JP2004006165A - Organic electroluminescent element - Google Patents

Organic electroluminescent element Download PDF

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JP2004006165A
JP2004006165A JP2002160989A JP2002160989A JP2004006165A JP 2004006165 A JP2004006165 A JP 2004006165A JP 2002160989 A JP2002160989 A JP 2002160989A JP 2002160989 A JP2002160989 A JP 2002160989A JP 2004006165 A JP2004006165 A JP 2004006165A
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light emitting
emitting layer
organic light
organic
mobility
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JP4211291B2 (en
JP2004006165A5 (en
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Satoshi Nakagawa
中川　敏
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Toyota Industries Corp
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Toyota Industries Corp
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/12—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising dopants
    • H10K50/121—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising dopants for assisting energy transfer, e.g. sensitization
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • H10K50/13—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element capable of suppressing variation of luminescent chromaticity accompanied with variation of drive current magnitude. <P>SOLUTION: On transparent glass substrate 11, an anode 12, a hole injection layer 13, a hole transporting layer 14, a red color emitting layer 15, a blue color emitting layer 16, a green color emitting layer 17, an electron injection layer 18, and a cathode 19 are laminated in this order. The red color emitting layer 15 has a structure doping a red color luminescent dopant 152 to a host 151 having a hole-transporting property. The blue color emitting layer 16 has a structure doping a blue color luminescent dopant 162 and a red color luminescent dopant 163 of the same material as the dopant 152 to a host 161 having an electronic transportation property. The green color emitting layer 17 has a structure doping a green color luminescent dopant 172 to a host 171 having a electronic transportation property. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、有機エレクトロルミネッセンス素子に関するものである。
【０００２】
【従来の技術】
特開２０００−２４３５６５号公報には、補色関係にある２色を混色して白色発光を得る有機エレクトロルミネッセンス素子が開示されている。赤、青、緑の３色を混色して白色発光を得る有機エレクトロルミネッセンス素子もある。このような有機エレクトロルミネッセンス素子としては、発光するドーパントをホストにドープした複数の有機発光層を陽極と陰極との間に挟んだ構成の有機エレクトロルミネッセンス素子がある。
【０００３】
【発明が解決しようとする課題】
複数の有機発光層を備えた有機エレクトロルミネッセンス素子では、明るさ調整等のために駆動電流の大きさが変わると、発光色が変化するという問題がある。駆動電流の大きさの変化に伴う発光色の変化は、以下のような理由によるものと考えられる。
【０００４】
例えば、赤色発光用の有機発光層（以下、赤色発光層という）、青色発光用の有機発光層（以下、青色発光層という）、緑色発光用の有機発光層（以下、緑色発光層という）をこの順に陽極側から積層した有機エレクトロルミネッセンス素子について考えてみる。そして、この有機エレクトロルミネッセンス素子では、赤色発光層のホストにおける正孔の移動度が大きく、青色発光層及び緑色発光層のホストにおける正孔の移動度が小さいものとする。
【０００５】
そうすると、駆動電流が小さいときには、正孔は、赤色発光層における正孔移動度と青色発光層における正孔移動度との差、又は赤色発光層における最高電子占有分子軌道のエネルギー準位（ＨＯＭＯ準位）と青色発光層におけるＨＯＭＯ準位との差によって、赤色発光層と青色発光層との界面に留まる。そのため、電子と正孔との再結合領域は専ら赤色発光層に位置し、有機エレクトロルミネッセンス素子全体の発光色度は、赤色発光層の発光色寄りとなる。即ち、駆動電流が小さいときには、赤みを帯びた白色発光が生じる。
【０００６】
しかし、駆動電流が大きくなってゆくと、正孔が陰極側へ伝播する割合が多くなってゆき、電子と正孔との再結合領域が青色発光層側へ移動する。そのため、有機エレクトロルミネッセンス素子全体の発光色度は、青色発光層の発光色寄りとなる。即ち、駆動電流が大きいときには、青みを帯びた白色発光が生じる。
【０００７】
本発明は、駆動電流の大きさの変化に伴う発光色度の変化を抑制し得る有機エレクトロルミネッセンス素子を提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明は、複数の有機発光層を陽極と陰極との間に挟み、前記陽極側から前記有機発光層へ注入される正孔と、前記陰極側から前記有機発光層へ注入される電子とを結合させて発光させる有機エレクトロルミネッセンス素子を対象とし、請求項１の発明では、１つの特定の有機発光層に前記陰極側又は陽極側で隣接する有機発光層に対して、前記特定の有機発光層における基本発光物質の発光色と同系の色の発光を行う補助発光物質をドープし、前記特定の有機発光層における正孔の移動度が電子の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陰極側に隣接させ、前記特定の有機発光層における電子の移動度が正孔の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陽極側に隣接させた。
【０００９】
請求項２の発明では、請求項１において、前記補助発光物質は、前記基本発光物質と同じ物質とした。
請求項１及び請求項２の発明において、特定の有機発光層における正孔の移動度が電子の移動度よりも大きい場合、駆動電流が大きくなってゆくと、正孔と電子との再結合領域が陰極側へ移動する。補助発光物質をドープされた有機発光層は、特定の有機発光層に対して陰極側で隣接している。従って、駆動電流が大きくなってゆくと、特定の有機発光層に隣接する有機発光層における補助発光物質の発光が増える。その結果、駆動電流の大きさの変化に伴う発光色度の変化が抑制される。
【００１０】
特定の有機発光層における電子の移動度が正孔の移動度よりも大きい場合、駆動電流が大きくなってゆくと、正孔と電子との再結合領域が陽極側へ移動する。補助発光物質をドープされた有機発光層は、特定の有機発光層に対して陽極側で隣接している。従って、駆動電流が大きくなってゆくと、特定の有機発光層に隣接する有機発光層における補助発光物質の発光が増える。その結果、駆動電流の大きさの変化に伴う発光色度の変化が抑制される。
【００１１】
請求項３の発明では、請求項２において、前記特定の有機発光層における正孔の移動度は、電子の移動度よりも大きく、前記特定の有機発光層に対して前記陰極側で隣接する有機発光層に前記補助発光物質をドープした。
【００１２】
請求項４の発明では、請求項３において、前記特定の有機発光層における正孔の移動度は、電子の移動度よりも大きく、前記特定の有機発光層に対して前記陰極側で隣接する有機発光層に前記補助発光物質をドープした。
【００１３】
請求項３及び請求項４の発明において、駆動電流が大きくなってゆくと、特定の有機発光層に隣接する有機発光層における補助発光物質の発光が増える。
請求項５の発明では、請求項３及び請求項４のいずれか１項において、前記複数の有機発光層は、赤色発光層と青色発光層と緑色発光層とし、有機エレクトロルミネッセンス素子は白色発光素子とした。
【００１４】
駆動電流の大きさの変化に伴う白色発光の色度の変化が抑制される。
請求項６の発明では、請求項５において、前記赤色発光層と青色発光層と緑色発光層とをこの順に前記陽極側から積層し、前記赤色発光層における前記基本発光物質を前記補助発光物質として前記青色発光層へドープした。
【００１５】
赤色発光層が特定の有機発光層となり、赤色発光層における正孔の移動度が電子の移動度よりも大きい。駆動電流が大きくなってゆくと、正孔と電子との再結合領域が陰極側へ移動する。赤色発光層における基本発光物質（赤色発光物質）をドープされた青色発光層は、赤色発光層に対して陰極側で隣接している。従って、駆動電流が大きくなってゆくと、赤色発光層に隣接する青色発光層における補助発光物質（赤色発光物質）の発光が増える。その結果、駆動電流の大きさの変化に伴う白色発光の色度の変化が抑制される。
【００１６】
請求項７の発明では、請求項１乃至請求項４のいずれか１項において、前記複数の有機発光層は、互いに補色の関係にある色を別々に発光する一対の有機発光層とした。
【００１７】
駆動電流の大きさの変化に伴う白色発光の色度の変化が抑制される。
請求項８の発明では、請求項１乃至請求項７のいずれか１項において、前記複数の有機発光層の全ては、発光するドーパントを前記基本発光物質として発光しないホストにドープして構成した有機発光層とし、１つの特定の有機発光層に前記陰極側又は陽極側で隣接する有機発光層に対して前記特定の有機発光層におけるドーパントを前記補助発光物質としてドープし、前記特定の有機発光層における正孔の移動度が電子の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陰極側に隣接させ、前記特定の有機発光層における電子の移動度が正孔の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陽極側に隣接させた。
【００１８】
特定の有機発光層における正孔の移動度が電子の移動度よりも大きい場合、駆動電流が大きくなってゆくと、正孔と電子との再結合領域が陰極側へ移動する。特定の有機発光層における基本発光物質としてのドーパントを補助発光物質としてドープされた有機発光層は、特定の有機発光層に対して陰極側で隣接している。従って、駆動電流が大きくなってゆくと、特定の有機発光層に隣接する有機発光層における前記ドーパントの発光が増える。その結果、駆動電流の大きさの変化に伴う発光色度の変化が抑制される。
【００１９】
特定の有機発光層における電子の移動度が正孔の移動度よりも大きい場合、駆動電流が大きくなってゆくと、正孔と電子との再結合領域が陽極側へ移動する。特定の有機発光層における基本発光物質としてのドーパントを補助発光物質としてドープされた有機発光層は、特定の有機発光層に対して陽極側で隣接している。従って、駆動電流が大きくなってゆくと、特定の有機発光層に隣接する有機発光層における前記ドーパントの発光が増える。その結果、駆動電流の大きさの変化に伴う発光色度の変化が抑制される。
【００２０】
【発明の実施の形態】
以下、本発明を具体化した第１の実施の形態を図１〜図３に基づいて説明する。
【００２１】
図１は、白色発光素子としての有機エレクトロルミネッセンス素子１０を示す。透明ガラス製の基板１１上には、陽極１２、正孔注入層１３、正孔輸送層１４、赤色発光層１５、青色発光層１６、緑色発光層１７、電子注入層１８及び陰極１９がこの順に積層されている。
【００２２】
陽極１２は、透明かつ導電性のＩＴＯ（インジウム錫酸化物）製であり、陰極１９は、アルミニウム製である。正孔注入層１３は、ＣｕＰｃ（銅フタロシアニン）製であり、電子注入層１８は、ＬｉＦ（フッ化リチウム）製である。正孔輸送層１４は、ＴＰＴＥ（トリフェニルアミンの４量体）製である。正孔注入層１３及び正孔輸送層１４は、陽極１２より正孔を注入して発光層１５，１６，１７へ伝達する機能を有する。電子注入層１８は、陰極１９より電子を発光層１５，１６，１７へ伝達する機能を有する。
【００２３】
正孔注入層１３、正孔輸送層１４、赤色発光層１５、青色発光層１６、緑色発光層１７及び電子注入層１８の厚みは、この順に、１０ｎｍ、１０ｎｍ、５ｎｍ、３０ｎｍ、２０ｎｍ、０．５ｎｍとなっている。
【００２４】
赤色発光層１５は、正孔輸送性を有するＴＰＴＥ製のホスト１５１にドーパント１５２をドープした構成となっている。ドーパント１５２は、下記（１）の化学式で示す赤色の発光物質である。
【００２５】
【化１】

Figure 2004006165
以下、化学式（１）で示す物質は、ＤＣＪＴと表す。赤色発光層１５における基本発光物質としてのドーパント１５２の重量％は、０．５重量％である。
【００２６】
青色発光層１６は、電子輸送性を有するＤＰＶＢｉ〔４，４’−ビス（２，２’−ジフェニルビニル）ビフェニル〕製のホスト１６１に２種類のドーパント１６２，１６３をドープした構成となっている。ドーパント１６２は、ＢＣｚＶＢｉ〔４，４’−ビス（９−エチル−３−カルバゾビニレン）−１，１’−ビフェニル〕製の青色の発光物質である。ドーパント１６３は、ＤＣＪＴ製の赤色の発光物質である。青色発光層１６における基本発光物質としてのドーパント１６２の重量％は、５．０重量％であり、青色発光層１６における補助発光物質としてのドーパント１６３の重量％は、０．５重量％である。ドーパント１６３の量は、同じ材質製のドーパント１５２の量よりも少なくしてある。
【００２７】
緑色発光層１７は、電子輸送性を有するＡｌｑ３〔トリス（８−キノリノラト）アルミニウム〕製のホスト１７１にドーパント１７２をドープした構成となっている。ドーパント１７２は、Ｃ５４５Ｔ〔１０−（２−ベンゾチアゾリル）−２，３，６，７−テトラヒドロ−１，２，７，７−テトラメチル−１Ｈ，５Ｈ，１１Ｈ−［１］ベンゾピラノ［６，７，８−ｉｊ］キノリジン−１１−オン〕製の緑色の発光物質である。緑色発光層１７における基本発光物質としてのドーパント１７２（Ｃ５４５Ｔは、イーストマン−コダック社の商品名）の重量％は、１．０重量％である。
【００２８】
赤色発光層１５、青色発光層１６及び緑色発光層１７は、いずれも陽極１２と陰極１９との間に挟まれた有機発光層である。青色発光層１６における正孔の移動度及び緑色発光層１７における正孔の移動度は、特定の有機発光層である赤色発光層１５における正孔の移動度よりも小さい。赤色発光層１５を構成するホスト１５１は、正孔の移動度が電子の移動度よりも大きい正孔輸送性の材質からなる。青色発光層１６を構成するホスト１６１は、電子輸送性の材質からなり、緑色発光層１７を構成するホスト１７１は、電子注入輸送性の材質からなる。青色発光層１６は、特定の有機発光層としての赤色発光層１５に対して陰極１９側で隣接している。
【００２９】
陽極１２と陰極１９との間に直流電界を印加すると、正孔が陽極１２から正孔注入層１３及び正孔輸送層１４を通って赤色発光層１５へ注入されると共に、電子が陰極１９から電子注入層１８を通って緑色発光層１７、青色発光層１６及び赤色発光層１５へ注入される。注入された正孔と電子とは再結合する。駆動電流が小さいときには正孔と電子との再結合領域の中心は赤色発光層１５内となり、駆動電流が大きくなると、再結合領域の中心が青色発光層１６へ移動する。
【００３０】
第１の実施の形態では以下の効果が得られる。
（１−１）駆動電流が大きくなってゆくと、正孔と電子との再結合領域が陰極１９側へ移動する。特定の有機発光層としての赤色発光層１５におけるドーパント１５２と同じ発光物質の１６３を微量ドープされた青色発光層１６は、赤色発光層１５に対して陰極１９側で隣接している。従って、駆動電流が大きくなってゆくと、赤色発光層１５に対して陰極１９側で隣接する青色発光層１６における補助発光物質としてのドーパント１６３の赤色発光が増える。
【００３１】
図２のグラフにおける曲線Ｅｘ，Ｄｘは、駆動電流（単位は、ｍＡ／ｃｍ２）と色度Ｘとの関係を示し、曲線Ｅｙ，Ｄｙは、駆動電流と色度Ｙとの関係を示す。曲線Ｅｘ，Ｅｙは、青色発光層１６にドーパント１６３をドープした本実施の形態の有機エレクトロルミネッセンス素子１０に直流電界を印加した実験結果を示す。曲線Ｄｘ，Ｄｙは、青色発光層１６にドーパント１６３をドープしていないが、その他の点では有機エレクトロルミネッセンス素子１０と同じ構成の図示しない有機エレクトロルミネッセンス素子１０Ａに直流電界を印加した実験結果を示す。白丸、黒丸、白四角及び黒四角は、実測データである。
【００３２】
図３は、色度図を表す。図３における曲線Ｄｏは、曲線Ｄｘ，Ｄｙに対応し、曲線Ｅｏは、曲線Ｅｘ，Ｅｙに対応する。即ち、曲線Ｄｏは、有機エレクトロルミネッセンス素子１０Ａに対する直流電界の印加によって得られ、曲線Ｅｏは、有機エレクトロルミネッセンス素子１０に対する直流電界の印加によって得られる。曲線Ｄｏ，Ｅｏ上の色度は、駆動電流が大きくなるにつれて曲線Ｄｏ上を右から左へ移動するように変化する。
【００３３】
図２及び図３から明らかなように、有機エレクトロルミネッセンス素子１０Ａでは、駆動電流の大きさの変化に伴う発光色度の変化が大きい。しかし、本実施の形態の有機エレクトロルミネッセンス素子１０では、駆動電流の大きさの変化に伴う発光色度の変化が抑制されている。又、図２及び図３は、有機エレクトロルミネッセンス素子１０における白色度が有機エレクトロルミネッセンス素子１０Ａの白色度に比べて高いことを示している。このような作用効果は、ドーパント１５２と同じ物質のドーパント１６３を青色発光層１６に微量ドープしたことによって得られたものである。
【００３４】
（１−２）白色発光する有機エレクトロルミネッセンス素子では、赤色発光層１５、青色発光層１６、緑色発光層１７のうちのいずれかが余分に発光すると、その発光色が目立ち易く、白色性が損なわれ易い。従って、白色発光する有機エレクトロルミネッセンス素子は、本発明の適用対象として特に好適である。
【００３５】
次に、図４の第２の実施の形態を説明する。第１の実施の形態と同じ構成部には同じ符号が付してある。
第２の実施の形態における有機エレクトロルミネッセンス素子１０Ｂでは、緑色発光層１７と電子注入層１８との間に電子輸送層２０が介在されている。電子輸送層２０は、電子輸送性を有するＡｌｑ３製である。緑色発光層１７の厚みは１５ｎｍであり、電子輸送層２０の厚みは５ｎｍである。その他の構成は、第１の実施の形態の場合と同じである。
【００３６】
第２の実施の形態において、第１の実施の形態の場合と同様の効果が得られる。
本発明は、図５に第３の実施の形態として示す白色発光素子としての有機エレクトロルミネッセンス素子１０Ｃにも適用可能である。
【００３７】
有機エレクトロルミネッセンス素子１０Ｃは、透明ガラス製の基板１１上に、陽極１２、正孔注入層１３、正孔輸送層１４、有機発光層２１、有機発光層２２、電子注入層１８及び陰極１９をこの順に積層して構成されている。有機発光層２１と有機発光層２２とは、互いに補色の関係にある色を別々に発光する。有機発光層２１は、例えばＤＰＶＤＰＡＮ（９，１０−ジ〔４−（２，２’−ジフェニルビニル−１−イル）フェニル）アントラセン）製のホスト２１１に、例えばＤＰＡＶＢｉ（４，４’−ビス〔２−（４−（Ｎ，Ｎ−ジフェニルアミノ）フェニル）ビニル〕ビフェニル）製のドーパント２１２をドープした構成となっている。有機発光層２２は、ＤＰＶＴＰ〔４，４’−ビス（２，２−ジフェニルビニル）−ターフェニレン〕製のホスト２２１に、ルブレン製のドーパント２２２をドープした構成となっている。ＤＰＶＤＰＡＮは、青色発光物質であり、ルブレンは、橙色発光物質である。基本発光物質であるドーパント２１２の発光色と、基本発光物質であるドーパント２２２の発光色とは、補色の関係にある。そして、微量のドーパント２２３が有機発光層２２にドープされている。
【００３８】
有機発光層２２は、特定の有機発光層としての有機発光層２１に対して陰極１９側で隣接している。補助発光物質としてのドーパント２２３は、ドーパント２１２と同じ材質であり、有機発光層２２におけるドーパント２２３の重量％は、ドーパント２２２の重量％よりもかなり小さくしてある。又、ドーパント２２３の量は、ドーパント２１２の量よりも少なくしてある。
【００３９】
有機発光層２１にドープされているドーパント２１２と同じ材質のドーパント２２３は、第１の実施の形態におけるドーパント１６３と同じ役割を果たす。即ち、ドーパント２２３は、駆動電流の大きさの変化に伴う有機エレクトロルミネッセンス素子１０Ｃにおける発光色度の変化を抑制する。
【００４０】
本発明では以下のような実施の形態も可能である。
（１）第１及び第２の実施の形態において、ドーパント１５２，１６３の材質としてＤＣＪＴの代わりに、ＤＣＭ２（［２−ｍｅｔｈｙｌ−６−［２−（２，３，６，７−ｔｅｔｒａｈｙｄｒｏ−１Ｈ，５Ｈ−ｂｅｎｚｏ［ｉｊ］ｑｕｉｎｏｌｉｊｉｎ−９−ｙｌ）ｅｔｈｅｎｙｌ］−４Ｈ−ｐｙｒａｎ−４−ｙｌｉｄｅｎｅ］ｐｒｏｐａｎｅ−ｄｉｎｉｔｒｉｌｅ）を用いること。
【００４１】
（２）第１及び第２の実施の形態において、赤色発光層１５におけるドーパント１５２の重量％を０．１〜２．０重量％の範囲とし、青色発光層１６におけるドーパント１６２の重量％を３．０〜８．０重量％の範囲とし、青色発光層１６におけるドーパント１６３の重量％を０．０１〜１．０重量％の範囲とし、緑色発光層１７におけるドーパント１７２の重量％を０．５〜２．０重量％の範囲とすること。この場合、ドーパント１６３の重量％をドーパント１６２の重量％よりも小さくし、ドーパント１６３の量をドーパント１５２の量よりも少なくすること。
【００４２】
（３）赤色発光層、青色発光層及び緑色発光層をこの順に陽極側から陰極側に積層した有機エレクトロルミネッセンス素子において、青色発光層にドープされている青系のドーパントと同じドーパントを補助発光物質として必要に応じて緑色発光層に微量ドープすること。
【００４３】
（４）赤色発光層、緑色発光層及び青色発光層をこの順に陽極側から陰極側に積層した有機エレクトロルミネッセンス素子において、赤色発光層にドープされている赤系のドーパントと同じドーパントを緑色発光層に微量ドープすること。
【００４４】
（５）青色発光層、赤色発光層及び緑色発光層をこの順に陽極側から陰極側に積層した有機エレクトロルミネッセンス素子において、青色発光層にドープされている青系のドーパントと同じドーパントを赤色発光層に微量ドープすること。
【００４５】
（６）補色の関係にない２種類の有機発光層を隣合わせて構成した有機エレクトロルミネッセンス素子に本発明を適用すること。
（７）第１及び第２の実施の形態において、基本発光物質であるドーパント１５２と同じ物質のドーパント１６３を青色発光層１６にドープする代わりに、ドーパント１５２の発光色と同系の色の発光を行う別の補助発光物質を青色発光層１６にドープすること。
【００４６】
（８）特定の有機発光層における電子の移動度が正孔の移動度よりも大きい場合、特定の有機発光層に対して隣接関係にある有機発光層を陽極側で隣接させ、特定の有機発光層における発光物質を特定の有機発光層に対して隣接関係にある前記有機発光層に補助発光物質としてドープすること。
【００４７】
この場合、駆動電流が大きくなってゆくと、正孔と電子との再結合領域が陽極側へ移動し、特定の有機発光層に隣接する前記有機発光層における前記ドーパントの発光が増える。その結果、駆動電流の大きさの変化に伴う発光色度の変化が抑制される。
【００４８】
前記した実施の形態から把握できる請求項記載以外の発明について以下に記載する。
〔１〕複数の有機発光層を陽極と陰極との間に挟み、前記陽極側から前記有機発光層へ注入される正孔と、前記陰極側から前記有機発光層へ注入される電子とを再結合させて発光させる有機エレクトロルミネッセンス素子において、
１つの特定の有機発光層に前記陰極側又は陽極側で隣接する有機発光層に対して前記特定の有機発光層における基本発光物質を補助発光物質としてドープし、駆動電流の増加に伴って前記正孔と電子との再結合領域が移動する方向の側で前記特定の有機発光層に対して隣接関係にある前記有機発光層を隣接させた有機エレクトロルミネッセンス素子。
【００４９】
〔２〕請求項１乃至請求項７のいずれか１項において、前記複数の有機発光層と前記陽極との間に正孔注入層を介在し、前記複数の有機発光層と前記陰極との間に電子注入層を介在した有機エレクトロルミネッセンス素子。
【００５０】
〔３〕前記〔２〕項において、前記複数の有機発光層と前記正孔注入層との間に正孔輸送層を介在した有機エレクトロルミネッセンス素子。
〔４〕前記〔２〕項及び〔３〕項のいずれか１項において、前記電子注入層と前記陰極との間に電子輸送層を介在した有機エレクトロルミネッセンス素子。
【００５１】
【発明の効果】
本発明では、特定の有機発光層に陰極側又は陽極側で隣接する有機発光層に対して、特定の有機発光層における基本発光物質の発光色と同系の色の発光を行う補助発光物質をドープしたので、駆動電流の大きさの変化に伴う発光色度の変化を抑制し得るという優れた効果を奏する。
【図面の簡単な説明】
【図１】第１の実施の形態を示す有機エレクトロルミネッセンス素子の構造を示す断面図。
【図２】駆動電流と色度との関係を示すグラフ。
【図３】色度図。
【図４】第２の実施の形態を示す有機エレクトロルミネッセンス素子の構造を示す断面図。
【図５】第３の実施の形態を示す有機エレクトロルミネッセンス素子の構造を示す断面図。
【符号の説明】
１０，１０Ｂ，１０Ｃ…白色発光素子である有機エレクトロルミネッセンス素子。１２…陽極。１５…特定の有機発光層である赤色発光層。１６…特定の有機発光層に隣接する有機発光層である青色発光層。１７…有機発光層である緑色発光層。１５１，１６１，１７１，２１１，２２１…ホスト。１５２，１６２，１７２，２１２，２２２…基本発光物質としてのドーパント。１６３，２２３…補助発光物質としてのドーパント。１９…陰極。２１…特定の有機発光層。２２…特定の有機発光層に隣接する有機発光層。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic electroluminescence device.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 2000-243565 discloses an organic electroluminescence device that obtains white light emission by mixing two colors having complementary colors. There is also an organic electroluminescence device that obtains white light emission by mixing three colors of red, blue and green. As such an organic electroluminescence device, there is an organic electroluminescence device having a configuration in which a plurality of organic light emitting layers in which a dopant that emits light is doped in a host are sandwiched between an anode and a cathode.
[0003]
[Problems to be solved by the invention]
An organic electroluminescent device having a plurality of organic light emitting layers has a problem that when the magnitude of a drive current changes for brightness adjustment or the like, the emission color changes. It is considered that the change of the emission color due to the change of the drive current is due to the following reason.
[0004]
For example, an organic light emitting layer for emitting red light (hereinafter, referred to as red light emitting layer), an organic light emitting layer for emitting blue light (hereinafter, referred to as blue light emitting layer), and an organic light emitting layer for emitting green light (hereinafter, referred to as green light emitting layer). Consider an organic electroluminescent element stacked in this order from the anode side. In this organic electroluminescent element, the mobility of holes in the host of the red light emitting layer is large, and the mobility of holes in the hosts of the blue light emitting layer and the green light emitting layer is small.
[0005]
Then, when the driving current is small, holes are generated by the difference between the hole mobility in the red light emitting layer and the hole mobility in the blue light emitting layer, or the energy level of the highest electron occupied molecular orbital (HOMO level) in the red light emitting layer. ) And the HOMO level of the blue light-emitting layer, it remains at the interface between the red light-emitting layer and the blue light-emitting layer. Therefore, the recombination region of electrons and holes is located exclusively in the red light-emitting layer, and the emission chromaticity of the entire organic electroluminescence element is closer to the emission color of the red light-emitting layer. That is, when the driving current is small, reddish white light emission is generated.
[0006]
However, as the drive current increases, the rate at which holes propagate toward the cathode increases, and the recombination region of electrons and holes moves toward the blue light emitting layer. Therefore, the emission chromaticity of the entire organic electroluminescence element is closer to the emission color of the blue light emitting layer. That is, when the driving current is large, bluish white light emission is generated.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to provide an organic electroluminescent device capable of suppressing a change in emission chromaticity due to a change in the magnitude of a drive current.
[0008]
[Means for Solving the Problems]
The present invention sandwiches a plurality of organic light emitting layers between an anode and a cathode, and holes injected from the anode side to the organic light emitting layer, and electrons injected from the cathode side to the organic light emitting layer. The invention of claim 1 is directed to an organic electroluminescence element that combines and emits light by combining the specific organic light emitting layer with the organic light emitting layer adjacent to one specific organic light emitting layer on the cathode side or the anode side. Doping an auxiliary light emitting substance that emits light of a color similar to the emission color of the basic light emitting substance in the specific organic light emitting layer, when the mobility of holes in the specific organic light emitting layer is larger than the mobility of electrons. The organic light emitting layer adjacent to the light emitting layer is adjacent to the cathode side, and when the electron mobility in the specific organic light emitting layer is larger than the hole mobility, the specific organic light emitting layer Adjacent to the layer The organic light-emitting layer in was adjacent to the anode side.
[0009]
In the invention according to claim 2, in claim 1, the auxiliary light emitting substance is the same substance as the basic light emitting substance.
According to the first and second aspects of the present invention, when the mobility of holes in a specific organic light emitting layer is larger than the mobility of electrons, the recombination region of holes and electrons increases as the drive current increases. Moves to the cathode side. The organic light emitting layer doped with the auxiliary light emitting substance is adjacent to the specific organic light emitting layer on the cathode side. Therefore, as the driving current increases, the light emission of the auxiliary light emitting substance in the organic light emitting layer adjacent to the specific organic light emitting layer increases. As a result, a change in emission chromaticity due to a change in the magnitude of the drive current is suppressed.
[0010]
When the mobility of electrons in a specific organic light emitting layer is higher than the mobility of holes, the recombination region of holes and electrons moves to the anode side as the drive current increases. The organic light emitting layer doped with the auxiliary light emitting substance is adjacent to the specific organic light emitting layer on the anode side. Therefore, as the driving current increases, the light emission of the auxiliary light emitting substance in the organic light emitting layer adjacent to the specific organic light emitting layer increases. As a result, a change in emission chromaticity due to a change in the magnitude of the drive current is suppressed.
[0011]
According to the third aspect of the present invention, in the second aspect, the mobility of holes in the specific organic light emitting layer is larger than the mobility of electrons, and the organic layer adjacent to the specific organic light emitting layer on the cathode side with respect to the specific organic light emitting layer. The light emitting layer was doped with the auxiliary light emitting material.
[0012]
According to a fourth aspect of the present invention, in the third aspect, the mobility of holes in the specific organic light emitting layer is larger than the mobility of electrons, and the mobility of the organic light emitting layer adjacent to the specific organic light emitting layer on the cathode side is higher than that of the specific organic light emitting layer. The light emitting layer was doped with the auxiliary light emitting material.
[0013]
According to the third and fourth aspects of the present invention, as the driving current increases, the emission of the auxiliary light emitting substance in the organic light emitting layer adjacent to the specific organic light emitting layer increases.
According to a fifth aspect of the present invention, in any one of the third and fourth aspects, the plurality of organic light emitting layers are a red light emitting layer, a blue light emitting layer, and a green light emitting layer, and the organic electroluminescent element is a white light emitting element. And
[0014]
A change in chromaticity of white light emission due to a change in the magnitude of the drive current is suppressed.
In the invention of claim 6, in claim 5, the red light emitting layer, the blue light emitting layer, and the green light emitting layer are laminated in this order from the anode side, and the basic light emitting substance in the red light emitting layer is used as the auxiliary light emitting substance. The blue light emitting layer was doped.
[0015]
The red light emitting layer becomes a specific organic light emitting layer, and the hole mobility in the red light emitting layer is larger than the electron mobility. As the driving current increases, the recombination region of holes and electrons moves to the cathode side. The blue light emitting layer doped with the basic light emitting substance (red light emitting substance) in the red light emitting layer is adjacent to the red light emitting layer on the cathode side. Therefore, as the drive current increases, the emission of the auxiliary light emitting substance (red light emitting substance) in the blue light emitting layer adjacent to the red light emitting layer increases. As a result, a change in chromaticity of white light emission due to a change in the magnitude of the drive current is suppressed.
[0016]
According to a seventh aspect of the present invention, in any one of the first to fourth aspects, the plurality of organic light emitting layers are a pair of organic light emitting layers that separately emit colors complementary to each other.
[0017]
A change in chromaticity of white light emission due to a change in the magnitude of the drive current is suppressed.
According to an eighth aspect of the present invention, in any one of the first to seventh aspects, all of the plurality of organic light emitting layers are formed by doping a non-light emitting host with a light emitting dopant as the basic light emitting material. A light-emitting layer, and doping a dopant in the specific organic light-emitting layer as an auxiliary light-emitting substance with respect to an organic light-emitting layer adjacent to one specific organic light-emitting layer on the cathode side or the anode side; When the mobility of the holes in is larger than the mobility of the electrons, the organic light emitting layer adjacent to the specific organic light emitting layer is adjacent to the cathode side, and in the specific organic light emitting layer When the mobility of electrons was larger than the mobility of holes, the organic light-emitting layer adjacent to the specific organic light-emitting layer was adjacent to the anode.
[0018]
When the mobility of holes in a specific organic light emitting layer is larger than the mobility of electrons, the recombination region of holes and electrons moves to the cathode side as the drive current increases. An organic light emitting layer doped with a dopant as a basic light emitting substance in a specific organic light emitting layer as an auxiliary light emitting substance is adjacent to the specific organic light emitting layer on the cathode side. Therefore, as the drive current increases, the emission of the dopant in the organic light emitting layer adjacent to the specific organic light emitting layer increases. As a result, a change in emission chromaticity due to a change in the magnitude of the drive current is suppressed.
[0019]
When the mobility of electrons in a specific organic light emitting layer is higher than the mobility of holes, the recombination region of holes and electrons moves to the anode side as the drive current increases. An organic light emitting layer doped with a dopant as a basic light emitting material in a specific organic light emitting layer as an auxiliary light emitting material is adjacent to the specific organic light emitting layer on the anode side. Therefore, as the drive current increases, the emission of the dopant in the organic light emitting layer adjacent to the specific organic light emitting layer increases. As a result, a change in emission chromaticity due to a change in the magnitude of the drive current is suppressed.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
[0021]
FIG. 1 shows an organic electroluminescence device 10 as a white light emitting device. On a transparent glass substrate 11, an anode 12, a hole injection layer 13, a hole transport layer 14, a red light emitting layer 15, a blue light emitting layer 16, a green light emitting layer 17, an electron injection layer 18 and a cathode 19 are arranged in this order. It is laminated.
[0022]
The anode 12 is made of transparent and conductive ITO (indium tin oxide), and the cathode 19 is made of aluminum. The hole injection layer 13 is made of CuPc (copper phthalocyanine), and the electron injection layer 18 is made of LiF (lithium fluoride). The hole transport layer 14 is made of TPTE (tetramer of triphenylamine). The hole injection layer 13 and the hole transport layer 14 have a function of injecting holes from the anode 12 and transmitting the holes to the light emitting layers 15, 16, and 17. The electron injection layer 18 has a function of transmitting electrons from the cathode 19 to the light emitting layers 15, 16, and 17.
[0023]
The thicknesses of the hole injection layer 13, the hole transport layer 14, the red light emitting layer 15, the blue light emitting layer 16, the green light emitting layer 17, and the electron injection layer 18 are 10 nm, 10 nm, 5 nm, 30 nm, 20 nm, 0. 5 nm.
[0024]
The red light emitting layer 15 has a configuration in which a dopant 152 is doped into a host 151 made of TPTE having a hole transporting property. The dopant 152 is a red light-emitting substance represented by the following chemical formula (1).
[0025]
Embedded image
Figure 2004006165
Hereinafter, the substance represented by the chemical formula (1) is referred to as DCJT. The weight% of the dopant 152 as the basic light emitting material in the red light emitting layer 15 is 0.5% by weight.
[0026]
The blue light emitting layer 16 has a configuration in which a host 161 made of DPVBi [4,4'-bis (2,2'-diphenylvinyl) biphenyl] having an electron transporting property is doped with two kinds of dopants 162 and 163. . The dopant 162 is a blue light-emitting substance made of BCzVBi [4,4′-bis (9-ethyl-3-carbazovinylene) -1,1′-biphenyl]. The dopant 163 is a red light-emitting substance manufactured by DCJT. The weight% of the dopant 162 as the basic light emitting material in the blue light emitting layer 16 is 5.0% by weight, and the weight% of the dopant 163 as the auxiliary light emitting material in the blue light emitting layer 16 is 0.5% by weight. The amount of the dopant 163 is smaller than the amount of the dopant 152 made of the same material.
[0027]
The green light emitting layer 17 has a configuration in which a dopant 172 is doped into a host 171 made of Alq3 [tris (8-quinolinolato) aluminum] having an electron transporting property. The dopant 172 is C545T [10- (2-benzothiazolyl) -2,3,6,7-tetrahydro-1,2,7,7-tetramethyl-1H, 5H, 11H- [1] benzopyrano [6,7, 8-ij] quinolinidin-11-one]. The weight% of the dopant 172 (C545T is a trade name of Eastman-Kodak) as a basic light emitting material in the green light emitting layer 17 is 1.0% by weight.
[0028]
The red light emitting layer 15, the blue light emitting layer 16, and the green light emitting layer 17 are all organic light emitting layers sandwiched between the anode 12 and the cathode 19. The hole mobility in the blue light emitting layer 16 and the hole mobility in the green light emitting layer 17 are smaller than the hole mobility in the red light emitting layer 15 which is a specific organic light emitting layer. The host 151 constituting the red light emitting layer 15 is made of a material having a hole transporting property in which the mobility of holes is larger than the mobility of electrons. The host 161 constituting the blue light emitting layer 16 is made of a material having an electron transporting property, and the host 171 constituting the green light emitting layer 17 is made of a material having an electron injecting and transporting property. The blue light emitting layer 16 is adjacent to the red light emitting layer 15 as a specific organic light emitting layer on the cathode 19 side.
[0029]
When a DC electric field is applied between the anode 12 and the cathode 19, holes are injected from the anode 12 into the red light emitting layer 15 through the hole injection layer 13 and the hole transport layer 14, and electrons are emitted from the cathode 19. The electrons are injected into the green light emitting layer 17, the blue light emitting layer 16 and the red light emitting layer 15 through the electron injection layer 18. The injected holes and electrons recombine. When the driving current is small, the center of the recombination region of holes and electrons is in the red light emitting layer 15, and when the driving current is large, the center of the recombination region moves to the blue light emitting layer 16.
[0030]
In the first embodiment, the following effects can be obtained.
(1-1) As the drive current increases, the recombination region of holes and electrons moves to the cathode 19 side. The blue light emitting layer 16 doped with a small amount of the same light emitting substance 163 as the dopant 152 in the red light emitting layer 15 as a specific organic light emitting layer is adjacent to the red light emitting layer 15 on the cathode 19 side. Therefore, as the driving current increases, the red light emission of the dopant 163 as an auxiliary light emitting substance in the blue light emitting layer 16 adjacent to the red light emitting layer 15 on the cathode 19 side increases.
[0031]
Curves Ex and Dx in the graph of FIG. 2 show the relationship between the drive current (unit: mA / cm 2 ) and chromaticity X, and curves Ey and Dy show the relationship between the drive current and chromaticity Y. Curves Ex and Ey show the results of an experiment in which a DC electric field was applied to the organic electroluminescence device 10 of the present embodiment in which the blue light emitting layer 16 was doped with the dopant 163. Curves Dx and Dy show the results of an experiment in which a DC electric field was applied to an organic electroluminescent element 10A (not shown) having the same configuration as the organic electroluminescent element 10 except that the blue light emitting layer 16 was not doped with the dopant 163. . White circles, black circles, white squares, and black squares are measured data.
[0032]
FIG. 3 shows a chromaticity diagram. The curve Do in FIG. 3 corresponds to the curves Dx and Dy, and the curve Eo corresponds to the curves Ex and Ey. That is, the curve Do is obtained by applying a DC electric field to the organic electroluminescent element 10A, and the curve Eo is obtained by applying a DC electric field to the organic electroluminescent element 10. The chromaticity on the curves Do and Eo changes so as to move from right to left on the curve Do as the drive current increases.
[0033]
As is clear from FIGS. 2 and 3, in the organic electroluminescence element 10A, the change in the emission chromaticity according to the change in the magnitude of the drive current is large. However, in the organic electroluminescence element 10 of the present embodiment, the change in the emission chromaticity due to the change in the drive current is suppressed. FIGS. 2 and 3 show that the whiteness of the organic electroluminescent element 10 is higher than the whiteness of the organic electroluminescent element 10A. Such an effect is obtained by doping a small amount of the dopant 163 of the same substance as the dopant 152 into the blue light emitting layer 16.
[0034]
(1-2) In an organic electroluminescent element that emits white light, if any one of the red light emitting layer 15, the blue light emitting layer 16, and the green light emitting layer 17 emits extra light, the light emission color is conspicuous and the whiteness is impaired. Easily. Therefore, an organic electroluminescent element that emits white light is particularly suitable as an application target of the present invention.
[0035]
Next, a second embodiment of FIG. 4 will be described. The same components as those in the first embodiment are denoted by the same reference numerals.
In the organic electroluminescence element 10B according to the second embodiment, the electron transport layer 20 is interposed between the green light emitting layer 17 and the electron injection layer 18. The electron transport layer 20 is made of Alq3 having an electron transport property. The thickness of the green light emitting layer 17 is 15 nm, and the thickness of the electron transport layer 20 is 5 nm. Other configurations are the same as those in the first embodiment.
[0036]
In the second embodiment, the same effect as in the first embodiment can be obtained.
The present invention is also applicable to the organic electroluminescent element 10C as a white light emitting element shown as the third embodiment in FIG.
[0037]
The organic electroluminescent element 10C includes an anode 12, a hole injection layer 13, a hole transport layer 14, an organic light emitting layer 21, an organic light emitting layer 22, an electron injection layer 18 and a cathode 19 formed on a transparent glass substrate 11. They are laminated in order. The organic light emitting layer 21 and the organic light emitting layer 22 separately emit colors having complementary colors. The organic light emitting layer 21 is formed on a host 211 made of, for example, DPVDPAN (9,10-di [4- (2,2′-diphenylvinyl-1-yl) phenyl) anthracene), for example, with DPAVBi (4,4′-bis [ The configuration is such that a dopant 212 made of 2- (4- (N, N-diphenylamino) phenyl) vinyl] biphenyl) is doped. The organic light emitting layer 22 has a configuration in which a host 221 made of DPVTP [4,4′-bis (2,2-diphenylvinyl) -terphenylene] is doped with a rubrene dopant 222. DPVDPAN is a blue luminescent material and rubrene is an orange luminescent material. The emission color of the dopant 212, which is the basic light emitting substance, and the emission color of the dopant 222, which is the basic light emitting substance, have a complementary color relationship. Then, a small amount of the dopant 223 is doped in the organic light emitting layer 22.
[0038]
The organic light emitting layer 22 is adjacent to the organic light emitting layer 21 as a specific organic light emitting layer on the cathode 19 side. The dopant 223 as the auxiliary light emitting substance is made of the same material as the dopant 212, and the weight% of the dopant 223 in the organic light emitting layer 22 is considerably smaller than the weight% of the dopant 222. The amount of the dopant 223 is smaller than the amount of the dopant 212.
[0039]
The dopant 223 made of the same material as the dopant 212 doped in the organic light emitting layer 21 plays the same role as the dopant 163 in the first embodiment. That is, the dopant 223 suppresses a change in the emission chromaticity of the organic electroluminescence device 10C due to a change in the magnitude of the drive current.
[0040]
In the present invention, the following embodiments are also possible.
(1) In the first and second embodiments, instead of DCJT, DCM2 ([2-methyl-6- [2- (2,3,6,7-tetrahydro-1H)) is used instead of DCJT. , 5H-benzo [ij] quinolijin-9-yl) ethenyl] -4H-pyran-4-ylidene] propane-dinitrile).
[0041]
(2) In the first and second embodiments, the weight% of the dopant 152 in the red light emitting layer 15 is in the range of 0.1 to 2.0% by weight, and the weight% of the dopant 162 in the blue light emitting layer 16 is 3%. 0.0 to 8.0% by weight, the weight% of the dopant 163 in the blue light emitting layer 16 is in the range of 0.01 to 1.0% by weight, and the weight% of the dopant 172 in the green light emitting layer 17 is 0.5%. To 2.0% by weight. In this case, the weight% of the dopant 163 is smaller than the weight% of the dopant 162, and the amount of the dopant 163 is smaller than the amount of the dopant 152.
[0042]
(3) In an organic electroluminescent device in which a red light emitting layer, a blue light emitting layer, and a green light emitting layer are stacked in this order from the anode side to the cathode side, the same dopant as the blue dopant doped in the blue light emitting layer is used as an auxiliary light emitting substance. Doping the green light emitting layer with a small amount as necessary.
[0043]
(4) In an organic electroluminescence device in which a red light emitting layer, a green light emitting layer, and a blue light emitting layer are laminated in this order from the anode side to the cathode side, the same dopant as the red dopant doped into the red light emitting layer is used for the green light emitting layer. Doping a small amount.
[0044]
(5) In an organic electroluminescent device in which a blue light emitting layer, a red light emitting layer, and a green light emitting layer are laminated in this order from the anode side to the cathode side, the same dopant as the blue-based dopant doped in the blue light emitting layer is used. Doping a small amount.
[0045]
(6) The present invention is applied to an organic electroluminescent device in which two types of organic light emitting layers having no complementary colors are arranged adjacent to each other.
(7) In the first and second embodiments, instead of doping the blue light-emitting layer 16 with the dopant 163 of the same substance as the dopant 152 as the basic light-emitting substance, light emission of a color similar to the emission color of the dopant 152 is performed. Doping the blue luminescent layer 16 with another auxiliary luminescent material.
[0046]
(8) When the mobility of electrons in the specific organic light-emitting layer is larger than the mobility of holes, an organic light-emitting layer adjacent to the specific organic light-emitting layer is made adjacent to the anode side, and the specific organic light-emitting Doping the luminescent material in the layer as an auxiliary luminescent material into said organic luminescent layer adjacent to a particular organic luminescent layer.
[0047]
In this case, as the drive current increases, the recombination region of holes and electrons moves to the anode side, and the emission of the dopant in the organic light emitting layer adjacent to a specific organic light emitting layer increases. As a result, a change in emission chromaticity due to a change in the magnitude of the drive current is suppressed.
[0048]
Inventions other than those described in the claims that can be grasped from the above-described embodiment will be described below.
[1] A plurality of organic light emitting layers are sandwiched between an anode and a cathode, and holes injected from the anode side into the organic light emitting layer and electrons injected from the cathode side into the organic light emitting layer are reproduced. In an organic electroluminescent device that emits light by bonding
An organic light-emitting layer adjacent to one specific organic light-emitting layer on the cathode side or the anode side is doped with a basic light-emitting substance in the specific organic light-emitting layer as an auxiliary light-emitting substance, and the positive light-emitting substance is increased with an increase in driving current. An organic electroluminescent element in which the organic light emitting layer adjacent to the specific organic light emitting layer is adjacent to the specific organic light emitting layer on the side of the direction in which the recombination region of holes and electrons moves.
[0049]
[2] The method according to any one of claims 1 to 7, wherein a hole injection layer is interposed between the plurality of organic light emitting layers and the anode, and between the plurality of organic light emitting layers and the cathode. Organic electroluminescence device with an electron injection layer interposed in the substrate.
[0050]
[3] The organic electroluminescence device according to the item [2], wherein a hole transport layer is interposed between the plurality of organic light emitting layers and the hole injection layer.
[4] The organic electroluminescence device according to any one of the above items [2] and [3], wherein an electron transport layer is interposed between the electron injection layer and the cathode.
[0051]
【The invention's effect】
In the present invention, an organic light emitting layer adjacent to a specific organic light emitting layer on the cathode side or the anode side is doped with an auxiliary light emitting substance that emits light of a color similar to the emission color of the basic light emitting substance in the specific organic light emitting layer. Therefore, an excellent effect that a change in emission chromaticity due to a change in the magnitude of the drive current can be suppressed is achieved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a structure of an organic electroluminescence element according to a first embodiment.
FIG. 2 is a graph showing a relationship between drive current and chromaticity.
FIG. 3 is a chromaticity diagram.
FIG. 4 is a cross-sectional view illustrating a structure of an organic electroluminescence element according to a second embodiment.
FIG. 5 is a cross-sectional view illustrating a structure of an organic electroluminescence element according to a third embodiment.
[Explanation of symbols]
10, 10B, 10C: Organic electroluminescent elements which are white light emitting elements. 12 ... Anode. 15 ... Red light emitting layer which is a specific organic light emitting layer. 16. Blue light emitting layer which is an organic light emitting layer adjacent to a specific organic light emitting layer. 17: green light-emitting layer which is an organic light-emitting layer. 151, 161, 171, 211, 221 ... host. 152, 162, 172, 212, 222 ... dopants as basic light emitting substances. 163, 223 ... Dopants as auxiliary light emitting substances. 19 ... cathode. 21 ... Specific organic light emitting layer. 22 ... an organic light emitting layer adjacent to a specific organic light emitting layer.

Claims (8)

複数の有機発光層を陽極と陰極との間に挟み、前記陽極側から前記有機発光層へ注入される正孔と、前記陰極側から前記有機発光層へ注入される電子とを結合させて発光させる有機エレクトロルミネッセンス素子において、
１つの特定の有機発光層に前記陰極側又は陽極側で隣接する有機発光層に対して、前記特定の有機発光層における基本発光物質の発光色と同系の色の発光を行う補助発光物質をドープし、前記特定の有機発光層における正孔の移動度が電子の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陰極側に隣接させ、前記特定の有機発光層における電子の移動度が正孔の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陽極側に隣接させた有機エレクトロルミネッセンス素子。A plurality of organic light emitting layers are sandwiched between an anode and a cathode, and light is emitted by combining holes injected from the anode side into the organic light emitting layer and electrons injected from the cathode side into the organic light emitting layer. In the organic electroluminescent element to be
An organic light emitting layer adjacent to one specific organic light emitting layer on the cathode side or the anode side is doped with an auxiliary light emitting substance that emits light of a color similar to the emission color of the basic light emitting substance in the specific organic light emitting layer. When the mobility of holes in the specific organic light emitting layer is larger than the mobility of electrons, the organic light emitting layer adjacent to the specific organic light emitting layer is adjacent to the cathode side. When the mobility of electrons in the specific organic light-emitting layer is larger than the mobility of holes, the organic light-emitting layer adjacent to the specific organic light-emitting layer is adjacent to the anode. Organic electroluminescent element. 前記補助発光物質は、前記基本発光物質と同じ物質である請求項１に記載の有機エレクトロルミネッセンス素子。The organic electroluminescent device according to claim 1, wherein the auxiliary light emitting material is the same as the basic light emitting material. 前記特定の有機発光層における正孔の移動度は、電子の移動度よりも大きく、前記補助発光物質は、前記特定の有機発光層に対して前記陰極側で隣接する有機発光層にドープされる請求項１及び請求項２のいずれか１項に記載の有機エレクトロルミネッセンス素子。The mobility of holes in the specific organic light emitting layer is larger than the mobility of electrons, and the auxiliary light emitting substance is doped into the organic light emitting layer adjacent to the specific organic light emitting layer on the cathode side with respect to the specific organic light emitting layer. The organic electroluminescence device according to claim 1. 前記特定の有機発光層に対して前記陰極側で隣接する有機発光層における正孔の移動度は、前記特定の有機発光層における正孔の移動度よりも小さい請求項３に記載の有機エレクトロルミネッセンス素子。The organic electroluminescence according to claim 3, wherein the mobility of holes in an organic light emitting layer adjacent to the specific organic light emitting layer on the cathode side is smaller than the mobility of holes in the specific organic light emitting layer. element. 前記複数の有機発光層は、赤色発光層と青色発光層と緑色発光層とであり、有機エレクトロルミネッセンス素子は白色発光素子である請求項３及び請求項４のいずれか１項に記載の有機エレクトロルミネッセンス素子。The organic electroluminescent device according to claim 3, wherein the plurality of organic light emitting layers are a red light emitting layer, a blue light emitting layer, and a green light emitting layer, and the organic electroluminescent element is a white light emitting element. Luminescent element. 前記赤色発光層と青色発光層と緑色発光層とをこの順に前記陽極側から積層し、前記赤色発光層における前記基本発光物質を前記補助発光物質として前記青色発光層へドープした請求項５に記載の有機エレクトロルミネッセンス素子。6. The red light emitting layer, the blue light emitting layer, and the green light emitting layer are laminated in this order from the anode side, and the blue light emitting layer is doped with the basic light emitting material in the red light emitting layer as the auxiliary light emitting material. Organic electroluminescence element. 前記複数の有機発光層は、互いに補色の関係にある色を別々に発光する一対の有機発光層であり、有機エレクトロルミネッセンス素子は白色発光素子である請求項１乃至請求項４のいずれか１項に記載の有機エレクトロルミネッセンス素子。5. The organic light-emitting device according to claim 1, wherein the plurality of organic light-emitting layers are a pair of organic light-emitting layers that separately emit colors having complementary colors, and the organic electroluminescent element is a white light-emitting element. 3. The organic electroluminescent device according to 1.). 前記複数の有機発光層の全ては、発光するドーパントを前記基本発光物質として発光しないホストにドープして構成した有機発光層であり、１つの特定の有機発光層に前記陰極側又は陽極側で隣接する有機発光層に対して前記特定の有機発光層におけるドーパントを前記補助発光物質としてドープし、前記特定の有機発光層における正孔の移動度が電子の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陰極側に隣接させ、前記特定の有機発光層における電子の移動度が正孔の移動度よりも大きい場合には、前記特定の有機発光層に対して隣接関係にある前記有機発光層を前記陽極側に隣接させた請求項１乃至請求項６のいずれか１項に記載の有機エレクトロルミネッセンス素子。All of the plurality of organic light-emitting layers are organic light-emitting layers formed by doping a light-emitting dopant into a host that does not emit light as the basic light-emitting substance, and are adjacent to one specific organic light-emitting layer on the cathode side or the anode side. The organic light emitting layer to be doped with the dopant in the specific organic light emitting layer as the auxiliary light emitting substance, and when the mobility of holes in the specific organic light emitting layer is larger than the mobility of electrons, The organic light emitting layer adjacent to the organic light emitting layer is adjacent to the cathode side, when the mobility of electrons in the specific organic light emitting layer is larger than the mobility of holes, the specific organic light emitting layer, The organic electroluminescent device according to claim 1, wherein the organic light emitting layer adjacent to the organic light emitting layer is adjacent to the anode.
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Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005074328A1 (en) * 2004-01-29 2005-08-11 Nippon Seiki Co., Ltd. Organic el panel
WO2005099313A1 (en) * 2004-04-02 2005-10-20 Idemitsu Kosan Co., Ltd. Organic electroluminescence element having two electroluminescent layers through electron barrier layer
WO2005115059A1 (en) * 2004-05-21 2005-12-01 Semiconductor Energy Laboratory Co., Ltd. Light emitting element and light emitting device using the element
WO2005117499A1 (en) 2004-05-31 2005-12-08 Kabushiki Kaisha Toyota Jidoshokki Organic el device
WO2006059512A1 (en) * 2004-12-01 2006-06-08 Idemitsu Kosan Co., Ltd. Organic electroluminescent device
JP2006172762A (en) * 2004-12-13 2006-06-29 Toyota Industries Corp Organic el element
JP2006172763A (en) * 2004-12-13 2006-06-29 Toyota Industries Corp Organic el element
WO2007052432A1 (en) 2005-10-31 2007-05-10 Idemitsu Kosan Co., Ltd. Organic el light emitting device
JP2007235081A (en) * 2006-01-31 2007-09-13 Optrex Corp Organic led element
JPWO2005106835A1 (en) * 2004-04-30 2008-03-21 富士フイルム株式会社 Organic electroluminescence device with adjustable chromaticity
US7501189B2 (en) 2004-05-27 2009-03-10 Idemitsu Kosan Co., Ltd. White organic electroluminescent device
KR20090040233A (en) * 2007-10-19 2009-04-23 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Light-emitting device
WO2009096397A1 (en) * 2008-01-30 2009-08-06 Sumitomo Chemical Company, Limited Organic electroluminescent device, method for manufacturing the same, surface light source, illuminating device and display device
WO2011027653A1 (en) 2009-09-04 2011-03-10 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light-emitting device, and method for manufacturing the same
US7919783B2 (en) 2006-11-30 2011-04-05 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element and light-emitting device employing the same
KR101069036B1 (en) 2008-03-31 2011-09-29 도시바 모바일 디스플레이 가부시키가이샤 Organic el display device and method of manufacturing the same
US8154192B2 (en) 2005-10-17 2012-04-10 Semiconductor Energy Laboratory Co., Ltd. Lighting system
US8362466B2 (en) 2008-12-17 2013-01-29 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light-emitting device, and electronic device
US8564195B2 (en) 2007-02-09 2013-10-22 Samsung Display Co., Ltd. Display device
KR101373370B1 (en) 2006-12-26 2014-03-13 엘지디스플레이 주식회사 Organic light emitting diodes device and method of fabricating the same
CN104078612A (en) * 2013-03-29 2014-10-01 海洋王照明科技股份有限公司 White organic light-emitting diode and manufacturing method thereof
CN104269500A (en) * 2014-10-29 2015-01-07 中国科学院长春应用化学研究所 Red organic electroluminescent device and preparation method thereof
KR20150118068A (en) * 2007-09-27 2015-10-21 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Light-emitting element
EP3035403A1 (en) * 2014-12-18 2016-06-22 LG Display Co., Ltd. White organic light-emitting display device
JPWO2014185075A1 (en) * 2013-05-17 2017-02-23 パナソニックＩｐマネジメント株式会社 Organic electroluminescence device
US9698354B2 (en) 2009-12-01 2017-07-04 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light-emitting device, electronic device, and lighting device

Cited By (73)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005074328A1 (en) * 2004-01-29 2005-08-11 Nippon Seiki Co., Ltd. Organic el panel
US7755274B2 (en) 2004-01-29 2010-07-13 Nippon Seiki Co., Ltd. Organic EL panel
JPWO2005099313A1 (en) * 2004-04-02 2008-03-06 出光興産株式会社 ORGANIC ELECTROLUMINESCENT ELEMENT HAVING TWO LIGHT EMITTING LAYERS THROUGH ELECTRON BARRIER LAYER
WO2005099313A1 (en) * 2004-04-02 2005-10-20 Idemitsu Kosan Co., Ltd. Organic electroluminescence element having two electroluminescent layers through electron barrier layer
KR101110890B1 (en) * 2004-04-02 2012-03-13 이데미쓰 고산 가부시키가이샤 Organic electroluminescence element having two electroluminescent layers through electron barrier layer
US7576486B2 (en) 2004-04-02 2009-08-18 Idemitsu Kosan Co., Ltd. Organic electroluminescence element having two electroluminescent layers through electron barrier layer
JPWO2005106835A1 (en) * 2004-04-30 2008-03-21 富士フイルム株式会社 Organic electroluminescence device with adjustable chromaticity
US7663140B2 (en) 2004-05-21 2010-02-16 Semiconductor Energy Laboratory Co., Ltd. Light emitting element and light emitting device using the element
US8536569B2 (en) 2004-05-21 2013-09-17 Semiconductor Energy Laboratory Co., Ltd. Light emitting element and light emitting device using the element
JP2016028394A (en) * 2004-05-21 2016-02-25 株式会社半導体エネルギー研究所 Light-emitting device
WO2005115059A1 (en) * 2004-05-21 2005-12-01 Semiconductor Energy Laboratory Co., Ltd. Light emitting element and light emitting device using the element
JP2015065176A (en) * 2004-05-21 2015-04-09 株式会社半導体エネルギー研究所 Light-emitting device
JP2012015127A (en) * 2004-05-21 2012-01-19 Semiconductor Energy Lab Co Ltd Light-emitting device
US8076671B2 (en) 2004-05-21 2011-12-13 Semiconductor Energy Laboratory Co., Ltd. Light emitting element and light emitting device using the element
JP2011233536A (en) * 2004-05-21 2011-11-17 Semiconductor Energy Lab Co Ltd Light-emitting device
JP2006012793A (en) * 2004-05-21 2006-01-12 Semiconductor Energy Lab Co Ltd Light emitting element and light emitting device using the same
JP2021193692A (en) * 2004-05-21 2021-12-23 株式会社半導体エネルギー研究所 Light-emitting device
US7501189B2 (en) 2004-05-27 2009-03-10 Idemitsu Kosan Co., Ltd. White organic electroluminescent device
WO2005117499A1 (en) 2004-05-31 2005-12-08 Kabushiki Kaisha Toyota Jidoshokki Organic el device
KR100903542B1 (en) * 2004-05-31 2009-06-23 가부시키가이샤 도요다 지도숏키 Organic el device
US7854998B2 (en) 2004-05-31 2010-12-21 Kabushiki Kaisha Toyota Jidoshokki Organic EL devices
JP4737086B2 (en) * 2004-05-31 2011-07-27 株式会社豊田自動織機 Organic EL device
JPWO2005117499A1 (en) * 2004-05-31 2008-04-03 株式会社豊田自動織機 Organic EL device
US7528542B2 (en) 2004-12-01 2009-05-05 Idemitsu Kosan Co., Ltd. Organic electroluminescent device
WO2006059512A1 (en) * 2004-12-01 2006-06-08 Idemitsu Kosan Co., Ltd. Organic electroluminescent device
JP4496949B2 (en) * 2004-12-13 2010-07-07 株式会社豊田自動織機 Organic EL device
JP4496948B2 (en) * 2004-12-13 2010-07-07 株式会社豊田自動織機 Organic EL device
JP2006172762A (en) * 2004-12-13 2006-06-29 Toyota Industries Corp Organic el element
JP2006172763A (en) * 2004-12-13 2006-06-29 Toyota Industries Corp Organic el element
US8154192B2 (en) 2005-10-17 2012-04-10 Semiconductor Energy Laboratory Co., Ltd. Lighting system
US8441184B2 (en) 2005-10-17 2013-05-14 Semiconductor Energy Laboratory Co., Ltd. Lighting system
US7843134B2 (en) 2005-10-31 2010-11-30 Idemitsu Kosan Co., Ltd. Organic EL emission devices connected in series
WO2007052432A1 (en) 2005-10-31 2007-05-10 Idemitsu Kosan Co., Ltd. Organic el light emitting device
JP2007235081A (en) * 2006-01-31 2007-09-13 Optrex Corp Organic led element
US7919783B2 (en) 2006-11-30 2011-04-05 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element and light-emitting device employing the same
US8436346B2 (en) 2006-11-30 2013-05-07 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element and light-emitting device employing the same
KR101373370B1 (en) 2006-12-26 2014-03-13 엘지디스플레이 주식회사 Organic light emitting diodes device and method of fabricating the same
US8564195B2 (en) 2007-02-09 2013-10-22 Samsung Display Co., Ltd. Display device
US11108009B2 (en) 2007-09-27 2021-08-31 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, lighting device, light-emitting device, and electronic device
KR101644469B1 (en) 2007-09-27 2016-08-01 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Light-emitting element
US11462704B2 (en) 2007-09-27 2022-10-04 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, lighting device, light-emitting device, and electronic device
US9685623B2 (en) 2007-09-27 2017-06-20 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, lighting device, light-emitting device, and electronic device
KR20150118068A (en) * 2007-09-27 2015-10-21 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Light-emitting element
US10115926B2 (en) 2007-09-27 2018-10-30 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, lighting device, light-emitting device, and electronic device
US10636992B2 (en) 2007-09-27 2020-04-28 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, lighting device, light-emitting device, and electronic device
CN101414665B (en) * 2007-10-19 2012-07-11 株式会社半导体能源研究所 Light-emitting device
KR20160026958A (en) * 2007-10-19 2016-03-09 가부시키가이샤 한도오따이 에네루기 켄큐쇼 A method for manufacturing a light-emitting element
KR20090040233A (en) * 2007-10-19 2009-04-23 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Light-emitting device
TWI479712B (en) * 2007-10-19 2015-04-01 Semiconductor Energy Lab Light-emitting device
TWI479710B (en) * 2007-10-19 2015-04-01 Semiconductor Energy Lab Light-emitting device
EP2051310B1 (en) * 2007-10-19 2014-05-07 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device
JP2013214523A (en) * 2007-10-19 2013-10-17 Semiconductor Energy Lab Co Ltd Light-emitting element and light-emitting device
KR101710355B1 (en) 2007-10-19 2017-02-27 가부시키가이샤 한도오따이 에네루기 켄큐쇼 A method for manufacturing a light-emitting element
US8251765B2 (en) 2007-10-19 2012-08-28 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device
KR101598440B1 (en) 2007-10-19 2016-02-29 가부시키가이샤 한도오따이 에네루기 켄큐쇼 Light-emitting device
US8040047B2 (en) * 2007-10-19 2011-10-18 Semiconductor Energy Laboratory Co., Ltd. Light-emitting device
US9879176B2 (en) 2008-01-30 2018-01-30 Sumitomo Chemical Company, Limited Organic electroluminescent element, production method for the same, planar light source, lighting device, and display device
WO2009096397A1 (en) * 2008-01-30 2009-08-06 Sumitomo Chemical Company, Limited Organic electroluminescent device, method for manufacturing the same, surface light source, illuminating device and display device
KR101069036B1 (en) 2008-03-31 2011-09-29 도시바 모바일 디스플레이 가부시키가이샤 Organic el display device and method of manufacturing the same
US8362466B2 (en) 2008-12-17 2013-01-29 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light-emitting device, and electronic device
US9437824B2 (en) 2008-12-17 2016-09-06 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light emitting device, and electronic device
US9209415B2 (en) 2009-09-04 2015-12-08 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element with multiple light-emitting layers having controlled carrier mobility and lighting device and electronic device using the same
JP2011077032A (en) * 2009-09-04 2011-04-14 Semiconductor Energy Lab Co Ltd Light-emitting element, light-emitting device, and method of manufacturing the same
WO2011027653A1 (en) 2009-09-04 2011-03-10 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light-emitting device, and method for manufacturing the same
US9698354B2 (en) 2009-12-01 2017-07-04 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light-emitting device, electronic device, and lighting device
US10756287B2 (en) 2009-12-01 2020-08-25 Semiconductor Energy Laboratory Co., Ltd. Light-emitting element, light-emitting device, electronic device, and lighting device
CN104078612A (en) * 2013-03-29 2014-10-01 海洋王照明科技股份有限公司 White organic light-emitting diode and manufacturing method thereof
US9748313B2 (en) 2013-05-17 2017-08-29 Panasonic Intellectual Property Management Co., Ltd. Organic electroluminescent element
JPWO2014185075A1 (en) * 2013-05-17 2017-02-23 パナソニックＩｐマネジメント株式会社 Organic electroluminescence device
CN104269500B (en) * 2014-10-29 2017-04-12 中国科学院长春应用化学研究所 Red organic electroluminescent device and preparation method thereof
CN104269500A (en) * 2014-10-29 2015-01-07 中国科学院长春应用化学研究所 Red organic electroluminescent device and preparation method thereof
US10020458B2 (en) 2014-12-18 2018-07-10 Lg Display Co., Ltd. White organic light-emitting display device
EP3035403A1 (en) * 2014-12-18 2016-06-22 LG Display Co., Ltd. White organic light-emitting display device

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