JP4058842B2 - Organic electroluminescence device - Google Patents
Organic electroluminescence device Download PDFInfo
- Publication number
- JP4058842B2 JP4058842B2 JP12884199A JP12884199A JP4058842B2 JP 4058842 B2 JP4058842 B2 JP 4058842B2 JP 12884199 A JP12884199 A JP 12884199A JP 12884199 A JP12884199 A JP 12884199A JP 4058842 B2 JP4058842 B2 JP 4058842B2
- Authority
- JP
- Japan
- Prior art keywords
- group
- electron
- aromatic
- organic electroluminescent
- hole injection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- 238000005401 electroluminescence Methods 0.000 title claims description 8
- 238000002347 injection Methods 0.000 claims description 53
- 239000007924 injection Substances 0.000 claims description 53
- 150000001875 compounds Chemical class 0.000 claims description 46
- 239000004721 Polyphenylene oxide Substances 0.000 claims description 38
- 150000004984 aromatic diamines Chemical class 0.000 claims description 38
- 229920000570 polyether Polymers 0.000 claims description 38
- 239000000758 substrate Substances 0.000 claims description 28
- -1 triazyl group Chemical group 0.000 claims description 18
- 125000003118 aryl group Chemical group 0.000 claims description 16
- 125000001424 substituent group Chemical group 0.000 claims description 15
- 230000009477 glass transition Effects 0.000 claims description 11
- 125000000217 alkyl group Chemical group 0.000 claims description 8
- 125000005843 halogen group Chemical group 0.000 claims description 8
- 125000005647 linker group Chemical group 0.000 claims description 5
- 125000001624 naphthyl group Chemical group 0.000 claims description 5
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 claims description 5
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- 125000005428 anthryl group Chemical group [H]C1=C([H])C([H])=C2C([H])=C3C(*)=C([H])C([H])=C([H])C3=C([H])C2=C1[H] 0.000 claims description 3
- 125000004093 cyano group Chemical group *C#N 0.000 claims description 3
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- 125000000449 nitro group Chemical group [O-][N+](*)=O 0.000 claims description 2
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- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 2
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- 125000003367 polycyclic group Chemical group 0.000 description 1
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Images
Description
【０００１】
【発明の属する技術分野】
本発明は有機電界発光素子に関するものであり、詳しくは、有機化合物から成る発光層に電界をかけて光を放出する薄膜型デバイスに関するものである。
【０００２】
【従来の技術】
従来、薄膜型の電界発光（ＥＬ）素子としては、無機材料のII−VI族化合物半導体であるＺｎＳ、ＣａＳ、ＳｒＳ等に、発光中心であるＭｎや希土類元素（Ｅｕ、Ｃｅ、Ｔｂ、Ｓｍ等）をドープしたものが一般的であるが、上記の無機材料から作製したＥＬ素子は、
１）交流駆動が必要（一般に50〜1000Ｈｚ）、
２）駆動電圧が高い（一般に200Ｖ程度）、
３）フルカラー化が困難で特に青色に問題がある、
４）周辺駆動回路のコストが高い、
という問題点を有している。
【０００３】
しかし、近年、上記問題点の改良のため、有機薄膜を用いたＥＬ素子の開発が行われるようになった。特に、発光効率を高めるため、電極からのキャリアー注入の効率向上を目的として電極の種類の最適化を行い、芳香族ジアミンから成る正孔輸送層と８−ヒドロキシキノリンのアルミニウム錯体から成る発光層とを設けた有機電界発光素子の開発（Appl. Phys. Lett., 51巻, 913頁，1987年）により、従来のアントラセン等の単結晶を用いたＥＬ素子と比較して発光効率の大幅な改善がなされ、実用特性に近づいている。
【０００４】
上記の様な低分子材料を用いた電界発光素子の他にも、発光層の材料として、ポリ（ｐ−フェニレンビニレン）、ポリ［2-メトキシ-5-(2-エチルヘキシルオキシ)-1,4-フェニレンビニレン］、ポリ（3-アルキルチオフェン）等の高分子材料を用いた電界発光素子の開発や、ポリビニルカルバゾール等の高分子に低分子の発光材料と電子移動材料を混合した素子の開発も行われている。
【０００５】
ところで、有機電界発光素子の最大の課題は、駆動時の寿命であり、駆動時の不安定性の現像としては、発光輝度の低下、定電流駆動時の電圧上昇、非発光部分（ダークスポット）の発生等が挙げられる。これらの不安定性の原因はいくつか存在するが、有機層の薄膜形状の劣化が支配的である。この薄膜形状の劣化は、素子駆動時の発熱による有機非晶質膜の結晶化（または凝集）等に起因すると考えられている。特に、駆動電圧の上昇については陽極と正孔輸送層のコンタクトが重要である。
【０００６】
そこで、陽極と正孔輸送層のコンタクトを向上させるために、両層の間に正孔注入層を設け、駆動電圧を低下させることが検討されている。この正孔注入層に用いられる材料に要求される条件としては、陽極とのコンタクトがよく、均一な薄膜が形成でき、熱的に安定、即ち、融点及びガラス転移温度Tgが高いこと、好ましくは 300℃以上の融点と 100℃以上のTgを有することが要求される。さらに、イオン化ポテンシャルが低く陽極からの正孔注入が容易なこと、正孔移動度が大きいことが挙げられる。
【０００７】
従来、正孔注入層の材料としても種々のものが検討されており、例えばポルフィリン誘導体やフタロシアニン化合物（特開昭63−295695号公報）、スターバスト型芳香族トリアミン（特開平４−308688号公報）、ヒドラゾン化合物（特開平４−320483号公報）、アルコキシ置換の芳香族ジアミン誘導体（特開平４−220995号公報）、p-（9-アントリル）-N,N-ジ-p- トリルアニリン、ポリチエニレンビニレンやポリ−ｐ−フェニレンビニレン、ポリアニリン等の有機化合物や、スパッタ・カーボン膜や、バナジウム酸化物、ルテニウム酸化物、モリブデン酸化物等の金属酸化物などが報告されている。
【０００８】
【発明が解決しようとする課題】
しかしながら、陽極と正孔輸送層との間に正孔注入層を挿入する方法において、ポルフィリン誘導体やフタロシアニン化合物を正孔注入層として用いた場合、これらの膜自体による光吸収のためにスペクトルが変化したり、外観上着色して透明でなくなるという問題がある。
【０００９】
スターバスト型芳香族トリアミン、ヒドラゾン化合物、アルコキシ置換の芳香族ジアミン誘導体、p-(9-アントリル)-N,N-ジ-p-トリルアニリン等では、イオン化ポテンシャルが低く透明性がよいという利点はあるものの、ガラス転移点や融点が低いために耐熱性に劣り、連続駆動時の局所加熱に対する安定性が悪く、輝度低下や電圧上昇が問題になる。
【００１０】
一方、ポリチエニレンビニレン、ポリ−ｐ−フェニレンビニレン、ポリアニリン等のポリマー系材料では、駆動電圧の低電圧化と駆動寿命の改善に関する報告はない。
【００１１】
有機電界発光素子の駆動時における電圧が高いこと、そして、耐熱性を含めた安定性が低いことは、ファクシミリ、複写機、液晶ディスプレイのバックライト等の光源としては大きな問題であり、特にフルカラーフラットパネル・ディスプレイ等の表示素子としても望ましくない。
【００１２】
従って、本発明は、低電圧、高発光効率で駆動させることができ、かつ良好な耐熱性を有し、長期間に亙って安定な発光特性を維持することができる有機電界発光素子を提供することを目的とする。
【００１３】
【課題を解決するための手段】
本発明の有機電界発光素子は、基板上に、陽極及び陰極により挟持された発光層が形成されると共に、該発光層と陽極との間に正孔注入層が形成された有機電界発光素子において、該正孔注入層が、下記一般式（Ｉ）または（II）で表わされる繰り返し単位を有し、かつ、重量平均分子量が1,000〜1,000,000であり、ガラス転移温度が１００℃以上である芳香族ジアミン含有ポリエーテルと、電子受容性化合物とを含有することを特徴とする有機電界発光素子。
【００１４】
【化６】
【化７】
（式中、Ａr1，Ａr2，Ａr3，Ａr4，Ａr5，Ａr6，Ａr7，Ａr8，Ａr9は、各々独立して置換基を有していてもよい２価の芳香族環残基を示し、Ｒ1，Ｒ2，Ｒ3，Ｒ4は置換基を有していてもよい芳香族環基または芳香族複素環基を示し、Ｘ及びＹは直接結合、または下記の連結基から選ばれる。）
【００１７】
【化８】
（式中、Ｒ′は置換基を有していてもよいアルキレン基を示し、Ｒ″はアルキル基または置換基を有していてもよい芳香族環基を示す。）
即ち、本発明者らは、従来の問題点を解決し、高温において安定な発光特性を維持できる有機電界発光素子を提供するべく鋭意検討した結果、基板上に、陽極及び陰極により挟持された発光層を有する有機電界発光素子において、陽極と発光層との間に、電子受容性化合物を含有し、かつ、高いTgを有する芳香族ジアミン含有ポリエーテルからなる正孔注入層を設けることで、上記課題を解決することができることを見出し、本発明を完成するに至った。
【００１９】
本発明においては、正孔注入層に、100℃以上のTgを有する芳香族ジアミン含有ポリエーテルと電子受容性化合物を混合して用いることで、素子の発光特性と耐熱性を同時に改善することを可能とした。即ち、電子供与性の芳香族ジアミン含有ポリエーテルに電子受容性化合物を混合することにより、電荷移動が起こり、結果としてフリーキャリアである正孔が生成し、正孔注入層の電気電導度が高くなる。発光層と陽極との電気的接合が、本発明による正孔注入層を設けることで改善され、駆動電圧が低下すると同時に連続駆動時の安定性も向上する。また、 100℃以上のガラス転移温度を有する芳香族ジアミン含有ポリエーテルを正孔注入層の母体とすることにより、素子の耐熱性も大きく改善される。本発明で用いる芳香族ジアミン含有ポリエーテルのガラス転移温度は特に120℃以上、とりわけ150℃以上であることが好ましい。
【００２０】
本発明において、正孔注入層の芳香族ジアミン含有ポリエーテルのイオン化ポテンシャルから電子受容性化合物の電子親和力を引いた値は0.7ｅＶ以下であることが好ましく、また、正孔注入層中の電子受容性化合物の含有量は、芳香族ジアミン含有ポリエーテルに対して0.1〜50重量％の範囲であることが好ましい。
【００２１】
本発明において、電子受容性化合物は、下記一般式（III）で表される化合物或いは、下記化合物群から選ばれる化合物の少なくとも１種であることが好ましい。
【００２２】
【化９】
（式中、Ｚはハロゲン原子を示し、Ｒ5は水素原子、ハロゲン原子、置換基を有していてもよいアルキル基、シアノ基またはニトロ基を示す。）
【００２４】
【化１０】
【発明の実施の形態】
以下に図面を参照して本発明の有機電界発光素子の実施の形態を詳細に説明する。
【００２６】
図１〜３は本発明の有機電界発光素子の実施の形態を示す模式的な断面図であり、１は基板、２は陽極、３は正孔注入層、４は正孔輸送層、５は発光層、６は電子輸送層、７は陰極を各々表わす。
【００２７】
基板１は有機電界発光素子の支持体となるものであり、石英やガラスの板、金属板や金属箔、プラスチックフィルムやシートなどが用いられる。特にガラス板や、ポリエステル、ポリメタクリレート、ポリカーボネート、ポリスルホンなどの透明な合成樹脂の板が好ましい。合成樹脂基板を使用する場合にはガスバリア性に留意する必要がある。基板のガスバリヤ性が低すぎると、基板を通過する外気により有機電界発光素子が劣化することがあるので好ましくない。このため、合成樹脂基板のどちらか片側もしくは両側に緻密なシリコン酸化膜等を設けてガスバリア性を確保する方法も好ましい方法の一つである。
【００２８】
基板１上には陽極２が設けられる。陽極２は正孔注入層３への正孔注入の役割を果たすものである。この陽極２は、通常、アルミニウム、金、銀、ニッケル、パラジウム、白金等の金属、インジウム及び／またはスズの酸化物などの金属酸化物、ヨウ化銅などのハロゲン化金属、カーボンブラック等により構成される。陽極２の形成は通常、スパッタリング法、真空蒸着法などにより行われることが多い。また、銀などの金属微粒子、ヨウ化銅などの微粒子、カーボンブラック、導電性の金属酸化物微粒子等を適当なバインダー樹脂溶液に分散し、基板１上に塗布することにより陽極２を形成することもできる。陽極２は異なる物質で積層して形成することも可能である。陽極２の厚みは、必要とする透明性により異なる。透明性が必要とされる場合は、可視光の透過率を、通常60％以上、好ましくは80％以上とすることが望ましく、この場合、厚みは、通常10〜1000nm、好ましくは20〜500nm 程度である。不透明でよい場合は陽極２は基板１と同一でもよい。また、上記の陽極２の上に異なる導電材料を積層することも可能である。
【００２９】
本発明では、図１〜３の素子構造においては、陽極２の上に正孔注入層３が設けられる。この正孔注入層３に用いられる材料に要求される条件としては、陽極２からの正孔注入効率が高く、かつ、注入された正孔を効率よく輸送することができる材料であることが挙げられる。そのためには、イオン化ポテンシャルが小さく、可視光の光に対して透明性が高く、しかも正孔移動度が大きく、さらに安定性に優れ、トラップとなる不純物が製造時や使用時に発生しにくいことが要求される。上記の一般的な要求条件以外に、車載表示用の応用を考えた場合、さらに 100℃以上の耐熱性が要求される。
【００３０】
本発明の有機電界発光素子は、正孔注入層が、前記一般式（Ｉ）または（II）で表わされる繰り返し単位を有する、重量平均分子量1,000〜1,000,000でガラス転移温度が１００℃以上の芳香族ジアミン含有ポリエーテルと、電子受容性化合物を含有することを特徴とする。
【００３１】
本発明においては、この100℃以上のTgを有する芳香族ジアミン含有ポリエーテルと電子受容性化合物を混合して用いることで、素子の発光特性と耐熱性を同時に改善することを可能とした。即ち、電子供与性の芳香族ジアミン含有ポリエーテルに電子受容性化合物を混合することにより、電荷移動が起こり、結果としてフリーキャリアである正孔が生成し、正孔注入層の電気電導度が高くなる。このため、このような正孔注入層を設けることで、発光層と陽極との電気的接合が改善され、駆動電圧が低下すると同時に連続駆動時の安定性も向上する。また、 100℃以上のガラス転移温度を有する芳香族ジアミン含有ポリエーテルを正孔注入層の母体とすることにより、素子の耐熱性も大きく改善される。本発明で用いる芳香族ジアミン含有ポリエーテルのガラス転移温度は特に120℃以上、とりわけ150℃以上であることが好ましい。
【００３２】
前記一般式（Ｉ）および（II）において、Ａr1〜Ａr9は、好ましくは、各々独立して置換基を有していてもよい２価のベンゼン環、ナフタレン環、アントラセン環、ビフェニルであり、前記置換基としてはハロゲン原子；メチル基、エチル基等の炭素数１〜６のアルキル基；ビニル基等のアルケニル基；メトキシカルボニル基、エトキシカルボニル基等の炭素数１〜６のアルコキシカルボニル基；メトキシ基、エトキシ基等の炭素数１〜６のアルコキシ基；フェノキシ基、ベンジルオキシ基などのアリールオキシ基；ジエチルアミノ基、ジイソプロピルアミノ基等のジアルキルアミノ基が挙げられる。前記置換基としては、好ましくは炭素数１〜３のアルキル基が、特に好ましくはメチル基が挙げられる。
【００３３】
Ｒ1〜Ｒ4は、好ましくは、各々独立して置換基を有していてもよいフェニル基、ナフチル基、アントリル基、ピリジル基、トリアジル基、ピラジル基、キノキサリル基、チエニル基、ビフェニル基であり、前記置換基としてはハロゲン原子；メチル基、エチル基等の炭素数１〜６のアルキル基；ビニル基等のアルケニル基；メトキシカルボニル基、エトキシカルボニル基等の炭素数１〜６のアルコキシカルボニル基；メトキシ基、エトキシ基等の炭素数１〜６のアルコキシ基；フェノキシ基、ベンジルオキシ基などのアリールオキシ基；ジエチルアミノ基、ジイソプロピルアミノ基等のジアルキルアミノ基が挙げられる。
【００３４】
Ｘ及びＹは直接結合または以下に示す連結基から選ばれる。
【００３５】
【化１１】
上記連結基において、Ｒ′は、好ましくはメチレン基、ジメチルメチレン基、エチレン基、プロピレン基であり、Ｒ″は、好ましくはメチル基、エチル基等の炭素数１〜６のアルキル基；フェニル基、ナフチル基、アントリル基、トリル基等の芳香族環基である。
【００３７】
前記一般式（Ｉ）及び（II）で表される化合物は、例えば、城戸らの方法（Polymers for Advanced Technologies， 7巻，31頁，1996年；特開平９−188756号公報）に開示されている経路で合成される。
【００３８】
前記一般式（Ｉ）で表される、本発明の芳香族ジアミン含有ポリエーテルが有する繰り返し単位の好ましい具体例を表１〜表３に示すが、これらに限定するものではない。
【００３９】
【表１】
【表２】
【表３】
また、前記一般式（II）で表される、本発明の芳香族ジアミン含有ポリエーテルが有する繰り返し単位の好ましい具体例を表４，表５に示すが、これらに限定するものではない。
【００４３】
【表４】
【表５】
上述の芳香族ジアミン含有ポリエーテルと組み合わせて用いる電子受容性化合物としては、該芳香族ジアミン含有ポリエーテルとの間で電荷移動を起こすものであればよいが、本発明者が鋭意検討した結果、芳香族ジアミン含有ポリエーテルのイオン化ポテンシャル：ＩＰ（ポリエーテル）と、電子受容性化合物（アクセプタ）の電子親和力：ＥＡ（アクセプタ）の２つの物性値が、
ＩＰ（ポリエーテル）−ＥＡ（アクセプタ）≦ 0.7ｅＶ
の関係式で表される場合に本発明の目的に有効であることを見出した。
【００４６】
このことを図４のエネルギー準位図を用いて説明する。一般に、イオン化ポテンシャル及び電子親和力は真空準位を基準として決定される。イオン化ポテンシャルは物質のＨＯＭＯ（最高被占分子軌道）レベルにある電子を真空準位に放出するのに必要なエネルギーで定義され、電子親和力は真空準位にある電子が物質のＬＵＭＯ（最低空分子軌道）レベルに落ちて安定化するエネルギーで定義される。本発明において、図４に示す芳香族ジアミン含有ポリエーテルのＨＯＭＯレベルのイオン化ポテンシャルと、電子受容性化合物のＬＵＭＯレベルの電子親和力の差が 0.7eV以下であることが好ましい。イオン化ポテンシャルは光電子分光法で直接測定されるか、電気化学的に測定した酸化電位を基準電極に対して補正しても求められる。後者の方法の場合は、例えば、飽和甘コウ電極（ＳＣＥ）を基準電極として用いたとき、
イオン化ポテンシャル＝酸化電位（vs.SCE）＋4.3 ｅＶ
で表される（"Molecular Semiconductors", Springer-Verlag, 1985年、98頁）。電子親和力は、上述のイオン化ポテンシャルから光学的バンドギャップを差し引いて求められるか、電気化学的な還元電位から上記の式で同様に求められる。
【００４７】
前記イオン化ポテンシャルと電子親和力の関係式は、酸化電位と還元電位を用いて、
ポリエーテルの酸化電位−アクセプタの還元電位≦ 0.7ｅＶ
と表現することもできる。
【００４８】
正孔注入層中の電子受容性化合物の芳香族ジアミン含有ポリエーテルに対する含有量は、通常0.1〜50重量％、特に１〜30重量％の範囲にあることが好ましい。
【００４９】
電子受容性化合物としては、上記の関係を満たすものであれば特に限定はされないが、好ましくは、以下に示す一般式（III）で表される化合物から選ばれる。
【００５０】
【化１２】
上記一般式（III）において、Ｚは好ましくは塩素、フッ素、臭素等のハロゲン原子であり、Ｒ5は好ましくは、水素原子；塩素、フッ素、臭素等のハロゲン原子；メチル基、エチル基等の炭素数１〜６のアルキル基；トリフロロメチル基等のハロアルキル基；シアノ基；ニトロ基である。置換位置は中心窒素原子に対してオルト位、メタ位、パラ位のいずれでもよい。
【００５２】
前記一般式（III）で表される電子受容性化合物の具体例としては、以下に示す化合物が挙げられる。
【００５３】
【化１３】
電子受容性化合物の他の好ましい例を、以下に省略名とともに示す。
【００５５】
【化１４】
本発明において、芳香族ジアミン含有ポリエーテルと電子受容性化合物とを含有する正孔注入層３は通常塗布法により前記陽極２上に形成される。例えば、前記一般式（Ｉ）または（II）で表されるポリエーテルと電子受容性化合物の所定量に、必要により正孔のトラップにならないバインダー樹脂や塗布性改良剤などの添加剤等を添加し、溶解して塗布溶液を調製し、スピンコート法やディップコート法などの方法により陽極２上に塗布し、乾燥して正孔注入層３を形成する。
【００５７】
このようにして形成される正孔注入層３の膜厚は、通常5〜1000 nm、好ましくは10〜500 nmである。
【００５８】
正孔注入層３の上には発光層５が設けられる。発光層５は、電界を与えられた電極間において陰極７から注入された電子と正孔注入層３から輸送された正孔を効率よく再結合し、かつ、再結合により効率よく発光する材料から形成される。
【００５９】
このような条件を満たす材料としては、８−ヒドロキシキノリンのアルミニウム錯体などの金属錯体（特開昭59−194393号公報）、10-ヒドロキシベンゾ[h]キノリンの金属錯体（特開平６−322362号公報）、ビススチリルベンゼン誘導体（特開平１−245087号公報、同２−222484号公報）、ビススチリルアリーレン誘導体（特開平２−247278号公報）、(2-ヒドロキシフェニル)ベンゾチアゾールの金属錯体（特開平８−315983号公報）、シロール誘導体等が挙げられる。これらの発光層材料は、通常は真空蒸着法により正孔注入層３上に積層形成される。
【００６０】
素子の発光効率を向上させるとともに発光色を変える目的で、例えば、８−ヒドロキシキノリンのアルミニウム錯体をホスト材料として、クマリン等のレーザ用蛍光色素をドープすること（J. Appl. Phys., 65巻, 3610頁, 1989年）等が行われている。この方法の利点は、
１）高効率の蛍光色素により発光効率が向上、
２）蛍光色素の選択により発光波長が可変、
３）濃度消光を起こす蛍光色素も使用可能、
４）薄膜性のわるい蛍光色素も使用可能、
等が挙げられる。
【００６１】
素子の駆動寿命を改善する目的においても、前記発光層材料をホスト材料として、蛍光色素をドープすることは有効である。例えば、８−ヒドロキシキノリンのアルミニウム錯体などの金属錯体をホスト材料として、ルブレンに代表されるナフタセン誘導体（特開平４−335087号公報）、キナクリドン誘導体（特開平５− 70773号公報）、ペリレン等の縮合多環芳香族環（特開平５−198377号公報）を、ホスト材料に対して 0.1〜10重量％ドープすることにより、素子の発光特性、特に駆動安定性を大きく向上させることができる。発光層のホスト材料に上記ナフタセン誘導体、キナクリドン誘導体、ペリレン等の蛍光色素をドープする方法としては、共蒸着による方法と蒸着源を予め所定の濃度で混合しておく方法がある。
【００６２】
高分子系の発光層材料としては、先に挙げたポリ（p-フェニレンビニレン）、ポリ［2-メトキシ-5-（2-エチルヘキシルオキシ）-1,4-フェニレンビニレン］、ポリ（3-アルキルチオフェン）等の高分子材料や、ポリビニルカルバゾール等の高分子に発光材料と電子移動材料を混合した系等が挙げられる。これらの材料は正孔注入層と同様にスピンコートやディップコート等の方法により正孔注入層３上に塗布して薄膜形成される
このようにして形成される発光層５の膜厚は、通常10〜200 nm、好ましくは30〜100 nmである。
【００６３】
素子の発光特性を向上させるために、図２に示すように、正孔輸送層４を正孔注入層３と発光層５との間に設けたり、さらには、図３に示す様に電子輸送層６を発光層５と陰極７との間に設けるなど機能分離型にすることが行われる。
【００６４】
図２及び図３の機能分離型素子において、正孔輸送層４の材料としては、正孔注入層３からの正孔注入効率が高く、かつ、注入された正孔を効率よく輸送することができる材料であることが必要である。そのためには、イオン化ポテンシャルが小さく、しかも正孔移動度が大きく、さらに安定性に優れ、トラップとなる不純物が製造時や使用時に発生しにくいことが要求される。
【００６５】
このような正孔輸送材料としては、例えば、1,1-ビス（4-ジ-p-トリルアミノフェニル）シクロヘキサン等の３級芳香族アミンユニットを連結した芳香族ジアミン化合物（特開昭59−194393号公報）、4,4'-ビス［N-（1-ナフチル）-N-フェニルアミノ］ビフェニルで代表される２個以上の３級アミンを含み２個以上の縮合芳香族環が窒素原子に置換した芳香族アミン（特開平５−234681号公報）、トリフェニルベンゼンの誘導体でスターバースト構造を有する芳香族トリアミン（米国特許第4,923,774号）、N,N'-ジフェニル-N,N'-ビス（3-メチルフェニル）ビフェニル-4,4'-ジアミン等の芳香族ジアミン（米国特許第4,764,625号）、分子全体として立体的に非対称なトリフェニルアミン誘導体（特開平４−129271号公報）、ピレニル基に芳香族ジアミノ基が複数個置換した化合物（特開平４−175395号公報）、エチレン基で３級芳香族アミンユニットを連結した芳香族ジアミン（特開平４−264189号公報）、スチリル構造を有する芳香族ジアミン（特開平４−290851号公報）、チオフェン基で芳香族３級アミンユニットを連結したもの（特開平４−304466号公報）、スターバースト型芳香族トリアミン（特開平４−308688号公報）、ベンジルフェニル化合物（特開平４−364153号公報）、フルオレン基で３級アミンを連結したもの（特開平５−25473号公報）、トリアミン化合物（特開平５−239455号公報）、ビスジピリジルアミノビフェニル（特開平５−320634号公報）、N,N,N-トリフェニルアミン誘導体（特開平６−1972号公報）、フェノキサジン構造を有する芳香族ジアミン（特開平７−138562号公報）、ジアミノフェニルフェナントリジン誘導体（特開平７−252474号公報）、シラザン化合物（米国特許第 4,950,950号公報）、シラナミン誘導体（特開平６− 49079号公報）、ホスファミン誘導体（特開平６−25659号公報）等が挙げられる。これらの化合物は、単独で用いてもよいし、必要に応じて、２種以上を混合して用いてもよい。
【００６６】
上記の化合物以外に、正孔輸送層４の材料としては、ポリビニルカルバゾールやポリシラン、ポリフォスファゼン（特開平５−310949号公報）、ポリアミド（特開平５−310949号公報）、ポリビニルトリフェニルアミン（特開平７−53953号公報）、トリフェニルアミン骨格を有する高分子（特開平４−133065号公報）、芳香族アミンを含有するポリメタクリレート等の高分子材料が挙げられる。
【００６７】
正孔輸送層４は上記の正孔輸送材料を塗布法あるいは真空蒸着法により前記正孔注入層３上に積層することにより形成される。
【００６８】
塗布法の場合は、正孔輸送材料の１種または２種以上に、必要により正孔のトラップにならないバインダー樹脂や塗布性改良剤などの添加剤とを添加し、溶解して塗布溶液を調製し、スピンコート法などの方法により正孔注入層３上に塗布し、乾燥して正孔輸送層４を形成する。ここで、バインダー樹脂としては、ポリカーボネート、ポリアリレート、ポリエステル等が挙げられる。バインダー樹脂は添加量が多いと正孔移動度を低下させるので、少ない方が望ましく、通常５０重量％以下が好ましい。
【００６９】
真空蒸着法の場合には、正孔輸送材料を真空容器内に設置されたルツボに入れ、真空容器内を適当な真空ポンプで10-4Pa程度にまで排気した後、ルツボを加熱して、正孔輸送材料を蒸発させ、ルツボと向き合って置かれた、陽極２および正孔注入層３が形成された基板１上に正孔輸送層４を形成する。
【００７０】
このようにして形成される正孔輸送層４の膜厚は、通常10〜300nm、好ましくは30〜100nmである。このように薄い膜を一様に形成するためには、一般に真空蒸着法がよく用いられる。
【００７１】
また、この電子輸送層６に用いられる化合物には、陰極からの電子注入が容易で、電子の輸送能力がさらに大きいことが要求される。このような電子輸送材料としては、既に発光層材料として挙げた８−ヒドロキシキノリンのアルミ錯体、オキサジアゾール誘導体（Appl. Phys. Lett., 55巻, 1489頁, 1989年） やそれらをポリメタクリル酸メチル（ＰＭＭＡ）等の樹脂に分散した系、フェナントロリン誘導体（特開平５−331459号公報）、2-t-ブチル-9,10-N,N'-ジシアノアントラキノンジイミン、ｎ型水素化非晶質炭化シリコン、ｎ型硫化亜鉛、ｎ型セレン化亜鉛等が挙げられる。電子輸送層６の膜厚は、通常5〜200nm、好ましくは10〜100 nmである。
【００７２】
陰極７は、発光層５に電子を注入する役割を果たす。陰極７として用いられる材料は、前記陽極２に使用される材料を用いることが可能であるが、効率よく電子注入を行なうには、仕事関数の低い金属が好ましく、スズ、マグネシウム、インジウム、カルシウム、アルミニウム、銀等の適当な金属またはそれらの合金が用いられる。具体例としては、マグネシウム−銀合金、マグネシウム−インジウム合金、アルミニウム−リチウム合金等の低仕事関数合金電極が挙げられる。
【００７３】
陰極７の膜厚は通常、陽極２と同様である。低仕事関数金属から成る陰極を保護する目的で、この上にさらに、仕事関数が高く大気に対して安定な金属層を積層することは素子の安定性を増す上で有効である。この目的のために、アルミニウム、銀、銅、ニッケル、クロム、金、白金等の金属が使われる。
【００７４】
さらに、陰極７と発光層５または電子輸送層６の界面にＬｉＦ、ＭｇＦ2、Ｌｉ2Ｏ等の極薄絶縁膜（0.1〜5nm）を挿入することも、素子の効率を向上させる有効な方法である（Appl. Phys. Lett., 70巻，152頁，1997年；特開平10− 74586号公報；IEEE Trans. Electron. Devices，44巻，1245頁，1997年）。
【００７５】
図１〜３は、本発明で採用される素子構造の一例であって、本発明は何ら図示のものに限定されるものではない。例えば、図１とは逆の構造、即ち、基板１上に陰極７、発光層５、正孔注入層３、陽極２の順に積層することも可能であり、既述したように少なくとも一方が透明性の高い２枚の基板の間に本発明の有機電界発光素子を設けることも可能である。同様に、図２及び図３に示したものについても、前記各構成層を逆の構造に積層することも可能である。
【００７６】
【実施例】
次に、本発明を実験例、比較実験例、実施例及び比較例によって更に具体的に説明するが、本発明はその要旨を超えない限り、以下の実施例の記載に限定されるものではない。
【００７７】
実験例１
ガラス基板を、アセトンで超音波洗浄、純水で水洗、イソプロピルアルコールで超音波洗浄、乾燥窒素で乾燥、ＵＶ／オゾン洗浄を行った後、既述の方法により合成した芳香族ジアミン含有ポリエーテル（表１の番号（Ｉ−１）に示す繰り返し単位１００％からなる；重量平均分子量9300；ガラス転移温度 190℃）を下記の条件で、上記ガラス基板上にスピンコートした。
【００７８】
溶媒 1,2-ジクロロエタン
塗布液濃度 30［mg／ml］
スピナ回転数 2500［rpm］
スピナ回転時間 25［秒］
乾燥条件 90分間−自然乾燥
上記のスピンコートにより30nmの膜厚の均一な薄膜が形成された。この薄膜試料のイオン化ポテンシャルを理研計器（株）製の紫外線電子分析装置（ＡＣ−１）を用いて測定したところ、5.23eVの値を示した。
【００７９】
還元電位が報告されているいくつかの電子受容性化合物について、電子親和力を表６に示す。また、上記芳香族ジアミン含有ポリエーテルのイオン化ポテンシャルとの差を表６に併記する。
【００８０】
【表６】
実験例２
芳香族ジアミン含有ポリエーテル（表１の番号（Ｉ−１）に示す繰り返し単位１００％からなる）に電子受容性化合物のＤＤＱを混合し、下記条件で、実験例１と同様にしてガラス基板上にスピンコートした。
【００８２】
溶媒 1,2-ジクロロエタン
Ｉ−１ 30mg
ＤＤＱ 2mg
塗布液濃度 30［mg／ml］
スピナ回転数 2500［rpm］
スピナ回転時間 25［秒］
乾燥条件 90分間−自然乾燥
上記のスピンコートにより30nmの膜厚の均一な、ＤＤＱを６重量％含む薄膜が形成された。この薄膜試料の可視部分の吸収スペクトルを測定した結果を図５に示す。図５に示す如く、可視光領域において透明な膜が得られた。
【００８３】
実験例３
芳香族ジアミン含有ポリエーテルとして、既述の方法により合成した芳香族ジアミン含有ポリエーテル（表３の番号（Ｉ−23）に示す繰り返し単位１００％からなる；重量平均分子量25100；ガラス転移温度183℃）を用いたこと以外は実験例１と同様にしてガラス基板上にスピンコートを行い、40nmの膜厚の均一な薄膜を形成した。この薄膜試料のイオン化ポテンシャルを測定したところ、5.12eVの値を示した。
【００８４】
従って、この（Ｉ−23）からなる芳香族ジアミン含有ポリエーテルのイオン化ポテンシャルと電子受容性化合物であるTBPAHの電子親和力との差は−0.24eVであることが確認された。
【００８５】
比較実験例１
実験例１と同様にして洗浄したガラス基板を真空蒸着装置内に設置した。上記装置の粗排気を油回転ポンプにより行った後、装置内の真空度が2×10-6Torr（約2.7×10-4Pa）以下になるまで液体窒素トラップを備えた油拡散ポンプを用いて排気した。上記装置内に配置されたモリブデンボートに入れた、下記構造式で示される銅フタロシアニンを加熱して蒸着を行った。蒸着時の真空度は2×10-6Torr（約2.7×10-4Pa）で、蒸着速度 0.2nm／秒で膜厚30nmの膜を成膜した。
【００８６】
【化１５】
この薄膜試料の可視部分の透過スペクトルを図５に示す。図５に示す如く、550〜700nmにおいて吸収があり、この膜はフルカラー表示への適用には問題がある。
【００８８】
実施例１
図２に示す構造を有する有機電界発光素子を以下の方法で作製した。
【００８９】
ガラス基板上にインジウム・スズ酸化物（ＩＴＯ）透明導電膜を 120nm堆積したもの（ジオマテック社製；電子ビーム成膜品；シート抵抗15Ω）を通常のフォトリソグラフィ技術と塩酸エッチングを用いて 2mm幅のストライプにパターニングして陽極２を形成した。パターン形成したＩＴＯ基板を、アセトンによる超音波洗浄、純水による水洗、イソプロピルアルコールによる超音波洗浄の順で洗浄後、窒素ブローで乾燥させ、最後に紫外線オゾン洗浄を行った。
【００９０】
このＩＴＯガラス基板上に、芳香族ジアミン含有ポリエーテル（表１の番号（Ｉ−１）に示す繰り返し単位１００％からなる）とＤＤＱとの混合物を実験例２と同一条件でスピンコートし、27nmの膜厚の均一な薄膜形状を有する正孔注入層３を形成した。
【００９１】
次に、上記正孔注入層３を塗布成膜した基板１を真空蒸着装置内に設置した。上記装置の粗排気を油回転ポンプにより行った後、装置内の真空度が2×10-6Torr（約2.7×10-4Pa）以下になるまで液体窒素トラップを備えた油拡散ポンプを用いて排気した。上記装置内に配置されたセラミックるつぼに入れた下記構造式で示される芳香族アミン化合物：4,4'-ビス［N-（1-ナフチル）-N-フェニルアミノ］ビフェニルを加熱して蒸着を行った。蒸着時の真空度は1.3×10-6Torr（約1.7×10-4Pa）、蒸着速度は0.3nm/秒で、膜厚60nmの膜をポリエーテルからなる正孔注入層３の上に積層して正孔輸送層４を完成させた。
【００９２】
【化１６】
引続き、発光層５の材料として、下記構造式で示されるアルミニウムの８−ヒドロキシキノリン錯体：Ａｌ（Ｃ9Ｈ6ＮＯ）3を正孔輸送層４と同様にして蒸着を行った。この時のアルミニウムの８−ヒドロキシキノリン錯体のるつぼ温度は 275〜285℃の範囲で制御し、蒸着時の真空度は1.1×10-6Torr（約1.5×10-4Pa）、蒸着速度は0.4nm/秒で、蒸着された発光層の膜厚は75nmであった。
【００９４】
【化１７】
なお、上記の正孔輸送層４及び発光層５を真空蒸着する時の基板温度は室温に保持した。
【００９６】
ここで、発光層５までの蒸着を行った素子を一度前記真空蒸着装置内より大気中に取り出して、陰極蒸着用のマスクとして 2mm幅のストライプ状シャドーマスクを、陽極２のＩＴＯストライプとは直交するように素子に密着させて、別の真空蒸着装置内に設置して有機層と同様にして装置内の真空度が2×10-6Torr（約2.7×10-4Pa）以下になるまで排気した。その後、陰極７として、まず、フッ化マグネシウム（ＭｇＦ2）をモリブデンボートを用いて、蒸着速度0.1nm／秒、真空度7.0×10-6Torr（約9.3×10-4Pa）で、 0.5nmの膜厚で発光層５の上に成膜した。次に、アルミニウムを同様にモリブデンボートにより加熱して、蒸着速度0.5nm/秒、真空度1×10-5Torr（約1.3×10-3Pa）で膜厚40nmのアルミニウム層を形成した。さらに、その上に、陰極の導電性を高めるために銅を、同様にモリブデンボートにより加熱して、蒸着速度0.5nm/秒、真空度1×10-5Torr（約1.3×10-3Pa）で膜厚40nmの銅層を形成して陰極７を完成させた。以上の３層型陰極７の蒸着時の基板温度は室温に保持した。
【００９７】
以上のようにして、2mmx×2mmのサイズの発光面積部分を有する有機電界発光素子が得られた。この素子の発光特性を表７に示す。表７において、発光輝度は250mA／cm2の電流密度での値、発光効率は 100cd／m2での値、輝度／電流は輝度−電流密度特性の傾きを、電圧は 100cd／m2での値を各々示す。
【００９８】
表７より、低電圧で高輝度かつ高発光効率で発光する素子が得られたことが明らかである。
【００９９】
実施例２
ＤＤＱの代わりにＴＢＰＡＨ（tris(4-bromophenyl)aminium hexachloroantimonate）を用いた他は、実施例１と同様にして図２に示す構造を有する有機電界発光素子を作製した。正孔注入層３に含まれるＴＢＰＡＨの量は14重量％とした。この素子の発光特性を表７に示す。
【０１００】
表７より、駆動電圧の低下が達成され、高輝度、高効率の素子が得られたことが明らかである。
【０１０１】
実施例３
正孔注入層を芳香族ジアミン含有ポリエーテル（表３の番号（Ｉ−23）に示す繰り返し単位１００％からなる）に電子受容性化合物としてTBPAHを9重量％ドープして膜厚40nmで形成したこと以外は実施例２と同様にして有機電界発光素子を作製した。この素子の発光特性を表７に示す。
【０１０２】
表７より、駆動電圧の低下が達成され、高輝度、高効率の素子が得られたことが明らかである。
【０１０３】
比較例１
電子受容性化合物を用いないで正孔注入層３を形成した他は、実施例１と同様にして素子を作製した。この素子の発光特性を表７に示す。
【０１０４】
比較例２
正孔注入層を設けない他は、実施例１と同様にして素子を作製した。この素子の発光特性を表７に示す。
【０１０５】
【表７】
【発明の効果】
以上詳述した通り、特定の芳香族ジアミン含有ポリエーテルと電子受容性化合物とを含有する正孔注入層を形成した本発明の有機電界発光素子によれば、低電圧での高発光効率駆動が可能で、しかも耐熱性が良好な素子が提供される。
【０１０７】
従って、本発明による有機電界発光素子は、フラットパネル・ディスプレイ（例えばＯＡコンピュータ用や壁掛けテレビ）や面発光体としての特徴を生かした光源（例えば、複写機の光源、液晶ディスプレイや計器類のバックライト光源）、表示板、標識灯への応用が考えられ、特に、高耐熱性が要求される車載用表示素子として、その技術的価値は大きいものである。
【図面の簡単な説明】
【図１】本発明の有機電界発光素子の実施の形態の一例を示す模式的な断面図である。
【図２】本発明の有機電界発光素子の実施の形態の他の例を示す模式的な断面図である。
【図３】本発明の有機電界発光素子の実施の形態の別の例を示す模式的な断面図である。
【図４】イオン化ポテンシャルと電子親和力の関係を示したエネルギー準位図である。
【図５】実験例２及び比較実験例１で形成した薄膜の可視部分における透過スペクトルを示すグラフである。
【符号の説明】
１ 基板
２ 陽極
３ 正孔注入層
４ 正孔輸送層
５ 発光層
６ 電子輸送層
７ 陰極[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic electroluminescent device, and more particularly to a thin film device that emits light by applying an electric field to a light emitting layer made of an organic compound.
[0002]
[Prior art]
Conventionally, as a thin film type electroluminescent (EL) element, there are ZnS, CaS, SrS, etc. which are inorganic material II-VI compound semiconductors, Mn which is an emission center, rare earth elements (Eu, Ce, Tb, Sm, etc.) ) Is generally used, but an EL element made from the above inorganic material is
1) AC drive is required (generally 50-1000Hz),
2) High drive voltage (generally around 200V)
3) Full color is difficult, especially blue
4) The cost of the peripheral drive circuit is high.
Has the problem.
[0003]
However, in recent years, EL devices using organic thin films have been developed to improve the above problems. In particular, in order to improve luminous efficiency, the type of electrode is optimized for the purpose of improving the efficiency of carrier injection from the electrode, and a hole transporting layer made of aromatic diamine and a light emitting layer made of 8-hydroxyquinoline aluminum complex, Development of an organic electroluminescent device equipped with a substrate (Appl. Phys. Lett., 51, 913, 1987) significantly improves luminous efficiency compared to conventional EL devices using single crystals such as anthracene. Has been made and practical characteristics are approaching.
[0004]
In addition to the electroluminescent device using the low molecular weight material as described above, as a material of the light emitting layer, poly (p-phenylene vinylene), poly [2-methoxy-5- (2-ethylhexyloxy) -1,4 Development of electroluminescent devices using polymer materials such as -phenylenevinylene] and poly (3-alkylthiophene), and devices that combine low molecular light emitting materials and electron transfer materials with polymers such as polyvinylcarbazole. Has been done.
[0005]
By the way, the biggest problem of the organic electroluminescence device is the lifetime at the time of driving, and as development of instability at the time of driving, the emission luminance decreases, the voltage increases at constant current driving, the non-light emitting portion (dark spot) Generation and the like. Although there are several causes of these instabilities, the deterioration of the thin film shape of the organic layer is dominant. It is considered that the deterioration of the thin film shape is caused by crystallization (or aggregation) of the organic amorphous film due to heat generated when the element is driven. In particular, contact between the anode and the hole transport layer is important for increasing the drive voltage.
[0006]
Therefore, in order to improve the contact between the anode and the hole transport layer, it has been studied to provide a hole injection layer between the two layers to lower the driving voltage. The conditions required for the material used for the hole injection layer include good contact with the anode, formation of a uniform thin film, and thermal stability, that is, a high melting point and glass transition temperature Tg, preferably It must have a melting point of 300 ° C or higher and a Tg of 100 ° C or higher. Furthermore, the ionization potential is low, hole injection from the anode is easy, and the hole mobility is high.
[0007]
Conventionally, various materials for the hole injection layer have been studied. For example, porphyrin derivatives, phthalocyanine compounds (Japanese Patent Laid-Open No. 63-295695), star bust type aromatic triamine (Japanese Patent Laid-Open No. 4-308688). ), Hydrazone compounds (JP-A-4-320483), alkoxy-substituted aromatic diamine derivatives (JP-A-4-220995), p- (9-anthryl) -N, N-di-p-tolylaniline, Organic compounds such as polythienylene vinylene, poly-p-phenylene vinylene, and polyaniline, sputtered carbon films, metal oxides such as vanadium oxide, ruthenium oxide, and molybdenum oxide have been reported.
[0008]
[Problems to be solved by the invention]
However, in the method of inserting a hole injection layer between the anode and the hole transport layer, when a porphyrin derivative or a phthalocyanine compound is used as the hole injection layer, the spectrum changes due to light absorption by these films themselves. Or is colored in appearance and is not transparent.
[0009]
Starbust type aromatic triamines, hydrazone compounds, alkoxy-substituted aromatic diamine derivatives, p- (9-anthryl) -N, N-di-p-tolylaniline have the advantage of low ionization potential and good transparency. However, since the glass transition point and melting point are low, the heat resistance is inferior, the stability against local heating during continuous driving is poor, and luminance reduction and voltage increase become problems.
[0010]
On the other hand, for polymer materials such as polythienylene vinylene, poly-p-phenylene vinylene, and polyaniline, there is no report on lowering driving voltage and improving driving life.
[0011]
High voltage during driving of organic electroluminescent devices and low stability including heat resistance are major problems for light sources such as facsimiles, copiers, and backlights for liquid crystal displays. It is not desirable as a display element such as a panel display.
[0012]
Accordingly, the present invention provides an organic electroluminescent device that can be driven at a low voltage and high luminous efficiency, has good heat resistance, and can maintain stable luminous characteristics over a long period of time. The purpose is to do.
[0013]
[Means for Solving the Problems]
The organic electroluminescent device of the present invention is an organic electroluminescent device in which a light emitting layer sandwiched between an anode and a cathode is formed on a substrate, and a hole injection layer is formed between the light emitting layer and the anode. The hole injection layer has a repeating unit represented by the following general formula (I) or (II) and has a weight average molecular weight of 1,000 to 1,000,000 The glass transition temperature is 100 ° C or higher An organic electroluminescent device comprising an aromatic diamine-containing polyether and an electron-accepting compound.
[0014]
[Chemical 6]
[Chemical 7]
(In the formula, Ar 1 , Ar 2 , Ar Three , Ar Four , Ar Five , Ar 6 , Ar 7 , Ar 8 , Ar 9 Each independently represents a divalent aromatic ring residue which may have a substituent, R 1 , R 2 , R Three , R Four Represents an aromatic ring group or an aromatic heterocyclic group which may have a substituent, and X and Y are selected from a direct bond or the following linking group. )
[0017]
[Chemical 8]
(In the formula, R ′ represents an alkylene group which may have a substituent, and R ″ represents an alkyl group or an aromatic ring group which may have a substituent.)
That is, the present inventors have intensively studied to solve the conventional problems and provide an organic electroluminescence device capable of maintaining stable light emission characteristics at a high temperature. As a result, the light emission sandwiched between the anode and the cathode on the substrate. In the organic electroluminescence device having a layer, by providing a hole injection layer made of an aromatic diamine-containing polyether containing an electron-accepting compound and having a high Tg between the anode and the light-emitting layer, The present inventors have found that the problem can be solved and have completed the present invention.
[0019]
In the present invention, the hole injection layer is used by mixing an aromatic diamine-containing polyether having an Tg of 100 ° C. or higher and an electron-accepting compound, thereby simultaneously improving the light emission characteristics and heat resistance of the device. It was possible. That is, by mixing an electron-accepting compound with an electron-donating aromatic diamine-containing polyether, charge transfer occurs, and as a result, holes that are free carriers are generated, and the electric conductivity of the hole injection layer is high. Become. The electrical junction between the light emitting layer and the anode is improved by providing the hole injection layer according to the present invention, and the driving voltage is lowered and the stability during continuous driving is also improved. Further, by using an aromatic diamine-containing polyether having a glass transition temperature of 100 ° C. or more as a base material of the hole injection layer, the heat resistance of the device is greatly improved. The glass transition temperature of the aromatic diamine-containing polyether used in the present invention is particularly preferably 120 ° C. or higher, particularly 150 ° C. or higher.
[0020]
In the present invention, the value obtained by subtracting the electron affinity of the electron-accepting compound from the ionization potential of the aromatic diamine-containing polyether in the hole-injecting layer is preferably 0.7 eV or less. The content of the functional compound is preferably in the range of 0.1 to 50% by weight with respect to the aromatic diamine-containing polyether.
[0021]
In the present invention, the electron-accepting compound is preferably at least one of a compound represented by the following general formula (III) or a compound selected from the following compound group.
[0022]
[Chemical 9]
(In the formula, Z represents a halogen atom, R Five Represents a hydrogen atom, a halogen atom, an optionally substituted alkyl group, a cyano group or a nitro group. )
[0024]
[Chemical Formula 10]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the organic electroluminescent element of the present invention will be described below in detail with reference to the drawings.
[0026]
1 to 3 are schematic cross-sectional views showing an embodiment of the organic electroluminescence device of the present invention, wherein 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, The light emitting layer, 6 represents an electron transport layer, and 7 represents a cathode.
[0027]
The substrate 1 serves as a support for the organic electroluminescent element, and a quartz or glass plate, a metal plate or a metal foil, a plastic film, a sheet, or the like is used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too low, the organic electroluminescent element may be deteriorated by the outside air passing through the substrate, which is not preferable. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on one side or both sides of the synthetic resin substrate is also a preferable method.
[0028]
An anode 2 is provided on the substrate 1. The anode 2 plays a role of hole injection into the hole injection layer 3. The anode 2 is usually composed of a metal such as aluminum, gold, silver, nickel, palladium, or platinum, a metal oxide such as an oxide of indium and / or tin, a metal halide such as copper iodide, or carbon black. Is done. In general, the anode 2 is often formed by sputtering, vacuum deposition, or the like. Also, the anode 2 is formed by dispersing fine particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, etc. in an appropriate binder resin solution and applying the solution onto the substrate 1. You can also. The anode 2 can also be formed by stacking different materials. The thickness of the anode 2 varies depending on the required transparency. When transparency is required, the visible light transmittance is preferably 60% or more, preferably 80% or more. In this case, the thickness is usually about 10 to 1000 nm, preferably about 20 to 500 nm. It is. If it may be opaque, the anode 2 may be the same as the substrate 1. It is also possible to laminate different conductive materials on the anode 2 described above.
[0029]
In the present invention, the hole injection layer 3 is provided on the anode 2 in the element structure of FIGS. Conditions required for the material used for the hole injection layer 3 include a material having high hole injection efficiency from the anode 2 and capable of efficiently transporting the injected holes. It is done. For this purpose, the ionization potential is small, the transparency to visible light is high, the hole mobility is high, the stability is high, and impurities that become traps are less likely to be generated during manufacturing and use. Required. In addition to the above general requirements, when considering applications for in-vehicle displays, heat resistance of 100 ° C or higher is required.
[0030]
In the organic electroluminescent device of the present invention, the hole injection layer has a repeating unit represented by the general formula (I) or (II), and has a weight average molecular weight of 1,000 to 1,000,000. With glass transition temperature of 100 ° C or higher It contains an aromatic diamine-containing polyether and an electron-accepting compound.
[0031]
In the present invention, the mixture of the aromatic diamine-containing polyether having a Tg of 100 ° C. or higher and the electron-accepting compound makes it possible to simultaneously improve the light emission characteristics and heat resistance of the device. That is, by mixing an electron-accepting compound with an electron-donating aromatic diamine-containing polyether, charge transfer occurs, and as a result, holes that are free carriers are generated, and the electric conductivity of the hole injection layer is high. Become. For this reason, by providing such a hole injection layer, the electrical junction between the light emitting layer and the anode is improved, the driving voltage is lowered, and the stability during continuous driving is also improved. Further, by using an aromatic diamine-containing polyether having a glass transition temperature of 100 ° C. or more as a base material of the hole injection layer, the heat resistance of the device is greatly improved. The glass transition temperature of the aromatic diamine-containing polyether used in the present invention is particularly preferably 120 ° C. or higher, particularly 150 ° C. or higher.
[0032]
In the general formulas (I) and (II), Ar 1 ~ Ar 9 Is preferably a divalent benzene ring, naphthalene ring, anthracene ring or biphenyl, each independently having a substituent, and the substituent is a halogen atom; a carbon such as a methyl group or an ethyl group. An alkyl group having 1 to 6 carbon atoms; an alkenyl group such as a vinyl group; an alkoxycarbonyl group having 1 to 6 carbon atoms such as a methoxycarbonyl group and an ethoxycarbonyl group; an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group; Examples thereof include aryloxy groups such as phenoxy group and benzyloxy group; and dialkylamino groups such as diethylamino group and diisopropylamino group. As the substituent, an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group is particularly preferable.
[0033]
R 1 ~ R Four Is preferably a phenyl group, a naphthyl group, an anthryl group, a pyridyl group, a triazyl group, a pyrazyl group, a quinoxalyl group, a thienyl group, or a biphenyl group, which may each independently have a substituent, As a halogen atom; an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group; an alkenyl group such as a vinyl group; an alkoxycarbonyl group having 1 to 6 carbon atoms such as a methoxycarbonyl group or an ethoxycarbonyl group; Examples thereof include alkoxy groups having 1 to 6 carbon atoms such as ethoxy group; aryloxy groups such as phenoxy group and benzyloxy group; and dialkylamino groups such as diethylamino group and diisopropylamino group.
[0034]
X and Y are selected from a direct bond or a linking group shown below.
[0035]
Embedded image
In the above linking group, R ′ is preferably a methylene group, a dimethylmethylene group, an ethylene group or a propylene group, and R ″ is preferably an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group; a phenyl group , Aromatic ring groups such as naphthyl group, anthryl group, and tolyl group.
[0037]
The compounds represented by the general formulas (I) and (II) are disclosed in, for example, the method of Kido et al. (Polymers for Advanced Technologies, Vol. 7, page 31, 1996; JP-A-9-188756). It is synthesized by the route.
[0038]
Although the preferable specific example of the repeating unit which the aromatic diamine containing polyether of this invention represented by the said general formula (I) has is shown in Table 1-Table 3, it does not limit to these.
[0039]
[Table 1]
[Table 2]
[Table 3]
Moreover, although the preferable specific example of the repeating unit which the aromatic diamine containing polyether of this invention which is represented with the said general formula (II) has is shown in Table 4, Table 5, it does not limit to these.
[0043]
[Table 4]
[Table 5]
As an electron-accepting compound used in combination with the above-mentioned aromatic diamine-containing polyether, any compound that causes charge transfer with the aromatic diamine-containing polyether may be used. Two physical property values of ionization potential of an aromatic diamine-containing polyether: IP (polyether) and electron affinity of an electron-accepting compound (acceptor): EA (acceptor)
IP (polyether) -EA (acceptor) ≤ 0.7 eV
The present invention has been found to be effective for the purpose of the present invention.
[0046]
This will be described with reference to the energy level diagram of FIG. In general, the ionization potential and the electron affinity are determined based on the vacuum level. The ionization potential is defined by the energy required to release electrons at the HOMO (highest occupied molecular orbital) level of the material to the vacuum level, and the electron affinity is the LUMO (lowest empty molecule) of the electron at the vacuum level. Defined by the energy that falls to the orbital level and stabilizes. In the present invention, the difference between the ionization potential at the HOMO level of the aromatic diamine-containing polyether shown in FIG. 4 and the electron affinity at the LUMO level of the electron accepting compound is preferably 0.7 eV or less. The ionization potential can be directly measured by photoelectron spectroscopy or can be obtained by correcting the electrochemically measured oxidation potential with respect to the reference electrode. In the case of the latter method, for example, when a saturated sweet potato electrode (SCE) is used as a reference electrode,
Ionization potential = oxidation potential (vs.SCE) + 4.3 eV
("Molecular Semiconductors", Springer-Verlag, 1985, p. 98). The electron affinity can be obtained by subtracting the optical band gap from the above-mentioned ionization potential, or similarly obtained by the above formula from the electrochemical reduction potential.
[0047]
The relational expression between the ionization potential and the electron affinity uses an oxidation potential and a reduction potential,
Polyether oxidation potential-Acceptor reduction potential ≤ 0.7 eV
It can also be expressed as
[0048]
The content of the electron-accepting compound in the hole injection layer with respect to the aromatic diamine-containing polyether is usually 0.1 to 50% by weight, particularly preferably 1 to 30% by weight.
[0049]
The electron-accepting compound is not particularly limited as long as it satisfies the above relationship, but is preferably selected from compounds represented by the following general formula (III).
[0050]
Embedded image
In the above general formula (III), Z is preferably a halogen atom such as chlorine, fluorine or bromine, and R Five Is preferably a hydrogen atom; a halogen atom such as chlorine, fluorine or bromine; an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group; a haloalkyl group such as a trifluoromethyl group; a cyano group; The substitution position may be any of the ortho, meta, and para positions with respect to the central nitrogen atom.
[0052]
Specific examples of the electron-accepting compound represented by the general formula (III) include the following compounds.
[0053]
Embedded image
Other preferred examples of the electron-accepting compound are shown below with abbreviations.
[0055]
Embedded image
In the present invention, the hole injection layer 3 containing an aromatic diamine-containing polyether and an electron accepting compound is usually formed on the anode 2 by a coating method. For example, additives such as binder resins and coating property improvers that do not trap holes if necessary are added to the predetermined amount of the polyether represented by the general formula (I) or (II) and the electron-accepting compound. Then, it is dissolved to prepare a coating solution, which is coated on the anode 2 by a method such as spin coating or dip coating, and dried to form the hole injection layer 3.
[0057]
The thickness of the hole injection layer 3 thus formed is usually 5 to 1000 nm, preferably 10 to 500 nm.
[0058]
A light emitting layer 5 is provided on the hole injection layer 3. The light emitting layer 5 is made of a material that efficiently recombines electrons injected from the cathode 7 and holes transported from the hole injection layer 3 between electrodes to which an electric field is applied, and emits light efficiently by recombination. It is formed.
[0059]
Materials satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (JP 59-194393 A), metal complexes of 10-hydroxybenzo [h] quinoline (JP 6-322362 A). Gazette), bisstyrylbenzene derivatives (JP-A-1-245087, JP-A-2-222484), bisstyrylarylene derivatives (JP-A-2-247278), metal complexes of (2-hydroxyphenyl) benzothiazole ( JP-A-8-315983), silole derivatives and the like. These light emitting layer materials are usually laminated on the hole injection layer 3 by a vacuum deposition method.
[0060]
For the purpose of improving the luminous efficiency of the device and changing the emission color, for example, doping a fluorescent dye for lasers such as coumarin with an aluminum complex of 8-hydroxyquinoline as a host material (J. Appl. Phys., Volume 65) , 3610, 1989). The advantage of this method is
1) Luminous efficiency is improved by highly efficient fluorescent dyes.
2) The emission wavelength is variable by selecting the fluorescent dye.
3) Fluorescent dyes that cause concentration quenching can also be used.
4) Thin fluorescent fluorescent dyes can be used.
Etc.
[0061]
In order to improve the driving life of the device, it is effective to dope a fluorescent dye using the light emitting layer material as a host material. For example, a metal complex such as an aluminum complex of 8-hydroxyquinoline as a host material, a naphthacene derivative typified by rubrene (JP-A-4-335087), a quinacridone derivative (JP-A-5-70773), perylene, etc. By doping a condensed polycyclic aromatic ring (Japanese Patent Laid-Open No. 5-198377) with 0.1 to 10% by weight with respect to the host material, the light emission characteristics of the device, particularly the driving stability, can be greatly improved. As a method of doping the host material of the light emitting layer with a fluorescent dye such as the naphthacene derivative, quinacridone derivative, or perylene, there are a method by co-evaporation and a method in which a deposition source is mixed in advance at a predetermined concentration.
[0062]
Polymeric light-emitting layer materials include poly (p-phenylene vinylene), poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene vinylene], poly (3-alkyl) mentioned above Examples thereof include a polymer material such as thiophene) and a system in which a light emitting material and an electron transfer material are mixed with a polymer such as polyvinyl carbazole. These materials are coated on the hole injection layer 3 by a method such as spin coating or dip coating in the same manner as the hole injection layer to form a thin film.
The film thickness of the light emitting layer 5 thus formed is usually 10 to 200 nm, preferably 30 to 100 nm.
[0063]
In order to improve the light emitting characteristics of the device, a hole transport layer 4 is provided between the hole injection layer 3 and the light emitting layer 5 as shown in FIG. 2, and further, as shown in FIG. For example, the layer 6 is provided between the light emitting layer 5 and the cathode 7 so as to have a function separation type.
[0064]
2 and 3, the material of the hole transport layer 4 has high hole injection efficiency from the hole injection layer 3 and can efficiently transport the injected holes. It must be a material that can be made. For this purpose, it is required that the ionization potential is low, the hole mobility is high, the stability is high, and impurities that become traps are not easily generated during production or use.
[0065]
As such a hole transport material, for example, an aromatic diamine compound in which a tertiary aromatic amine unit such as 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane is linked (Japanese Patent Laid-Open No. 59-151). No. 194393), including two or more tertiary amines typified by 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl, and two or more condensed aromatic rings are nitrogen atoms Substituted aromatic amines (JP-A-5-234681), triphenylbenzene derivatives and starburst aromatic triamines (US Pat. No. 4,923,774), N, N'-diphenyl-N, N'- Aromatic diamines such as bis (3-methylphenyl) biphenyl-4,4′-diamine (US Pat. No. 4,764,625), sterically asymmetric triphenylamine derivatives as a whole molecule (JP-A-4-129271), A plurality of aromatic diamino groups are substituted on the pyrenyl group. Compounds (Japanese Patent Laid-Open No. 4-175395), aromatic diamines having tertiary aromatic amine units linked by an ethylene group (Japanese Patent Laid-Open No. 4-264189), aromatic diamines having a styryl structure (Japanese Patent Laid-Open No. 4-290851) Patent Publication), aromatic tertiary amine units linked by a thiophene group (JP-A-4-304466), starburst aromatic triamine (JP-A-4-308688), benzylphenyl compound (JP-A-4-304688) 364153), a tertiary amine linked by a fluorene group (JP-A-5-25473), a triamine compound (JP-A-5-239455), bisdipyridylaminobiphenyl (JP-A-5-320634) N, N, N-triphenylamine derivatives (JP-A-6-1972), aromatic diamines having a phenoxazine structure (JP-A-7-138562), diaminophenylphena Examples include toridine derivatives (JP-A-7-252474), silazane compounds (US Pat. No. 4,950,950), silanamin derivatives (JP-A-6-49079), phosphamine derivatives (JP-A-6-25659), and the like. . These compounds may be used alone or as a mixture of two or more as necessary.
[0066]
In addition to the above-mentioned compounds, materials for the hole transport layer 4 include polyvinyl carbazole, polysilane, polyphosphazene (JP-A-5-310949), polyamide (JP-A-5-310949), polyvinyltriphenylamine ( JP-A-7-53953), a polymer having a triphenylamine skeleton (JP-A-4-133065), and a polymer material such as polymethacrylate containing an aromatic amine.
[0067]
The hole transport layer 4 is formed by laminating the above hole transport material on the hole injection layer 3 by a coating method or a vacuum deposition method.
[0068]
In the case of the coating method, an additive such as a binder resin or a coating property improving agent that does not trap holes is added to one or more of the hole transport materials, if necessary, and dissolved to prepare a coating solution. Then, it is applied onto the hole injection layer 3 by a method such as spin coating, and dried to form the hole transport layer 4. Here, examples of the binder resin include polycarbonate, polyarylate, and polyester. When the binder resin is added in a large amount, the hole mobility is lowered.
[0069]
In the case of the vacuum deposition method, the hole transport material is put in a crucible installed in a vacuum vessel, and the inside of the vacuum vessel is filled with an appropriate vacuum pump. -Four After evacuating to about Pa, the crucible is heated to evaporate the hole transport material, and the hole transport layer is formed on the substrate 1 on which the anode 2 and the hole injection layer 3 are placed facing the crucible. 4 is formed.
[0070]
The thickness of the hole transport layer 4 thus formed is usually 10 to 300 nm, preferably 30 to 100 nm. In order to uniformly form such a thin film, a vacuum deposition method is often used in general.
[0071]
In addition, the compound used for the electron transport layer 6 is required to be capable of easily injecting electrons from the cathode and further having an electron transport capability. Examples of such an electron transport material include 8-hydroxyquinoline aluminum complexes and oxadiazole derivatives (Appl. Phys. Lett., 55, 1489, 1989), which have already been mentioned as light emitting layer materials, and polymethacrylic acid. System dispersed in resin such as methyl acid (PMMA), phenanthroline derivative (JP-A-5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinone diimine, n-type hydrogenation Examples thereof include crystalline silicon carbide, n-type zinc sulfide, and n-type zinc selenide. The film thickness of the electron transport layer 6 is usually 5 to 200 nm, preferably 10 to 100 nm.
[0072]
The cathode 7 serves to inject electrons into the light emitting layer 5. The material used for the cathode 7 can be the material used for the anode 2, but a metal having a low work function is preferable for efficient electron injection, such as tin, magnesium, indium, calcium, A suitable metal such as aluminum or silver or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.
[0073]
The film thickness of the cathode 7 is usually the same as that of the anode 2. For the purpose of protecting the cathode made of a low work function metal, it is effective to increase the stability of the device by further laminating a metal layer having a high work function and stable to the atmosphere. For this purpose, metals such as aluminum, silver, copper, nickel, chromium, gold, platinum are used.
[0074]
Further, LiF, MgF at the interface between the cathode 7 and the light emitting layer 5 or the electron transport layer 6 2 , Li 2 Inserting an ultra-thin insulating film (0.1-5 nm) such as O is also an effective method for improving the efficiency of the device (Appl. Phys. Lett., 70, 152, 1997; 74586, IEEE Trans. Electron. Devices, 44, 1245 (1997).
[0075]
1-3 are examples of the element structure employed in the present invention, and the present invention is not limited to the illustrated one. For example, the structure opposite to that shown in FIG. 1, that is, the cathode 7, the light emitting layer 5, the hole injection layer 3, and the anode 2 can be laminated on the substrate 1 in this order. It is also possible to provide the organic electroluminescent element of the present invention between two highly functional substrates. Similarly, with respect to those shown in FIGS. 2 and 3, the constituent layers can be laminated in the opposite structure.
[0076]
【Example】
Next, the present invention will be described more specifically with reference to experimental examples, comparative experimental examples, examples and comparative examples. However, the present invention is not limited to the description of the following examples unless it exceeds the gist. .
[0077]
Experimental example 1
The glass substrate was subjected to ultrasonic cleaning with acetone, water with pure water, ultrasonic cleaning with isopropyl alcohol, drying with dry nitrogen, UV / ozone cleaning, and then an aromatic diamine-containing polyether synthesized by the method described above ( The glass substrate was spin-coated under the following conditions consisting of 100% of the repeating unit shown in the number (I-1) in Table 1; weight average molecular weight 9300; glass transition temperature 190 ° C.).
[0078]
Solvent 1,2-dichloroethane
Coating solution concentration 30 [mg / ml]
Spinner speed 2500 [rpm]
Spinner rotation time 25 [seconds]
Drying conditions 90 minutes-natural drying
A uniform thin film having a thickness of 30 nm was formed by the above spin coating. The ionization potential of this thin film sample was measured using an ultraviolet electron analyzer (AC-1) manufactured by Riken Keiki Co., Ltd. and showed a value of 5.23 eV.
[0079]
The electron affinity is shown in Table 6 for several electron accepting compounds for which the reduction potential is reported. The difference from the ionization potential of the aromatic diamine-containing polyether is also shown in Table 6.
[0080]
[Table 6]
Experimental example 2
DDQ of an electron-accepting compound is mixed with an aromatic diamine-containing polyether (consisting of 100% of the repeating unit shown in number (I-1) in Table 1), and on the glass substrate in the same manner as in Experimental Example 1 under the following conditions. Spin coated.
[0082]
Solvent 1,2-dichloroethane
I-1 30mg
DDQ 2mg
Coating solution concentration 30 [mg / ml]
Spinner speed 2500 [rpm]
Spinner rotation time 25 [seconds]
Drying conditions 90 minutes-natural drying
A thin film containing 6% by weight of DDQ having a uniform film thickness of 30 nm was formed by the above spin coating. The result of measuring the absorption spectrum of the visible portion of this thin film sample is shown in FIG. As shown in FIG. 5, a transparent film was obtained in the visible light region.
[0083]
Experimental example 3
As an aromatic diamine-containing polyether, an aromatic diamine-containing polyether synthesized by the above-described method (consisting of 100% repeating units shown in Table 3, number (I-23); weight average molecular weight 25100; glass transition temperature 183 ° C. ) Was used, and spin coating was performed on the glass substrate in the same manner as in Experimental Example 1 to form a uniform thin film having a thickness of 40 nm. When the ionization potential of this thin film sample was measured, it showed a value of 5.12 eV.
[0084]
Therefore, it was confirmed that the difference between the ionization potential of the aromatic diamine-containing polyether composed of (I-23) and the electron affinity of TBPAH, which is an electron accepting compound, was −0.24 eV.
[0085]
Comparative Experiment Example 1
A glass substrate cleaned in the same manner as in Experimental Example 1 was placed in a vacuum deposition apparatus. After rough evacuation of the above device with an oil rotary pump, the degree of vacuum in the device is 2 × 10 -6 Torr (about 2.7 x 10 -Four Pa) until evacuated using an oil diffusion pump equipped with a liquid nitrogen trap. Vapor deposition was performed by heating copper phthalocyanine represented by the following structural formula placed in a molybdenum boat disposed in the apparatus. Vacuum degree during deposition is 2 × 10 -6 Torr (about 2.7 x 10 -Four Pa), a film having a film thickness of 30 nm was formed at a deposition rate of 0.2 nm / second.
[0086]
Embedded image
The transmission spectrum of the visible part of this thin film sample is shown in FIG. As shown in FIG. 5, there is absorption at 550 to 700 nm, and this film has a problem in application to full color display.
[0088]
Example 1
An organic electroluminescent element having the structure shown in FIG. 2 was produced by the following method.
[0089]
An indium tin oxide (ITO) transparent conductive film deposited on a glass substrate with a thickness of 120 nm (manufactured by Geomat Corp .; electron beam film-formed product; sheet resistance 15 Ω) is 2 mm wide using normal photolithography and hydrochloric acid etching. The anode 2 was formed by patterning into a stripe. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.
[0090]
On this ITO glass substrate, a mixture of aromatic diamine-containing polyether (consisting of 100% of the repeating unit shown in number (I-1) in Table 1) and DDQ was spin-coated under the same conditions as in Experimental Example 2, and 27 nm A hole injection layer 3 having a uniform thin film shape was formed.
[0091]
Next, the substrate 1 on which the hole injection layer 3 was applied and formed was placed in a vacuum evaporation apparatus. After rough evacuation of the above device with an oil rotary pump, the degree of vacuum in the device is 2 × 10 -6 Torr (about 2.7 x 10 -Four Pa) until evacuated using an oil diffusion pump equipped with a liquid nitrogen trap. Aromatic amine compound represented by the following structural formula: 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl placed in a ceramic crucible placed in the above apparatus is heated for vapor deposition. went. Vacuum degree during deposition is 1.3 × 10 -6 Torr (approximately 1.7 × 10 -Four Pa), the deposition rate was 0.3 nm / second, and a film having a thickness of 60 nm was laminated on the hole injection layer 3 made of polyether to complete the hole transport layer 4.
[0092]
Embedded image
Subsequently, as a material of the light emitting layer 5, an 8-hydroxyquinoline complex of aluminum represented by the following structural formula: Al (C 9 H 6 NO) Three Was deposited in the same manner as the hole transport layer 4. At this time, the crucible temperature of the aluminum 8-hydroxyquinoline complex is controlled in the range of 275 to 285 ° C., and the degree of vacuum during the deposition is 1.1 × 10. -6 Torr (about 1.5 × 10 -Four Pa), the deposition rate was 0.4 nm / second, and the thickness of the deposited light-emitting layer was 75 nm.
[0094]
Embedded image
In addition, the substrate temperature at the time of vacuum-depositing said positive hole transport layer 4 and the light emitting layer 5 was kept at room temperature.
[0096]
Here, the element that has been vapor-deposited up to the light emitting layer 5 is once taken out from the vacuum vapor deposition apparatus to the atmosphere, and a 2 mm wide stripe shadow mask is orthogonal to the ITO stripe of the anode 2 as a mask for cathode vapor deposition. In close contact with the element, install it in another vacuum vapor deposition device, and the degree of vacuum in the device is 2 x 10 like the organic layer -6 Torr (about 2.7 x 10 -Four Pa) exhausted until below. Thereafter, as the cathode 7, first, magnesium fluoride (MgF 2 ) Using a molybdenum boat, the deposition rate is 0.1 nm / second, and the degree of vacuum is 7.0 × 10. -6 Torr (approximately 9.3 × 10 -Four Pa), a film having a thickness of 0.5 nm was formed on the light emitting layer 5. Next, aluminum was similarly heated by a molybdenum boat, the deposition rate was 0.5 nm / second, and the degree of vacuum was 1 × 10. -Five Torr (about 1.3 × 10 -3 An aluminum layer with a thickness of 40 nm was formed by Pa). Furthermore, in order to increase the conductivity of the cathode, copper is similarly heated by a molybdenum boat, the deposition rate is 0.5 nm / second, and the degree of vacuum is 1 × 10. -Five Torr (about 1.3 × 10 -3 The cathode 7 was completed by forming a copper layer with a thickness of 40 nm by Pa). The substrate temperature at the time of vapor deposition of the above three-layered cathode 7 was kept at room temperature.
[0097]
As described above, an organic electroluminescent element having a light emitting area portion having a size of 2 mm × 2 mm was obtained. The light emission characteristics of this device are shown in Table 7. In Table 7, the luminance is 250mA / cm 2 Current density value, luminous efficiency is 100cd / m 2 Value, brightness / current is the slope of brightness-current density characteristics, voltage is 100cd / m 2 The values at are shown respectively.
[0098]
From Table 7, it is clear that an element that emits light with high luminance and high luminous efficiency at a low voltage was obtained.
[0099]
Example 2
An organic electroluminescent device having the structure shown in FIG. 2 was prepared in the same manner as in Example 1 except that TBPAH (tris (4-bromophenyl) aminium hexachloroantimonate) was used instead of DDQ. The amount of TBPAH contained in the hole injection layer 3 was 14% by weight. The light emission characteristics of this device are shown in Table 7.
[0100]
From Table 7, it is clear that a reduction in driving voltage was achieved, and a device with high luminance and high efficiency was obtained.
[0101]
Example 3
A hole injection layer was formed to a thickness of 40 nm by doping 9 wt% TBPAH as an electron accepting compound into an aromatic diamine-containing polyether (consisting of 100% of the repeating unit indicated by the number (I-23) in Table 3). Except for this, an organic electroluminescent element was produced in the same manner as in Example 2. The light emission characteristics of this device are shown in Table 7.
[0102]
From Table 7, it is clear that a reduction in driving voltage was achieved, and a device with high luminance and high efficiency was obtained.
[0103]
Comparative Example 1
A device was fabricated in the same manner as in Example 1 except that the hole injection layer 3 was formed without using an electron accepting compound. The light emission characteristics of this device are shown in Table 7.
[0104]
Comparative Example 2
A device was fabricated in the same manner as in Example 1 except that the hole injection layer was not provided. The light emission characteristics of this device are shown in Table 7.
[0105]
[Table 7]
【The invention's effect】
As described above in detail, according to the organic electroluminescence device of the present invention in which the hole injection layer containing a specific aromatic diamine-containing polyether and an electron accepting compound is formed, high luminous efficiency driving at low voltage can be achieved. An element which is possible and has good heat resistance is provided.
[0107]
Accordingly, the organic electroluminescent device according to the present invention is a light source (for example, a light source of a copying machine, a liquid crystal display, or a back of an instrument) utilizing characteristics of a flat panel display (for example, for OA computers or wall-mounted televisions) or a surface light emitter. It can be applied to a light source), a display panel, and a marker lamp, and its technical value is particularly great as an in-vehicle display element that requires high heat resistance.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an example of an embodiment of an organic electroluminescent element of the present invention.
FIG. 2 is a schematic cross-sectional view showing another example of the embodiment of the organic electroluminescent element of the present invention.
FIG. 3 is a schematic cross-sectional view showing another example of the embodiment of the organic electroluminescent element of the present invention.
FIG. 4 is an energy level diagram showing the relationship between ionization potential and electron affinity.
5 is a graph showing a transmission spectrum in a visible portion of a thin film formed in Experimental Example 2 and Comparative Experimental Example 1. FIG.
[Explanation of symbols]
1 Substrate
2 Anode
3 Hole injection layer
4 hole transport layer
5 Light emitting layer
6 Electron transport layer
7 Cathode
Claims (7)
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2010140553A1 (en) | 2009-06-01 | 2010-12-09 | 日立化成工業株式会社 | Organic electronic material, ink composition containing same, and organic thin film, organic electronic element, organic electroluminescent element, lighting device, and display device formed therewith |
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1999
- 1999-05-10 JP JP12884199A patent/JP4058842B2/en not_active Expired - Lifetime
Cited By (1)
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|---|---|---|---|---|
| WO2010140553A1 (en) | 2009-06-01 | 2010-12-09 | 日立化成工業株式会社 | Organic electronic material, ink composition containing same, and organic thin film, organic electronic element, organic electroluminescent element, lighting device, and display device formed therewith |
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