, nitrogen, oxygen, silicon, phosphorus, and contains electron-accepting nitrogen It is preferable to use a compound having a structure.

Electron-accepting nitrogen here refers to the nitrogen atom which forms the multiple bond between adjacent atoms. The multiple bonds have electron accepting properties because nitrogen atoms have high electronegativity. Therefore, the aromatic heterocycle containing electron accepting nitrogen has high electron affinity. The electron transporting material having electron-accepting nitrogen is likely to receive electrons from the cathode having a high electron affinity, thereby enabling lower voltage driving. In addition, since the supply of electrons to the light emitting layer is increased and the recombination probability is high, the light emission efficiency is improved.

Examples of the heteroaryl ring containing an electron-accepting nitrogen include pyridine ring, pyrazine ring, pyrimidine ring, quinoline ring, quinoxaline ring, naphthyridine ring, pyrimidopyrimidine ring, benzoquinoline ring, phenanthroline ring, and the like. The diazole ring, the oxazole ring, the oxadiazole ring, the triazole ring, the thiazole ring, the thiadiazole ring, the benzoxazole ring, the benzothiazole ring, the benzimidazole ring, the phenanthroimidazole ring, and the like.

Examples of the compound having a heteroaryl ring structure include benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazine derivatives and phenanthroline derivatives. , Quinoxaline derivatives, quinoline derivatives, benzoquinoline derivatives, oligopyridine derivatives such as bipyridine and terpyridine, quinoxaline derivatives and naphthyridine derivatives, and the like are listed as preferred compounds. Among them, imidazole derivatives such as tris (N-phenylbenzimidazol-2-yl) benzene, 1,3-bis [(4-tert-butylphenyl) 1,3,4-oxadiazolyl] phenylene and the like Triazole derivatives such as oxadiazole derivatives, N-naphthyl-2,5-diphenyl-1,3,4-triazole, vasocupuroin and 1,3-bis (1,10-phenanthroline -9-yl) phenanthroline derivatives such as benzene, benzoquinoline derivatives such as 2,2'-bis (benzo [h] quinolin-2-yl) -9,9'-spirobifluorene, 2,5- Bipyridine derivatives such as bis (6 '-(2', 2 "-bipyridyl))-1,1-dimethyl-3,4-diphenylsilol, and 1,3-bis (4 '-(2,2 Terpyridine derivatives, such as "6'2" -terpyridinyl)) benzene, and naphthyridine derivatives such as bis (1-naphthyl) -4- (1,8-naphthyridin-2-yl) phenylphosphine oxide Is preferably used from the viewpoint of electron transport ability. Moreover, when these derivatives have a condensed polycyclic aromatic skeleton, since glass transition temperature improves and electron mobility becomes large, the effect of the low voltage of a light emitting element is more preferable. In addition, in consideration of the improvement in device durability life, ease of synthesis, and easy availability of raw materials, the condensed polycyclic aromatic skeleton is particularly preferably an anthracene skeleton, a pyrene skeleton, or a phenanthroline skeleton. Although the said electron carrying material is used independently, you may mix and use 2 or more types of the said electron carrying materials, or you may mix and use 1 or more types of other electron carrying materials to said electron carrying material.

Although it does not specifically limit as a preferable electron transport material, Specifically, the following examples are mentioned.

Although the said electron transport material is used independently, you may mix and use 2 or more types of the said electron transport materials, or you may mix and use 1 or more types of other electron transport materials to said electron transport material. Moreover, you may contain a donor compound. Here, a donor compound is a compound which makes electron injection to a electron carrying layer from a cathode or an electron injection layer easy by the improvement of an electron injection barrier, and improves the electrical conductivity of an electron carrying layer.

Preferred examples of the donor compound include alkali metals, inorganic salts containing alkali metals, complexes of alkali metals and organic substances, alkaline earth metals, inorganic salts containing alkaline earth metals, or complexes of alkaline earth metals and organic substances. Preferred types of alkali metals and alkaline earth metals include alkali metals such as lithium, sodium, potassium, rubidium, and cesium, which are highly effective in improving electron transporting ability, and alkaline earth metals such as magnesium, calcium, cerium, and barium. do.

Moreover, since vapor deposition in a vacuum is easy and handling is excellent, it is preferable that it is a state of an inorganic salt or a complex with organic substance rather than a metal single body. Moreover, it is more preferable to be in the state of a complex with organic substance from the point of the ease of handling in air | atmosphere, and the control of addition concentration. Examples of the inorganic salts include oxides such as LiO and Li ₂ O, nitrides, fluorides such as LiF, NaF and KF, carbonates such as Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , Rb ₂ CO ₃ , and Cs ₂ CO ₃ And the like. Moreover, lithium and cesium are mentioned as a preferable example of an alkali metal or alkaline earth metal from a viewpoint of obtaining a large low voltage drive effect. Preferable examples of the organic substance in the complex with the organic substance include quinolinol, benzoquinolinol, pyridylphenol, flavonol, hydroxyimidazopyridine, hydroxybenzazole, hydroxytriazole and the like. Especially, the complex of alkali metal and organic substance is preferable from a viewpoint that the effect of the low voltage reduction of a light emitting element is larger, and the complex of lithium and organic substance is more preferable from a viewpoint of easy synthesis | combination and thermal stability, and it is comparatively cheap. Lithium quinolinol is particularly preferred.

Although the ionization potential of an electron carrying layer is not specifically limited, Preferably it is 5.6 eV or more and 8.0 eV or less, More preferably, they are 6.0 eV or more and 7.5 eV or less.

The method for forming each of the layers constituting the light emitting device is not particularly limited, such as resistive heating deposition, electron beam deposition, sputtering, molecular lamination, coating, etc., but generally, resistive heating deposition or electron beam deposition is preferable from the viewpoint of device characteristics. .

The thickness of the organic layer is not limited because it depends on the resistance of the light emitting material, but is preferably 1 to 1000 nm. The film thickness of a light emitting layer, an electron carrying layer, and a positive hole transport layer becomes like this. Preferably they are 1 nm or more and 200 nm or less, More preferably, they are 5 nm or more and 100 nm or less.

The light emitting device of the present invention has a function capable of converting electrical energy into light. Here, although direct current is mainly used as electric energy, it is also possible to use a pulse current or an alternating current. The current value and the voltage value are not particularly limited, but considering the power consumption and the lifetime of the device, it should be selected so that the maximum luminance can be obtained with the lowest possible energy.

The light emitting element of the present invention is preferably used, for example, as a display for displaying in a matrix and / or segment manner.

In the matrix system, pixels for display are arranged two-dimensionally, such as a lattice shape or a mosaic shape, and display a character or an image by a set of pixels. The shape and size of the pixel is determined by the use. For example, a square pixel having one side of 300 µm or less is usually used for displaying images and characters of a PC, a monitor, a television, and in the case of a large display such as a display panel, one side uses a pixel of mm order. In the case of monochrome display, pixels of the same color may be arranged, but in the case of color display, pixels of red, green, and blue are arranged in a cascade. In this case, there are typically delta types and stripe types. The matrix driving method may be either a linear sequential driving method or an active matrix. Although the linear sequential drive has a simple structure, when the operation characteristics are taken into consideration, the active matrix may be superior, and this also needs to be distinguished according to the use.

The segment method in the present invention is a method of forming a pattern so as to display predetermined information, and emitting a region determined by the arrangement of the pattern. For example, time and temperature display in a digital clock or a thermometer, operation state display of an audio device or an electronic cooker, an automobile panel display, etc. are mentioned. The matrix display and the segment display may coexist in the same panel.

The light emitting element of this invention is used suitably also as backlight of various apparatuses. The backlight is mainly used for the purpose of improving the visibility of a display device that does not emit light, and is used in liquid crystal displays, watches, audio devices, automobile panels, display panels, and markings. In particular, the light emitting element of the present invention is preferably used for a liquid crystal display device, especially a backlight for PC use, where thinning is studied, and a thinner and lighter backlight than the conventional one can be provided.

( Example )

Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited by these Examples. In addition, the number of the compound in each following example shows the number of the compound described above.

Synthesis Example 1

Synthesis of HT-1

A mixed solution of 46.7 g of 3-iodine-9-phenyl-9H-carbazole, 22.5 g of N-bromosuccinimide, and 1264 ml of tetrahydrofuran was stirred at room temperature for 4 hours under a nitrogen stream. After the reaction solution was concentrated, 300 ml of water was added to precipitate a solid, and filtration was performed. The obtained solid was washed with water and dried in vacuo to give 55.5 g of 3-bromo-6-iodine-9-phenyl-9H-carbazole.

Next, 55.0 g of 3-bromo-6-iodine-9-phenyl-9H-carbazole, 35.2 g of phenylcarbazole-3-boric acid, 1.29 g of palladium (II) acetate, 260 ml of 2M aqueous sodium carbonate, and 613 ml of dimethoxyethane The mixed solution was refluxed under nitrogen stream for 6 hours. After cooling at room temperature, water was added, filtered and vacuum dried. The obtained individual was refluxed with 500 ml of ethyl acetate, stirred at room temperature for 2 hours, filtered and dried under vacuum to obtain 6-bromo-9,9'-diphenyl-9H, 9'H-3,3'-. 49.3 g of bicarbazole were obtained.

6-bromo-9,9'-diphenyl-9H, 9'H-3,3'-bicarbazole 3.69 g, 9,9-dimethyl-2-fluorene boric acid 1.71 g, bis (triphenyl A mixed solution of 46 mg of phosphine) palladium (II) dichloride, 8 ml of a 2M aqueous sodium carbonate solution, and 66 ml of dimethoxyethane was refluxed under a nitrogen stream for 5 hours. After completion of the reaction, the mixture was cooled to toluene extraction and concentrated. The resulting brown oily solid was purified by silica gel column chromatography and dried in vacuo to yield 1.3 g of a white powder.

The <^1> H-NMR analysis result of the obtained powder was as follows, and it was confirmed that the white crystal obtained above is HT-1.

¹ H-NMR (CDCl ₃ (d = ppm)): 1.596 (s, 6H), 7.33-7.85 (m, 26H) 8.24-8.27 (d, 1H, J = 8.10 Hz), 8.45-8.55 (m, 4H ).

In addition, HT-1 was used as a light emitting element material after carrying out sublimation purification at about 320 degreeC under the pressure of 1x10 <^-3> Pa using an oil diffusion pump. HPLC purity (area% at the measurement wavelength 254 nm) was 99.8% before sublimation purification and 99.9% after sublimation purification.

Example 1

The glass substrate (GEOMATEC Co., Ltd. product, 11 ohms / square, the sputter | spatter) which 165 nm of ITO transparent conductive film was deposited was cut into 38x46 mm, and the etching was performed. The obtained board | substrate was ultrasonic-cleaned for 15 minutes with "Semico-Clean 56" (brand name, the product of Furuuchi Chemical Corporation), and it wash | cleaned with ultrapure water. The substrate was UV-ozone treated for 1 hour immediately before fabrication of the device, placed in a vacuum deposition apparatus, and evacuated until the vacuum in the apparatus was 5 × 10 ⁻⁴ Pa or less. By resistive heating, 10 nm of HI-1 was deposited as a hole injection layer. Next, 60 nm of HT-1 was deposited as a hole transport layer. Next, compound H-1 was used as a host material as a light emitting layer, and compound D-1 was used as a dopant material, and it deposited in thickness of 40 nm so that the dope concentration of a dopant material might be 5 weight%. Next, Compound E-1 was laminated to a thickness of 20 nm as the electron transporting layer.

Next, 0.5 nm of lithium fluoride and 60 nm of aluminum were vapor-deposited, and it was set as the cathode, and the element which is 5 * 5mm square was produced. The film thickness here is a crystal oscillation film thickness monitor display value. When the direct current | flow drive of this light emitting element was carried out at 10 mA / cm <^2> , blue light emission of 4.5 V of drive voltages and 5.3% of external quantum efficiency was obtained. When the device was set to an initial luminance of 1000 cd / m ² and the endurance life was measured, the time of 20% reduction from the initial luminance was 560 hours. In addition, compound HI-1, H-1, D-1, E-1 is a compound shown below.

Examples 2-10

The light emitting element was produced and evaluated similarly to Example 1 except having used the material of Table 1 as a positive hole transport layer. The results are shown in Table 1. In addition, HT-2-HT-10 are compounds shown below.

Examples 11-25

The light emitting element was produced and evaluated similarly to Example 1 except having used the material of Table 1 as a hole transport layer, a host material of a light emitting layer, and a dopant material. The results are shown in Table 1. In addition, H-2, H-3, and D-2 are the structures shown below.

Comparative Examples 1 to 12

Except having used the material of Table 2 as a positive hole transport layer, it carried out similarly to Example 1, and produced and evaluated the light emitting element. The results are shown in Table 2. In addition, HT-11-HT-22 are compounds shown below.

Example 26

The glass substrate (GEOMATEC Co., Ltd. product, 11 ohms / square, the sputter | spatter) which 165 nm of ITO transparent conductive film was deposited was cut into 38x46 mm, and the etching was performed. The obtained board | substrate was ultrasonic-cleaned for 15 minutes with "Semico-Clean 56" (brand name, the product of Furuuchi Chemical Corporation), and it wash | cleaned with ultrapure water. The substrate was UV-ozone treated for 1 hour immediately before fabrication of the device, placed in a vacuum deposition apparatus, and evacuated until the vacuum in the apparatus was 5 × 10 ⁻⁴ Pa or less. 10 nm of HI-1 was deposited as a hole injection layer by the resistance heating method. Next, 60 nm of HT-1 was deposited as a hole transporting layer. Next, compound H-4 was used as a light emitting layer and compound D-3 was used as a dopant material, and it deposited in thickness of 40 nm so that the dope concentration of a dopant material might be 10 weight%. Next, Compound E-2 was laminated at a thickness of 20 nm as the electron transporting layer.

Next, 0.5 nm of lithium fluoride and 60 nm of aluminum were deposited, and a device having a cathode of 5 x 5 mm was produced as a cathode. The film thickness here is a crystal oscillation film thickness monitor display value. When the direct current | flow drive of this light emitting element was carried out at 10 mA / cm <^2> , red light emission of 3.5 V of drive voltages and 15.2% of external quantum efficiency was obtained. When the device was set to an initial luminance of 1000 cd / m ² and the endurance life was measured, a time of 20% reduction from the initial luminance was 390 hours. In addition, compound H-4, D-3, E-2 is a compound shown below.

Examples 27-40

The light emitting element was produced and evaluated similarly to Example 26 except having used the material of Table 3 as a host material of a positive hole transport layer and a light emitting layer. The results are shown in Table 3. In addition, compound H-5 is a compound shown below.

Comparative Examples 13 to 24

Except having used the material of Table 3 as a positive hole transport layer, it carried out similarly to Example 26, and produced and evaluated the light emitting element. The results are shown in Table 3.

Examples 41 to 55 (green phosphorescent device)

The light emitting element was produced and evaluated similarly to Example 26 except having used the material of Table 4 as a hole transport layer, a host material of a light emitting layer, and a dopant material. The results are shown in Table 4. In addition, compound H-6, H-7, D-4 is a compound shown below.

Comparative Examples 25-36

A light emitting device was constructed and evaluated in the same manner as in Example 41 except that the compound shown in Table 4 was used as the hole transport layer. The results are shown in Table 4.

Examples 56-70

The light emitting element was produced and evaluated similarly to Example 26 except having used the material of Table 5 as a hole transport layer, a host material of a light emitting layer, and a dopant material. The results are shown in Table 5. In addition, compound H-8, H-9, D-5 is a compound shown below.

Comparative Examples 37 to 48

Except having used the compound of Table 5 as a positive hole transport layer, it carried out similarly to Example 56, and produced and evaluated the light emitting element. The results are shown in Table 5.

Claims (14)

It has a compound represented by General formula (1), The light emitting element material characterized by the above-mentioned.

[R ¹ , R ² , R ⁴ to R ¹³ may be the same as or different from each other, and each hydrogen, alkyl group, cycloalkyl group, aryl group, heterocyclic group, heteroaryl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkyl Thio group, arylether group, arylthioether group, halogen, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, -P (= O) R ¹⁶ R ¹⁷ and silyl group. R ³ is hydrogen, alkyl group, cycloalkyl group, aryl group, non-aromatic heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, arylether group, arylthioether group, halogen, cyano group, It is selected from the group consisting of a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, -P (= O) R ¹⁶ R ¹⁷ and a silyl group. R ¹⁶ and R ¹⁷ are each an aryl group or a heteroaryl group. These substituents may further be substituted and the adjacent substituents may further form the ring. R <^14> and R <^15> may be same or different, respectively, and is selected from the group which consists of an alkyl group, an unsubstituted aryl group (except a fluorenyl group and fluoranthenyl group), an alkenyl group, an alkylthio group, and an arylthio group. Ar is selected from the following structures. And Ar and R ³ are different groups.]

delete The method of claim 1,
In the general formula (1), R ¹⁴ and R ¹⁵ are selected from unsubstituted aryl groups having 6 to 30 nuclear carbon atoms (except for fluorenyl and fluoranthenyl groups). . The method according to claim 1 or 3,
In said General formula (1), R <^14> and R <^15> is an unsubstituted phenyl group, The light emitting element material characterized by the above-mentioned. The method according to claim 1 or 3,
Wherein in the general formula (1), the light-emitting element-forming material, characterized in that R ¹ ~R ¹³ is hydrogen. A light emitting device in which an organic layer exists between an anode and a cathode and emits light by electrical energy, wherein the light emitting device material according to claim 1 or 3 is contained in the organic layer. The method of claim 6,
At least a hole transport layer exists as said organic layer, The light emitting element characterized by containing the compound represented by General formula (1) in the said hole transport layer. The method of claim 6,
At least a light emitting layer exists as said organic layer, The light emitting element characterized by containing the compound represented by General formula (2) in the said light emitting layer.

[Z and R ¹⁸ to R ²² are hydrogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, arylether group, arylthioether group, aryl group, heteroaryl Group, halogen, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, silyl group, -P (= O) R ²³ R ²⁴ . R ²³ and R ²⁴ are aryl groups or heteroaryl groups. R ¹⁸ to R ²² may form a ring between adjacent substituents. L ¹ is a single bond or a divalent linking group. X ^{1 to} X ⁵ represent a carbon atom or a nitrogen atom, and in the case of a nitrogen atom, R ¹⁸ to R ^{22, which} is a substituent on the nitrogen atom, do not exist. In X ^1- X ⁵ , the number of nitrogen atoms is 1-4. m and n are each independently an integer of 1-5.] The method of claim 8,
In said General formula (2), X <^1> , X <^3> and X <^5> are nitrogen atoms, The light emitting element characterized by the above-mentioned. The method of claim 6,
The light emitting element which has a light emitting layer at least as said organic layer, and a light emitting layer contains the compound which has an anthracene frame | skeleton or a pyrene skeleton. The method of claim 6,
A light emitting element comprising at least a triplet light emitting material as the organic layer. The method of claim 7, wherein
A hole injection layer is present between the hole transport layer and the anode, and the hole injection layer is composed of an acceptor compound alone or contains an acceptor compound. The method of claim 6,
At least an electron transport layer is present between the organic layer and the cathode, the electron transport layer contains a compound consisting of a heteroaryl ring having an electron-accepting nitrogen, the compound consisting of the heteroaryl ring is carbon, hydrogen, nitrogen, oxygen, silicon, phosphorus A light emitting device comprising at least one element selected from. The method of claim 13,
The electron transport layer contains a donor compound, and the donor compound contains an alkali metal, an inorganic salt containing an alkali metal, a complex of an alkali metal and an organic substance, an inorganic earth containing an alkaline earth metal and an alkaline earth metal, or an alkaline earth. A light emitting device comprising a complex of a metal and an organic material.