JP3565870B2 - Electroluminescent device - Google Patents

Description

（式中、Ｂ ¹ 及びＢ ² はそれぞれ独立に選ばれる置換もしくは無置換のビフェニレン基を、Ａｒ¹、Ａｒ²、Ａｒ³、Ａｒ⁴、Ａｒ⁵はそれぞれ独立に選ばれる水素原子、置換もしくは無置換のアルキル基またはアリール基を表す。）
【０００８】
上記のビフェニレン基は以下で定義される置換基（１）〜（９）を複数個有することができる。
（１）ハロゲン原子、トリフルオロメチル基、シアノ基、ニトロ基。
（２）アルキル基：好ましくは、Ｃ₁〜Ｃ₂₀とりわけＣ₁〜Ｃ₁₂の直鎖または分岐鎖のアルキル基であり、これらのアルキル基は更に水酸基、シアノ基、フェニル基またはハロゲン原子、Ｃ₁〜Ｃ₁₂のアルコキシ基、アルキル基、もしくはＣ₁〜Ｃ₁₂のアルコキシ基で置換されたフェニル基を有しても良い。
（３）アルコキシ基（−ＯＲ¹）：Ｒ¹は（２）で定義したアルキル基を表す。
（４）アリールオキシ基：アリール基としてフェニル基、ナフチル基が挙げられ、これらはＣ₁〜Ｃ₁₂のアルコキシ基、Ｃ₁〜Ｃ₁₂のアルキル基またはハロゲン原子を置換基として含有しても良い。
（５）アルキルチオ基（−ＳＲ¹）：Ｒ¹は（２）で定義したアルキル基を表す。
（６）

したアルキル基、アセチル基、ベンゾイル基等のアシル基、またはアリール基を表わし、アリール基としては、例えば、フェニル基、ビフェニリル基、またはナフチル基が挙げられ、これらはＣ₁〜Ｃ₁₂のアルコキシ基、Ｃ₁〜Ｃ₁₂のアルキル基またはハロゲン原子を置換基として含有しても良い。また、ピペリジル基、モルホリル基のように、Ｒ¹とＲ²が窒素原子と共同で環を形成しても良い。また、ユロリジル基のようにアリール基状の炭素原子と共同で環を形成しても良い。
（７）アルコキシカルボニル基（−ＣＯＯＲ⁴）：Ｒ⁴は（２）で定義したアルキル基、または（４）で定義したアリール基を表す。
（８）アシル基、（−ＣＯＲ⁴）、スルホニル基、カルバモイル基

：式中、Ｒ²、Ｒ³及びＲ⁴は上記で定義した意味を表す。但し、Ｒ²及びＲ³においてアリール基上の炭素原子と共同で環を形成する場合を除く。
（９）メチレンジオキシ基またはメチレンジチオ基等のアルキレンジオキシ基またはアルキレンジチオ基。
【０００９】
一般式化１におけるＡｒ^１、Ａｒ^２、Ａｒ^３、Ａｒ^４、Ａｒ^５がアリール基である場合、それらは炭素環式の芳香族基、または複素環式の芳香族基であり、前者の例としては、フェニル基、ビフェニリル基、ターフェニリル基等の非縮合炭素環式芳香族基及び縮合多環式炭化水素基をあげることができる。縮合多環式炭化水素基としては、好ましくは環を形成する炭素数が１８個以下のものが挙げられる。例えば、ペンタレニル基、インデニル基、ナフチル基、アズレニル基、ヘプタレニル基、ｓ−インダセニル基、アセナフチレニル基、プレイアデニル基、アセナフテニル基、フェナレニル基、フェナントリル基、アントリル基、フルオランテニル基、アセフェナントリレニル基、アセアントリレニル基、トリフェニレニル基、ピレニル基、クリセニル基、ビフェニレニル基、ａｓ−インダセニル基、フルオレニル基及びナフタセニル基等が挙げられる。
【００１０】
Ａｒ^１、Ａｒ^２、Ａｒ^３、Ａｒ^４、Ａｒ^５が複素環式の芳香族基の例としては、次のような基が挙げられる。
ピリジル基、ピリミジル基、ピラジニル基、トリアジニル基、フラニル基、ピロリル基、チオフェニル基、キノリル基、クマリニル基、ベンゾフラニル基、ベンズイミダゾリル基、ベンズオキサゾリル基、ジベンゾフラニル基、ベンゾチオフェニル基、ジベンゾチオフェニル基、インドリル基、カルバゾリル基、ピラゾリル基、イミダゾリル基、オキサゾリル基、イソオキサゾリル基、チアゾリル基、インダゾリル基、ベンゾチアゾリル基、ピリダジニル基、シンノリル基、キナゾリル基、キノキサリル基、フタラジニル基、フタラジンジオニル基、フタルアミジル基、クロモニル基、ナフトラクタミル基、キノロニル基、ｏ−スルホ安息香酸イミジル基、マレイン酸イミジル基、ナフタリジニル基、ベンズイミダゾロニル基、ベンゾオキサゾロニル基、ベンゾチアゾロニル基、ベンゾチアゾチオニル基、キナゾロニル基、キノキサロニル基、フタラゾニル基、ジオキソピリミジニル基、ピリドニル基、イソキノロニル基、イソキノリニル基、イソチアゾリル基、ベンズイソキサゾリル基、ベンズイソチアゾリル基、インダジロニル基、アクリジニル基、アクリドニル基、キナゾリンジオニル基、キノキサリンジオニル基、ベンズオキサジンジオニル基、ベンゾキサジノニル基、及びナフタルイミジル基。
また、これらのアリール基は前記で定義した置換基（１）〜（９）を有することができる。
【００１１】
次に、本発明で使用される一般化式化１で表わされる化合物の具体例を表１に示すが、本発明はこれに限定されるものではない。
【表１−（１）】

【表１−（２）】

【表１−（３）】

【００１２】
表１において、Ｄ_１〜Ｄ _７ は次の基を意味する。
【表２】

【００１３】
本発明における電界発光素子は、以上で説明した有機化合物を真空蒸着法、溶液塗布等により、有機化合物全体で２μｍより小さい厚み、さらに好ましくは、０．０５μｍ〜０．５μｍの厚みに薄膜化することにより有機化合物層を形成し、陽極及び陰極で挾持することにより構成される。
【００１４】
以下、図面に沿って本発明を更に詳細に説明する。
図１は本発明の電界発光素子の代表的な例であって、基板上にホール注入電極（陽極）、発光層及び電子注入電極（陰極）を順次設けた構成のものである。
図１に係る電界発光素子は使用する化合物が単一でホール輸送性、電子輸送性、発光性の特性を有する場合あるいは各々の特性を有する化合物を混合して使用する場合に特に有用である。
【００１５】
図２はホール輸送性化合物と電子輸送性化合物との組み合わせにより発光層を形成したものである。この構成は有機化合物の好ましい特性を組み合わせるものであり、ホール輸送性あるいは電子輸送性の優れた化合物を組み合わせることにより電極からのホールあるいは電子の注入を円滑に行ない発光特性の優れた素子を得ようとするものである。なお、このタイプの電界発光素子の場合、組み合わせる有機化合物によって発光物質が異なるため、どちらの化合物が発光するかは一義的に定めることはできない。
【００１６】
図３は、ホール輸送性化合物、発光性化合物、電子輸送性化合物の組み合わせにより発光層を形成するものであり、これは上記の機能分離の考えをさらに進めたタイプのものと考えることができる。
【００１７】
このタイプの電界発光素子はホール輸送性、電子輸送性及び発光性の各特性を適合した化合物を適宜組み合わせることによって得ることができるので、化合物の対象範囲が極めて広くなるため、その選定が容易となる。
【００１８】
本発明の電界発光素子は発光層に電気的にバイアスを付与し発光させるものであるが、わずかなピンホールによって短絡をおこし素子として機能しなくなる場合もあるので、発光層の形成には皮膜形成性に優れた化合物を併用することが望ましい。更にこのような皮膜形成性に優れた化合物とたとえばポリマー結合剤を組み合わせて発光層を形成することもできる。この場合に使用できるポリマー結合剤としては、ポリスチレン、ポリビニルトルエン、ポリ−Ｎ−ビニルカルバゾール、ポリメチルメタクリレート、ポリメチルアクリレート、ポリエステル、ポリカーボネート、ポリアミド等を挙げることができる。また、電極からの電荷注入効率を向上させるために、電荷注入輸送層を電極との間に別に設けることも可能である。
【００１９】
ホール注入電極（陽極）材料としてはニッケル、金、白金、パラジウムやこれらの合金或いは酸化錫（ＳｎＯ_２）、酸化錫インジウム（ＩＴＯ）、沃化銅などの仕事関数の大きな金属やそれらの合金、化合物、更にはポリ（３−メチルチオフェン）、ポリピロール等の導電性ポリマーなどを用いることができる。
【００２０】
一方、電子注入電極（陰極）材料としては、仕事関数の小さな銀、錫、鉛、マグネシウム、マンガン、アルミニウム、或いはこれらの合金が用いられる。ホール注入電極（陽極）及び電子注入電極（陰極）として用いる材料のうち少なくとも一方は、素子の発光波長領域において十分透明であることが望ましい。具体的には８０％以上の光透過率を有することが望ましい。
【００２１】
本発明においては、透明なホール注入電極（陽極）を透明基板上に形成し、図１〜図３の様な構成とすることが好ましいが、場合によってはその逆の構成をとっても良い。また透明基板としてはガラス、プラスチックフィルム等が使用できる。
【００２２】
また、本発明においては、この様にして得られた電界発光素子の安定性の向上、特に大気性の水分に対する保護のために、別に保護層を設けたり、素子全体をセル中に入れ、シリコンオイル等を封入するようにしても良い。
【００２３】
【実施例】
以下実施例に基いて、本発明をより具体的に説明する。
実施例１
ＩＴＯ（インジウム錫酸化物：シート抵抗２０Ω／□）基板を順次、中性洗剤、アセトン、イソプロピルアルコールで超音波洗浄した。そして煮沸したイソプロピルアルコールにＩＴＯ基板を５分間浸漬し、乾燥した。
ホール輸送材料として化合物Ｎｏ．２１の化合物を用い１０−^６ｔｏｒｒの真空下でアルミナるつぼを加熱することにより５００Åのホール輸送層を蒸着により形成した。次に、下記化２に示す発光層材料を５００Å蒸着した。さらに、発光層上に１０：１の原子比のＭｇＡｇ電極を２０００Å蒸着した。
この電界発光素子は最初、３０ｍＡ／ｃｍ^２の電流密度において７４０ｃｄ／ｍ^２の発光輝度を示した。その後、１００時間経過後、４００ｃｄ／ｍ^２、５００時間経過後でも４００ｃｄ／ｍ^２の高輝度を維持した。以下に３０ｍＡ／ｃｍ^２の定電流下における発光輝度の変化及び駆動電圧の経時変化を示す。
【化２】

【００２４】
【表３】

【００２５】
比較例１
ホール輸送層に下記化３で示されるトリフェニルジアミンを用いた以外は実施例１と同様に電界発光素子を作製した。この素子は最初２０ｍＡ／ｃｍ^２の電流密度で７５０ｃｄ／ｍ^２の発光輝度を示したが、わずか１０時間経過後に４０ｃｄ／ｍ^２の発光輝度しか示さなかった。以下にその結果を示す。
【化３】

【００２６】
【表４】

【００２７】
【発明の効果】
本発明の電界発光素子は有機化合物層の構成材料として前記一般式化１で示される化合物を用いたことから、低い駆動電圧でも長期間にわたって輝度の高い発光を得ることが出来ると共に耐久性に優れたものである。
【図面の簡単な説明】
【図１】本発明に係る電界発光素子の模式断面図である。
【図２】本発明に係る他の電界発光素子の模式断面図である。
【図３】本発明に係る更に別の電界発光素子の模式断面図である。[0001]
[Industrial applications]
The present invention relates to an electroluminescent device, and more particularly, to an organic electroluminescent device using a novel organic material having high durability for a hole transport layer.
[0002]
[Prior art]
Due to the difference in the light emission excitation mechanism, the electroluminescent element has (1) an intrinsic electroluminescent element which excites a light emitter by local movement of electrons and holes in a light emitting layer and emits light only in an alternating electric field; Ii) Electrons and holes are injected from electrodes and recombination in the light-emitting layer excites the light-emitting body. The light emitting element of intrinsic electroluminescence type (1) generally uses an inorganic compound obtained by adding Mn, Cu, or the like to ZnS, but requires a high AC voltage of 200 V or more for driving, and a manufacturing cost. And many problems such as insufficient brightness and durability.
[0003]
The carrier-injection type electroluminescent device of (2) has obtained a high-luminance device since a thin-film organic compound was used as a light-emitting layer. For example, JP-A-59-194393, U.S. Pat. No. 4,539,507, JP-A-63-2956695, U.S. Pat. No. 4,720,432 and JP-A-63-264692 disclose an anode, an organic hole injecting / transporting material, and an organic material. An electroluminescent device comprising an electron-injecting light emitter and a cathode is disclosed.
[0004]
These organic electroluminescent elements have a light emission luminance of 1000 cd / m ² or more at a current density of 100 mA / cm ² , and have sufficient light emission characteristics at the beginning. Examples of hole transport layer materials include, for example, 1,1-Bis (4-di-tolylaminophenyl) -cyclohexane and N, N, N ′, N′-Tetra-p-tolyl-4,4′-diaminobiphenyl. Triphenylamine-based materials have been used. However, when these conventional hole transport materials are used, a decrease in light output and an increase in drive voltage are observed within several hours, and there is a problem in durability of the electroluminescent device.
[0005]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in view of the above situation of the related art, and has as its object to provide an organic electroluminescent device having excellent durability.
[0006]
[Means for Solving the Problems]
The present inventors have conducted intensive studies on the components of the hole transport layer in order to solve the above-mentioned problems. As a result, the organic hole transport layer and the organic light-emitting layer were located between the hole injection electrode and the electron injection electrode. An organic light emitting device having an organic two-layer structure formed in this order or an organic three-layer structure in which an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer are sequentially formed from the hole injection electrode side. The inventors have found that an electroluminescent element whose layer is a layer containing a specific triamine compound as a component is effective for the above-mentioned problem, and have completed the present invention.
[0007]
That is, according to the present invention, between the hole injection electrode and the electron injection electrode, an organic two-layer structure in which an organic hole transport layer and an organic light emitting layer are sequentially formed from the hole injection electrode side, or the organic hole transport layer and the organic In an electroluminescent device having an organic three-layer structure in which a light emitting layer and an organic electron transport layer are sequentially formed from a hole injection electrode side, the organic hole transport layer comprises a triamine compound represented by the following general formula 1 as a structural component. An organic electroluminescent device, characterized in that the organic electroluminescent device is a layer to be formed.
Embedded image

(Wherein, B ¹ 及 beauty B ² a substituted or unsubstituted biphenylene group each independently ^{selected, Ar 1, Ar 2, Ar} 3, Ar 4, Ar 5 are each independently chosen hydrogen atom, a substituted or Represents an unsubstituted alkyl or aryl group.)
[0008]
The biphenylene group may have a plurality of substituents (1) to (9) defined below.
(1) A halogen atom, a trifluoromethyl group, a cyano group, and a nitro group.
(2) Alkyl groups: preferably C ₁ -C _20, especially C ₁ -C ₁₂ linear or branched alkyl groups, these alkyl groups may further be hydroxyl, cyano, phenyl or halogen atoms, alkoxy groups of ₁ -C _12, alkyl group, or may have a phenyl group substituted by an alkoxy group C ₁ -C _12.
(3) alkoxy group (-OR ¹ ): R ¹ represents an alkyl group defined in (2).
(4) Aryloxy group: Examples of the aryl group include a phenyl group and a naphthyl group, which may contain a C _{1 to} C ₁₂ alkoxy group, a C _{1 to} C ₁₂ alkyl group or a halogen atom as a substituent. .
(5) an alkylthio group (-SR ^1): R ¹ represents an alkyl group specified in (2).
(6)

Represents an acyl group such as an alkyl group, an acetyl group, or a benzoyl group, or an aryl group. Examples of the aryl group include a phenyl group, a biphenylyl group, and a naphthyl group, and these are a C _{1 to} C ₁₂ alkoxy group. , C _{1 to} C ₁₂ alkyl groups or halogen atoms as substituents. Further, like a piperidyl group and a morpholyl group, R ¹ and R ² may form a ring together with a nitrogen atom. Further, a ring may be formed together with an aryl group-like carbon atom such as a eurololidyl group.
(7) Alkoxycarbonyl group (—COOR ⁴ ): R ⁴ represents an alkyl group defined in (2) or an aryl group defined in (4).
(8) acyl group, (—COR ⁴ ), sulfonyl group, carbamoyl group

: In the formula, R ² , R ³ and R ⁴ have the meanings defined above. However, the case where a ring is formed together with the carbon atom on the aryl group in R ² and R ³ is excluded.
(9) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
[0009]
When Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , and Ar ⁵ in the general formula 1 are aryl groups, they are a carbocyclic aromatic group or a heterocyclic aromatic group. Examples thereof include a non-condensed carbocyclic aromatic group such as a phenyl group, a biphenylyl group and a terphenylyl group, and a condensed polycyclic hydrocarbon group. As the condensed polycyclic hydrocarbon group, those having 18 or less carbon atoms forming a ring are preferred. For example, pentalenyl group, indenyl group, naphthyl group, azulenyl group, heptalenyl group, s-indacenyl group, acenaphthylenyl group, preyadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthryl Examples thereof include a phenyl group, an aceanthrenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a biphenylenyl group, an as-indacenyl group, a fluorenyl group, and a naphthacenyl group.
[0010]
Examples of the aromatic group in which Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , and Ar ⁵ are heterocyclic include the following groups.
Pyridyl group, pyrimidyl group, pyrazinyl group, triazinyl group, furanyl group, pyrrolyl group, thiophenyl group, quinolyl group, coumarinyl group, benzofuranyl group, benzimidazolyl group, benzoxazolyl group, dibenzofuranyl group, benzothiophenyl group, Dibenzothiophenyl group, indolyl group, carbazolyl group, pyrazolyl group, imidazolyl group, oxazolyl group, isoxazolyl group, thiazolyl group, indazolyl group, benzothiazolyl group, pyridazinyl group, cinnolyl group, quinazolyl group, quinoxalyl group, phthalazinyl group, phthalazinyl group Nyl group, phthalamidyl group, chromonyl group, naphthactamyl group, quinolonyl group, imidyl o-sulfobenzoate group, imidyl maleate group, naphthalidinyl group, benzimidazolonyl group, benzoxa Ronyl group, benzothiazolonyl group, benzothiazothionyl group, quinazolonyl group, quinoxalonyl group, phthalazonyl group, dioxopyrimidinyl group, pyridonyl group, isoquinolonyl group, isoquinolinyl group, isothiazolyl group, benzisoxazolyl group, benzisothi An azolyl group, an indazilonyl group, an acridinyl group, an acrylonyl group, a quinazolindionyl group, a quinoxalinedionyl group, a benzoxazinedionyl group, a benzoxazinonyl group, and a naphthalimidyl group.
Further, these aryl groups can have the substituents (1) to (9) defined above.
[0011]
Next, specific examples of the compound represented by the general formula 1 used in the present invention are shown in Table 1, but the present invention is not limited thereto.
[Table 1- (1)]

[Table 1- (2)]

[Table 1- (3)]

[0012]
In Table 1, D ₁ to D ₇ mean the following groups.
[Table 2]

[0013]
The electroluminescent device of the present invention is formed by thinning the organic compound described above to a thickness of less than 2 μm, more preferably 0.05 μm to 0.5 μm, as a whole, by vacuum evaporation, solution coating, or the like. In this manner, an organic compound layer is formed and sandwiched between an anode and a cathode.
[0014]
Hereinafter, the present invention will be described in more detail with reference to the drawings.
FIG. 1 shows a typical example of the electroluminescent device of the present invention, which has a configuration in which a hole injection electrode (anode), a light emitting layer, and an electron injection electrode (cathode) are sequentially provided on a substrate.
The electroluminescent device according to FIG. 1 is particularly useful when a single compound has hole transporting, electron transporting, and luminescent properties, or when a compound having each property is used in combination.
[0015]
FIG. 2 shows a light-emitting layer formed by a combination of a hole transporting compound and an electron transporting compound. This configuration combines the preferable characteristics of the organic compound. By combining a compound having an excellent hole-transport property or an electron-transport property, holes or electrons can be smoothly injected from the electrode to obtain an element having excellent light-emitting properties. It is assumed that. In the case of this type of electroluminescent device, since the luminescent material differs depending on the organic compound to be combined, it cannot be unambiguously determined which compound emits light.
[0016]
FIG. 3 shows a structure in which a light-emitting layer is formed by a combination of a hole-transporting compound, a light-emitting compound, and an electron-transporting compound, which can be considered as a type in which the above-described function separation is further advanced.
[0017]
This type of electroluminescent device can be obtained by appropriately combining compounds having the properties of hole transporting property, electron transporting property, and light emitting property. Become.
[0018]
Although the electroluminescent device of the present invention applies an electric bias to the light emitting layer to emit light, a short circuit may occur due to a slight pinhole, and the device may not function as an element. It is desirable to use a compound having excellent properties in combination. Further, the light emitting layer can be formed by combining such a compound having excellent film-forming properties with, for example, a polymer binder. Examples of the polymer binder that can be used in this case include polystyrene, polyvinyl toluene, poly-N-vinyl carbazole, polymethyl methacrylate, polymethyl acrylate, polyester, polycarbonate, and polyamide. In order to improve the efficiency of charge injection from the electrode, a charge injection transport layer may be separately provided between the electrode and the electrode.
[0019]
Examples of the material for the hole injection electrode (anode) include nickel, gold, platinum, palladium, alloys thereof, and metals having a large work function such as tin oxide (SnO ₂ ), indium tin oxide (ITO), and copper iodide, and alloys thereof. Compounds, and conductive polymers such as poly (3-methylthiophene) and polypyrrole can be used.
[0020]
On the other hand, silver, tin, lead, magnesium, manganese, aluminum, or an alloy thereof having a small work function is used as an electron injection electrode (cathode) material. It is desirable that at least one of the materials used as the hole injection electrode (anode) and the electron injection electrode (cathode) is sufficiently transparent in the emission wavelength region of the device. Specifically, it is desirable to have a light transmittance of 80% or more.
[0021]
In the present invention, it is preferable that a transparent hole injection electrode (anode) is formed on a transparent substrate and has a configuration as shown in FIGS. 1 to 3, but the configuration may be reversed in some cases. Further, glass, plastic film and the like can be used as the transparent substrate.
[0022]
In the present invention, in order to improve the stability of the electroluminescent device obtained in this way, particularly to protect against atmospheric moisture, a separate protective layer is provided, or the entire device is placed in a cell, Oil or the like may be sealed.
[0023]
【Example】
Hereinafter, the present invention will be described more specifically based on examples.
Example 1
An ITO (indium tin oxide: sheet resistance: 20Ω / □) substrate was sequentially ultrasonically cleaned with a neutral detergent, acetone, and isopropyl alcohol. Then, the ITO substrate was immersed in boiled isopropyl alcohol for 5 minutes and dried.
Compound No. as a hole transport material. It was formed by depositing a hole transport layer of 500Å by heating an alumina crucible under a vacuum of ^10- 6 torr with a compound of 21. Next, a light emitting layer material represented by the following chemical formula 2 was deposited at 500 °. Further, a MgAg electrode having an atomic ratio of 10: 1 was vapor-deposited at 2000 ° on the light emitting layer.
This electroluminescent device initially showed an emission luminance of 740 cd / m ² at a current density of 30 mA / cm ² . Thereafter, high luminance of 400 cd / m ² was maintained after elapse of 100 hours and 400 cd / m ² even after elapse of 500 hours. The change in the light emission luminance and the change over time in the driving voltage under a constant current of 30 mA / cm ² are shown below.
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[0024]
[Table 3]

[0025]
Comparative Example 1
An electroluminescent device was produced in the same manner as in Example 1 except that triphenyldiamine represented by the following formula 3 was used for the hole transport layer. This device initially showed an emission luminance of 750 cd / m ² at a current density of 20 mA / cm ² , but showed an emission luminance of only 40 cd / m ² after only 10 hours. The results are shown below.
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[0026]
[Table 4]

[0027]
【The invention's effect】
Since the electroluminescent device of the present invention uses the compound represented by the general formula 1 as a constituent material of the organic compound layer, it can provide high-luminance light emission for a long period even at a low driving voltage and has excellent durability. It is a thing.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of an electroluminescent device according to the present invention.
FIG. 2 is a schematic sectional view of another electroluminescent device according to the present invention.
FIG. 3 is a schematic sectional view of still another electroluminescent device according to the present invention.

Claims (2)

An organic two-layer structure in which an organic hole transport layer and an organic light emitting layer are sequentially formed from the hole injection electrode side between the hole injection electrode and the electron injection electrode, or an organic hole transport layer, an organic light emitting layer, and an organic electron transport layer. Wherein the organic hole transport layer is a layer containing a triamine compound represented by the following general formula 1 as a structural component in an electroluminescent device having an organic three-layer structure formed in order from the hole injection electrode side. Organic electroluminescent device.

(Wherein, ^{B 1} 及 beauty ^{B 2} a substituted or unsubstituted biphenylene group each independently ^{selected, Ar 1, Ar 2, Ar} 3, Ar 4, Ar 5 are each independently chosen hydrogen atom, a substituted or Represents an unsubstituted alkyl or aryl group.) Any of Ar ¹ and Ar ² in the triamine compound, and one of Ar ³ and Ar ⁴ are an organic electroluminescent device of claim 1, wherein the aryl group.

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