WO2016009823A1

WO2016009823A1 - Monoamine derivative, luminescent element material comprising same, and luminescent element

Info

Publication number: WO2016009823A1
Application number: PCT/JP2015/068780
Authority: WO
Inventors: 松木真一; 田中大作
Original assignee: 東レ株式会社
Priority date: 2014-07-16
Filing date: 2015-06-30
Publication date: 2016-01-21
Also published as: JPWO2016009823A1

Abstract

Provided is an organic thin-film luminescent element which includes a monoamine derivative represented by a specific structure and hence combines a high luminescent efficiency with durability.

Description

Monoamine derivative, light emitting device material and light emitting device using the same

The present invention relates to a light-emitting element capable of converting electric energy into light and a monoamine derivative useful as a light-emitting element material used therefor. More specifically, the present invention relates to a light-emitting element that can be used in the fields of display elements, flat panel displays, backlights, lighting, interiors, signs, signboards, electrophotographic machines, optical signal generators, and light-emitting element materials used therefor. .

In recent years, research on organic thin-film light emitting devices that emit light when electrons injected from a cathode and holes injected from an anode are recombined in an organic phosphor sandwiched between both electrodes has been actively conducted. This light emitting element is characterized by thin light emission with high luminance under a low driving voltage and multicolor light emission by selecting a fluorescent material.

This research was conducted by C.D. W. Since Tang et al. Showed that organic thin film devices emit light with high brightness, many practical studies have been made, and organic thin film light emitting devices have been steadily put into practical use, such as being used in mobile phone main displays. Is progressing. However, there are still many technical issues. Above all, it is one of the major issues to achieve both high efficiency and long life of the device.

The luminous efficiency of the device is greatly influenced by the carrier transport material that transports carriers such as holes and electrons to the light emitting layer. Among these, materials having a monoamine skeleton are known as materials that transport holes (hole transport materials) (see, for example, Patent Documents 1 to 6).

Japanese Patent No. 5261887 JP 2010-222268 A International Publication No. 2012/134203 International Publication No. 2013/157367 International Publication No. 2013/061805 Korean Patent Application Publication No. 2011-0034977

However, it is difficult to improve the durability while increasing the light emission efficiency of the element with the conventional technology, and even if the drive voltage can be lowered, the light emission efficiency and the durability life of the element are not sufficient. there were. Thus, no technology has yet been found to achieve both high luminous efficiency and durable life.

An object of the present invention is to provide an organic thin film light emitting device that solves the problems of the prior art and has improved luminous efficiency and durability.

The present invention is a monoamine derivative represented by the following general formula (1).

In the formula, L ¹ and L ² are a single bond or a substituted or unsubstituted arylene group having 6 to 12 nuclear carbon atoms. At least one of R ¹ to R ⁵ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or a substituted or unsubstituted group Selected from the terphenyl group, all others are deuterium. A ¹ and A ² may be the same or different and each represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or substituted or unsubstituted It is selected from unsubstituted terphenyl groups.

According to the present invention, it is possible to provide an organic electroluminescent device having high luminous efficiency and further having a sufficient durability life.

(Monoamine derivative represented by the general formula (1))
The monoamine derivative represented by the general formula (1) will be described in detail.

The arylene group is a divalent group derived from an aryl group, and examples thereof include a phenylene group, a naphthylene group, a biphenylene group, a fluorenylene group, a phenanthrylene group, a terphenylene group, an anthracenylene group, and a pyrenylene group. These may or may not have a substituent. The carbon number of the arylene group is not particularly limited, but is usually in the range of 6 or more and 40 or less. Moreover, when an arylene group has a substituent, it is preferable that carbon number is 6 or more and 60 or less including a substituent.

An arylene group having 6 to 12 nuclear carbon atoms means an arylene group having 6 to 12 carbon layers contained in a skeleton other than a substituent.

The aryl group refers to, for example, an aromatic hydrocarbon group such as a phenyl group, a biphenyl group, a fluorenyl group, a phenanthryl group, a triphenylenyl group, or a terphenyl group. 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 fluorenyl group is preferred because both of the hydrogen atoms of the methylene group present in the molecule are replaced with alkyl groups, particularly methyl groups, because electron donating properties are increased.

A conventional compound having a monoamine skeleton does not necessarily have sufficient performance as a light emitting device material. For example, Patent Documents 1 to 6 show compounds A to F having a monoamine skeleton represented by the following formula.

However, devices using these compounds in the hole injection layer and the hole transport layer have not yet been able to provide sufficient performance, and the creation of compounds that can further improve the properties in terms of efficiency and durability can be achieved. It has been demanded.

In the study of the improvement, the present inventors paid attention to the effect of the substituent directly linked to the nitrogen atom. In general, when a nitrogen atom in a compound having a monoamine skeleton is substituted with an aryl group, the fluorescence quantum efficiency is increased, and the stability of the singlet excited state is increased accordingly, so that the molecule is hardly decomposed in the excited state. However, when an aryl group having a large number of nuclear carbons is directly linked to the nitrogen atom or coexists in the molecule, the fluorescence quantum efficiency tends to be high, but the conjugation is too wide and the energy in the singlet state is increased. The gap becomes smaller. As a result, the electron blocking property, which is important as one of the required characteristics of the hole transport material, is impaired, which is not preferable from the viewpoint of increasing the light emission efficiency. In addition, the triplet level, which is an important value in triplet emission type light-emitting elements and thermally activated delayed fluorescent elements, is also significantly reduced, so even in an element using a dopant via a triplet excited state, light emission Since it becomes a factor which reduces efficiency, it is not preferable. For example, compound F contains a pyrene skeleton in the molecule and is not preferred for the above reasons.

Therefore, the substituent directly linked to the nitrogen atom can achieve high emission efficiency by limiting the number of carbon atoms such as a phenyl group. In order to achieve high efficiency, it is important to introduce substituents in the molecule, such as phenyl, naphthyl, phenanthrenyl, terphenyl, and fluorenyl groups, which have few nuclear carbon atoms and are not too wide. It is. However, even if the number of nuclear carbon atoms is large, a substituent having a high triplet energy such as a triphenylenyl group is a preferable substituent because it does not cause a decrease in light emission efficiency.

Furthermore, the present inventors have found that many of the conventional compounds having a monoamine skeleton are not deuterated on a substituent on the nitrogen atom, so that the fluorescence quantum efficiency is lowered, and the luminance is deteriorated during continuous driving of the device, that is, I thought it might have led to a decrease in durability. Therefore, by deuterating the phenyl group on the nitrogen atom like the compound of the present invention, the fluorescence quantum efficiency can be improved, the stability of the excited state can be improved, and the durability at the time of driving the device can be improved. Thought.

As described above, as a result of intensive studies, the inventors have found that the monoamine derivative represented by the general formula (1) improves the light emission efficiency and durability, and have reached the present invention.

It is preferable for the monoamine derivative represented by the general formula (1) to have at least one deuterated phenyl group in the molecule because of high fluorescence quantum efficiency.

From the viewpoint of not spreading the conjugation too much, at least one of R ¹ to R ⁵ in the general formula (1) is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group. , A substituted or unsubstituted phenanthrenyl group, or a substituted or unsubstituted terphenyl group. In addition, it is preferable that all other than that is deuterium because fluorescence quantum efficiency is improved and stability of a singlet excited state is increased.

When L ¹ and L ² in the general formula (1) are substituted arylene groups having 6 to 12 nuclear carbon atoms, the substituent has little influence on conjugation and can maintain a high triplet level. From the viewpoint of being able to do so, an alkyl group or halogen is preferable.

The alkyl group represents, for example, a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group, which is a substituent. It may or may not have. The number of carbon atoms of the alkyl group is not particularly limited, but is usually in the range of 1 to 20 and more preferably 1 to 8 in terms of availability and cost.

Halogen means fluorine, chlorine, bromine and iodine.

In the general formula (1), A, that is, when A ¹ and A ² are substituted, the substituent has little influence on conjugation and can maintain a high triplet level. Alkyl groups or halogens are preferred.

Preferable examples of L ¹ and L ² are preferably a phenylene group, a naphthylene group, a phenanthrenylene group, a terphenylene group, and a fluorenylene group from the viewpoint of not spreading the conjugation too much. Preferable examples of A ¹ and A ² are preferably a phenyl group, a naphthyl group, a phenanthrenyl group, a terphenyl group, and a fluorenyl group from the viewpoint of not spreading the conjugation too much.

Among them, as the general formula (1) is represented by the general formula (2), the substitution of two deuterated benzene rings on the nitrogen atom further improves the fluorescence quantum efficiency. preferable.

In the formula, L ¹ and A ¹ are the same as those in the general formula (1). At least one of R ¹ to R ¹⁰ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or a substituted or unsubstituted group Selected from the terphenyl group, all others are deuterium.

Furthermore, as represented by the general formula (3), the general formula (2) has a substituted or unsubstituted aryl group having 6 to 12 nuclear carbon atoms at the para position on the deuterated benzene ring. Therefore, it is preferable that the conjugation is widened to improve the stability of the excited state and further improve the hole transport property, which leads to a lower driving voltage of the element.

In the formula, L ¹ and A ¹ are the same as those in the general formula (1). Ar ¹ and Ar ² may be the same or different and each represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or substituted or unsubstituted It is selected from unsubstituted terphenyl groups.

Moreover, the general formula (3) is, as represented by the general formula (4), by Ar ¹ and Ar ² are substituted or unsubstituted phenyl group, a hole transport without reducing an energy gap larger This is preferable because the property is improved. In addition, since the molecular weight does not increase too much, the sublimation stability is also improved, which is preferable.

In the formula, L ¹ and A ¹ are the same as those in the general formula (1). R ¹⁰¹ to R ¹¹⁰ may be the same or different and are each hydrogen, deuterium, alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, substituted or unsubstituted phenyl group. , Substituted or unsubstituted naphthyl group, substituted or unsubstituted phenanthrenyl group, substituted or unsubstituted terphenyl group, halogen, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, silyl group, and —P (═O) R ¹¹¹ is selected from the group consisting of R ¹¹² . R ¹¹¹ and R ¹¹² are an aryl group or a heteroaryl group. R ¹¹¹ and R ¹¹² may be condensed to form a ring.

Of these substituents, hydrogen may be deuterium.

The cycloalkyl group represents, for example, a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, etc., which 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 alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond such as a vinyl group, an allyl group, or a butadienyl group, which 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.

The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexenyl group, which may have a substituent. You don't have to. Although carbon number of a cycloalkenyl group is not specifically limited, Usually, it is the range of 2-20.

The alkynyl group indicates, for example, an unsaturated aliphatic hydrocarbon group containing a triple bond such as an ethynyl group, which 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.

The alkoxy group refers to a functional group to which an aliphatic hydrocarbon group is bonded through an ether bond such as a methoxy group, an ethoxy group, or a propoxy group, and the aliphatic hydrocarbon group may have a substituent. It does not have to be. Although carbon number of an alkoxy group is not specifically limited, Usually, it is the range of 1-20.

The alkylthio group is a group 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 1-20.

The carbonyl group, carboxyl group, oxycarbonyl group and carbamoyl group may or may not have a substituent.

The silyl group refers to, for example, a functional group having a bond to a silicon atom such as a trimethylsilyl group, which 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. The number of silicon is usually in the range of 1 to 6.

—P (═O) R ¹¹ R ¹² may or may not have a substituent.

A heteroaryl group is a ring having one or more atoms other than carbon such as furanyl group, thiophenyl group, pyridyl group, pyrazinyl group, pyrimidinyl group, triazinyl group, benzofuranyl group, benzothiophenyl group, indolyl group in the ring. Represents an aromatic group, which may be unsubstituted or substituted. Although carbon number of heteroaryl group is not specifically limited, Usually, it is the range of 2-30.

Furthermore, as represented by general formula (5), R ¹⁰¹ , R ¹⁰² , R ¹⁰⁴ to R ¹⁰⁷ , R ^109, and R ¹¹⁰ in Ar ¹ and Ar ² are hydrogen or heavy as represented by general formula (5). Since it is hydrogen, the fluorescence quantum efficiency is further improved, leading to higher efficiency of the device, which is preferable.

In the formula, L ¹ and A ¹ are the same as those in the general formula (1). R ¹⁰³ and R ¹⁰⁸ are the same as those in the general formula (4), and may be the same or different. a and b are each 0 to 4, and when a and b are 0 to 3, the portion other than deuterium is hydrogen.

Furthermore, as general formula (5) is represented by general formula (6), R ¹⁰¹ , R ¹⁰² , R ¹⁰⁴ to R ¹⁰⁷ , R ¹⁰⁹ and R ¹¹⁰ in Ar ¹ and Ar ² are deuterium. Therefore, it is preferable because the fluorescence quantum efficiency is further improved and the stability of the excited state is improved.

In the formula, L ¹ and A ¹ are the same as those in the general formula (1). R ¹⁰³ and R ¹⁰⁸ are the same as those in the general formula (4), and may be the same or different.

R ¹⁰³ and R ¹⁰⁸ are preferably a substituted or unsubstituted phenyl group from the viewpoint of molecular weight, and those in which all hydrogen is deuterated are preferable in order to improve the fluorescence quantum efficiency.

The monoamine derivative represented by the general formula (1) is not particularly limited, but specific examples include the following. In addition, the following is an illustration, and even if it is other than the compound specified here, if it is represented by General formula (1), it is preferably used similarly.

A known method can be used for the synthesis of a compound having a monoamine skeleton as described above. Examples of the synthesis method include, but are not limited to, a method using a coupling reaction between a primary or secondary amine derivative using a palladium or copper catalyst and a halide or triflate. As an example, an example using p-chloroaniline and bromobiphenyl is shown below.

(Light-emitting element material)
The monoamine derivative represented by the general formula (1) is preferably used as a light emitting device material. Here, the light emitting device material in the present invention represents a material used for any layer of the light emitting device, and as described later, in the hole injection layer, the hole transport layer, the light emitting layer and / or the electron transport layer. In addition to the materials used, the materials used for the cathode protective film are also included. By using the monoamine derivative represented by the general formula (1) in the present invention in any layer of the light-emitting element, a light-emitting element having high luminous efficiency and excellent durability can be obtained.

(Light emitting element)
Next, embodiments of the light emitting device of the present invention will be described in detail. The light emitting device of the present invention has an anode and a cathode and an organic layer interposed between the anode and the cathode, and the organic layer emits light by electric energy.

In such a light emitting device, the layer structure between the anode and the cathode is composed of only the light emitting layer, 1) light emitting layer / electron transport layer, 2) hole transport layer / light emitting layer, and 3) hole transport. Layer / light emitting layer / electron transport layer, 4) hole injection layer / hole transport layer / light emitting layer / electron transport layer, 5) hole transport layer / light emitting layer / electron transport layer / electron injection layer, 6) hole A laminated structure such as injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer may be mentioned.

Furthermore, a tandem type in which a plurality of the above-described laminated structures are laminated via an intermediate layer may be used. The intermediate layer is generally called an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, or an intermediate insulating layer, and a known material structure can be used. Specific examples of the tandem type are, for example, 7) hole transport layer / light emitting layer / electron transport layer / charge generation layer / hole transport layer / light emitting layer / electron transport layer, 8) hole injection layer / hole transport layer / A charge generation layer as an intermediate layer between an anode and a cathode, such as a light emitting layer / electron transport layer / electron injection layer / charge generation layer / hole injection layer / hole transport layer / light emission layer / electron transport layer / electron injection layer The laminated structure including is mentioned. Specifically, pyridine derivatives and phenanthroline derivatives are preferably used as the material constituting the intermediate layer.

Further, each of the above layers may be either a single layer or a plurality of layers, and may be doped. Further, each of the above layers includes an anode, one or more organic layers including a light emitting layer, a cathode, and an element configuration including a layer using a capping material for improving light emission efficiency due to an optical interference effect.

The monoamine derivative represented by the general formula (1) may be used in any 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 of supplying a sufficient current for light emission of the device, and it is desirable that at least one of them is transparent or translucent in order to extract light. Usually, the anode formed on the substrate is a transparent electrode.

(anode)
If the material used for the anode is a material that can efficiently inject holes into the organic layer and is transparent or translucent to extract light, zinc oxide, tin oxide, indium oxide, indium tin oxide (ITO), zinc oxide In particular, conductive metal oxides such as indium (IZO), 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 are particularly limited. Although not intended, it is particularly desirable to use ITO glass or Nesa 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 a current sufficient for light emission of the element can be supplied, but it is desirable that the resistance be low from the viewpoint of power consumption of the element. For example, an ITO substrate with a resistance of 300Ω / □ or less will function as a device electrode, but since it is now possible to supply a substrate with a resistance of approximately 10Ω / □, use a substrate with a low resistance of 20Ω / □ or less. Is particularly desirable. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually used in a range of 45 to 300 nm.

In order to maintain the mechanical strength of the light emitting element, the light emitting element is preferably formed over a substrate. As the substrate, a glass substrate such as soda glass or non-alkali glass is preferably used. As the thickness of the glass substrate, it is sufficient that the thickness is sufficient to maintain the mechanical strength. As for the glass material, alkali-free glass is preferred because it is better that there are fewer ions eluted from the glass. Alternatively, soda lime glass provided with a barrier coat such as SiO ₂ is also commercially available and can be used. Furthermore, if the first electrode functions stably, the substrate need not be glass, and for example, an anode may be formed on a plastic substrate. The ITO film forming method is not particularly limited, such as an electron beam method, a sputtering method, and a chemical reaction method.

(cathode)
The material used for the cathode is not particularly limited as long as it can efficiently inject electrons into the light emitting layer. Generally, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys and multilayer stacks of these metals with low work function metals such as lithium, sodium, potassium, calcium, and magnesium Is preferred. Among these, aluminum, silver, and magnesium are preferable as the main component from the viewpoints of electrical resistance, ease of film formation, film stability, luminous efficiency, and the like. In particular, magnesium and silver are preferable because electron injection into the electron transport layer and the electron injection layer in the present invention is facilitated and low voltage driving is possible.

Furthermore, for cathode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, inorganic materials such as silica, titania and silicon nitride, polyvinyl alcohol, polyvinyl chloride As a preferred example, an organic polymer compound such as a hydrocarbon polymer compound is laminated on the cathode as a protective film layer. However, in the case of an element structure (top emission structure) that extracts light from the cathode side, the protective film layer is selected from materials that are light transmissive in the visible light region. The production method of these electrodes is not particularly limited, such as resistance heating, electron beam, sputtering, ion plating and coating.

(Hole injection layer)
The hole injection layer is a layer inserted between the anode and the hole transport layer. The hole injection layer may be either a single layer or a plurality of layers stacked. The presence of a hole injection layer between the hole transport layer and the anode is preferable because it not only drives at a lower voltage and improves the durability life, but also improves the carrier balance of the device and the light emission efficiency.

The material used for the hole injection layer is not particularly limited. 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'-diphenyl- Benzidine derivatives such as 4-aminophenyl) -N, N-diphenyl-4,4 ′ -diamino-1,1′-biphenyl (TPD232), 4,4 ′, 4 ″ -tris (3-methylphenyl (phenyl) amino ) Starboards such as triphenylamine (m-MTDATA), 4,4 ′, 4 ″ -tris (1-naphthyl (phenyl) amino) triphenylamine (1-TNATA) Material group called store reel amine, biscarbazole derivatives such as bis (N-arylcarbazole) or bis (N-alkylcarbazole), pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives , Phthalocyanine derivatives, heterocyclic compounds such as porphyrin derivatives, and polymer systems such as polycarbonates and styrene derivatives, polythiophene, polyaniline, polyfluorene, polyvinylcarbazole, and polysilane having the above monomers in the side chain are used. Moreover, the monoamine derivative represented by General formula (1) can also be used. Among these, a benzidine derivative and a starburst arylamine group of materials have a shallower HOMO level than the monoamine derivative represented by the general formula (1), and from the viewpoint of smoothly injecting and transporting holes from the anode to the hole transport layer. More preferably used.

These materials may be used alone or as a mixture of two or more materials. A plurality of materials may be stacked to form a hole injection layer. Further, it is more preferable that the hole injection layer is composed of an acceptor compound alone or that the hole injection material is doped with an acceptor compound so that the above-described effects can be obtained more remarkably. . An acceptor compound is a material that forms a charge transfer complex with a material that forms a hole-injecting layer in contact with a hole-transporting layer when used as a single-layer film and a material that forms a hole-injecting layer when used as a doped layer. When such a material is used, the conductivity of the hole injection layer is improved, which contributes to lowering of the driving voltage of the device, and the effects of improving the light emission efficiency and improving the durability life can be obtained.

Examples of acceptor compounds include metal chlorides such as iron (III) chloride, aluminum chloride, gallium chloride, indium chloride, antimony chloride, metal oxides such as molybdenum oxide, vanadium oxide, tungsten oxide, ruthenium oxide, A charge transfer complex such as tris (4-bromophenyl) aminium hexachloroantimonate (TBPAH). In addition, organic compounds having a nitro group, cyano group, halogen or trifluoromethyl group in the molecule, quinone compounds, acid anhydride compounds, fullerenes, and the like are also preferably used. Specific examples of these compounds include hexacyanobutadiene, hexacyanobenzene, tetracyanoethylene, tetracyanoquinodimethane (TCNQ), tetrafluorotetracyanoquinodimethane (F4-TCNQ), a radiane derivative, p-fluoranil, p-chloranil, p-bromanyl, p-benzoquinone, 2,6-dichlorobenzoquinone, 2,5-dichlorobenzoquinone, tetramethylbenzoquinone, 1,2,4,5-tetracyanobenzene, o-dicyanobenzene, p-dicyano Benzene, 1,4-dicyanotetrafluorobenzene, 2,3-dichloro-5,6-dicyanobenzoquinone, p-dinitrobenzene, m-dinitrobenzene, o-dinitrobenzene, p-cyanonitrobenzene, m-cyanonitrobenzene, o - Anonitrobenzene, 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-tetranitrocarbazole, 2,4,7-trinitro-9-fluorenone, 2,3,5,6-tetracyanopyridine, maleic anhydride, phthalic anhydride Product, C60, and C70.

Among these, metal oxides and cyano group-containing compounds are preferable because they are easy to handle and can be easily deposited, so that the above-described effects can be easily obtained. In any case where the hole injection layer is composed of an acceptor compound alone or when the hole injection layer is doped with an acceptor compound, the hole injection layer may be a single layer, A plurality of layers may be laminated.

(Hole transport layer)
The hole transport layer is a layer that transports holes injected from the anode to the light emitting layer. The hole transport layer may be a single layer or may be configured by laminating a plurality of layers.

The monoamine derivative represented by the general formula (1) has an ionization potential of 5.1 to 6.0 eV (measured value of deposited film AC-2 (RIKEN Keiki)), a high triplet energy level, and a high hole transport property. In addition, since it has thin film stability, it is preferably used for a hole injection layer and a hole transport layer of a light-emitting element. In addition, the monoamine derivative represented by the general formula (1) has a large LUMO level and an excellent electron blocking property because it has a large energy gap with respect to a conventional hole transport material having a benzidine skeleton. Furthermore, the monoamine derivative represented by the general formula (1) is preferably used as a hole transport material of an element using a triplet light emitting material. A conventional hole transport material having a benzidine skeleton has a low triplet level, and if it is in direct contact with a light-emitting layer containing a triplet light-emitting material, leakage of triplet energy occurs and the light emission efficiency decreases. This is because the monoamine derivative represented by the formula (1) has a high triplet energy and does not cause such a problem.

In the case of being composed of a plurality of hole transport layers, the hole transport layer containing the monoamine derivative represented by the general formula (1) is preferably in direct contact with the light emitting layer. This is because the monoamine derivative represented by the general formula (1) has high electron blocking properties and can prevent intrusion of electrons flowing out from the light emitting layer. Furthermore, since the monoamine derivative represented by the general formula (1) has a high triplet level, it also has an effect of confining the excitation energy of the triplet light-emitting material. Therefore, even when a triplet light emitting material is included in the light emitting layer, the hole transport layer containing the monoamine derivative represented by the general formula (1) is preferably in direct contact with the light emitting layer.

The hole transport layer may be composed only of the monoamine derivative represented by the general formula (1), or may be mixed with other materials as long as the effects of the present invention are not impaired. In this case, as other materials 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'-diphenyl-4-amino) Benzidine derivatives such as phenyl) -N, N-diphenyl-4,4′-diamino-1,1′-biphenyl (TPD232), 4,4 ′, 4 ″ -tris (3-methylphenyl (phenyl) amino) triphenyl Starburst aryl such as amine (m-MTDATA), 4,4 ′, 4 ″ -tris (1-naphthyl (phenyl) amino) triphenylamine (1-TNATA) A group of materials called min, biscarbazole derivatives such as bis (N-arylcarbazole) or bis (N-alkylcarbazole), pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, phthalocyanines Derivatives, heterocyclic compounds such as porphyrin derivatives, in the case of polymer systems, polycarbonates and styrene derivatives, polythiophene, polyaniline, polyfluorene, polyvinylcarbazole, polysilane and the like having the above-mentioned monomer in the side chain are exemplified.

The organic layer includes at least a light emitting layer and a plurality of organic layers between the light emitting layer and the anode, and a layer in contact with the light emitting layer among the plurality of organic layers is represented by the general formula (1). A structure containing a monoamine derivative and having a compound represented by the following general formula (7) or (8) in a layer other than the layer in contact with the light emitting layer among the plurality of organic layers is also preferable.

In the formula, L ¹⁰¹ and L ²⁰¹ are substituted or unsubstituted arylene groups having 10 to 40 nuclear carbon atoms. Ar ¹⁰¹ to Ar ¹⁰⁴ may be the same as or different from each other, and are a substituted or unsubstituted aryl group having 6 to 60 nuclear carbon atoms, or a substituted or unsubstituted heteroaryl group having 6 to 60 nuclear carbon atoms. R ⁴⁰¹ to R ⁴⁰⁸ may be the same or different and each represents hydrogen, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, a substituted or unsubstituted phenyl group, a substituted or Unsubstituted naphthyl group, substituted or unsubstituted phenanthrenyl group, substituted or unsubstituted terphenyl group, halogen, carbonyl group, carboxyl group, oxycarbonyl group and carbamoyl group, silyl group and —P (═O) R ¹⁶ R Selected from the group consisting of ¹⁷ . R ¹⁶ and R ¹⁷ are an aryl group or a heteroaryl group. R ¹⁶ and R ¹⁷ may be condensed to form a ring. Ar ²⁰¹ to Ar ²⁰⁴ are each a substituted or unsubstituted aryl group having 6 to 60 nuclear carbon atoms, or a substituted or unsubstituted heteroaryl group having 6 to 60 nuclear carbon atoms.

(Light emitting layer)
The light emitting layer may be either a single layer or a plurality of layers, each formed by a light emitting material (host material, dopant material), which may be a mixture of a host material and a dopant material or a host material alone, It may be a mixture of two types of host materials and one type of dopant material. That is, in the light emitting element of the present invention, only the host material or the dopant material may emit light in each light emitting layer, or both the host material and the dopant material may emit light. From the viewpoint of efficiently using electric energy and obtaining light emission with high color purity, the light emitting layer is preferably composed of a mixture of a host material and a dopant material. Further, the host material and the dopant material may be either one kind or a plurality of combinations, respectively. The dopant material may be included in the entire host material or may be partially included. The dopant material may be laminated or dispersed. The dopant material can control the emission color. When the amount of the dopant material is too large, a concentration quenching phenomenon occurs, so that it is preferably used at 30% by weight or less, more preferably 20% by weight or less with respect to the host material. The doping method can be formed by a co-evaporation method with a host material, but may be simultaneously deposited after being previously mixed with the host material.

Luminescent materials include monoamine derivatives represented by the general formula (1), metal ring chelates including fused ring derivatives such as anthracene and pyrene, tris (8-quinolinolato) aluminum, which have been known as light emitters. Oxynoid compounds, bisstyryl derivatives such as bisstyryl anthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, oxadiazole derivatives, For thiadiazolopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives Derivatives and the like can be used but are not particularly limited.

The host material contained in the light-emitting material is not limited to a single compound, and a plurality of compounds of the present invention may be mixed and used, or one or more other host materials may be mixed and used. . Further, they may be used in a stacked manner. The host material is not particularly limited, but is a compound having a condensed aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, indene, or a derivative thereof, N, N′-dinaphthyl- Aromatic amine derivatives such as N, N′-diphenyl-4,4′-diphenyl-1,1′-diamine, metal chelated oxinoid compounds such as tris (8-quinolinato) aluminum (III), distyrylbenzene Bisstyryl derivatives such as derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, pyrrolopyrrole derivatives, thiadiazolopyridines In derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinyl carbazole derivatives, polythiophene derivatives, etc. can be used but are not particularly limited. Absent. Among them, as a host used when the light emitting layer performs triplet light emission (phosphorescence light emission), metal chelated oxinoid compounds, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, triphenylene derivatives, etc. Are preferably used. Among them, a host material having an anthracene skeleton or a pyrene skeleton is preferable because high luminous efficiency can be easily obtained.

The dopant material contained in the light-emitting material is not particularly limited, but a compound having an aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, fluoranthene, triphenylene, perylene, fluorene, indene, or a derivative thereof (for example, 2- (benzothiazole- 2-yl) -9,10-diphenylanthracene and 5,6,11,12-tetraphenylnaphthacene), furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, Compounds having heteroaryl rings such as benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene and derivatives thereof , Distyrylbenzene derivatives, 4,4′-bis (2- (4-diphenylaminophenyl) ethenyl) biphenyl, 4,4′-bis (N- (stilben-4-yl) -N-phenylamino) stilbene Aminostyryl derivatives, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyromethene derivatives, diketopyrrolo [3,4-c] pyrrole derivatives, 2,3,5,6-1H, 4H-tetrahydro- 9- (2′-benzothiazolyl) quinolidino [9,9a, 1-gh] coumarin derivatives such as coumarin, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and metal complexes thereof, N, N′-diphenyl-N, '- and di (3-methylphenyl) -4,4'-aromatic amine derivative typified by diphenyl 1,1'-diamine. Among them, it is preferable to use a dopant including a diamine skeleton or a dopant including a fluoranthene skeleton because high-efficiency light emission is easily obtained. A dopant containing a diamine skeleton has a high hole trapping property, and a dopant containing a fluoranthene skeleton has a high electron trapping property.

The dopant used when the light emitting layer emits triplet light (phosphorescence) includes iridium (Ir), ruthenium (Ru), palladium (Pd), platinum (Pt), osmium (Os), and rhenium. A metal complex compound containing at least one metal selected from the group consisting of (Re) is preferable. The ligand preferably has a nitrogen-containing aromatic heterocycle such as a phenylpyridine skeleton, a phenylquinoline skeleton, or a carbene skeleton. However, it is not limited to these, and an appropriate complex is selected from the relationship with the required emission color, device performance, and host compound. Specifically, tris (2-phenylpyridyl) iridium complex, tris {2- (2-thiophenyl) pyridyl} iridium complex, tris {2- (2-benzothiophenyl) pyridyl} iridium complex, tris (2-phenyl) Benzothiazole) iridium complex, tris (2-phenylbenzoxazole) iridium complex, trisbenzoquinoline iridium 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-phenylbenzoxazole) (acetylacetate) Iridium complex, bisbenzoquinoline (acetylacetonato) iridium complex, bis {2- (2,4-difluorophenyl) pyridyl} (acetylacetonato) iridium complex, tetraethylporphyrin platinum complex, {tris (cenoyltrifluoro) Acetone) mono (1,10-phenanthroline)} europium complex, {tris (cenoyltrifluoroacetone) mono (4,7-diphenyl-1,10-phenanthroline)} europium complex, {tris (1,3-diphenyl-1 , 3-propanedione) mono (1,10-phenanthroline)} europium complex, trisacetylacetone terbium complex, and the like. Further, a phosphorescent dopant described in JP2009-130141A is also preferably used. Although not limited thereto, an iridium complex or a platinum complex is preferably used because high-efficiency light emission is easily obtained.

The triplet light-emitting material used as the dopant material may contain only one type in the light-emitting layer, or a mixture of two or more types. When two or more triplet light emitting materials are used, the total weight of the dopant material is preferably 30% by weight or less, more preferably 20% by weight or less, based on the host material.

In addition to the host material and the triplet light emitting material, the light emitting layer may further include a third component for adjusting the carrier balance in the light emitting layer or stabilizing the layer structure of the light emitting layer. . However, as the third component, a material that does not cause an interaction between the host material composed of the monoamine derivative represented by the general formula (1) and the dopant material composed of the triplet light emitting material is selected.

The preferred host and dopant in the triplet emission system are not particularly limited, but specific examples include the following.

(Electron transport layer)
In the present invention, the electron transport layer is a layer in which electrons are injected from the cathode and further transports electrons. The electron transport layer has high electron injection efficiency, and it is desired to efficiently transport injected electrons. 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 a trapping impurity that is unlikely to be generated during manufacture and use. In particular, in the case of stacking a thick film, a compound having a molecular weight of 400 or more that maintains a stable film quality is preferable because a low molecular weight compound is likely to be crystallized to deteriorate the film quality. However, considering the transport balance between holes and electrons, if the electron transport layer mainly plays a role of effectively preventing the holes from the anode from recombining and flowing to the cathode side, the electron transport Even if it is made of a material that does not have a high capability, the effect of improving the luminous efficiency is equivalent to that of a material that has a high electron transport capability. Therefore, the electron transport layer in the present invention includes a hole blocking layer that can efficiently block the movement of holes as the same meaning.

Examples of the electron transport material used for the electron transport layer include condensed polycyclic aromatic derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives represented by 4,4′-bis (diphenylethenyl) biphenyl, anthraquinone and diphenoquinone Quinoline derivatives, phosphorus oxide derivatives, quinolinol complexes such as tris (8-quinolinolato) aluminum (III), benzoquinolinol complexes, hydroxyazole complexes, azomethine complexes, tropolone metal complexes, and flavonol metal complexes. A compound having a heteroaryl ring structure composed of an element selected from carbon, hydrogen, nitrogen, oxygen, silicon, and phosphorus and containing electron-accepting nitrogen, because driving voltage is reduced and high-efficiency light emission is obtained. Is preferably used.

The electron-accepting nitrogen mentioned here represents a nitrogen atom forming a multiple bond with an adjacent atom. Since the nitrogen atom has a high electronegativity, the multiple bond has an electron accepting property. Therefore, an aromatic heterocycle containing electron-accepting nitrogen has a high electron affinity. An electron transport material having electron-accepting nitrogen makes it easier to receive electrons from a cathode having a high electron affinity, and can be driven at a lower voltage. In addition, since the number of electrons supplied to the light emitting layer is increased and the recombination probability is increased, the light emission efficiency is improved.

Examples of the heteroaryl ring containing an electron-accepting nitrogen include, for example, triazine ring, pyridine ring, pyrazine ring, pyrimidine ring, quinoline ring, quinoxaline ring, naphthyridine ring, pyrimidopyrimidine ring, benzoquinoline ring, phenanthroline ring, imidazole ring, Examples thereof include an oxazole ring, an oxadiazole ring, a triazole ring, a thiazole ring, a thiadiazole ring, a benzoxazole ring, a benzothiazole ring, a benzimidazole ring, and a phenanthrimidazole ring.

Examples of these compounds having a heteroaryl ring structure include triazine derivatives, benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, quinoline. Preferred examples include derivatives, benzoquinoline derivatives, oligopyridine derivatives such as bipyridine and terpyridine, quinoxaline derivatives, and naphthyridine derivatives. Among them, imidazole derivatives such as tris (N-phenylbenzimidazol-2-yl) benzene, oxadiazole derivatives such as 1,3-bis [(4-tert-butylphenyl) 1,3,4-oxadiazolyl] phenylene, Triazole derivatives such as N-naphthyl-2,5-diphenyl-1,3,4-triazole, phenanthroline derivatives such as bathocuproine and 1,3-bis (1,10-phenanthroline-9-yl) benzene, 2,2 ′ A benzoquinoline derivative such as bis (benzo [h] quinolin-2-yl) -9,9′-spirobifluorene, 2,5-bis (6 ′-(2 ′, 2 ″ -bipyridyl))-1, Bipyridine derivatives such as 1-dimethyl-3,4-diphenylsilole, 1,3-bis (4 ′-(2,2 ′: 6′2 ″ -ta Terpyridine derivatives such as pyridinyl)) benzene, naphthyridine derivatives such as bis (1-naphthyl) -4- (1,8-naphthyridin-2-yl) phenylphosphine oxide are preferably used from the viewpoint of electron transporting capability.

In addition, it is more preferable that these derivatives have a condensed polycyclic aromatic skeleton because the glass transition temperature is improved, the electron mobility is increased, and the effect of lowering the voltage of the light emitting element is great. Furthermore, considering that the device durability life is improved, the ease of synthesis, and the availability of raw materials are taken into consideration, the condensed polycyclic aromatic skeleton is more preferably a fluoranthene skeleton, anthracene skeleton, pyrene skeleton or phenanthroline skeleton. A fluoranthene skeleton is particularly preferable. That is, it is particularly preferable that the electron transport layer contains a compound containing a fluoranthene skeleton.

Specifically, the compound containing a fluoranthene skeleton is preferably a compound represented by the following general formula (9).

In the formula, Ar ³⁰¹ represents a group containing a fluoranthene skeleton. L ¹⁰¹ and L ¹⁰² are a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. A ¹⁰¹ and A ¹⁰² are each a substituted or unsubstituted benzene ring having 6 to 40 carbon atoms, a substituted or unsubstituted condensed aromatic hydrocarbon ring having 6 to 40 carbon atoms, and a substituted or unsubstituted one having 1 to 40 carbon atoms. A substituted monocyclic aromatic heterocyclic ring or a substituted or unsubstituted condensed aromatic heterocyclic ring having 1 to 40 carbon atoms is represented. However, at least one atom constituting A ¹⁰¹ and A ¹⁰² is electron-accepting nitrogen. L ¹⁰² is a substituted or unsubstituted arylene group, and A ¹⁰² is a substituted or unsubstituted benzene ring having 6 to 40 carbon atoms, or a substituted or unsubstituted condensed aromatic hydrocarbon having 6 to 40 carbon atoms. In the case of a ring, L ¹⁰² and A ¹⁰² may form a ring. When L ¹⁰¹ , L ¹⁰² , A ¹⁰¹ , and A ¹⁰² are substituted, the substituents are alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, respectively. , Aryl ether group, aryl thioether group, aryl group, heteroaryl group, halogen, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group and —P (═O) R ²⁰¹ R ²⁰² . R ²⁰¹ and R ²⁰² are an aryl group or a heteroaryl group. R ²⁰¹ and R ²⁰² may be condensed to form a ring. However, when both L ¹⁰¹ and L ¹⁰² are single bonds, A ¹⁰¹ and A ¹⁰² are not both heteroaryl groups having two or more electron-accepting nitrogens. When either L ¹⁰¹ or L ¹⁰² is a single bond, the other L ¹⁰¹ or L ¹⁰² does not become a heteroarylene group having two or more electron-accepting nitrogens. n is 1 or 2. When n is 2, two L ² —N (A ¹ ) (A ² ) may be the same or different. However, a carbazolylene group is not included as a heteroarylene group. In addition, when n is 2 and L ¹⁰² is a single bond, L ¹⁰¹ does not become an acene having 3 or more rings.

The group containing a fluoranthene skeleton is a group having a fluoranthene skeleton in the molecular structure, and may or may not have a substituent. A ring may be formed by adjacent substituents, and the size of the ring formed by adjacent substituents is not particularly limited, but a 5-membered ring or a 6-membered ring is preferable from the viewpoint of the stability of the molecular structure. The formed ring may be an aliphatic ring or an aromatic ring. A ring formed by adjacent substituents may further have a substituent, or may be further condensed. The formed ring may contain heteroatoms other than carbon. In particular, it is preferable that the ring is composed of only carbon and hydrogen because the electrochemical stability is increased and the durability of the device is improved. The number of carbon atoms of the group containing the fluoranthene skeleton is not particularly limited, but is preferably in the range of 16 or more and 40 or less. Specific examples include a fluoranthenyl group, a benzofluoranthenyl group, a benzoaceanthrylenyl group, a benzoacephenanthrenyl group, an indenofluoranthenyl group, and an acenaphthofluoranthenyl group.

In L ¹⁰² -N (A ¹⁰¹ ) (A ¹⁰² ) of the fluoranthene derivative represented by the general formula (9), at least one atom constituting A ¹⁰¹ and A ¹⁰² is electron-accepting nitrogen. In the substituents represented by A ¹⁰¹ and A ¹⁰² , an electron-accepting nitrogen-containing group may be directly bonded to N, or the electron-accepting nitrogen-containing group is substituted via a linking group. May be. Specifically, A ¹⁰¹ may be a benzene ring and A ¹⁰² may be a benzene ring substituted with a pyridyl group. Here, the electron-accepting nitrogen represents a nitrogen atom that forms a multiple bond with an adjacent atom. Since the nitrogen atom has high electronegativity, the multiple bond has an electron accepting property. Therefore, L ¹⁰² -N (A ¹⁰¹ ) (A ¹⁰² ) having electron-accepting nitrogen has a high electron affinity. Therefore, when the fluoranthene derivative represented by the general formula (9) is used for the electron transport layer and the monoamine derivative represented by the general formula (1) is used for the hole transport layer, the carrier of the light emitting device The balance can be improved and the luminous efficiency can be greatly improved. In addition, it contributes to extending the life of the light emitting element.

Among the compounds having the heteroaryl ring structure described above, compounds represented by the following general formula (10) are preferable.

In the formula, Ar ⁴⁰¹ to Ar ^{402 each} represents a substituted or unsubstituted phenyl group, pyridyl group, or pyrimidyl group. Ar ⁴⁰³ to Ar ^{404 each} represents a substituted or unsubstituted aryl group having 10 to 20 nuclear carbon atoms or a substituted or unsubstituted carbazolyl group. X ¹ to X ^{3 each} represents a carbon atom or a nitrogen atom. However, at least two of X ¹ to X ³ are nitrogen atoms. L _p ¹ and L _q ² represent a phenylene group or a pyridylene group. p to q each represents an integer of 0 to 2. Ar ¹ and Ar ² are preferably substituted or unsubstituted phenyl groups in consideration of thermal stability during sublimation purification. In view of the thermal stability during sublimation purification, an alkyl group, a cyano group, or a halogen is preferable as the substituent when substituting for these. Ar ⁴⁰³ to Ar ⁴⁰⁴ are naphthyl group, anthryl group, phenanthryl group, fluorenyl group, benzofluorenyl group, pyrenyl group, triphenylenyl from the viewpoint of easy formation of an amorphous thin film and improved electron mobility. Group, carbazolyl group is preferable. In view of the thermal stability during sublimation purification, an alkyl group, a cyano group, or a halogen is preferable as the substituent when substituting for these. When X ¹ to X ³ are all nitrogen atoms, the LUMO level is deepened, so that the electron injectability from the cathode is improved, and high luminous efficiency can be achieved. Furthermore, the use of the monoamine derivative of the general formula (1) in the hole transport layer in the light emitting element is preferable because the carrier balance is greatly improved, and the driving voltage can be reduced, the luminous efficiency can be improved, and the lifetime can be increased. .

L _p ¹ to L _q ² represent a phenylene group or a pyridylene group from the viewpoint of not increasing the molecular weight too much. In the case of substituting these, an alkyl group, a cyano group, or a halogen is preferable in consideration of thermal stability during sublimation purification. p to q are each preferably 0 or 1 from the viewpoint of not increasing the molecular weight too much.

The electron transport material may be used alone, but two or more of the electron transport materials may be mixed and used, or one or more of the other electron transport materials may be mixed and used in the electron transport material. Absent.

The preferred electron transport material is not particularly limited, but specific examples include the following.

The electron transport material may be used alone, but two or more of the electron transport materials may be mixed and used, or one or more of the other electron transport materials may be mixed and used in the electron transport material. Absent. Moreover, you may contain a donor compound. Here, the donor compound is a compound that facilitates electron injection from the cathode or the electron injection layer to the electron transport layer by improving the electron injection barrier and further improves the electrical conductivity of the electron transport layer.

Preferred examples of the donor compound include an alkali metal, an inorganic salt containing an alkali metal, a complex of an alkali metal and an organic substance, an alkaline earth metal, an inorganic salt containing an alkaline earth metal, or an alkaline earth metal and an organic substance. And the like. Preferred types of alkali metals and alkaline earth metals include alkaline metals such as lithium, sodium, potassium, rubidium, and cesium that have a large effect of improving the electron transport ability with a low work function, and alkaline earths such as magnesium, calcium, cerium, and barium. A metal is mentioned.

In addition, since it is easy to deposit in vacuum and is excellent in handling, it is preferably in the form of a complex with an inorganic salt or an organic substance rather than a single metal. Furthermore, it is more preferable that it is in the state of a complex with an organic substance in terms of facilitating handling in the air and easy control of the addition concentration. Examples of inorganic salts include oxides such as LiO and Li ₂ O, nitrides, fluorides such as LiF, NaF, and KF, Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , Rb ₂ CO ₃ , Examples thereof include carbonates such as Cs ₂ CO ₃ . Further, preferred examples of the alkali metal or alkaline earth metal include lithium and cesium from the viewpoint that a large low-voltage driving effect can be obtained. In addition, preferable examples of the organic substance in the complex with the organic substance include quinolinol, benzoquinolinol, pyridylphenol, flavonol, hydroxyimidazopyridine, hydroxybenzazole, and hydroxytriazole. Among them, a complex of an alkali metal and an organic substance is preferable from the viewpoint that the effect of lowering the voltage of the light emitting device is larger, and a complex of lithium and an organic substance is more preferable from the viewpoint of ease of synthesis and thermal stability, Particularly preferred is lithium quinolinol (Liq), which is available at a low cost.

The ionization potential of the electron transport layer is not particularly limited, but is preferably 5.6 eV or more and 8.0 eV or less, and more preferably 5.6 eV or more and 7.0 eV or less.

The method of forming each layer constituting the light emitting element is not particularly limited, such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, coating method, etc., but resistance heating vapor deposition or electron beam vapor deposition is usually used in terms of element characteristics. preferable.

The thickness of the organic layer is not limited because it depends on the resistance value of the luminescent material, but is preferably 1 to 1000 nm. The film thicknesses of the light emitting layer, the electron transport layer, and the hole transport layer are each preferably 1 nm to 200 nm, and more preferably 5 nm to 100 nm.

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

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

In the matrix method, pixels for display are arranged two-dimensionally such as a lattice shape or a mosaic shape, and characters and images are displayed by a set of pixels. The shape and size of the pixel are determined by the application. For example, a square pixel with a side of 300 μm or less is usually used for displaying images and characters on a personal computer, monitor, TV, and a pixel with a side of mm order for a large display such as a display panel. become. In monochrome display, pixels of the same color may be arranged. However, in color display, red, green, and blue pixels are displayed side by side. In this case, there are typically a delta type and a stripe type. The matrix driving method may be either a line sequential driving method or an active matrix. Although the structure of the line sequential drive is simple, the active matrix may be superior in consideration of the operation characteristics, and it is necessary to use it depending on the application.

The segment system in the present invention is a system in which a pattern is formed so as to display predetermined information and a region determined by the arrangement of the pattern is caused to emit light. For example, the time and temperature display in a digital clock or a thermometer, the operation state display of an audio device or an electromagnetic cooker, the panel display of an automobile, and the like can be mentioned. The matrix display and the segment display may coexist in the same panel.

The light-emitting element of the present invention is also preferably used as a backlight for various devices. The backlight is used mainly for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, a sign, and the like. In particular, the light-emitting element of the present invention is preferably used for a backlight for a liquid crystal display device, particularly a personal computer for which a reduction in thickness is being considered, and a backlight that is thinner and lighter than conventional ones can be provided.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In addition, the number of the compound in each following Example points out the number of the compound described above.

Synthesis example 1
Synthesis of Compound [59] 4.13 g of 4-chloroaniline, bromobenzene-d5 · 11.54 g, 372 mg of bis (dibenzylideneacetone) palladium, 376 mg of trit-butylphosphine tetrafluoroborate, 8.71 g of sodium tert-butoxide The mixed solution of 162 ml of orthoxylene was heated and stirred for 5 hours under reflux in a nitrogen stream. After cooling to room temperature, water was added to separate and recover the organic layer. The organic layer was dried over magnesium sulfate and evaporated. The obtained concentrate was purified by silica gel column chromatography, and the solid obtained by evaporation was vacuum-dried, and then 4-chloro-N, N-di ( ² H ₅ ) phenylaniline (intermediate A) 7. 44 g was obtained.

Next, a mixed solution of Intermediate A (7.44 g), N-bromosuccinimide (9.60 g), and tetrahydrofuran (178 ml) was stirred at room temperature for 4 hours under a nitrogen stream. Water and toluene were added to extract the organic layer, and the collected organic layer was dried over magnesium sulfate and evaporated. Methanol was added to the concentrate for filtration, and the resulting solid was vacuum-dried to obtain 10.91 g of Intermediate B.

Next, a mixed solution of Intermediate B 3.34 g, phenylboronic acid-d5 · 2.0 g, dichlorobis (triphenylphosphine palladium) dichloride 211 mg, 1.5 M aqueous sodium carbonate solution 21 ml, and dimethoxyethane 38 ml under a nitrogen stream under reflux. And stirred for 3 hours. After cooling to room temperature, water and toluene were added to recover the organic layer, and the recovered organic layer was dried over magnesium sulfate and evaporated. The obtained concentrate was purified by silica gel column chromatography, and the solid obtained by evaporation was vacuum-dried to obtain 2.49 g of intermediate C.

Next, Intermediate C 5.60 g, [1,1 ′: 3 ′, 1 ″ -terphenyl] -5′-ylboronic acid 3.75 g, bis (dibenzylideneacetone) palladium 429 mg, tricyclohexylphosphine tetrafluoroborate A mixed solution of 550 mg of salt, 14 ml of 1.27M potassium phosphate aqueous solution and 62 ml of 1,4-dioxane was heated and stirred for 3 hours under reflux in a nitrogen stream. After cooling to room temperature, water was added for filtration, washing with methanol and vacuum drying. The obtained solid was purified by silica gel column chromatography, and the solid obtained by evaporation was vacuum dried to obtain 4.78 g of compound [59].

The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the white solid obtained above was Compound [59].
¹ H-NMR (CDCl ₃ (d = ppm)): 7.26-7.29 (m, 2H), 7.36-7.51 (m, 5H), 7.61-7.79 (m, 10H).

This compound [59] was used as a light emitting device material after sublimation purification at about 320 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.9% before sublimation purification and 99.9% after sublimation purification.

Example 1
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which ITO transparent conductive film was deposited at 165 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. Compound HI-1 was deposited as a hole injection layer by 10 nm by resistance heating. As a hole transport layer, Compound [59] was deposited by 50 nm. Next, as a light emitting layer, the compound H-1 was used as the host material, the compound D-1 was used as the dopant material, and the dopant material was evaporated to a thickness of 20 nm so that the doping concentration was 3 wt%. Next, Compound E-1 was laminated to a thickness of 30 nm as an electron transport layer.

Next, after depositing 1 nm of lithium quinolinol, a cathode co-deposited film of magnesium and silver was deposited at a deposition rate ratio of magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s) to 60 nm. Then, a 5 × 5 mm square element was produced. The film thickness referred to here is a crystal oscillation type film thickness monitor display value. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with an external quantum efficiency of 4.8% was obtained. For the external quantum efficiency (%), the front luminance (cd / m ² ) obtained from a spectral radiance meter (CS-1000, manufactured by Konica Minolta), and a value calculated from an EL spectrum were used. However, for the obtained EL spectrum, the external quantum efficiency was calculated on the assumption of Lambasian (complete diffusion surface). When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 1550 hours. Compounds HI-1, H-1, D-1, and ET-1 are the compounds shown below.

Examples 2-8, Comparative Examples 1-8
A light emitting device was produced in the same manner as in Example 1 except that the materials described in Table 1 were used as the hole transport layer. The results of each example and comparative example are shown in Table 1. HT-1 to HT-8 are the compounds shown below.

Examples 9 to 16
A light emitting device was produced in the same manner as in Example 1 except that the materials described in Table 1 were used for the hole transport layer, the light emitting layer, and the electron transport layer. The results of each example are shown in Table 1. H-2, D-2 and ET-2 are the compounds shown below.

Example 17
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which ITO transparent conductive film was deposited at 165 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. Compound HI-1 was deposited as a hole injection layer by 10 nm by resistance heating. Next, 40 nm of HT-1 was deposited as a first hole transport layer. Next, the compound [59] was deposited by 10 nm as a second hole transport layer. Next, as a light emitting layer, the compound H-1 was used as the host material, the compound D-1 was used as the dopant material, and the dopant material was evaporated to a thickness of 20 nm so that the doping concentration was 3 wt%. Next, Compound ET-1 was laminated to a thickness of 30 nm as an electron transport layer.

Next, after depositing 1 nm of lithium quinolinol, a cathode co-deposited film of magnesium and silver was deposited at a deposition rate ratio of magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s) to 60 nm. Then, a 5 × 5 mm square element was produced. The film thickness referred to here is a crystal oscillation type film thickness monitor display value. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with an external quantum efficiency of 4.9% was obtained. When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 1570 hours.

Examples 18 to 40, Comparative Examples 9 to 16
A light emitting device was produced in the same manner as in Example 17 except that the materials described in Table 2 were used as the first hole transport layer and the second hole transport layer. The results of each example are shown in Table 2.

Example 41
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited by 90 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. Compound HI-1 was deposited as a hole injection layer by 10 nm by resistance heating. Next, HT-1 was deposited to 110 nm as the first hole transport layer. Next, 20 nm of compound [59] was vapor-deposited as a 2nd positive hole transport layer. Next, as a light emitting layer, the compound H-2 was used as the host material, the compound D-2 was used as the dopant material, and vapor deposition was performed to a thickness of 40 nm so that the dopant concentration was 10 wt%. Next, Compound E-1 was laminated to a thickness of 20 nm as an electron transport layer.

Next, after depositing 1 nm of lithium quinolinol, a cathode co-deposited film of magnesium and silver was deposited at a deposition rate ratio of magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s) to 60 nm. Then, a 5 × 5 mm square element was produced. The film thickness referred to here is a crystal oscillation type film thickness monitor display value. When this light emitting device was DC-driven at 10 mA / cm ² , green light emission with a luminous efficiency of 46.5 lm / W was obtained. The effective efficiency (lm / W) is the front luminance (cd / cm ² ) obtained by measurement with a spectral radiance meter (CS-1000, manufactured by Konica Minolta), and the power density (W / cm ² ) input to the device. ² ) and the radiation angle (sr, steradian). When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 5450 hours. H-3 and D-3 are the compounds shown below.

Examples 42 to 48, Comparative Examples 17 to 24
A light emitting device was prepared and evaluated in the same manner as in Example 41 except that the materials described in Table 3 were used as the hole transport layer. The results are shown in Table 3.

Example 49
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited by 90 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. Compound HI-1 was deposited as a hole injection layer by 10 nm by resistance heating. Next, HT-1 was deposited to 110 nm as the first hole transport layer. Next, 20 nm of compound [59] was vapor-deposited as a 2nd positive hole transport layer. Next, as a light-emitting layer, Compound H-3 was used as the host material, Compound D-3 was used as the dopant material, and the dopant material was deposited to a thickness of 40 nm so that the doping concentration was 10 wt%. Next, Compound ET-1 was laminated to a thickness of 20 nm as an electron transport layer.

Next, after depositing 1 nm of lithium quinolinol, a cathode co-deposited film of magnesium and silver was deposited at a deposition rate ratio of magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s) to 60 nm. Then, a 5 × 5 mm square element was produced. The film thickness referred to here is a crystal oscillation type film thickness monitor display value. When this light emitting device was DC-driven at 10 mA / cm ² , red light emission with a light emission efficiency of 8.8 lm / W was obtained. When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 1480 hours. H-4 and D-4 are the compounds shown below.

Examples 50 to 56, Comparative Examples 25 to 32
A light emitting device was prepared and evaluated in the same manner as in Example 49 except that the materials described in Table 4 were used as the second hole transport layer. The results are shown in Table 4.

Example 57
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 50 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. Using a resistance heating method, Compound HT-8 and Compound HI-2 were used as the hole injection layer, and 10 nm was deposited so that the doping concentration of Compound HI-2 was 5 wt% with respect to Compound HT-9. Next, 80 nm of HT-8 was deposited as a first hole transport layer. Next, the compound [59] was deposited by 10 nm as a second hole transport layer. Next, as a light emitting layer, the compound H-1 was used as the host material, the compound D-1 was used as the dopant material, and the dopant material was evaporated to a thickness of 20 nm so that the doping concentration was 3 wt%. Next, as an electron transport layer, a layer in which ET-2 and lithium quinolinol were mixed at a deposition rate ratio of 1: 1 was deposited by 30 nm.

Next, after depositing 1 nm of lithium quinolinol, a co-deposited film of magnesium and silver was deposited at a deposition rate ratio of magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s) to 60 nm to form a cathode. Then, a 5 × 5 mm square element was produced. The film thickness referred to here is a crystal oscillation type film thickness monitor display value. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with an external quantum efficiency of 5.1% was obtained. When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 1670 hours. HI-2, HT-8, and ET-3 are the compounds shown below.

Examples 58 to 72, Comparative Examples 33 to 40
A light emitting device was produced and evaluated in the same manner as in Example 57 except that the materials described in Table 5 were used as the second hole transport layer. The results are shown in Table 5. ET-4 and ET-5 are the compounds shown below.

Claims

A monoamine derivative represented by the following general formula (1).

(Wherein L 1 to L 2 are a single bond or a substituted or unsubstituted arylene group having 6 to 12 nuclear carbon atoms. At least one of R 1 to R 5 is a substituted or unsubstituted phenyl group. , substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or selected from a substituted or unsubstituted terphenyl group,, .A 1 and the others are all deuterium A 2 may be the same or different and each represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or a substituted or unsubstituted group Selected from terphenyl groups.)
The monoamine derivative according to claim 1, wherein the general formula (1) is represented by the following general formula (2).

(Wherein L 1 and A 1 are the same as those in formula (1). At least one of R 1 to R 10 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, It is selected from a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or a substituted or unsubstituted terphenyl group, and everything else is deuterium.)
In the general formula (1), A 1 and A 2 may be the same or different from each other, and are substituted or unsubstituted phenyl group, substituted or unsubstituted naphthyl group, substituted or unsubstituted fluorenyl group, substituted or unsubstituted The monoamine derivative according to claim 1, wherein the monoamine derivative is selected from a substituted phenanthrenyl group or a substituted or unsubstituted terphenyl group, and when A 1 and A 2 are substituted, the substituent is an alkyl group or a halogen.
The monoamine derivative according to claim 2, wherein the general formula (2) is represented by the following general formula (3).

(In the formula, L 1 and A 1 are the same as those in the general formula (1). Ar 1 and Ar 2 may be the same or different, and each may be a substituted or unsubstituted phenyl group, a substituted or unsubstituted group; (Selected from a naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, or a substituted or unsubstituted terphenyl group.)
The monoamine derivative according to claim 3, wherein the general formula (3) is represented by the following general formula (4).

(In the formula, L 1 and A 1 are the same as those in the general formula (1). R 101 to R 110 may be the same as or different from each other, and may be hydrogen, deuterium, an alkyl group, a cycloalkyl group, or an alkenyl. Group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, substituted or unsubstituted phenyl group, substituted or unsubstituted naphthyl group, substituted or unsubstituted phenanthrenyl group, substituted or unsubstituted terphenyl group, halogen, The group is selected from the group consisting of a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, a silyl group, and —P (═O) R 111 R 112. R 111 and R 112 are an aryl group or a heteroaryl group. 111 and R 112 may be condensed to form a ring.)
The monoamine derivative according to claim 4, wherein the general formula (4) is represented by the following general formula (5).

(In the formula, L 1 and A 1 are the same as those in the general formula (1). R 103 and R 108 are the same as those in the general formula (4), and may be the same or different from each other. And b are each 0 to 4, and when a and b are 0 to 3, the portion other than deuterium is hydrogen.)
The monoamine derivative according to claim 5, wherein the general formula (5) is represented by the following general formula (6).

(In the formula, L 1 and A 1 are the same as those in general formula (1). R 103 and R 108 are the same as those in general formula (4) and may be the same or different.)
7. A light-emitting element in which an organic layer exists between an anode and a cathode and emits light by electric energy, and the monoamine derivative according to claim 1 is contained in any layer between the anode and the cathode. A light emitting element characterized by the above.
The light-emitting element according to claim 7, wherein at least a hole transport layer is present in the organic layer, and the monoamine derivative according to any one of claims 1 to 6 is contained in the hole transport layer.
The light-emitting element according to claim 7 or 8, wherein at least a light-emitting layer is present in the organic layer, and the light-emitting layer includes a host material having an anthracene or pyrene skeleton.
The light emitting element of Claim 9 containing the dopant containing a diamine skeleton or a fluoranthene skeleton in the said light emitting layer.
7. The organic layer according to claim 1, wherein the organic layer includes at least a light emitting layer and a plurality of organic layers between the light emitting layer and the anode, and a layer in contact with the light emitting layer among the plurality of organic layers. The monoamine derivative is contained, and the compound represented by the following general formula (7) or (8) is included in a layer other than the layer in contact with the light emitting layer among the plurality of organic layers. Light emitting element.

(In the formula, L 101 and L 201 are substituted or unsubstituted arylene groups having 10 to 40 nuclear carbon atoms. Ar 101 to Ar 104 may be the same as or different from each other, and substituted or unsubstituted nuclear carbon numbers are the same. An aryl group having 6 to 60, or a substituted or unsubstituted heteroaryl group having 6 to 60 nuclear carbon atoms, R 401 to R 408 may be the same or different from each other, and may be hydrogen, an alkyl group, a cycloalkyl group, Alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, substituted or unsubstituted phenyl group, substituted or unsubstituted naphthyl group, substituted or unsubstituted phenanthrenyl group, substituted or unsubstituted terphenyl group, halogen Carbonyl group, carboxyl group, oxycarbonyl group and carbamoyl group, .R 16 and R 17 is selected from the group consisting of Lil group and -P (= O) R 16 R 17 is an aryl or heteroaryl group. Also have engaged R 16 and R 17 are condensed to form a ring Ar 201 to Ar 204 are each a substituted or unsubstituted aryl group having 6 to 60 nuclear carbon atoms, or a substituted or unsubstituted heteroaryl group having 6 to 60 nuclear carbon atoms.)
12. The light emitting device according to claim 11, wherein at least one of Ar 201 to Ar 202 in the general formula (8) is a substituted or unsubstituted dimethylfluorenyl group.
An element that has at least a hole transport layer and a light-emitting layer between an anode and a cathode and emits light by electric energy, wherein the hole transport layer contains the monoamine derivative according to any one of claims 1 to 6, and emits light. A light-emitting element including a triplet light-emitting material in a layer.
14. The light emitting device according to claim 7, wherein a hole injection layer exists between the hole transport layer and the anode, and the hole injection layer contains an acceptor compound.
There is at least an electron transport layer between the light-emitting layer and the cathode, the electron transport layer contains electron-accepting nitrogen, and is further composed of an element selected from carbon, hydrogen, nitrogen, oxygen, silicon, and phosphorus. 15. The light emitting device according to claim 7, wherein the light emitting device is a compound having an aryl ring structure.
The light emitting device according to any one of claims 8 to 16, wherein the electron transport layer is represented by the following general formula (10).

(In the formula, Ar 1 to Ar 2 represent a substituted or unsubstituted phenyl group, pyridyl group, or pyrimidyl group. Ar 3 to Ar 4 represent a substituted or unsubstituted aryl group having 10 to 20 nuclear carbon atoms or a substituted group. Or an unsubstituted carbazolyl group, wherein X 1 to X 3 each represents a carbon atom or a nitrogen atom, provided that at least two of X 1 to X 3 are nitrogen atoms, L p 1 and L q 2 represent phenylene Represents a group or a pyridylene group, and p to q each represents an integer of 0 to 2.)
The light emitting device according to any one of claims 8 to 16, wherein the electron transport layer contains a compound containing a fluoranthene skeleton.