JP2004139798A - Electrode substrate and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To aim at a removal of a surface defect layer existing on the surface of an anode of a CCM board, protection of the anode surface, and, by extension, at prevention of rise of drive voltage of an organic EL element as well as maintenance of luminous uniformity. <P>SOLUTION: A CCM layer 14 is laminated on a board 12 for making wave-length change of light, and an anode 16 made of an IZO is formed on the CCM layer 14. A surface protection layer 18 made of an inorganic compound is laminated on the anode 16 by a sputtering process with a plasma-supporting magnetron sputter of an inductive coupling type. SiO<SB>2</SB>is preferable as the inorganic compound. While removing the surface defect layer of the anode 16 the inorganic compound can maintain a state in which the surface defect is removed. As a result, electric stability of the anode 16 can be maintained for a long period of time to improve display image quality of an organic EL display device 100. <P>COPYRIGHT: (C)2004,JPO

Description

で表されるジスチリアリレーン系化合物を用いるのが好ましい。この化合物は、たとえば特開平２−２４７２７８号公報に開示されている。
【０１６９】
上記一般式において、Ｙ１〜Ｙ４はそれぞれ水素分子、炭素数１〜６のアルキリ基、炭素数１〜６のアルコキシ基、炭素数７〜８のアラルキル基、置換あるいは無置換の炭素数６〜１８のアリール基、置換あるいは無置換のシクロヘキシル基、置換あるいは無置換の炭素数６〜１８のアリールオキシ基、炭素数１〜６のアルコキシ基を示す。
【０１７０】
ここで置換基は、炭素数１〜６のアリキル基、炭素数１〜６のアルコキシ基、炭素数７〜８アラルキル基、炭素数６〜１８のアリールオキシ基、炭素数１〜６のアシル基、炭素数１〜６のアシルオキシ基、カルボキシル基、スチリル基、炭素数６〜２０のアリールカルボニル基、炭素数６〜２０のアリールオキシカルボニル基、炭素数１〜６のアルコキシカルボニル基、ビニル基、アニリノカルボニル基、カルバモイル基、フェニル基、ニトロ基、水酸基、あるいはハロゲンを示す。
【０１７１】
これらの置換基は単一でも複数でもよい。また、Ｙ１〜Ｙ４は同一でも、また互いに異なってもよく、Ｙ１とＹ２及びＹ３とＹ４は互いに置換している基と結合して、置換あるいは無置換の飽和五員環又は置換あるいは無置換の飽和六員環を形成してもよい。Ａｒは置換あるいは無置換の炭素数６〜２０のアリレーン基を表し、単一置換されていても、複数置換されていてもよく、また結合部分は、オルト、パラ、メタいずれでもよい。但し、Ａｒが無置換フェニレン基の場合、Ｙ１〜Ｙ４はそれぞれ炭素数１〜６のアルコキシ基、炭素数７〜８のアラルキル基、置換あるいは無置換のナフチル基、ビフェニル基、シクロヘキシル基、アリールオキシ基より選ばれたものである。このようなジスチルアリレーン系化合物としては、たとえば、下記を示すものが挙げられる。
【０１７２】
【化２】

【化３】

また、別の好ましい発光材料（ホスト材料）として、８−ヒドロキシキノリン、又はその誘導体の金属錯体を挙げることができる。具体的には、オキシン（一般に８−キノリノール又は８−ヒドロキシキノリン）のキレートを含む金属キレートオキサノイド化合物である。このような化合物は高水準の性能を示し、容易に薄膜形態に形成される。このオキサノイド化合物の例は、下記構造式を満たすものである。
【０１７３】
【化４】

尚、式中、Ｍｔは金属を表し、ｎは１〜３の整数であり、Ｚはそのそれぞれの位置が独立であって、少なくとも２以上の縮合芳香族環を完成させるために必要な原子を示す。
【０１７４】
ここで、Ｍｔで表される金属は、一価、二価又は三価の金属とすることができるものであり、たとえばリチウム、ナトリウム、カリウムなどのアルカリ金属、マグネシウムやカルシウムなどのアルカリ土類金属、あるいはホウ素又はアルミニウムなどの土類金属である。一般に、有用なキレート化合物であると知られている一価、二価又は三価の金属はいずれも使用することができる。
【０１７５】
また、上の式でＺは、少なくとも２以上の縮合芳香族環の一方がアゾール又はアジンからなる複素環を形成させる原子を示す。ここで、もし必要であれば、上記縮合芳香族環に他の異なる環を付加することが可能である。また、機能上の改善がないまま嵩ばった分子を回避するため、Ｚで示される原子の数は１８以下に維持することが好ましい。さらに、具体的にキレート化オキサノイド化合物を例示すると、トリス（８−キノリノール）アルミニウム、ビス（８−キノリノール）マグネシウム、ビス（ベンゾ−８−キノリノール）亜鉛、ビス（２−メチル−８−キノリノラート）アルミニウムオキシド、トリス（８−キノリノール）インジウム、トリス（５−メチル−８−キノリノール）アルミニウム、８−キノリノールリチウム、トリス（５−クロロ−８−キノリノール）ガリウム、ビス（５−クロロ−８−キノリノール）カルシウム、５，７−ジクロル−８−キノリノールアルミニウム、トリス（５，７−ジプロモー８−ヒドロキシキノリノール）アルミニウムなどがある。
【０１７６】
さらに、特開平５−１９８３７８号公報に記載されているフェノラート置換８−ヒドロキシキノリンの金属錯体は、青色発光材料として好ましいものである。このフェラート置換８−ヒドロキシキノリンの金属錯体の具体例としては、ビス（２−メチル−８−キノリノラート）（フェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（ｏ−クレゾラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（ｍ−クレゾラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（ｐ−クレゾラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（ｏ−フェニルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（ｍ−フェニルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（ｐ−フェニルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（２，３ジメチルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（２，６ジメチルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（３，４ジメチルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（３，５ジメチルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（３，５−ジーｔ−ブチルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（２，６ジフェニルフェノラート）アルミニウム（ＩＩＩ）、ビス（２−メチル−８−キノリノラート）（２，４，６−トリフェニルフェノラート）アルミニウム（ＩＩＩ）などが挙げられる。これらの発光材料は、一種用いてもよく、二種以上を組み合わせて用いてもよい。
【０１７７】
以下、発光層に関しさらに具体的に説明する。一般に白色の光を発光させる場合には、発光層を２層構成とする場合が多い。これらを、第一発光層、第二発光層と呼ぶ。
【０１７８】
本実施の形態に用いられる第一発光層としては、各種公知の発光材料が用いることができるが、好ましい第一発光層としては、上記オキサノイド化合物に緑色蛍光色素を０．２〜３重量％微量添加したものを挙げることができる。ここで添加される緑色蛍光色素としては、クマリン系、キナクリドン系である。これらを添加することにより第一発光層を保有する素子は、５〜２０（ｌｍ／ｗ）の高効率の緑色発光を実現することができる。一方、第一発光層から高効率にて黄色又は橙色を取り出したい場合には、オキサノイド化合物にルブレン及びその誘導体、ジシアノピラン誘導体、ペリレン誘導体を０．２〜３重量％添加したものを用いる。これらの素子は３〜１０（ｌｍ／ｗ）の高効率で発光出力をすることが可能である。また、緑色蛍光色素と赤色蛍光色素を同時に添加しても橙色が可能である。たとえば、好ましくはクマリンとジシアノピラン系色素、キナクリドンとペリレン色素、クマリンとペリレン色素を同時に用いてもよい。他の特に好ましい第一発光層はポリアリーレンビニレン誘導体である。これは緑色又は橙色を高効率に出力することが可能である。
【０１７９】
本実施の形態に用いられる第二発光層としては各種公知の青色発光材料を用いることができる。たとえばジスチリルアリレーン誘導体、トリススチリルアリレーン誘導体、アリルオキシ化キノリラート金属錯体が高効率で純度の高い青色を発光可能な青色発光材料である。また、ポリマーとしては、ポリパラフェニリン誘導体を挙げることができる。
【０１８０】
本実施の形態に用いられる有機ＥＬ素子における発光層の形成方法としては、たとえば、蒸着法、スピンコート法、キャスト法、ＬＢ法などの公知の方法により薄膜化することで形成することができるが、特に分子堆積膜であることが好ましい。ここで、分子堆積膜とは、該化合物の気相状態から沈着され形成された薄膜や、該化合物の溶融状態又は液相状態から固体化され形成された膜のことである。通常、この分子堆積膜は、ＬＢ法により形成された薄膜（分子累積膜）と凝集構造、高次構造の相違や、それに起因する機能的な相違により区別することができる。また、この発光層は、樹脂などの結着材と共に溶剤に溶かして溶液とした後、これをスピンコート法などにより薄膜化して形成することができる。このようにして形成された発光層の膜厚については、特に制限はなく、適宜状況に応じて選ぶことができるが、好ましくは１ｎｍ〜１０μｍ、特に好ましいのは５ｎｍ〜５μｍの範囲である。
【０１８１】
（８）　正孔注入層
次に、正孔注入層は、有機ＥＬ表示装置１００として必須の構成ではないが、発光性能の向上のために一般的に用いられるものであるので、本実施の形態でも正孔注入層を用いる例について説明する。
【０１８２】
この正孔注入層は発光層への正孔注入を助ける層であって、正孔移動度が大きく、イオン化エネルギーが、通常５．５ｅＶ以下と小さいものがよい。このような正孔注入層としては、より低い電界で正孔を発光層に輸送する材料が好ましく、さらに正孔の移動度が、たとえば１０^４〜１０^６Ｖ／ｃｍの電界印加時に、少なくとも１０^−６ｃｍ^２／Ｖ・秒〜（すなわち、１０^−６ｃｍ^２／Ｖ・秒以上）であればなお好ましい。このような正孔注入材料については、前記の好ましい性質を有するものであれば特に制限はなく、従来、光導伝材料において、正孔の電荷輸送材として慣用されているものや、ＥＬ素子の正孔注入層に使用される公知のもの中から任意のものを選択して用いることができる。
【０１８３】
具体例としては、たとえばトリアゾール誘導体（米国特許３，１１２，１９７号明細書等参照）、オキサジアゾール誘導体（米国特許３，１８９，４４７号明細書等参照）、イミダゾール誘導体（特公昭３７−１６０９６号公報等参照）、ポリアリールアルカン誘導体（米国特許３，６１５，４０２号明細書、同第３，８２０，９８９号明細書、同第３，５４２，５４４号明細書、特公昭４５−５５５号公報、同５１−１０９８３号公報、同５５−１７１０５号公報、同５６−４１４８号公報、同５５−１０８６６７号公報、同５５−１５６９５３号公報、同５６−３６６５６号公報等参照）、ピラゾリン誘導体及びピラゾロン誘導体（米国特許第３，１８０，７２９号明細書、同第４，２７８，７４６号明細書、特開昭５５−８８０６４号公報、同５５−８８０６５号公報、同４９−１０５５３７号公報、同５５−５１０８６号公報、同５６−８００５１号公報、同５６−８８１４１号公報、同５７−４５５４５号公報、同５４−１１２６３７号公報、同５５−７４５４６号公報等参照）等を挙げることができる。
【０１８４】
具体例としては、たとえばさらに、フェニレンジアミン誘導体（米国特許第３，６１５，４０４号明細書、特公昭５１−１０１０５号公報、同４６−３７１２号公報、同４７−２５３３６号公報、特開昭５４−５３４３５号公報、同５４−１１０５３６号公報、同５４−１１９９２５号公報等参照、）、アリールアミン誘導体（米国特許第３，５６７，４５０号明細書、同第３，１８０，７０３号明細書、同第３，２４０，５９７号明細書、同第３，６５８，５２０号明細書、同第４，２３２，１０３号明細書、同４，１７５，９６１号明細書、同第４，０１２，３７６号明細書、特公昭４９−３５７０２号公報、同３９−２７５７７号公報、特開昭５５−１４４２５０号公報、同５６−１１９１３２号公報、同５６−２２４３７号公報、西独特許第１，１１０，５１８号明細書等参照）、アミノ置換カルコン誘導体（米国特許第３，５２６，５０１号明細書等参照）、オキサゾール誘導体（米国特許第３，２５７，２０３号明細書等に開示のもの）、フルオレノン誘導体（特開昭５４−１１０８３７号公報等参照）、ヒドラゾン誘導体（米国特許第３，７１７，４６２号明細書、特開昭５４−５９１４３号公報、同５５−５２０６３号公報、同５５−５２０６４号公報、同５５−４６７６０号公報、同５５−８５４９５号公報、同５７−１１３５０号公報、同５７−１４８７４９号公報、特開平２−３１１５９１号公報等参照）、スチリルアントラセン誘導体（特開昭５６−４６２３４号公報等参照）、スチルベン誘導体（特開昭６１−２１０３６３号公報、同６１−２２８４５１号公報、同６１−１４６４２号公報、同６１−７２２５５号公報、同６２−４７６４６号公報、同６２−３６６７４号公報、同６２−１０６５２号公報、同６２−３０２５５号公報、同６０−９３４４５号公報、同６０−９４４６２号公報、同６０−１７４７４９号公報、同６０−１７５０５２号公報等参照）、シラザン誘導体（米国特許第４，９５０，９５０号明細書）、ポリシラン系（特開平２−２０４９９６号公報）、アニリン系共重合体（特開平２−２８２２６３号公報）、特開平１−２１１３９９号公報に開示されている導電性高分子オリゴマー（特にチオフェンオリゴマー）等を挙げることができる。
【０１８５】
正孔注入層の材料としては上記のものを使用することができるが、ポルフィリン化合物（特開昭６３−２９５６９６５号公報等に開示のもの）、芳香族第三級アミン化合物及びスチルアミン化合物（米国特許第４，１２７，４１２号明細書、特開昭５３−２７０３３号公報、同５４−５８４４５号公報、同５４−１４９６３４号公報、同５４−６４２９９号公報、同５５−７９４５０号公報、同５５−１４４２５０号公報、同５６−１１９１３２号公報、同６１−２９５５５８号公報、同６１−９８３５３号公報、同６３−２９５６９５号公報等参照）、特に芳香族第三級アミン化合物を用いることが好ましい。
【０１８６】
上記ポルフィリン化合物の代表例としては、ポルフィン、１，１０，１５，２０−テトラフェニルー２１Ｈ、２３Ｈ−ポルフィン銅（ＩＩ）、１，１０，１５，２０−テトラフェニル−２１Ｈ、２３Ｈ−ポルフィン亜鉛（ＩＩ）、５，１０，１５，２０−テトラキス（ペンタフルオロフェニル）−２１Ｈ，２３Ｈ−ポルフィン、シリコンフタロシアニンオキシド、アルミニウムフタロシアニンクロリド、フタロシアニン（無金属）、ジリチウムフタロシアニン、銅テトラメチルフタロシアニン、銅フタロシアニン、クロムフタロシアニン、亜鉛フタロシアニン、鉛フタロシアニン、チタニウムフタロシアニンオキシド、Ｍｇフタロシアニン、銅オクタメチルフタロシアニン等を挙げることができる。
【０１８７】
また、前記芳香族第三級アミン化合物及びスチリルアミン化合物の代表例としては、Ｎ，Ｎ，Ｎ’，Ｎ’−テトラフェニル−４，４’−ジアミノフェニル、Ｎ，Ｎ’−ジフェニル−Ｎ，Ｎ’−ビスー（３−メチルフェニル）−［１，１’−ビフェニル］−４，４’−ジアミン（以下ＴＰＤと略記する）、２，２−ビス（４−ジ−ｐ−トリルアミノフェニル）プロパン、１，１−ビス（４−ジ−ｐートリルアミノフェニル）シクロヘキサン、Ｎ，Ｎ，Ｎ’，Ｎ’−テトラ−ｐ−トリル−４，４’−ジアミノフェニル、１，１−ビス（４−ジ−ｐ−トリルアミノェニル）−４−フェニルシクロヘキサン、ビス（４−ジメチルアミノ−２−メチルフェニル）フェニルメタン、ビス（４−ジ−ｐ−トリルアミノフェニル）フェニルメタン、Ｎ，Ｎ’−ジフェニル−Ｎ，Ｎ’−ジ（４−メトキシフェニル）−４，４’−ジアミノビフェニル、Ｎ，Ｎ，Ｎ’，Ｎ’−テトラフェニル−４，４’−ジアミノフェニルエーテル、４，４’−ビス（ジフェニルアミノ）クオードリフェニル、Ｎ，Ｎ，Ｎ−トリ（ｐ−トリル）アミン、４−（ジ−ｐ−トリルアミノ）−４’−［４（ジ−ｐ−トリルアミノ）スチリル］スチルベン、４−Ｎ，Ｎ−ジフェニルアミノ−（２−ジフェニルビニル）ベンゼン、３−メトキシ−４’−Ｎ，Ｎ−ジフェニルアミノスチルベンゼン、Ｎ−フェニルカルバゾール、米国特許第５，０６１，５６９号に記載されている２個の縮合芳香族環を分子内に有する、たとえば、４，４’−ビス［Ｎ−（１−ナフチル）−Ｎ−フェニルアミノ］ビフェニル（以下ＮＰＤと略記する）、また、特開平４−３０８６８８号公報で記載されているトリフェニルアミンユニットが３つスターバースト型に連結された４，４’、４”−トリス［Ｎ−（３−メチルフェニル）−Ｎ−フェニルアミノ］トリフェニルアミン（以下ＭＴＤＡＴＡと略記する）等を挙げることができる。
【０１８８】
また、発光層の材料として示した前述の芳香族ジメチリディン系化合物の他、ｐ型―Ｓｉ，ｐ型ＳｉＣ等の無機化合物も正孔注入層の材料として使用することができる。正孔注入層は、上述した化合物を、たとえば真空蒸着法、スピンコート法、キャスト法、ＬＢ法等の公知の方法により薄膜化することにより形成することができる。正孔注入層としての膜厚は、特に制限はないが、通常は５ｎｍ〜５μｍである。この正孔注入層は、上述した材料の一種又は二種以上からなる一層で構成されてもよいし、又は、前記正孔注入層とは別種の化合物からなる正孔注入層を積層したものであってもよい。また、有機半導体層は、発光層への正孔注入又は電子注入を助ける層であって、１０−１０Ｓ／ｃｍ以上の導電率を有するものが好適である。このような有機半導体層の材料としては、含チオフェンオリゴマーや含アリールアミンオリゴマーなどの導電性オリゴマー、含アリールアミンデンドリマーなどの導電性デンドリマーなどを用いることができる
（９）　電子注入層・付着改善層
一方、電子注入層は、発光層への電子注入を助ける層であって、電子移動が大きく、また付着改善層は、この電子注入層の中で、特に陰極との付着がよい材料からなる層である。電子注入層に用いられる材料としては、たとえば８−ヒドロキシキノリン又はその誘導体の金属錯体、あるいはオキサジアゾール誘導体が好ましく挙げられる。また、付着改善層に用いられる材料としては、特に８−ヒドロキシキノリン又はその誘導体の金属錯体が好適である。上記８−ヒドロキシキノリン又はその誘導体の金属錯体の具体例としては、オキシン（一般に８−キノリノール又は８−ヒドロキシキノリン）のキレートを含む金属キレートオキサノイド化合物が挙げられる。一方、オキサジアゾール誘導体としては、以下に示す一般式（ＩＩ）、（ＩＩＩ）及び（ＩＶ）で示すものが挙げられよう。
【０１８９】
【化５】

この各式中、Ａｒ１０〜Ａｒ１３はそれぞれ置換又は無置換のアリール基を示し、Ａｒ１０とＡｒ１１及びＡｒ１２とＡｒ１３はそれぞれにおいて互いに同一であっても異なっていてもよく、Ａｒ１４は、置換又は無置換のアリレーン基を示す。
【０１９０】
オキサジアゾール誘導体としては、これらの式で表される電子伝達化合物が挙げられる。ここで、アリール基としてはフェニル基、ビフェニル基、アントラニル基、ペリレニル基、ピレニル基などが挙げられ、アリレーン基としてはフェニレン基、ナフチレン基、ビフェニレン基、アントラセニレン基、ペニレニレン基、ピレニレン基などが挙げられる。また、置換基としては炭素数１〜１０のアルキリ基、炭素数１〜１０のアルコキシ基又はシアノ基などが挙げられる。この電子伝達化合物は、薄膜形成性のものが好ましい。上記電子伝達化合物の具体例としては、以下の式で示される化合物が挙げられる。
【０１９１】
【化６】

（１０）　陰極２０
陰極２０としては、仕事関数の小さい（４ｅＶ以下）金属、合金、電気伝導性化合物及びこれらの混合物を電極物質とするものが用いられる。このような電極物質の具体例としては、ナトリウム、ナトリウム―カリウム合金、マグネシウム、リチウム、マグネシウム・銀合金、アルミニウム／酸化アルミニウム（Ａｌ_２Ｏ_３）、アルミニウム・リチウム合金、インジウム、希土類金属などが挙げられる。この陰極２０は、これらの電極物質を蒸着やスパッタリングなどの方法により、薄膜を形成することにより、作成することができる。また、陰極２０としてのシート抵抗は数百Ω／□以下が好ましく、膜厚は通常１０ｎｍ〜１μｍの中から選ぶことができ、特に５０〜２００ｎｍの範囲が好ましい。
【０１９２】
尚、本実施の形態に用いられる有機ＥＬ素子においては、該陽極１６又は陰極２０のいずれか一方が透明又は半透明であることが好ましい。透明又は半透明であれば、発光を透過するため、発光の取り出し効率がよいからである。
【０１９３】
（１１）有機ＥＬ素子１２２を構成する層の積層方法
ａ．陽極１６（基板電極）
基板１２側に積層する電極を基板電極と呼ぶ。したがって、既に上述した陽極１６は基板電極である。基板電極の積層方法としては、特に制限はないが、たとえば、蒸着法、スパッタリング法、イオンブレーティング法、電子ビーム蒸着法、ＣＶＤ法（ＣＶＤ：Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ：化学気相堆積法）、ＭＯＣＶＤ法（ＭＯＣＶＤ：Ｍｅｔａｌｏｒｇａｎｉｃ　ＣＶＤ：有機金属化学堆積法）、プラズマＣＶＤ法などのドライ成膜法が好ましい。陽極１６もこのような積層方法で積層される。
【０１９４】
ｂ．有機物層１８
上記「（７）発光層」で説明した手法と同様の手法で積層する。
【０１９５】
ｃ．対向電極
前記基板電極と対向する電極を対向電極と呼ぶ。したがって、既に上述した陰極２０は対向電極である。対向電極も上記基板電極と同様の手法で積層する。
【０１９６】
【実施例】
以下、本実施の形態のＣＣＭ電極基板及びその上で有機ＥＬ素子を構築した場合の有機ＥＬ表示装置（ＣＣＭパネル）に関して、具体的な数値を挙げて実施例を説明する。
【０１９７】
［実施例１］
本実施例１では、ＣＣＭ基板１２４（ＣＣＭ電極基板とも呼ぶこともある）上の陽極１６の上に表面保護層１０２を設けることによって、そのＣＣＭ基板１２４を利用して有機ＥＬ表示装置１２２（ＣＣＭパネルとも呼ばれる）を作成した場合、その有機ＥＬ表示装置１２２がより高性能化することを検証する。
【０１９８】
▲１▼ＣＣＭ基板１２４（色変換基板）の作製その１（色変換膜形成まで）
１０２ｍｍ×１３３ｍｍ×１．１ｍｍの支持基板（ＯＡ２ガラス：日本電気硝子社製）上に、ブラックマトリックス（ＢＭ）の材料としてＶ２５９ＢＫ（新日鉄化学社製）をスピンコートし、格子状のパターンになるような紫外線露光し、２％炭酸ナトリウム水溶液で現像後、２００℃でベーク（Ｂａｋｅ：焼成）して、ブラックマトリックス（膜厚１．５μｍ）のパターンを形成した。
【０１９９】
次に、青色カラーフィルタの材料として、Ｖ２５９Ｂ（新日鉄化学社製）をスピンコートし、長方形（９０μｍライン、２４０μｍギャップ）のストライプパターンが３２０本得られるようなフォトマスクを介して、ＢＭに位置合わせして紫外線露光し、２％炭酸ナトリウム水溶液で現像後、２００℃でベーク（焼成）して、青色カラーフィルタ（膜厚１．５μｍ）のパターンを形成した。
【０２００】
次に、緑色カラーフィルタの材料として、Ｖ２５９Ｇ（新日鉄化学社製）をスピンコートし、長方形（９０μｍライン、２４０μｍギャップ）のストライプパターンが３２０本得られるようなフォトマスクを介して、ＢＭに位置合わせして紫外線露光し、２％炭酸ナトリウム水溶液で現像後、２００℃でベーク（焼成）して、青色カラーフィルタの隣に緑色カラーフィルタ（膜厚１．５μｍ）のパターンを形成した。
【０２０１】
次に、赤色カラーフィルタの材料として、Ｖ２５９Ｒ（新日鉄化学社製）をスピンコートし、長方形（９０μｍライン、２４０μｍギャップ）のストライプパターンが３２０本得られるようなフォトマスクを介して、ＢＭに位置合わせして紫外線露光し、青色カラーフィルタと緑色カラーフィルタの間に赤色カラーフィルタ（膜厚１．５μｍ）のパターンを形成した。
【０２０２】
次に、緑色ＣＣＭ層１４Ｇの材料として、０．０４ｍｏ１／ｋｇ（対固形分）となる量のクマリン６をアクリル系ネガ型フォトレジスト（Ｖ２５９ＰＡ、固形分濃度５０％：新日鉄化学社製）に溶解させたインキを調製した。
【０２０３】
このインキを、先の基板上にスピンコートし、緑色カラーフィルタ上を紫外線露光し、２％炭酸ナトリウム水溶液で現像後、２００℃でベーク（焼成）して、緑色カラーフィルタ上に緑色変換膜のパターン（膜厚１０μｍ）を形成した。
【０２０４】
次に、赤色ＣＣＭ層１４Ｒの材料として、クマリン６：０．５３ｇ、ベーシックバイオレット１１：１．５ｇ、ローダミン６Ｇ：１．５ｇ、アクリル系ネガ型フォトレジスト（Ｖ２５９ＰＡ、固形分濃度５０％：新日鉄化学社製）：１００ｇに溶解させたインキを調製した。
【０２０５】
このインキを、先の基板上にスピンコートし、赤色カラーフィルタ上を紫外線露光し、２％炭酸ナトリウム水溶液で現像後、１８０℃でベーク（焼成）して、赤色カラーフィルタ上に赤色変換膜のパターン（膜厚１０μｍ）を形成し、色変換基板を得た。
【０２０６】
▲２▼ＣＣＭ基板１２４（色変換基板）の作製その２（平坦化膜〜陽極１６〜隔壁形成まで）
次に、平坦化膜としてアクリル系熱硬化性樹脂（Ｖ２５９ＰＨ：新日鉄化学社製）を先の基板上にスピンコートし、１８０℃でベーク（焼成）して、平坦化膜（膜厚５μｍ）を形成した。
【０２０７】
次に、酸素遮断層として、透明無機膜としてＳｉＯｘＮｙ（Ｏ／Ｏ＋Ｎ＝５０％：Ａｔｏｍｉｃ　ｒａｔｉｏ）を低温ＣＶＤにより２００ｎｍの厚さで成膜した。酸素透過量は０．１ｃｃ／ｍ^２・ｄａｙ未満であった。
【０２０８】
次に、ＩＺＯ（インジウム亜鉛酸化物）をスパッタリングにより２００ｎｍ膜厚で成膜した。
【０２０９】
次に、この基板上にポジ型レジスト（ＨＰＲ２０４：富士フィルムアーチ製）９０μｍライン、２０μｍギャップのストライプ状のパターンになるようなフォトマスクを介して、ＣＣＭ層又はカラーフィルタパターンと重なるように位置合わせをして紫外線露光し、ＴＭＡＨ（テトラメチルアンモニウムヒドロキシド）の現像液で現像し、１３０℃でベーク（焼成）して、レジストパターンを得た。
【０２１０】
次に、５％蓚酸水溶液からなるＩＺＯエッチャントにて、露出している部分のＩＺＯをエッチングした。次に、レジストをエタノールアミンを主成分とする剥離液（Ｎ３０３：長瀬産業製）で処理して、ＩＺＯパターン（下部電極：陽極１６、ライン数９６０本）を得た。
【０２１１】
次に、第一の層間絶縁膜として、ネガ型レジスト（Ｖ２５９ＰＡ：新日鉄化学社製）をスピンコートし、紫外線露光し、ＴＭＡＨ（テトラメチルアンモニウムヒドロキシド）の現像液で現像した。次に、１８０℃でベーク（焼成）して、ＩＴＯのエッジを被覆し、ＩＺＯの開口部が７０μｍ×２９０μｍとなるようにした。
【０２１２】
次に、第二の層間絶縁膜（隔壁）として、ネガ型レジスト（ＺＰＮ１１００：日本ゼオン製）をスピンコートし、２０μｍライン、３１０μｍギャップのストライプパターンになるようなフォトマスクを介して、紫外線露光後、さらに露光後ベーク（焼成）を行った。次に、ＴＭＡＨ（テトラメチルアンモニウムヒドロキシド）の現像液でネガレジストを現像し、ＩＺＯストライプに直交した有機膜の第二の層間絶縁膜（隔壁）を形成した。
【０２１３】
▲３▼ＣＣＭ基板１２４（色変換基板）の作製その３（陽極１６上に表面保護層１０２を成膜）
上記のようにして層間絶縁膜を設けた基板の上に誘導結合型ＲＦプラズマ支援マグネトロンスパッタ法（以下ヘリカルスパッタ法と呼ぶ）にてＳｉＯ_２を２０Å成膜した。詳細な手順は以下の通りである。
【０２１４】
上記基板を洗浄後、その洗浄後の基板をスパッタチャンバーへセットし、真空排気を行った。尚、実験に用いた装置では、ＳｉＯ_２のターゲットから基板までの距離は３０ｃｍである。
【０２１５】
真空度が２．０×１０^４Ｐａ以下となったことを確認後、放電ガスとしてＡｒをマスクフローコントローラーにて８０ｓｃｃｍ導入した。このときの真空度は０．３８Ｐａであった。
【０２１６】
ターゲット直上のメインシャッターが閉の状態で、周波数１３．５６ＭＨｚの誘導結合用コイルに５０Ｗ、ＳｉＯ_２ターゲット（カソード）に同じく周波数１３．５６ＭＨｚ　５００Ｗの高周波を印加し、プラズマ放電を起こした。このとき各コイルの反射はいずれも５Ｗ以下であった。このメインシャッター閉の状態で５分上記放電を継続させ、ＳｉＯ_２ターゲット表面をクリーニングした。
【０２１７】
この後メインシャッターを開け、あらかじめ計測しておいた成膜レートの値より推測して、６分２０秒間のプラズマ放電によって成膜し、その結果、膜厚２０ÅのＳｉＯ_２をＩＺＯ上に形成した。
【０２１８】
▲４▼ＣＣＭ基板１２４（色変換基板）上への有機ＥＬ素子の形成及びパネル封止
このようにして得られた基板を純水及びイソプロピルアルコール中で超音波洗浄し、乾燥窒素ブローにて乾燥した。
【０２１９】
基板を有機蒸着装置（日本真空技術製）内部に移動させ、基板を基板ホルダーに固定した。
【０２２０】
尚、有機蒸着装置にはモリブデン製の加熱ポートが備えられている。そして、あらかじめ、それぞれのモリブテン製の加熱ポートには、各種材料が仕込まれている。
【０２２１】
具体的には、正孔注入材料として、４，４’、４”−トリス［Ｎ−（３−メチルフェニル）−Ｎ−フェニルアミノ］トリフェニルアミン（ＭＴＤＡＴＡ）、４，４’−ビス［Ｎ−（１−ナフチル）−Ｎ−フェニルアミノ］ビフェニル（ＮＰＤ）が仕込まれている。発光材料のホストとしては、４，４’−ビス（２，２−ジフェニルビニル）ビフェニル（ＤＰＶＢｉ）が仕込まれている。ドーパントとしては、１，４−ビス［４−（Ｎ，Ｎ−ジフェニルアミノスチリルベンゼン）］（ＤＰＡＶＢ）が仕込まれている。電子注入材料としては、トリス（８−キノリノール）アルミニウム（Ａｌｑ）とＬｉが仕込まれている。さらに陰極２０としてはＡｌが仕込まれている。
【０２２２】
その後、真空槽を５×１０^−７ｔｏｒｒまで減圧したのち、以下の手順で正孔注入層から陰極２０まで積層した。尚、積層工程の途中では、一度も真空を破らずに、一回の真空引きで各層を順次積層した。
【０２２３】
まず、正孔注入層としては、ＭＴＤＡＴＡを蒸着速度０．１〜０．３ｎｍ／秒で成膜し、膜厚６０ｎｍを得た。さらに、ＮＰＤを蒸着速度０．１〜０．３ｎｍ／秒で成膜し、膜厚２０ｎｍを得た。また、発光層としては、ＤＰＶＢｉとＤＰＡＶＢをそれぞれ蒸着速度０．１〜０．３ｎｍ／秒、蒸着速度０．０３〜０．０５ｎｍ／秒で共蒸着して膜厚５０ｎｍを得た。電子注入層としては、Ａｌｑを蒸着速度０．１〜０．３ｎｍ／秒で成膜し、膜厚２０ｎｍを得た。さらに、Ａ１ｑとＬｉをそれぞれ０．１〜０．３ｎｍ／秒、０．００５ｎｍ／秒で共蒸着して成膜し、膜厚２０ｎｍを得た。最後に、陰極２０としてＡ１を蒸着速度０．１〜０．３ｎｍ／秒で成膜し、膜厚１５０ｎｍの陰極２０を構成した。このようにして、有機ＥＬ素子を作製した。
【０２２４】
次に、この基板を乾燥窒素（露点―５０℃）を循環したグローブボックス内に移動し、１０２ｍｍ×１３３ｍｍ×１．１ｍｍの青色ガラスにて表示部を被覆し、表示部周辺部はカチオン硬化製の接着剤（ＴＢ３１０２：スリーボンド製）で光硬化させて貼り合わせ、パッシブ型有機ＥＬ表示装置を作製した。
【０２２５】
▲５▼色変換パネル封止の駆動評価
その下部電極（陽極１６：ＩＺＯ）と上部電極（陰極２０：Ａｌ）にＤｕｔｙ＝１／１２０にて、１５Ｖの電圧を印加（下部電極：（＋）、上部電極：（−））したところ、各電極の交差部分（画素）が発光した。
【０２２６】
発光輝度は、色彩色差計（ＣＳ１００、ミノルタ製）にて、青色カラーフィルタ部（青色画素）で１６ｃｄ／ｍ^２でＣＩＥ色度座標はＸ＝０．１５、Ｙ＝０．１６の青色の発光、緑ＣＣＭ層／緑色カラーフィルタ部（緑色画素）で４５ｃｄ／ｍ^２でＣＩＥ色度座標はＸ＝０．２７、Ｙ＝０．６７の緑色の発光、赤ＣＣＭ層／赤色カラーフィルタ部（赤色画素）で１５ｃｄ／ｍ^２でＣＩＥ色度座標はＸ＝０．６４、Ｙ＝０．３５の赤色の発光が得られ、光の３原色が得られた。
【０２２７】
尚、その時の有機ＥＬ素子の発光輝度は２００ｃｄ／ｍ^２（全画素発光に相当）でＣＩＥ色度座標はＸ＝０．１７、Ｙ＝０．２８の青色の発光であった。
【０２２８】
次にこの駆動条件で、室温２２℃で１０００時間駆動させたところ、青色画素が１０ｃｄ／ｍ^２（初期値を１とすると、比率０．６７）、緑色画素が２７ｃｄ／ｍ^２（初期値を１とすると、比率０．６０）、赤色画素が９ｃｄ／ｍ^２（初期値を１とすると、比率０．６０）であり、有機ＥＬ素子の輝度は１２６ｃｄ／ｍ^２（初期値を１とすると、比率０．６３）であった。
【０２２９】
また、有機ＥＬ素子を通常の乾燥窒素のような不活性気体にて封止した場合の有機ＥＬ素子の輝度劣化は、上記駆動条件と同様の駆動条件下で、初期値を１とすると、比率０．６５であった。
【０２３０】
［比較例１］
実施例１における▲３▼ＣＣＭ基板１２４の作製（陽極１６上に表面保護層１０２成膜）において表面保護層１０２としてのＳｉＯ_２を成膜工程を実行せずに、すぐに▲４▼ＣＣＭ基板１２４上への有機ＥＬ素子層形成及びパネル封止の処理を全く同様に行い、有機ＥＬ表示装置（有機ＥＬパネル）を作製した。実施例１と同様、▲５▼色変換パネル封止の駆動評価を行い、以下のような結果を得た。
【０２３１】
発光輝度は、色彩色差計（ＣＳ１００、ミノルタ製）にて、青色カラーフィルタ部（青色画素）で１１ｃｄ／ｍ^２でＣＩＥ色度座標はＸ＝０．１５、Ｙ＝０．１６の青色の発光、緑ＣＣＭ層／緑色カラーフィルタ部（緑色画素）で３ｃｄ／ｍ^２でＣＩＥ色度座標はＸ＝０．２７、Ｙ＝０．６７の緑色の発光、赤ＣＣＭ層／赤色カラーフィルタ部（赤色画素）で１２ｃｄ／ｍ^２でＣＩＥ色度座標はＸ＝０．６４、Ｙ＝０．３６の赤色の発光が得られ、光の３原色が得られた。
【０２３２】
尚、その時のＥＬ素子の発光輝度は１５０ｃｄ／ｍ^２（全画素発光に相当）でＣＩＥ色度座標はＸ＝０．１７、Ｙ＝０．２７の青色の発光であった。
【０２３３】
次にこの駆動条件で、室温２２℃で１０００時間駆動させたところ、青色画素が６ｃｄ／ｍ^２（初期値を１とすると、比率０．５５）、緑色画素が１６ｃｄ／ｍ^２（初期値を１とすると、比率０．４８）、赤色画素が６ｃｄ／ｍ^２（初期値を１とすると、比率０．５０）であり、有機ＥＬ素子の輝度は８４ｃｄ／ｍ^２（初期値を１とすると、比率０．５６）であった。
【０２３４】
また、有機ＥＬ素子を通常の乾燥窒素のような不活性気体にて封止した場合の有機ＥＬ素子の輝度劣化は、この駆動条件は、初期値を１とすると、比率０．５８であった。
【０２３５】
以上の結果よりＣＣＭ基板１２４の陽極１６であるＩＺＯ上に表面保護層１０２を成膜すると、成膜しなかった場合に比べて、各色とも同じ電圧に対する発光輝度が増加していることが理解できよう。すなわち、本実施例によれば、発光効率の向上が確認できたことになる。
【０２３６】
また、連続駆動した場合にも表面保護層１０２を成膜した方が、成膜しない場合に比べて発光輝度の劣化の進行速度が抑制されていることが理解できる。
【０２３７】
このように、陽極１６上に表面保護層１０２を成膜した場合に、発光性能が向上し、しかも連続駆動時のパネルの安定性（すなわち、寿命）が向上することが判明した。
【０２３８】
実施の形態２　ＴＦＴを構成に含む例
図１に示した例では、ＣＣＭ層１４の上に陽極１６が示されている。図１では、この陽極１６の駆動方式については特に示されていないが、たとえば、ＴＦＴ（Ｔｈｉｎ　Ｆｉｌｍ　Ｔｒａｎｓｉｓｔｏｒ：薄膜トランジスタ）で駆動することも好ましい。このような構成が図４に示されている。この図４においては、図１で示した１画素中の１色の部位に関して、その断面模式図が示されている。すなわち、図１中の赤、青、緑のうち、いずれか１色分の部位を示している。
【０２３９】
この図に示すように、本実施の形態では、基板１２上にＣＣＭ層１４が設けられている。そして、ＣＣＭ層１４の上に、オーバーコート層２１０、パッシべーション膜２１２が設けられている。パッシベーション膜２１２上には、薄膜トランジスタ２２０のゲート２２６が設けられ、さらにその上を覆うように絶縁膜２３０が積層されている。
【０２４０】
絶縁膜２３０上には、陽極１６と、この陽極１６を駆動する薄膜トランジスタ２２０のドレイン２２４とソース２２２とが形成されている。そして、ドレイン２２４は、陽極１６と電気的に接続している。
【０２４１】
本実施の形態２において特徴的な事項は、陽極１６が薄膜トランジスタ（ＴＦＴ）で駆動されていることである。そして、この薄膜トランジスタ２２０のゲート２２６に印加する電位によって陽極１６への電力供給を制御する。尚、この薄膜トランジスタ２２０は、請求の範囲の「駆動素子」の一例に相当する。
【０２４２】
本発明の特徴の一つに、陽極１６の上に表面保護層１０２が設けられている点が挙げられるが、この陽極と同層に薄膜トランジスタ２２０が備えられていてもかまわないことを本実施の形態２は示すものである。
【０２４３】
換言すれば、本実施の形態２において、図２と本質的に相違する点は、薄膜トランジスタ２２０によって陽極１６が駆動される点のみである。すなわち、陽極及び薄膜トランジスタ２２０の上には、図１と同様に表面保護層１０２が設けられている。この表面保護層は、これまで説明してきた表面保護層１０２と同様のものである。
【０２４４】
また、図１と同様に、表面保護層１０２の上には有機物層１８、陰極２０が設けられ、全体として有機ＥＬ表示装置２００が構成されている。
【０２４５】
本実施の形態２では、陽極１６の駆動方式として薄膜トランジスタ２２０を利用することを示したが、もちろん他の種々の駆動素子・駆動方式を適宜採用することが可能である。
【０２４６】
【発明の効果】
以上述べたように、本発明の電極基板によれば、表面不良層を減少させた電極を用いているので、電気的安定性が改善されている。したがって、この電極基板をたとえば、有機ＥＬ素子の陽極として用いれば、素子の寿命を延ばすことができるという効果を奏する。さらに、この有機ＥＬ素子の駆動電圧の上昇を抑えることができるという効果を奏する。さらに、この有機ＥＬ素子の耐熱性を向上させることができる。
【０２４７】
また、本発明によれば、電極基板上の電極を駆動する駆動素子が設けられているので、たとえばＴＦＴ方式等の表示装置の製造に適した電極基板を提供することができる。
【０２４８】
また、本発明の電極基板を有機ＥＬ素子の電極として用いて、有機ＥＬ表示装置を構成すれば、発光むらや輝度のばらつきが減少し、画質が向上した有機ＥＬ表示装置を得ることができる。さらに、その有機ＥＬ表示装置の画質品質の経時的信頼性を向上させることが可能である。
【０２４９】
また、本発明の電極基板製造方法によれば、上記のような効果を奏する電極基板を製造することができる。
【図面の簡単な説明】
【図１】本発明の好適な有機ＥＬ表示装置の構成を表す断面模式図である。
【図２】Ｉｎ含有化合物をＸＰＳで検査した場合のスペクトルを表すグラフの模式図である。
【図３】実施の形態２に係る有機ＥＬ表示装置の構成を表す断面模式図である。
【図４】従来のＣＣＭ型有機ＥＬ表示装置の断面模式図である。
【符号の説明】
１０、１００、２００　有機ＥＬ表示装置
１２　基板
１４　ＣＣＭ層
１４Ｂ　青色ＣＣＭ層
１４Ｒ　赤色ＣＣＭ層
１４Ｇ　緑色ＣＣＭ層
１６　陽極
１８　有機物層
２０　陰極
２２、１２２　有機ＥＬ素子
２４、１２４　ＣＣＭ基板
１０２　表面保護層
２１０　オーバーコート層
２１２　パッシメーション膜
２２０　薄膜トランジスタ
２２２　ゲート
２２４　ドレイン
２２６　ゲート[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a structure of a substrate of an organic EL device and a method of manufacturing the same. In particular, the present invention relates to an electrode substrate used for an organic EL device using the CCM method. More specifically, the present invention relates to a color conversion (CCM) substrate that takes measures against deterioration of the surface of a transparent electrode serving as an anode of the substrate.
[0002]
[Prior art]
A. [Technical background]
2. Description of the Related Art In recent years, organic EL (Electroluminescence) elements have attracted attention in terms of application as light emitting devices and display devices. For example, utilization as color and full-color display devices such as information display devices and in-vehicle display devices has been promoted.
[0003]
(1) Basic structure of organic EL device
In general, an organic EL element has a configuration in which a transparent electrode is used as an anode, an Al (aluminum) or the like is used as a cathode as a counter electrode, and an organic material layer is sandwiched between the two electrodes. Various applications of such an organic EL element are considered, and among them, expectations for application to a color display are great.
[0004]
(2) CCM method
The present invention particularly relates to an organic EL device to which a CCM (Color Changing Medium) method is applied. Here, the CCM method is one of the methods for colorizing a display device.
It is. When a color display device is formed using an organic EL element, for example, it is conceivable to use an organic substance that emits light of three primary colors (red, blue, and green). However, the use of three types of organic substances (hereinafter, simply referred to as organic substances) complicates the manufacturing process. Therefore, it is desirable that colorization can be achieved with only one type of organic substance. The CCM method has been devised based on such a request, and converts monochromatic light (for example, blue) emitted from one kind of organic substance into light of another wavelength (for example, red or green) as appropriate using a fluorescence conversion layer. This is a method for creating three primary colors.
[0005]
The CCM method is one of the most promising methods among colorization methods for a display device, from the viewpoint of manufacturing cost and high definition of a pattern (full colorization). Incidentally, in the CCM method, there may be a case where a device is used to increase the purity of the emission color by using not only a simple fluorescence conversion layer but also a color filter. That is, it is known that the emission color of the organic EL is changed using the fluorescence conversion layer and / or the color filter layer.
[0006]
FIG. 6 is a schematic cross-sectional view illustrating a basic structure of the organic EL display device 10 using the CCM method. As shown in this figure, a CCM layer 14 is provided on a transparent glass substrate 12. The CCM layer 14 includes a green CCM layer 14G that emits green fluorescence, a red CCM layer 14R that emits red fluorescence, and a blue CCM layer 14B of a transparent material that directly transmits the blue light emitted by the organic material layer 18. One pixel on the screen as a display device includes a green CCM layer 14G, a red CCM layer 14R, and a blue CCM layer 14B.
[0007]
On the CCM layer 14, an anode 16 which is a transparent electrode is laminated. As the anode 16, ITO (indium tin oxide: Indium Tin Oxide) or IZO (indium zinc oxide: Indium Zinc Oxide) is used. An organic layer 18 and a cathode 20 (for example, aluminum (Al)) are provided on the anode 16 in this order. The organic layer 18 emits light when an electric field is applied, and is therefore sometimes called a light emitting layer.
[0008]
The CCM type organic EL display device 10 often uses an organic material layer 18 that emits blue light. Then, the wavelength of the blue light is converted to green light by the green CCM layer 14G, and the wavelength is converted to red light by the red CCM layer 14R. On the other hand, the blue CCM layer 14B transmits the blue light emitted from the organic material layer 18 as it is. With such a configuration, three primary colors of red, blue, and green light can be obtained.
[0009]
In FIG. 6 and the above description, only the basic structure of the organic EL display device 10 of the CCM system has been described. However, actually, the CCM layer 14 may include a color filter to improve the color purity. Many. The organic material layer 18 is provided with an electron injection layer and a hole injection layer, and the mechanism for efficiently supplying electrons from the cathode 20 and holes from the anode 16 to the light emitting layer (organic material layer 18) is actually wide. It's being used.
[0010]
Note that, in the organic EL display device 10, the structure from the anode 16 to the cathode 20 is particularly called "organic EL element 22". That is, the anode 16, the organic material layer 18, and the cathode 20.
[0011]
In the organic EL display device 10, the structure from the substrate 12 to the anode 16 is referred to as an "electrode substrate" in the sense of a substrate with electrodes. The organic EL display device 10 can be easily manufactured by stacking an organic material constituting an EL element and a cathode on the electrode substrate. Further, when the CCM layer 14 is provided between the substrate 12 and the anode 16, the CCM type organic EL display device 10 can be easily manufactured. Call. That is, an electrode substrate including the substrate 12, the CCM layer 14, and the anode 16 is called a CCM substrate 24.
[0012]
(3) Surface defect layer on anode
The organic EL element is formed on a substrate. When the CCM method is adopted, the above-described fluorescence conversion layer and / or color filter layer are provided on the substrate. Then, an anode is further provided on the fluorescence conversion layer and the like, and thereafter, an organic material layer and a cathode are sequentially stacked, and an organic EL element is formed on the substrate.
[0013]
Further, as described above, when the CCM method is used, the substrate, the fluorescent conversion layer and / or the color filter layer, and the anode laminated thereon are referred to as the CCM substrate 24. As the anode 16 constituting the CCM substrate 24, a transparent electrode such as IZO (Indium Zinc Oxide) is used. The present inventors have conducted research on the formation of a surface defect layer of the anode, and have found the following.
[0014]
{Circle around (1)} When preparing a CCM substrate, the substrate preparation involves a large number of steps, substrate contamination is likely to progress, and a surface defect layer is likely to be formed on the anode surface. In particular, the surface of a transparent electrode such as IZO is easily damaged by an excessive cleaning step or an etching residue for patterning. Furthermore, a so-called poor surface layer tends to be formed on the anode due to adsorption of water on the electrode surface, precipitation of trace impurity atoms contained in the bulk of the electrode (an internal portion other than the surface portion) on the surface, and the like. It is in.
[0015]
{Circle around (2)} Further, the CCM layer (fluorescence conversion layer) itself is often formed of a resin, and volatile gas components such as moisture from the resin may gradually contaminate the anode surface.
[0016]
(4) The present inventors have found that the following phenomena occur due to the presence of such a defective surface layer.
[0017]
(1) The driving voltage of the organic EL element increases. That is, the so-called EL performance is reduced.
[0018]
(2) The uniformity of light emission of the organic EL element is reduced. Specifically, when a CCM panel (a display panel using an organic EL element using the CCM method) is formed, a reduction phenomenon of each pixel has been observed.
[0019]
{Circle around (3)} When the above-mentioned CCM panel is evaluated for acceleration in a heating environment, a phenomenon in which the speed of pixel reduction is accelerated has been observed (for example, a heating environment of ８５85 ° C. or the like is used).
[0020]
The problems as described above have been found by the study of the present inventors.
[0021]
(5) Improvement of conventional anode
Conventionally, various measures have been taken to improve the adhesion and conductivity between the anode 16 of the organic EL element and the organic material laminated on the anode.
[0022]
As one of the measures, there is a method of inserting an organic compound or an inorganic substance of metal or semiconductor as a buffer layer between the anode 16 and the organic layer. This technique has been widely studied for quite some time.
[0023]
However, this method of inserting the buffer layer does not have the effect of modifying the deterioration of the surface of the transparent electrode (anode) as described in (3) and (4) above. Therefore, the technique of simply inserting a buffer layer cannot modify the deterioration of the anode surface, so that its effect is naturally limited.
[0024]
B. [Examples of prior art documents]
Next, the prior art will be introduced with reference to specific prior art documents, and the contents, disadvantages, problems and the like will be described.
[0025]
(1) Passivation film ( passivation film )
For example, WO 0072637 Al (hereinafter referred to as Reference 1) discloses an organic EL display by a CCM method including a barrier film (= passivation film) made of silicon oxide.
[0026]
First, according to Document 1, a substrate and a CCM layer (including a color filter layer) thereon are covered with an organic layer for flattening and flattening, and an organic EL element is stacked thereon. It is also said that no "cut" occurs.
[0027]
When there is a step on the surface on which the organic EL elements are stacked, there is a possibility that discontinuous portions may occur in the film of the organic EL elements to be stacked. This discontinuity is called "break". Further, as an example of an organic layer for flattening, an example of a thermosetting resin or an ultraviolet curable resin is disclosed in Document 1.
[0028]
Further, in Document 1, when an organic EL element is directly laminated on an organic layer for planarization, the components of the organic layer for planarization volatilize due to heat during the lamination of the organic EL or during driving, and this is It is pointed out that it may have a bad influence on each constituent material of the organic EL. As a result, it is pointed out in Document 1 that it is assumed that a non-light-emitting area called a dark spot is generated or that light emission of a predetermined quality cannot be maintained.
[0029]
Therefore, in this document 1, the barrier layer (passivation film) made of SiOx is laminated between the organic layer for planarization and the organic EL element, so that the organic layer component for planarization is an organic EL element. It is shown that diffusion into each layer material is prevented to prevent deterioration of the device.
[0030]
However, this barrier layer (passivation film) is effective in preventing the diffusion of volatile components from the organic layer and the CCM layer, but has little effect on the incorporation of moisture and the like from portions other than the CCM layer. Can be
[0031]
It is considered that the moisture mixed into the device is adsorbed between the anode 16 and the organic layer, lowering the adhesiveness and deteriorating the charge injection property. As a result, a so-called poor surface layer of the anode is expected to be formed. The present invention is an invention for realizing a method (surface protective layer) for suppressing the occurrence of such a surface defective layer.
[0032]
(2) Lamination of buffer layer on anode
The purpose of the buffer layer laminated on the anode is to improve the adhesion, to improve the conductivity by an inorganic material, to use an insulating thin film layer, or to reverse the sputtering of the anode surface (reverse sputtering). ), Etc. This will be described sequentially below.
[0033]
(1) Inserting a buffer layer for the purpose of improving the adhesion (adhesion of organic substances) of the anode / organic substance layer
In Japanese Patent Application Laid-Open No. Hei 10-214683 (hereinafter referred to as Reference 2), since the crystalline state of polycrystalline ITO (Indium Tin Oxide) is different from that of an organic material, the anode and the organic material layer are not joined well and partially joined. This indicates that a defect may occur, a dark spot (dark spot) may occur, or that heat generated in a defective bonding portion may cause deterioration of the organic layer.
[0034]
In Document 2, in order to solve these problems, a conductive junction improving layer (a metal such as Au or Pt, a metal oxide such as MoOx, VOx, SnOx, InOx, or BaOx, or an amorphous film such as a conjugated polymer) is used. Is provided in a thickness range of 1 to 500 μm.
[0035]
Also, Japanese Patent Application Laid-Open No. 9-324176 (hereinafter referred to as Document 3) discloses a technique for improving the adhesion between an electrode and an organic film to prevent generation of a non-light-emitting portion, and improving long-term storage and continuous driving half-life. It is shown. In order to achieve such an object, Document 3 discloses a technique of interposing a layer made of a material in which the terminal of a compound conventionally used as a hole injection / transport material is substituted with a silane coupling group.
[0036]
Japanese Patent Application Laid-Open No. 9-204985 (hereinafter referred to as Reference 4) discloses a technique for treating the ITO electrode itself with a titanate-based coupling agent from the same viewpoint as Reference 3.
[0037]
(2) The use of inorganic materials (semiconductors, conductors) to improve conductivity etc.
In Japanese Patent Application Laid-Open No. 3-105898 (hereinafter referred to as Document 5), a hole transport layer or an electron transport layer, which is usually made of an organic material, is formed of a P-type or N-type amorphous semiconductor having a good film formation state to improve luminous performance. The technology is disclosed.
[0038]
In JP-A-10-260062 (hereinafter referred to as Reference 6), a mixed layer of ITO and an inorganic semiconductor is formed instead of using an expensive hole injecting and transporting material, and the resistivity is set to 20 Ω · cm or less. The configuration is disclosed. Since this configuration is low-cost and avoids direct connection between the organic substance and ITO, a good result can be obtained even from the viewpoint of the above-mentioned improvement in adhesion, and an element in which generation of a dark spot or the like is suppressed. Can be formed.
[0039]
In Japanese Patent Application Laid-Open No. 9-63771 (hereinafter referred to as Reference 7), a metal oxide (RuO, MoO, VO, etc.) having a work function larger than that of ITO is provided between ITO as an anode and a hole transport layer. By forming the layer to have a thickness of 5 to 30 nm, the energy barrier between the anode and the hole transport layer is reduced, and the luminous efficiency is improved.
[0040]
Japanese Patent Application Laid-Open No. 08-031573 (hereinafter referred to as Reference 8) discloses a configuration in which a part of the anode or the entire anode is formed of a carbon thin film.
[0041]
In addition, JP-A-03-210791, JP-A-03-262170, and JP-A-06-119973 disclose that a P-type semiconductor is used as a hole transport material.
[0042]
(3) Forming an insulator thin film layer between the anode and the organic material layer
U.S. Pat. No. 5,853,905 (hereinafter referred to as "Reference 9") describes a proposal for a new element configuration utilizing a tunnel injection mechanism by improving the adhesion between a transparent electrode and an organic substance or by positively forming a charge barrier.
[0043]
Also, in Japanese Patent Application Laid-Open No. 08-288069 (hereinafter referred to as Document 10), a nitride such as aluminum nitride is coated with a thin film of about 50 ° between the anode and the organic material layer in order to avoid the occurrence of leakage occurring during continuous driving. The configuration provided is disclosed.
[0044]
(4) Reverse anode sputtering of anode surface in advance
Japanese Patent Application Laid-Open No. H11-126689 (hereinafter referred to as Reference 11) recognizes that the cause of the leakage current or dark spot is caused by unevenness on the anode surface, and proposes an anode surface treatment by reverse sputtering to eliminate the unevenness. Have been.
[0045]
[Problems to be solved by the invention]
In the prior art described in the paragraphs (1) to (3) of "(2) Lamination of the buffer layer on the anode" in "B. [Examples of prior art documents]", the adhesion between the anode and the organic material layer is improved. The purpose of the present invention is to improve the bonding characteristics such as the above and the hole injection characteristics from the anode to the organic layer.
[0046]
However, as described in “(3) Surface defective layer on anode” in “A. [Technical background]” and (4), a surface defective layer originally existing on the surface of a transparent electrode such as ITO is used. Causes various troubles. For example, the presence of the surface defect layer may increase the driving voltage during continuous driving and may shorten the life. In addition, it is difficult to ensure heat resistance, and this is expected to be a problem particularly when applied to various display devices for vehicles. Further, in particular, in the case of a high-definition CCM panel, reduction in the number of luminescent pixels due to generation and increase of a defective surface layer becomes a problem. This is considered to be apparent particularly in a high-temperature environment. There is no known example in which attention is paid to such points and measures are taken.
[0047]
In item (4) of “(2) Lamination of buffer layer on anode”, anode surface treatment by reverse sputtering is proposed, but it is considered insufficient for the following reasons. That is, since the inorganic compound is not laminated after the reverse sputtering, there is a high possibility that the inorganic compound is contaminated in a vacuum, and there is a possibility that the surface state returns to the original surface state due to moisture and the like existing in the vacuum chamber. Deemed sufficient.
[0048]
The present invention has been made in view of these problems, and the objects are as follows.
[0049]
(1) An object is to remove a defective surface layer present on the anode surface of a CCM substrate and to protect the anode surface.
[0050]
(2) The purpose is to stabilize the performance of the organic EL element and thus the CCM panel, specifically, to prevent a rise in drive voltage, maintain uniform light emission, and improve heat resistance.
[0051]
[Means for Solving the Problems]
The present invention proposes a new configuration different from the conventional one in which an inorganic compound is laminated after removing the defective surface layer in order to solve the above-described problem. This has the effect of preventing the occurrence of a phenomenon that is not provided by the conventional technology.
[0052]
The presence of the surface protective layer of the present invention can prevent the formation of a defective surface layer on the anode. For example, in a state where a barrier layer for cathode separation is formed on the anode of a CCM substrate for a full-color panel, storage and movement can be performed without special consideration for contamination or the like. In addition, when the panel is manufactured (at the time of forming the organic EL film), a process may be performed according to a conventional predetermined manufacturing process.
[0053]
The present invention specifically adopts the following configuration.
[0054]
In order to solve the above problems, the present invention provides a substrate, an electrode made of an In atom-containing compound, and a layer located between the electrode and the substrate, which converts the wavelength of light incident on this layer. A fluorescence conversion layer, and a surface protection layer made of an inorganic compound on the surface of the electrode, on the surface opposite to the surface facing the fluorescence conversion layer. It is characterized by being formed. With such a configuration, formation of a defective surface layer can be prevented. Specifically, it is possible to effectively prevent the formation of a defective surface layer due to exposure to the atmosphere or the like.
[0055]
Further, the present invention is characterized in that a constituent material of the substrate and / or the electrode of the above electrode substrate is a transparent material. By using such a transparent material, an electrode substrate that can be used for display means can be obtained.
[0056]
Further, the present invention is characterized in that the electrode surface of the above-mentioned electrode substrate is subjected to reverse sputtering. With such a configuration, a defective surface layer on the electrode surface can be effectively reduced, and the electrode surface and the inside can be made uniform.
[0057]
Further, the present invention is characterized in that the reverse sputtering process is a reverse sputtering process using inductively coupled RF plasma-assisted magnetron sputtering. According to such a configuration, discharge gas ions having a kinetic energy just suitable for removing the defective surface layer on the anode surface can be easily obtained, so that the defective surface layer can be removed without damaging the electrode.
[0058]
In addition, the present invention provides the above-mentioned surface protection layer, wherein the inorganic compound is Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, K, Cd, Mg, Si, Ta, Ge, Sb, Zn. , Cs, Eu, Y, Ce, W, Zr, La, Sc, Rb, Lu, Ti, Cr, Ho, Cu, Er, Sm, W, Co, Se, Hf, Tm, Fe, Nb It is characterized by being at least one of an oxide, a nitride, a composite oxide, a sulfide, and a fluoride of a metal. According to such a configuration, a dense surface protective layer can be formed on the electrode surface.
[0059]
Further, the present invention is characterized in that the surface protective layer is formed by a sputtering method. With such a configuration, the defective surface layer can be formed while removing the defective surface layer of the electrode.
[0060]
Further, the present invention is characterized in that the surface protective layer is formed by a sputtering method using inductively coupled RF plasma-assisted magnetron sputtering. With such a configuration, the surface protective layer can be effectively formed.
[0061]
Further, the present invention is characterized in that the thickness of the surface protective layer is a value within a range of 5 to 100 °. According to such a configuration, it is possible to prevent re-generation of the defective surface layer, and it is possible to secure a predetermined light transmittance.
[0062]
Further, the present invention is characterized in that the electrode is made of indium tin oxide (ITO) or indium zinc oxide (IZO). According to such a configuration, excellent light transmittance can be obtained.
[0063]
Further, the present invention is characterized in that the electrode is an amorphous oxide. According to such a configuration, excellent etching characteristics can be obtained. In addition, ITO is usually crystalline, but it can be made amorphous by a method of forming a moisture atmosphere at the time of film formation or doping a trace element.
[0064]
Further, the invention includes a driving element for driving the electrode. In recent years, in particular, liquid crystal display devices and organic EL display devices in which a thin film transistor (TFT) is provided for each pixel to improve display performance have been widely used. Therefore, by providing an electrode substrate provided with a driving element such as a TFT in advance, it becomes easy to manufacture the above-described TFT type liquid crystal display device or organic EL display device.
[0065]
Hereinafter, the present invention relates to a method for manufacturing an electrode substrate.
[0066]
Next, in order to solve the above-mentioned problems, the present invention provides a substrate, an electrode made of an In atom-containing compound, and a layer located between the electrode and the substrate. A method of manufacturing an electrode substrate including a fluorescence conversion layer for converting a wavelength, wherein the step of forming the fluorescence conversion layer on the substrate and the step of forming the electrode on the formed fluorescence conversion layer And performing a reverse sputtering process on the formed electrode surface, and in the process of performing the reverse sputtering process on the electrode surface, after performing the reverse sputtering process, or when performing the reverse sputtering process. And forming a surface protective layer made of an inorganic compound.
[0067]
With such a configuration, it is possible to manufacture an electrode substrate in which a defective surface layer on the electrode is reduced.
[0068]
With the surface protective layer made of an inorganic compound, the state in which the defective surface layer has been removed can be maintained, and the defective surface layer can be effectively prevented from being reformed.
[0069]
Further, in the invention, it is preferable that the reverse sputtering is performed by using an inductively coupled RF plasma-assisted magnetron sputtering. According to such a configuration, discharge gas ions having a kinetic energy just suitable for removing the defective surface layer on the anode surface can be easily obtained, so that the defective surface layer can be removed without damaging the electrode.
[0070]
Further, in the present invention, in the reverse sputtering process, a high frequency power of 50 to 200 W and a frequency of 13.56 to 100 MHz is applied to the helical coil of the inductively coupled RF plasma-assisted magnetron sputtering, and the inductively coupled RF plasma is applied. A high frequency power of 200 to 500 W and a frequency of 13.56 to 100 MHz is applied to the cathode of the plasma-assisted magnetron sputter to cause plasma discharge, and the intensity of the magnetron magnetic field of the inductively coupled RF plasma-assisted magnetron sputter is 200 to 300 gauss. Is a value within the range of the above.
[0071]
According to such a configuration, a defective surface layer on the electrode surface can be more effectively removed.
[0072]
Particularly, the present invention relating to the electrode substrate is defined as follows from the measured values by XPS.
[0073]
In order to solve the above problems, the present invention provides a substrate, an electrode made of an In atom-containing compound, and a layer located between the electrode and the substrate, which converts the wavelength of light incident on this layer. A fluorescence conversion layer, and a surface protection layer made of an inorganic compound on the surface of the electrode, on the surface opposite to the surface facing the fluorescence conversion layer. An electrode substrate characterized in that the measurement results of X-ray photoelectron spectroscopy on the electrode surface are as follows.
[0074]
That is, the present invention provides a method for measuring 3d of In atoms measured on the electrode surface by X-ray photoelectron spectroscopy._5/2The half width of the orbital spectrum peak is [In3d_5/2]_hAnd 3d of In atoms measured inside the electrode by X-ray photoelectron spectroscopy_5/2The half width of the orbital spectrum peak is [In3d_5/2]_nIn the case where it is expressed by the following formula, the ratio is the ratio of each half width ([In3d_5/2]_h/ [In3d_5/2]_n) Is in the range of 0.9 to 1.2.
[0075]
With such a configuration, In3d “inside” the electrode_5/2By limiting the ratio of the half-width of the orbital spectrum peak to the half-width of the “surface” of the electrode to a value within a predetermined range, it is possible to configure an electrode substrate having no defective surface layer on the electrode.
[0076]
In the present invention, “measured on the surface” means that the measurement is performed on at least a part of the surface or one point on the surface.
[0077]
The present invention also provides a substrate, an electrode made of an In atom-containing compound, and a layer located between the electrode and the substrate, and a fluorescence conversion layer for converting the wavelength of light incident on the layer. And a surface protection layer made of an inorganic compound is formed on the surface of the electrode on the surface opposite to the surface facing the fluorescence conversion layer. An electrode substrate characterized by the following measurement values measured by X-ray photoelectron spectroscopy.
[0078]
That is, the present invention provides a method for measuring the 3d of In_5/2The peak value of the orbital spectrum is represented by Inpeak, and 3d of Sn atom measured at the electrode by X-ray photoelectron spectroscopy._5/2The peak value of the orbital spectrum is represented by Snpeak, and the ratio of each peak measured on the electrode surface is (Inpeak / Snpeak)._h, And the ratio of each peak measured inside the electrode is (Inpeak / Snpeak)_nWhen expressed as ((Snpeak / Inpeak)_h/ (Snpeak / Inpeak)_n) <1.5.
[0079]
With such a configuration, the ratio between the peak value of the In atom and the peak value of the Sn atom is measured inside and outside the electrode, and the ratio between the inside and the outside is limited to a value within a predetermined range. Thereby, an electrode substrate having no surface defect layer on the electrode can be formed.
[0080]
This “measured at the surface” means that it is measured at least at a part of the surface or at one point of the surface, similarly to the invention described above.
[0081]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[0082]
A. Basic structure
This embodiment proposes a configuration in which an inorganic compound layer is stacked on an anode of a color conversion (CCM) substrate, and an organic material layer is stacked thereon. FIG. 1 is a schematic diagram showing a cross section showing the configuration of such an organic EL display device 100.
[0083]
As shown in this figure, a feature of the present embodiment is that a surface protective layer 102 made of an inorganic compound or an organic compound is provided on the anode 16. The organic layer 18 is laminated on the surface protection layer 102.
[0084]
Note that the organic material layer 18 is a portion that controls light emission, and thus is also referred to as a light emitting layer. In addition, since an organic substance is a compound in many cases, it may be referred to as an organic compound layer. The organic layer 18 has at least a recombination region and a light emitting region. The organic material layer 18 may be called an organic EL element layer in some cases.
[0085]
Regarding the organic material layer 18, if necessary, other layers such as a hole injection layer, an electron injection layer, an organic semiconductor layer, an electron barrier layer, and an adhesion improving layer may be provided in addition to the organic material layer 18 (light emitting layer). In such a case, a plurality of layers including the hole injection layer and the like are generally called an organic material layer 18. Then, the cathode 20 is formed on the organic material layer 18 composed of the plurality of layers.
[0086]
In the present embodiment, an example of the organic EL display device 100 is shown, but this organic EL display device corresponds to an example of a “light emitting device” in the claims. Since the organic EL itself is a light emitting element, it constitutes a light emitting device having a function of emitting light. In the present embodiment, the organic EL display device 100 will be described as an example of the light emitting device, but the “light emitting device” of the present invention is not limited to the organic EL display device.
[0087]
A representative configuration example (variation) of the organic EL display device 100 described in this embodiment is shown. Of course, it is not limited to this.
[0088]
The basic layer structure of the organic EL display device 100 is as follows.
[0089]
Substrate / color conversion film (CCM layer) / passivation film / organic EL device
Here, the organic EL element 122 has the following variations.
[0090]
(1) Transparent electrode (anode) / surface protective layer /Light-emitting layer / electrode (cathode)
(2) Transparent electrode (anode) / surface protective layer /Hole injection layer / light-emitting layer / electrode (cathode)
(3) Transparent electrode (anode) / surface protective layer /Emission layer / Electron injection layer / Electrode (cathode)
(4) Transparent electrode (anode) / surface protective layer /Hole injection layer / light emitting layer / electron injection layer / electrode (cathode)
(5) anode / surface protective layer /Organic semiconductor layer / light emitting layer / cathode
(6) anode / surface protective layer /Organic semiconductor layer / electron barrier layer / light emitting layer / cathode
(7) anode / surface protective layer /Hole injection layer / light emitting layer / adhesion improving layer / cathode
The structure as described above can be given. Of these, the configuration (4) is preferably used.
[0091]
The feature of this embodiment is the surface protection layer 102 included in the organic EL element 122.
[0092]
B. About the defective surface layer of transparent electrode such as ITO
Here, the surface defective layer of the electrode will be described.
[0093]
As described in (4) of "A. Background Art" of the related art, the surface of a transparent electrode such as ITO is damaged by excessive cleaning in a cleaning process or an etching residue for patterning. In addition, the following so-called defective surface layers are also formed due to adsorption of water on the surface, precipitation of trace impurity atoms contained in the bulk, and the like. There is no known example of trying to improve by focusing on the problem of the surface defective layer. As a result, in the conventional organic EL device, the organic material is laminated with the surface defective layer on the anode, and the device performance that can be originally obtained cannot be secured due to a decrease in charge injection property at the interface. It is thought that there are many.
[0094]
(1) Surface defective layer
This is the embodiment.Surface defect layerIs, for example, one that meets one of the following requirements.
[0095]
(1) Sn, which is a dopant, is deposited on the surface. In the case of IZO, Zn deficiency can be mentioned.
[0096]
{Circle around (2)} Occurrence of vacancies on the surface of the oxidized vacancies (ie, excess oxygen atoms).
[0097]
(3) Moisture is adsorbed on the surface.
[0098]
(4) Trace impurities (such as nitrogen) contained in the bulk are deposited on the surface.
[0099]
Due to the presence of such a defective surface layer, the conductivity (hole injecting property) is reduced, and in the region where the adhesion of the organic substance laminated thereon is reduced, diffusion of impurities in the defective surface layer into the organic substance layer is observed.
[0100]
It has been found that the following problems occur due to the presence of such a surface defect layer.
[0101]
{Circle around (1)} The voltage rise is large at the time of constant current continuous driving, and the life is short.
[0102]
{Circle around (2)} Adhesion with the organic material laminated on the defective surface layer is reduced, resulting in non-uniform luminescence when driven at high temperatures and non-uniform luminescence even after storage at high temperatures. I do. Similarly, the so-called heat resistance is lowered, for example, the current injection property and the luminous efficiency at high temperatures are lowered.
[0103]
(2) Detection method of defective surface layer
It is detected analytically by X-ray photoelectron spectroscopy (XPS: X-ray @ Photoelectron @ Spectroscoy).
[0104]
{Circle around (1)} The spectrum of the In atom reflecting the situation around the In atom In 原子 3d_5/2The magnitude of the peak (hereinafter referred to as Inpeak) at (binding energy 444.4 eV) and the value of Sn 3d of Sn atom_5/2The magnitude of the peak (binding energy 486.2 eV) (hereinafter referred to as Snpeak) was determined, and the ratio Snpeak / Inpeak increased near the surface from the inside (bulk) of the electrode. To detect the presence of Here, the calculation of Inpeak and Snpeak is actually performed by correcting the obtained value with the sensitivity by atoms to obtain a final value.
[0105]
Generally, Snpeak / Inpeak is a value of 0.1 to 0.2, but if the value on the surface is 1.5 times or more that of the bulk, it is considered that Sn is precipitated on the surface, The presence of a defective surface layer is observed.
[0106]
That is, the value of Snpeak / Inpeak on the electrode surface is calculated as (Snpeak / Inpeak)._hAnd the value of Snpeak / Inpeak inside the electrode is (Snpeak / Inpeak)_nWhen expressed as (Snpeak / Inpeak)_h/ (Snpeak / Inpeak)_nWhen> = 1.5, the presence of a defective surface layer is recognized. Conversely, (Snpeak / Inpeak)_h/ (Snpeak / Inpeak)_nIf an electrode with a value of <1.5 is formed, it can be considered that the defective surface layer does not substantially exist.
[0107]
Since the XPS measurement on the electrode surface is generally performed on a part of the surface or one point on the surface, the above-described measurement also means a measurement on a part of the electrode surface or one point on the surface.
[0108]
{Circle around (2)} The spectrum of the In atom reflecting the situation around the In atom In 3d_5/2If the peak half width (FWHM: Full-Width @ Half-Maximum) of the surface is clearly larger than that of the bulk, the surface atomic composition is different, and a defective surface layer is formed. An example will be described below with reference to the schematic diagram of FIG. This schematic diagram is a schematic diagram in which the vertical axis indicates spectrum intensity (arbitrary unit) and the horizontal axis indicates binding energy.
[0109]
For example, when the electrode (provided on the substrate) that has been washed with a normal organic solvent and completed with the UV washing is quickly put into the XPS measurement chamber and observed, the half width is 1.9 eV (FIG. 2). A). This is the surface In 3d_5/2Is the half width at peak. When this was sputtered with an argon ion gun for 30 seconds and the resurface digged at about 50 ° was observed, the half width was 1.7 eV (shown by B in FIG. 2). Conceivable.
[0110]
The surface value of the peak half-value width of Inｄ3d5 / 2 is [In3d_5/2]_hAnd In 3d_5/2The bulk (internal) value of the peak half width of_5/2]_nAnd the ratio [In3d_5/2]_h/ [In3d_5/2]_nIs not in the range of 0.9 to 1.2, the atomic composition of the electrode surface is different from that of the inside, and it is recognized that a defective surface layer exists. For example, when this value is calculated using the above example, it is determined that 1.9 / 1.2 = 1.58, which is not in the range of 0.9 to 1.2. I do.
[0111]
In contrast to the example shown in (2), the SiO electrode was formed on the ITO electrode.₂After the same cleaning as described above, the electrode on which_5/2Was 1.7 eV, which was similar to the value of the ITO bulk. From this result, it can be seen that the surface defect layer was removed from the surface of the substrate on which the SiO2 was formed. [In3d_5/2]_h/ [In3d_5/2]_nIs 1.0, which is in the range of 0.9 to 1.2. In addition, this SiO₂Is performed using helical sputtering. In other words, in this film forming step, a surface protective layer of SiO 2 is formed on the electrode surface while removing the defective surface layer by sputtering.
[0112]
The inductively coupled RF plasma-assisted magnetron sputtering is referred to as "helical sputtering".
[0113]
When the discharge gas flow rate during helical sputtering film formation is changed, SiO₂In 3d on the substrate surface on which_5/2It has been found that the peak half width changes. Specifically, it was found that when the flow rate of the discharge gas was increased, the half width became narrower, and the defective surface layer was more likely to be removed.
[0114]
From the above, the inventors of the present application have found that the surface defective layer on the surface of the ITO electrode can be removed by the sputtering action of the discharge gas.
[0115]
The feature of the present invention is that SiO 2₂The surface protection layer made of an inorganic compound such as that described above was formed on the electrode surface by sputtering. By this sputtering, a defective surface layer on the electrode surface can be removed, and a protective layer for protecting the surface can be provided.
[0116]
{Circle around (3)} The thickness of the surface protective layer can be selected from a thickness of about 5 to 100 °. Preferably it is 10 to 50 °, more preferably 20 to 40 °.
[0117]
Generally, when the film thickness is 5 to 20 °, the film has an island-like structure, and it is difficult to form a uniform interface. However, the reproducibility of the effect was obtained at a film thickness of 5 mm or more, and the inventors of the present application confirmed that the film was at least uniform at a film thickness of 20 mm by observation with a transmission electron microscope. In particular, it has been confirmed that a helical sputtered film can form a stable and dense film.
[0118]
On the other hand, if the film thickness becomes too thick (about 100 ° or more), the SiO 2₂Inorganic compounds such as these have inherently many insulators and low conductivity in many cases. Therefore, an injection barrier between the anode and the organic material layer becomes a problem, and the voltage of the device becomes high, which is not preferable.
[0119]
C. Configuration of each layer
Hereinafter, each layer constituting the organic EL display device 100 will be described.
[0120]
The organic EL display device 100, as described above,
Substrate / color conversion film (CCM layer) / passivation film / organic EL device
Configuration. In addition, the organic EL element 122
Transparent electrode (anode) / surface protective layer /Hole injection layer / light emitting layer / electron injection layer / electrode (cathode)
Each layer will be described below for an example having the configuration described above.
[0121]
(1) Surface protective layer 102-inorganic compound layer
First, the surface protection layer 102102 formed from an inorganic compound, which is a point of the present invention, will be described.
[0122]
This surface protective layer 102 is made of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, K, Cd, Mg, Si, Ta, Ge, Sb, Zn, Cs, Eu, Y, Ce, W , Zr, La, Sc, Rb, Lu, Ti, Cr, Ho, Cu, Er, Sm, W, Co, Se, Hf, Tm, Fe, Nb and other metals, oxides, nitrides and composite oxides , Sulfides and fluorides are preferred. In this example, silicon oxide SiOx (x indicates an atomic ratio) is effective.
[0123]
More preferred examples include LiOx, @LiNx, @NaOx, @KOx, @RbOx, @CsOx, @BeOx, @MgOx, @MgNx, @CaOx, @CaNx, @SrOx, @BaOx, @ScOx, @YOx, @Ox, @Ox, @Ox, @Ox, @Ox, @LaOx SmOx, EuOx, GdOx, TbOx, DyOx, HoOx, ErOx, TmOx, YbOx, Luox, TiOx, TiNx, ZrOx, Nx, Tx, Nx, Tx, Nx, Tx MoOx, @MoNx, @WOx, @WNx, @MnOx, @ReOx, @FeOx, @FeNx, @Ru x, OsOx, CoOx, RhOx, IrOx, NiOx, PdOx, PtOx, CuOx, CuNx, AgOx, AuOx, ZnOx, CdOx, HgOx, BOx, Nx, Nx, Nx, ＯNx, Nx, Alx, Alx, Alx, Nx, Nx, PbOx, POx, ＰPNx, AsOx, SbOx, ScOx, TeOx, and other metal oxides or metal nitrides are also preferable.
[0124]
Furthermore, LiAlO₂, Li₂SiO₃, Li₂TiO₃, Na₂Al₂₂O₃₄, NaFeO₂, Na₄SiO₄, K₂SiO₃, K₂TiO₃, K₂WO₄, Rb₂CrO₄, Cs₂CrO₄, MgAl₂O₄, MgFe₂O₄, MgTiO₃, CaTiO₃, @CaWO₄, @CaZrO₃, SrFe₁₂O₁₉, SrTiO₃, SrZrO₃, BaAl₂O₄, BaFe₁₂O₁₉, BaTiO₃, Y₃Al₅O₁₂, Y₃Fe₅O₁₂, @LaFeO₃, @La₃Fe₅O₁₂, @La₂Ti₂O₇, @ CeSnO₄, CeTiO₄, Sm₃Fe₅O₁₂, EuFeO₃, @Eu₃Fe₅O₁₂, GdFeO₃, Gd₃Fe₅O₁₂, DyFeO₃, Dy₃Fe₅O₁₂, @HoFeO₃, @Ho₃Fe₅O₁₂, ErFeO₃, Er₃Fe₅O₁₂, Tm₃Fe₅O₁₂, @ LuFeO₃, @Lu₃Fe₅O₁₂, @NiTiO₃, Al₂TiO₃, FeTiO₃, BaZrO₃, @ LiZrO₃, MgZrO₃, HfTiO₄, NH₄VO₃, @ AgVO₃, @ LiVO₃, BaNb₂O6, @NaNbO₃, SrNb₂O₆, @ KTaO₃, NaTaO₃, SrTa₂O₆, CuCr₂O₄, Ag₂CrO₄, BaCrO₄, K₂MoO₄, Na₂MoO₄, @ NiMoO₄, @BaWO₄, Na₂WO₄, @ SrWO₄, MnCr₂O₄, MnFe₂O₄, MnTiO₃, @MnWO₄, CoFe₂O₄, ZnFe₂O₄, FeWO₄, @ CoMoO₄, CoTiO₃, @ CoWO₄, NiFe₂O₄, @NiWO₄, CuFe₂O₄, @CuMoO₄, CuTiO₃, @CuWO₄, Ag₂MoO₄, Ag₂WO₄, ZnAl₂O₄, ZnMoO₄, @ ZnWO₄, CdSnO₃, CdTiO₃, @ CdMoO₄, @ CdWO₄, NaAlO₂, MgAl₂O₄, SrAl₂O₄, Gd₃Ga₅O₁₂, @InFeO₃, @MgIn₂O₄, Al₂TiO₅, FeTiO₃, MgTiO₃, Na₂SiO₃, @CaSiO₃, ZrSiO₄, K₂GeO₃, Li₂GeO₃, Na₂GeO₃, Bi₂Sn₃O₉, MgSnO₃, SrSnO₃, PbSiO₃, PbMoO₄, PbTiO₃, SnO₂-Sb₂O₃, CuScO₄, Na₂SeO₃, ZnSeO₃, K₂TeO₃, K₂TeO₄, Na₂TeO₃, Na₂TeO₄Metal composite oxides such as may be used.
[0125]
Also, FeS, Al₂S₃, {MgS, {ZnS}, etc., LiF, {MgF₂, SmF₃Fluoride such as 、, HgCl, FeCl₂, @CrCl₃, And the like, AgBr, @CuBr, @MnBr₂Bromide such as, PbI₂, CuI, FeI₂Suitable materials include iodides such as and metal oxides such as SiAlON.
[0126]
Of these, oxides are preferred, and the Gibbs energy of standard formation is particularly preferably -520 kJmol.^-1In the above, a stable oxide is preferable. For example, SiO₂(-855 kjmol^-1), GeO₂(-497 kJmol^-1), CeO₂(-1025 kJmol^-1), Al₂O₃(-1581.9 kJmol^-1).
[0127]
As other compounds, AlN, SiC, CaS and the like are also stable compounds and are preferable.
[0128]
Next, a procedure for forming the surface protective layer 102 on the electrode will be described.
[0129]
Overview of deposition procedure
Process 1: A substrate with an anode (transparent electrode) is subjected to wet cleaning. This is the same as the usual substrate cleaning performed before element deposition. Specifically, a combination of ultrasonic cleaning using an organic solvent such as 2-propanol and rinsing with pure water is effective, and ultrasonic cleaning using a neutral detergent or the like depending on the degree of stain on the anode surface. Preferably, washing is performed.
[0130]
Process 2: An inorganic oxide film is formed by a sputtering method such as helical sputtering. Here, the reason why the inorganic compound is formed by the sputtering method is as follows.
[0131]
First, oxides or nitrides generally require a high temperature for vapor deposition, and vapor deposition is difficult with a resistance heating method.
-Furthermore, although it is possible to form a film by an electron beam evaporation method, unlike sputtering, there is no effect of modifying the surface defective layer of ITO.
[0132]
The effect of improving the surface defective layer of ITO by the sputtering method is that discharge gas ions generated by the plasma are accelerated by the self-bias electric field generated by the plasma, and the surface defective layer is hit, and sputter cleaning (so-called reverse cleaning) is performed. This is considered to be due to sputtering.
[0133]
Helical sputtering is particularly preferred among the sputtering. The reason for this is that helical sputtering generally increases the distance between the target and the substrate, so that ordinary sputtering gives excessive energy to the substrate and damages the substrate, whereas helical sputtering causes damage to the anode surface defect layer. This is because it was confirmed by an experiment that the kinetic energy was just right for removing (about 0.1 to 1 eV).
[0134]
Specific example of film formation procedure
Step 1: The degree of vacuum before introducing gas into the vacuum chamber is 10^-3Check that it is in the first half of the Pa range.
[0135]
Step 2: A discharge gas such as Ar is introduced into the vacuum chamber. The degree of vacuum at this time is 1 × 10⁰1 × 10 from Pa^-2It is about Pa. For example, 0.3 Pa to 1.0 Pa is preferable so that the pressure is not too low. This is because the effect of removing the defective surface layer decreases at low pressure. The type of the discharge gas can be selected from rare gases such as Ar, Xe, and Kr, but Ar is preferable in terms of cost.
[0136]
Step 3: A high frequency of 50 to 200 W is applied to the helical coil (coil for inductive coupling) and 200 to 500 W to the cathode, and a frequency of 13.56 MHz to 100 MHz is applied to the cathode to cause plasma discharge. The strength of the magnetron magnetic field at this time is preferably about 200 to 300 Gauss.
[0137]
Step 4: The target surface is cleaned by sufficient pre-sputter. It is preferable to perform at least 5 minutes or more, particularly 10 minutes or more at the first time after the target exchange.
[0138]
Step 5: Next, the main shutter of the sputtering apparatus is opened, and the inorganic compound is deposited until a predetermined thickness (5 to 100 °) is reached.
[0139]
(2) Substrate 12
As the substrate used in this embodiment mode, a material which is transparent and rigid enough to support a color display device is preferable. In the present embodiment, the color display device is reinforced by arranging the substrate to increase mechanical strength such as impact resistance.
[0140]
Specific examples of the material include a glass plate, a ceramic plate, and a plastic plate (polycarbonate, acrylic, vinyl chloride, polyethylene terephthalate, polyimide, polyester resin, and the like).
[0141]
(3) CCM layer 14
The CCM layer 14 (also referred to as a color conversion layer) has a function of absorbing light emitted by the organic EL element 122 and emitting longer-wavelength fluorescence. For example, blue light is converted into green light or red light. Note that, in addition to the CCM layer 14, a color filter may be included for improving color reproducibility.
[0142]
Each CCM layer 14 is preferably arranged corresponding to a light emitting region of the organic EL element 122, for example, a position of an intersection between the anode 16 and the cathode 20. The anode 16 and the cathode 20 are arranged in a stripe shape with respect to the display surface, and both are provided above in a direction orthogonal to the display plane. Then, the organic material layer 18 at the position where the anode 16 and the cathode 20 overlap on the plane (intersecting position) emits light. The superimposed position (intersecting position) corresponds to “1 pixel” on the display plane.
[0143]
Now, with such a configuration, when the organic material layer 18 (organic EL light emitting layer) emits light at the intersection of the anode 16 and the cathode 20, the light is received by each CCM layer 14 and a different color ( Wavelength) can be extracted to the outside.
[0144]
In this case, in particular, if the organic EL element 122 emits blue light and can be converted into green and red light by the CCM layer 14, even if the organic EL element 122 is composed of one type of organic material layer 18, the organic EL element 122 can emit blue light. This is preferable because three primary colors of green, red and light can be obtained, and full-color display is possible.
[0145]
(3-1) Material
The material of the CCM layer 14 is not particularly limited. For example, it is composed of a fluorescent dye or a fluorescent dye and a binder resin. Among them, a typical example of the CCM layer 14 composed of a fluorescent dye and a binder resin may be a solid state in which the fluorescent dye is dissolved or dispersed in a pigment resin and / or a binder resin.
[0146]
Describing a specific fluorescent dye, 1,4-bis (2-methylstyryl) benzene (Bis-MBS) is a fluorescent dye that converts violet light from near-ultraviolet light into blue light emission in the organic EL element 122. And stilbene dyes such as trans-4,4'-diphenylstilbene (DPS) and coumarin dyes such as 7-hydroxy-4-methylcoumarin (coumarin 4).
[0147]
The fluorescent dye for converting blue, blue-green, or white light emission into green light emission in the organic EL element 122 is, for example, 2,3,5,6-1H, 4H-tetrahydro-8-trifluoromethylmethyl. Noridino (9,9a, 1-gh) coumarin (coumarin 153), 3- (2'-benzothiazolyl) -7-diethylaminocoumarin (coumarin 6), 3- (2'-benzimidazolyl) -7-N, N Coumarin dyes such as diethylaminocoumarin (coumarin 7); and naphthalimide dyes such as Basic Yellow 51, which is a coumarin dye-based dye, and Solvent Yellow 11 and Solvent Yellow 116.
[0148]
In addition, as for a fluorescent dye in the case where light emission from blue to green or white light emission in the organic EL element 122 is converted into light emission from orange to red, for example, 4-dicyanomethylene-2-methyl-6- ( cyanine dyes such as p-dimethylaminostillyl) -4H pyran (DCM), 1-ethyl-2- (4- (p-dimethylaminophenyl) -1,3-butadienyl) -pyridinium-perchlorate (pyridine 1) ), Rhodamine B such as rhodamine B and rhodamine 6G, and oxazine dyes.
[0149]
Further, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can also be selected as fluorescent dyes if they have fluorescence.
[0150]
In addition, the fluorescent dye is kneaded in advance into a pigment resin such as polymethacrylic acid ester, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, alkyd resin, aromatic sulfonamide resin, urea resin, melanin resin, and benzoguanamine resin. May be pigmented.
[0151]
On the other hand, the binder resin is preferably a transparent material (having a visible light transmittance of 50% or more). For example, a transparent resin (polymer) such as polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethylcellulose, carboxymethylcellulose and the like can be mentioned.
[0152]
Note that a photosensitive resin to which a photolithography method can be applied can be selected in order to separate and arrange the fluorescent medium in a plane. For example, a photocurable resist material having a reactive vinyl group such as an acrylic acid type, a methacrylic acid type, a polyvinyl cinnamate type, and a ring rubber type may be used. When a printing method is used, a printing ink (medium) using a transparent resin is selected. For example, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin monomers, oligomers, polymers, polymethyl methacrylate, polyacrylate, polycarbonate, Transparent resins such as polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethylcellulose, carboxymethylcellulose and the like can be used.
[0153]
(3-2) Forming method
When the CCM layer 14 is mainly made of a fluorescent dye, it is preferable that the CCM layer 14 is formed by a vacuum evaporation or sputtering method via a mask capable of obtaining a desired CCM layer 14 pattern.
[0154]
On the other hand, when the CCM layer 14 is made of a fluorescent dye and a resin, the fluorescent dye, the resin, and an appropriate solvent are mixed, dispersed, or solubilized to form a liquid material, and the liquid material is spin-coated, roll-coated, or cast. It is preferable to form the CCM layer 14 by forming a film by a method such as a method, and then patterning it into a desired pattern of the CCM layer 14 by a photolithography method, or patterning it into a desired pattern by a method such as screen printing. .
[0155]
(3-3) thickness
The thickness of the CCM layer 14 is not particularly limited as long as the light emission of the organic EL element 122 is sufficiently received (absorbed) and the function of generating fluorescence is not hindered. 000 μm, preferably 0.1 μm to 500 μm
More preferably, it is more preferably 5 μm to 100 μm.
[0156]
The reason for this is that if the thickness of the CCM layer 14 is less than 10 nm, the mechanical strength may be reduced, or it may be difficult to stack. On the other hand, if the thickness of the CCM layer 14 exceeds 1 mm, the light transmittance is significantly reduced, and the amount of light that can be extracted to the outside is reduced, or it may be difficult to reduce the thickness of the organic EL light emitting device. .
[0157]
(4) Passivation film
The passivation film can prevent the volatile component from the resin film such as the CCM layer 14 thereunder from coming into contact with the organic EL element 122, and can be made of any material as long as it is transparent in the visible light region. There are no restrictions.
[0158]
Specific materials include transparent inorganic substances.
[0159]
More specifically, SiO₂, SiO_x, SiO_xN_y, Si₃N₄, Al₂O₃, AlO_xN_y, TiO₂, Tio_x, ITO (In₂O₃-SnO₂), IZO (In₂O₃-ZnO), SnO₂, ZnO, indium copper (CuIn), gold, platinum, palladium and the like, alone or in combination of two or more.
[0160]
When the above-mentioned transparent inorganic material is used, it is preferable to form the film at a low temperature (200 ° C. or lower) and at a low film forming rate so as not to deteriorate the CCM layer 14. Methods such as vapor deposition, CVD, and ion plating are preferred.
[0161]
Here, the thickness of the passivation film can be selected from the range of 0.01 μm to 100 μm, depending on the definition of the organic EL element 122. Preferably, the thickness is 0.05 μm to 10 μm, more preferably, 0.1 μm to 1 μm.
[0162]
When the film thickness is less than 0.01 μm, the volatile components cannot be sufficiently blocked, and when the film thickness is more than 100 μm, the light from the organic EL element 122 is diffused and the desired CCM layer 14 is prevented from being incident. (Depending on color blur, color mixing, viewing angle).
[0163]
(5) Organic EL element 122
In the organic EL display device 100 according to the present embodiment, the above-described inorganic compound layer (surface protective layer 102) is formed on the anode 16 included in the CCM substrate 124, and furthermore, the central part of the organic EL element 122 is formed. An organic material layer 18 (also referred to as an organic compound layer) as a material is stacked. The organic layer 18 has at least a recombination region and a light emitting region. The recombination region and the light emitting region are often present in a light emitting layer having a light emitting function. For this reason, in the present embodiment, only the light emitting layer may be used as the organic material layer 18, but if necessary, other than the light emitting layer, for example, a hole injection layer, an electron injection layer, an organic semiconductor layer, an electron barrier layer, An adhesion improving layer or the like may be included in the organic layer 18. A cathode 20 is formed on these organic layers 18.
[0164]
In the present embodiment, the portion from the anode 16 (transparent electrode) to the cathode 20 is referred to as an organic EL element 122. That is, the organic EL display device 100 simply has an organic EL element 122 formed on a substrate 12 made of glass or the like. In the present embodiment, these layers will be described from the next section, taking the following configuration already described as an organic EL element as an example.
[0165]
Transparent electrode (anode) / surface protective layer /Hole injection layer / light emitting layer / electron injection layer / electrode (cathode)
That is, here, the organic material layer 18Hole injection layer / light emitting layer / electron injection layerA description will be given by taking the configuration consisting of Of course, the organic layer 18 composed of a single light emitting layer may be employed.
[0166]
(6) Anode 16 (transparent electrode)
Representative materials for the anode 16 include ITO (Indium Tin Oxide) and IZO having a large work function (4 eV or more). The anode 16 can be formed by forming a thin film from these electrode substances by a method such as a vapor deposition method or a sputtering method. When light emitted from the light-emitting layer is extracted from the anode 16, it is preferable that the transmittance of the anode 16 with respect to the light emission be greater than 10%. The sheet resistance of the anode 16 is several hundred Ω / □ (Ω / m²The following are preferred. The thickness of the anode 16 depends on the material, but is preferably in the range of usually 10 nm to 1 μm and 10 nm to 200 nm. In this embodiment, a substrate electrode is used as the anode 16.
[0167]
Here, it is also preferable to employ an amorphous oxide as a material of the anode 16 and obtain good etching characteristics. The ITO is usually crystalline, but can be made amorphous by forming a moisture atmosphere at the time of film formation or by doping a trace element.
[0168]
(7) Light emitting layer
In the light-emitting layer in this embodiment, a light-emitting material (host material) represented by the general formula (I)
Embedded image

It is preferable to use a distilly arylene compound represented by the following formula. This compound is disclosed, for example, in JP-A-2-247278.
[0169]
In the above formula, Y1 to Y4 each represent a hydrogen molecule, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, a substituted or unsubstituted 6 to 18 carbon atoms. An aryl group, a substituted or unsubstituted cyclohexyl group, a substituted or unsubstituted aryloxy group having 6 to 18 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms.
[0170]
Here, the substituent is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, an aryloxy group having 6 to 18 carbon atoms, an acyl group having 1 to 6 carbon atoms. An acyloxy group having 1 to 6 carbon atoms, a carboxyl group, a styryl group, an arylcarbonyl group having 6 to 20 carbon atoms, an aryloxycarbonyl group having 6 to 20 carbon atoms, an alkoxycarbonyl group having 1 to 6 carbon atoms, a vinyl group, Anilinocarbonyl, carbamoyl, phenyl, nitro, hydroxyl, or halogen.
[0171]
These substituents may be single or plural. Further, Y1 to Y4 may be the same or different from each other, and Y1 and Y2 and Y3 and Y4 are bonded to a mutually substituted group to form a substituted or unsubstituted saturated 5-membered ring or a substituted or unsubstituted ring. It may form a saturated six-membered ring. Ar represents a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, which may be monosubstituted or plurally substituted, and the bonding portion may be any of ortho, para and meta. However, when Ar is an unsubstituted phenylene group, Y1 to Y4 are each an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, a substituted or unsubstituted naphthyl group, a biphenyl group, a cyclohexyl group, an aryloxy group. Selected from the group. Examples of such a distilarylene-based compound include the following.
[0172]
Embedded image

Embedded image

Another preferable light-emitting material (host material) includes a metal complex of 8-hydroxyquinoline or a derivative thereof. Specifically, it is a metal chelate oxanoid compound containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline). Such compounds exhibit a high level of performance and are easily formed in thin film form. Examples of this oxanoid compound satisfy the following structural formula.
[0173]
Embedded image

In the formula, Mt represents a metal, n is an integer of 1 to 3, Z is an independent position of each atom, and represents an atom necessary to complete at least two or more fused aromatic rings. Show.
[0174]
Here, the metal represented by Mt can be a monovalent, divalent or trivalent metal, for example, an alkali metal such as lithium, sodium and potassium, and an alkaline earth metal such as magnesium and calcium. Or an earth metal such as boron or aluminum. Generally, any of the monovalent, divalent or trivalent metals known to be useful chelating compounds can be used.
[0175]
In the above formula, Z represents an atom in which at least one of two or more fused aromatic rings forms a heterocyclic ring composed of azole or azine. Here, if necessary, another different ring can be added to the fused aromatic ring. Further, in order to avoid bulky molecules without improving the function, the number of atoms represented by Z is preferably maintained at 18 or less. Further, specific examples of chelated oxanoid compounds include tris (8-quinolinol) aluminum, bis (8-quinolinol) magnesium, bis (benzo-8-quinolinol) zinc, and bis (2-methyl-8-quinolinolate) aluminum. Oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-quinolinollithium, tris (5-chloro-8-quinolinol) gallium, bis (5-chloro-8-quinolinol) calcium , 5,7-dichloro-8-quinolinol aluminum, tris (5,7-dipromo 8-hydroxyquinolinol) aluminum, and the like.
[0176]
Further, a metal complex of phenolate-substituted 8-hydroxyquinoline described in JP-A-5-198338 is preferable as a blue light-emitting material. Specific examples of the metal complex of the ferrate-substituted 8-hydroxyquinoline include bis (2-methyl-8-quinolinolate) (phenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (o-cresolate) aluminum (III), bis (2-methyl-8-quinolinolate) (m-cresolate) aluminum (III), bis (2-methyl-8-quinolinolate) (p-cresolate) aluminum (III), bis (2-methyl- 8-quinolinolate) (o-phenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (m-phenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (p -Phenylphenolate) aluminum (III), bis 2-methyl-8-quinolinolate) (2,3 dimethylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (2,6 dimethylphenolate) aluminum (III), bis (2-methyl- 8-quinolinolate) (3,4 dimethylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (3,5 dimethylphenolate) aluminum (III), bis (2-methyl-8-quinolinolate) (3,5-di-tert-butylphenolato) aluminum (III), bis (2-methyl-8-quinolinolate) (2,6 diphenylphenolato) aluminum (III), bis (2-methyl-8-quinolinolate) (2,4,6-triphenylphenolate) aluminum (III) and the like It is. These luminescent materials may be used alone or in combination of two or more.
[0177]
Hereinafter, the light emitting layer will be described more specifically. In general, when white light is emitted, the light-emitting layer often has a two-layer structure. These are called a first light emitting layer and a second light emitting layer.
[0178]
As the first light emitting layer used in the present embodiment, various known light emitting materials can be used. A preferable first light emitting layer is a green fluorescent dye in the oxanoid compound in a trace amount of 0.2 to 3% by weight. Additions can be given. The green fluorescent dye added here is a coumarin type or a quinacridone type. By adding these, the element having the first light emitting layer can realize high efficiency green light emission of 5 to 20 (lm / w). On the other hand, when it is desired to extract yellow or orange from the first light emitting layer with high efficiency, an oxanoid compound obtained by adding 0.2 to 3% by weight of rubrene and its derivative, a dicyanopyran derivative, and a perylene derivative is used. These elements can emit light with high efficiency of 3 to 10 (lm / w). In addition, orange color is possible even when a green fluorescent dye and a red fluorescent dye are simultaneously added. For example, preferably, coumarin and a dicyanopyran dye, quinacridone and a perylene dye, or coumarin and a perylene dye may be used simultaneously. Another particularly preferred first light emitting layer is a polyarylene vinylene derivative. This can output green or orange with high efficiency.
[0179]
As the second light emitting layer used in this embodiment, various known blue light emitting materials can be used. For example, a distyryl arylene derivative, a tristyryl arylene derivative, and an allyloxylated quinolylate metal complex are blue light-emitting materials that can emit blue light with high efficiency and high purity. Examples of the polymer include a polyparaphenylene derivative.
[0180]
As a method for forming the light emitting layer in the organic EL element used in the present embodiment, for example, the light emitting layer can be formed by thinning by a known method such as an evaporation method, a spin coating method, a casting method, and an LB method. In particular, a molecular deposition film is preferable. Here, the molecular deposition film refers to a thin film formed by depositing the compound from a gaseous state or a film formed by solidifying the compound from a molten state or a liquid state. Usually, this molecular deposited film can be distinguished from a thin film (molecule accumulation film) formed by the LB method by a difference in an aggregated structure and a higher-order structure and a functional difference caused by the difference. The light emitting layer can be formed by dissolving in a solvent together with a binder such as a resin to form a solution, and then forming a thin film by spin coating or the like. The thickness of the light emitting layer formed in this manner is not particularly limited and can be appropriately selected depending on the situation, but is preferably 1 nm to 10 μm, and particularly preferably 5 nm to 5 μm.
[0181]
(8) Hole injection layer
Next, the hole injection layer is not an essential component of the organic EL display device 100, but is generally used for improving the light emitting performance. Therefore, the hole injection layer is also used in the present embodiment. An example will be described.
[0182]
This hole injection layer is a layer that assists hole injection into the light emitting layer, and preferably has a high hole mobility and a small ionization energy of usually 5.5 eV or less. As such a hole injecting layer, a material that transports holes to the light emitting layer with a lower electric field is preferable.⁴-10⁶When an electric field of V / cm is applied, at least 10^-6cm²/ V · sec to (ie, 10^-6cm²/ V · sec or more). Such a hole injecting material is not particularly limited as long as it has the above-mentioned preferable properties. Conventionally, in a photoconductive material, a material commonly used as a hole charge transporting material, or a positive hole in an EL element, is used. Any one of known materials used for the hole injection layer can be selected and used.
[0183]
Specific examples include, for example, a triazole derivative (see U.S. Pat. No. 3,112,197), an oxadiazole derivative (see U.S. Pat. No. 3,189,447), and an imidazole derivative (Japanese Patent Publication No. 37-1696). And polyarylalkane derivatives (U.S. Pat. Nos. 3,615,402, 3,820,989, 3,542,544, and JP-B-45-555). JP-A-51-10983, JP-A-55-17105, JP-A-56-4148, JP-A-55-108667, JP-A-55-156953, JP-A-56-36656, etc.), pyrazoline derivatives and Pyrazolone derivatives (U.S. Pat. Nos. 3,180,729 and 4,278,746; JP-A-55-88064) No. 55-88065, No. 49-105537, No. 55-51086, No. 56-80051, No. 56-88141, No. 57-45545, No. 54-112637. And JP-A-55-74546).
[0184]
Specific examples include, for example, phenylenediamine derivatives (U.S. Pat. No. 3,615,404, JP-B-51-10105, JP-B-46-3712, JP-B-47-25336, and JP-A-54-25336). JP-A-53435, JP-A-54-110536, JP-A-54-119925, etc.), arylamine derivatives (U.S. Pat. Nos. 3,567,450 and 3,180,703), No. 3,240,597, No. 3,658,520, No. 4,232,103, No. 4,175,961, No. 4,012,376 JP-B-49-35702, JP-B-39-27577, JP-A-55-144250, JP-A-56-119132, JP-A-56-22437, West Patent No. 1,110,518, etc.), amino-substituted chalcone derivatives (see US Pat. No. 3,526,501, etc.), and oxazole derivatives (US Pat. No. 3,257,203). Disclosed), fluorenone derivatives (see JP-A-54-110837 and the like), and hydrazone derivatives (US Pat. No. 3,717,462, JP-A-54-59143 and JP-A-55-52063). No. 55-52064, No. 55-46760, No. 55-85495, No. 57-11350, No. 57-148749, JP-A-2-311591, etc.), styryl anthracene derivative (See JP-A-56-46234, etc.) and stilbene derivatives (JP-A-61-210363, 61-22845). No. 61-14642, No. 61-72255, No. 62-47646, No. 62-36674, No. 62-10652, No. 62-30255, No. 60-93445. JP-A-60-94462, JP-A-60-174747, JP-A-60-175052, etc.), silazane derivatives (U.S. Pat. No. 4,950,950), polysilanes (JP-A-2-204996). And aniline-based copolymers (JP-A-2-282263) and conductive polymer oligomers (especially thiophene oligomers) disclosed in JP-A-1-213399.
[0185]
As the material for the hole injection layer, the above-mentioned materials can be used, and porphyrin compounds (those disclosed in JP-A-63-2959695), aromatic tertiary amine compounds and stilamine compounds (US Pat. No. 4,127,412, JP-A-53-27033, JP-A-54-58445, JP-A-54-149634, JP-A-54-64299, JP-A-55-79445, and JP-A-55-79445. 144250, 56-119132, 61-295558, 61-98353, 63-295695, etc.), and in particular, aromatic tertiary amine compounds are preferably used.
[0186]
Representative examples of the porphyrin compound include porphine, 1,10,15,20-tetraphenyl-21H, 23H-porphine copper (II), 1,10,15,20-tetraphenyl-21H, and 23H-porphine zinc ( II), 5,10,15,20-tetrakis (pentafluorophenyl) -21H, 23H-porphine, silicon phthalocyanine oxide, aluminum phthalocyanine chloride, phthalocyanine (metal-free), dilithium phthalocyanine, copper tetramethyl phthalocyanine, copper phthalocyanine, Examples thereof include chromium phthalocyanine, zinc phthalocyanine, lead phthalocyanine, titanium phthalocyanine oxide, Mg phthalocyanine, and copper octamethylphthalocyanine.
[0187]
Representative examples of the aromatic tertiary amine compound and styrylamine compound include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl, N, N'-diphenyl-N, N'-bis- (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (hereinafter abbreviated as TPD), 2,2-bis (4-di-p-tolylaminophenyl) Propane, 1,1-bis (4-di-tolylaminophenyl) cyclohexane, N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminophenyl, 1,1-bis ( 4-di-p-tolylaminoenyl) -4-phenylcyclohexane, bis (4-dimethylamino-2-methylphenyl) phenylmethane, bis (4-di-p-tolylaminophenyl) phenylmethane, N, N ' − Phenyl-N, N'-di (4-methoxyphenyl) -4,4'-diaminobiphenyl, N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl ether, 4,4'- Bis (diphenylamino) quadriphenyl, N, N, N-tri (p-tolyl) amine, 4- (di-p-tolylamino) -4 ′-[4 (di-p-tolylamino) styryl] stilbene, 4 -N, N-diphenylamino- (2-diphenylvinyl) benzene, 3-methoxy-4'-N, N-diphenylaminostilbenzene, N-phenylcarbazole, described in U.S. Pat. No. 5,061,569. Having two fused aromatic rings in the molecule, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (hereinafter abbreviated as NPD); Also, 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenyl in which three triphenylamine units described in JP-A-4-308688 are connected in a starburst form. Amino] triphenylamine (hereinafter abbreviated as MTDATA) and the like.
[0188]
Further, in addition to the above-mentioned aromatic dimethylidin-based compound shown as the material of the light emitting layer, inorganic compounds such as p-type Si and p-type SiC can also be used as the material of the hole injection layer. The hole injection layer can be formed by thinning the above-described compound by a known method such as a vacuum evaporation method, a spin coating method, a casting method, and an LB method. The thickness of the hole injection layer is not particularly limited, but is usually 5 nm to 5 μm. The hole injection layer may be composed of one or more layers of the above-described materials, or may be a layer obtained by laminating a hole injection layer made of a compound different from the hole injection layer. There may be. Further, the organic semiconductor layer is a layer that assists hole injection or electron injection into the light emitting layer, and preferably has a conductivity of 10 −10 S / cm or more. As a material of such an organic semiconductor layer, a conductive oligomer such as a thiophene-containing oligomer or an arylamine-containing oligomer, or a conductive dendrimer such as an arylamine-containing dendrimer can be used.
(9) Electron injection layer / adhesion improvement layer
On the other hand, the electron injection layer is a layer that assists the injection of electrons into the light emitting layer, has a large electron transfer, and the adhesion improving layer is a layer made of a material having a good adhesion to the cathode, particularly in the electron injection layer. It is. Preferred examples of the material used for the electron injection layer include a metal complex of 8-hydroxyquinoline or a derivative thereof, or an oxadiazole derivative. As a material used for the adhesion improving layer, a metal complex of 8-hydroxyquinoline or a derivative thereof is particularly preferable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include a metal chelate oxanoid compound containing a chelate of oxine (generally, 8-quinolinol or 8-hydroxyquinoline). On the other hand, oxadiazole derivatives may include those represented by the following general formulas (II), (III) and (IV).
[0189]
Embedded image

In each of these formulas, Ar10 to Ar13 each represent a substituted or unsubstituted aryl group, Ar10 and Ar11 and Ar12 and Ar13 may be the same or different from each other, and Ar14 is a substituted or unsubstituted. An arylene group is shown.
[0190]
The oxadiazole derivative includes an electron transfer compound represented by these formulas. Here, the aryl group includes a phenyl group, a biphenyl group, an anthranyl group, a perylenyl group, a pyrenyl group, and the like. Can be Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a cyano group. The electron transfer compound is preferably a thin film-forming compound. Specific examples of the electron transfer compound include a compound represented by the following formula.
[0191]
Embedded image

(10) Cathode 20
As the cathode 20, a metal, an alloy, an electrically conductive compound, or a mixture thereof having a small work function (4 eV or less) as an electrode material is used. Specific examples of such an electrode material include sodium, sodium-potassium alloy, magnesium, lithium, magnesium-silver alloy, aluminum / aluminum oxide (Al₂O₃), Aluminum / lithium alloys, indium, rare earth metals and the like. The cathode 20 can be formed by forming a thin film of these electrode substances by a method such as evaporation or sputtering. Further, the sheet resistance of the cathode 20 is preferably several hundred Ω / □ or less, and the film thickness can be usually selected from 10 nm to 1 μm, and particularly preferably in the range of 50 to 200 nm.
[0192]
In the organic EL device used in the present embodiment, it is preferable that either the anode 16 or the cathode 20 is transparent or translucent. This is because, if the material is transparent or translucent, light is transmitted, so that the efficiency of extracting light is good.
[0193]
(11) Method of laminating layers constituting organic EL element 122
a. Anode 16 (substrate electrode)
The electrode laminated on the substrate 12 side is called a substrate electrode. Therefore, the anode 16 already described above is a substrate electrode. The method for laminating the substrate electrodes is not particularly limited. For example, a vapor deposition method, a sputtering method, an ion plating method, an electron beam vapor deposition method, a CVD method (CVD: Chemical Vapor Deposition), a MOCVD method (MOCVD: Metalorganic CVD: metalorganic chemical deposition), a dry film forming method such as a plasma CVD method is preferable. The anode 16 is also laminated by such a lamination method.
[0194]
b. Organic layer 18
The layers are stacked by a method similar to the method described in “(7) Light emitting layer” above.
[0195]
c. Counter electrode
The electrode facing the substrate electrode is called a counter electrode. Therefore, the above-described cathode 20 is a counter electrode. The counter electrode is also laminated in the same manner as the substrate electrode.
[0196]
【Example】
Hereinafter, examples of the CCM electrode substrate of the present embodiment and an organic EL display device (CCM panel) in the case where an organic EL element is constructed thereon will be described with specific numerical values.
[0197]
[Example 1]
In the first embodiment, the surface protection layer 102 is provided on the anode 16 on the CCM substrate 124 (also referred to as a CCM electrode substrate), so that the organic EL display device 122 (CCM In this case, it is verified that the organic EL display device 122 has higher performance.
[0198]
{Circle around (1)} Production of CCM substrate 124 (color conversion substrate) 1 (until color conversion film formation)
V259BK (manufactured by Nippon Steel Chemical Co., Ltd.) as a material of a black matrix (BM) is spin-coated on a 102 mm × 133 mm × 1.1 mm support substrate (OA2 glass: manufactured by Nippon Electric Glass Co., Ltd.) so as to form a lattice pattern. After exposure to an ultraviolet ray and development with a 2% aqueous sodium carbonate solution, baking (baking) was performed at 200 ° C. to form a black matrix (1.5 μm thick) pattern.
[0199]
Next, as a material for a blue color filter, V259B (manufactured by Nippon Steel Chemical Co., Ltd.) is spin-coated, and is aligned with the BM through a photomask capable of obtaining 320 rectangular (90 μm lines, 240 μm gap) stripe patterns. The film was exposed to ultraviolet light, developed with a 2% aqueous sodium carbonate solution, and baked (baked) at 200 ° C. to form a blue color filter (1.5 μm thick) pattern.
[0200]
Next, as a material for a green color filter, V259G (manufactured by Nippon Steel Chemical Co., Ltd.) is spin-coated, and is aligned with the BM through a photomask capable of obtaining 320 rectangular (90 μm line, 240 μm gap) stripe patterns. After exposure to ultraviolet light and development with a 2% aqueous sodium carbonate solution, baking (baking) was performed at 200 ° C. to form a pattern of a green color filter (1.5 μm thick) next to the blue color filter.
[0201]
Next, as a material of a red color filter, V259R (manufactured by Nippon Steel Chemical Co., Ltd.) is spin-coated, and is aligned with the BM through a photomask capable of obtaining 320 rectangular (90 μm line, 240 μm gap) stripe patterns. Then, ultraviolet light exposure was performed to form a pattern of a red color filter (1.5 μm thick) between the blue color filter and the green color filter.
[0202]
Next, as a material for the green CCM layer 14G, coumarin 6 in an amount of 0.04 mol / kg (based on solid content) is dissolved in an acrylic negative photoresist (V259PA, solid content concentration 50%: manufactured by Nippon Steel Chemical Co., Ltd.). The prepared ink was prepared.
[0203]
This ink is spin-coated on the substrate, exposed to ultraviolet light on the green color filter, developed with a 2% aqueous solution of sodium carbonate, and baked (baked) at 200 ° C. to form a green conversion film on the green color filter. A pattern (film thickness: 10 μm) was formed.
[0204]
Next, as the material of the red CCM layer 14R, coumarin 6: 0.53 g, basic violet 11: 1.5 g, rhodamine 6G: 1.5 g, acrylic negative photoresist (V259PA, solid content concentration 50%: Nippon Steel Chemical Co., Ltd.) (Manufactured by the company): An ink dissolved in 100 g was prepared.
[0205]
This ink is spin-coated on the substrate, exposed to ultraviolet light on the red color filter, developed with a 2% aqueous solution of sodium carbonate, and baked (fired) at 180 ° C. to form a red conversion film on the red color filter. A pattern (film thickness: 10 μm) was formed to obtain a color conversion substrate.
[0206]
{Circle around (2)} Preparation of CCM substrate 124 (color conversion substrate), part 2 (from planarization film to anode 16 to partition wall formation)
Next, an acrylic thermosetting resin (V259PH: manufactured by Nippon Steel Chemical Co., Ltd.) is spin-coated on the previous substrate as a flattening film, and baked (fired) at 180 ° C. to form a flattening film (thickness: 5 μm). Formed.
[0207]
Next, as an oxygen barrier layer, SiOxNy (O / O + N = 50%: atomic ratio) was formed as a transparent inorganic film to a thickness of 200 nm by low-temperature CVD. Oxygen permeation rate is 0.1cc / m²-It was less than day.
[0208]
Next, IZO (indium zinc oxide) was formed to a thickness of 200 nm by sputtering.
[0209]
Next, on this substrate, a positive resist (HPR204: manufactured by Fuji Film Arch) is positioned so as to overlap with the CCM layer or the color filter pattern via a photomask having a 90 μm line and a 20 μm gap stripe pattern. And exposed to ultraviolet light, developed with a developer of TMAH (tetramethylammonium hydroxide), and baked (baked) at 130 ° C. to obtain a resist pattern.
[0210]
Next, the exposed portion of IZO was etched with an IZO etchant composed of a 5% oxalic acid aqueous solution. Next, the resist was treated with a stripping solution containing ethanolamine as a main component (N303: manufactured by Nagase & Co., Ltd.) to obtain an IZO pattern (lower electrode: 16 anodes, 960 lines).
[0211]
Next, as a first interlayer insulating film, a negative resist (V259PA: manufactured by Nippon Steel Chemical Co., Ltd.) was spin-coated, exposed to ultraviolet light, and developed with a developing solution of TMAH (tetramethylammonium hydroxide). Next, baking (firing) was performed at 180 ° C. to cover the edges of the ITO, so that the opening of the IZO was 70 μm × 290 μm.
[0212]
Next, as a second interlayer insulating film (partition wall), a negative resist (ZPN1100: manufactured by Zeon Corporation) is spin-coated, and exposed to ultraviolet light through a photomask having a stripe pattern of 20 μm line and 310 μm gap. Then, a post-exposure bake (firing) was performed. Next, the negative resist was developed with a developer of TMAH (tetramethylammonium hydroxide) to form a second interlayer insulating film (partition) of an organic film orthogonal to the IZO stripe.
[0213]
{Circle around (3)} Preparation of CCM substrate 124 (color conversion substrate) 3 (film of surface protective layer 102 on anode 16)
An inductively coupled RF plasma assisted magnetron sputtering method (hereinafter referred to as a helical sputtering method) is used to form SiO on the substrate provided with the interlayer insulating film as described above.₂Was deposited at 20 °. The detailed procedure is as follows.
[0214]
After washing the substrate, the washed substrate was set in a sputtering chamber and evacuated. In the apparatus used for the experiment, SiO 2 was used.₂The distance from the target to the substrate is 30 cm.
[0215]
The degree of vacuum is 2.0 × 10⁴After confirming that the pressure became Pa or less, 80 sccm of Ar was introduced as a discharge gas by a mask flow controller. The degree of vacuum at this time was 0.38 Pa.
[0216]
With the main shutter immediately above the target closed, 50 W, SiO₂A high frequency of 13.56 MHz @ 500 W was applied to the target (cathode) to generate plasma discharge. At this time, the reflection of each coil was 5 W or less. With the main shutter closed, the discharge is continued for 5 minutes,₂The target surface was cleaned.
[0219]
Thereafter, the main shutter is opened, and a film is formed by plasma discharge for 6 minutes and 20 seconds, as estimated from the value of the film formation rate measured in advance.₂Was formed on IZO.
[0218]
(4) Formation of organic EL element on CCM substrate 124 (color conversion substrate) and panel sealing
The substrate thus obtained was subjected to ultrasonic cleaning in pure water and isopropyl alcohol, and dried by blowing dry nitrogen.
[0219]
The substrate was moved inside an organic vapor deposition apparatus (manufactured by Nippon Vacuum Technology), and the substrate was fixed to a substrate holder.
[0220]
The organic vapor deposition device is provided with a heating port made of molybdenum. Various materials are charged in advance in the molybdenum heating ports.
[0221]
Specifically, as hole injection materials, 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA), 4,4′-bis [N -(1-naphthyl) -N-phenylamino] biphenyl (NPD) and 4,4'-bis (2,2-diphenylvinyl) biphenyl (DPVBi) as a host of the light emitting material. The dopant is 1,4-bis [4- (N, N-diphenylaminostyrylbenzene)] (DPAVB), and the electron injecting material is tris (8-quinolinol) aluminum (Alq). ) And Li, and Al as the cathode 20.
[0222]
After that, the vacuum chamber is^-7After the pressure was reduced to torr, the layers from the hole injection layer to the cathode 20 were laminated in the following procedure. In the course of the laminating step, each layer was sequentially laminated by one evacuation without breaking the vacuum.
[0223]
First, as a hole injection layer, MTDATA was formed at a deposition rate of 0.1 to 0.3 nm / sec to obtain a film thickness of 60 nm. Further, NPD was formed at a deposition rate of 0.1 to 0.3 nm / sec to obtain a film thickness of 20 nm. Further, as the light emitting layer, DPVBi and DPAVB were co-deposited at a deposition rate of 0.1 to 0.3 nm / sec and a deposition rate of 0.03 to 0.05 nm / sec to obtain a film thickness of 50 nm. As the electron injection layer, Alq was deposited at a deposition rate of 0.1 to 0.3 nm / sec to obtain a film thickness of 20 nm. Further, A1q and Li were co-evaporated at 0.1 to 0.3 nm / sec and 0.005 nm / sec, respectively, to form a film, thereby obtaining a film thickness of 20 nm. Finally, A1 was formed as the cathode 20 at a deposition rate of 0.1 to 0.3 nm / sec to form the cathode 20 having a thickness of 150 nm. Thus, an organic EL device was manufactured.
[0224]
Next, the substrate was moved into a glove box in which dry nitrogen (dew point −50 ° C.) was circulated, and the display portion was covered with a blue glass of 102 mm × 133 mm × 1.1 mm. And cured by photocuring with an adhesive (TB3102: Three Bond) to produce a passive organic EL display device.
[0225]
(5) Driving evaluation of sealing of color conversion panel
When a voltage of 15 V was applied to the lower electrode (anode 16: IZO) and the upper electrode (cathode 20: Al) at Duty = 1/120 (lower electrode: (+), upper electrode: (-)), The intersection (pixel) of each electrode emitted light.
[0226]
The emission luminance was 16 cd / m2 with a blue color filter (blue pixel) using a colorimeter (CS100, manufactured by Minolta).²And the CIE chromaticity coordinates are X = 0.15, Y = 0.16, blue light emission, and 45 cd / m in the green CCM layer / green color filter section (green pixel).²In the CIE chromaticity coordinates, X = 0.27, green light emission of Y = 0.67, 15 cd / m in the red CCM layer / red color filter section (red pixel)²As a result, red light emission with CIE chromaticity coordinates of X = 0.64 and Y = 0.35 was obtained, and three primary colors of light were obtained.
[0227]
The emission luminance of the organic EL element at that time was 200 cd / m2.²(Corresponding to all pixel light emission), and the CIE chromaticity coordinates were blue light emission with X = 0.17 and Y = 0.28.
[0228]
Next, when driving was performed at room temperature 22 ° C. for 1000 hours under these driving conditions, the blue pixel was 10 cd / m 2.²(Assuming that the initial value is 1, the ratio is 0.67), and the green pixel is 27 cd / m.²(Assuming that the initial value is 1, the ratio is 0.60), and the number of red pixels is 9 cd / m.²(Assuming that the initial value is 1, the ratio is 0.60), and the luminance of the organic EL element is 126 cd / m 2.²(Assuming that the initial value is 1, the ratio is 0.63).
[0229]
Further, when the organic EL element is sealed with a normal inert gas such as dry nitrogen, the luminance degradation of the organic EL element is determined by the ratio of the initial value being 1 under the same driving conditions as the above driving conditions. 0.65.
[0230]
[Comparative Example 1]
In Example 1(3) Preparation of CCM substrate 124 (surface protective layer 102 formed on anode 16)SiO 2 as the surface protective layer 102₂Immediately without performing the film formation process(4) Organic EL element layer formation on CCM substrate 124 and panel sealingThe organic EL display device (organic EL panel) was manufactured in exactly the same manner. As in Example 1, (5)Driving evaluation of color conversion panel sealingAnd the following results were obtained.
[0231]
The emission luminance was measured at 11 cd / m with a blue color filter (blue pixel) using a colorimeter (CS100, manufactured by Minolta).²And the CIE chromaticity coordinates are X = 0.15, blue light emission of Y = 0.16, 3 cd / m in the green CCM layer / green color filter section (green pixel).²And the CIE chromaticity coordinates are X = 0.27, green light emission of Y = 0.67, and 12 cd / m in the red CCM layer / red color filter portion (red pixel).²As a result, red light emission with CIE chromaticity coordinates of X = 0.64 and Y = 0.36 was obtained, and three primary colors of light were obtained.
[0232]
The emission luminance of the EL element at that time was 150 cd / m.²(Corresponding to all pixel light emission), and the CIE chromaticity coordinates were blue light emission with X = 0.17 and Y = 0.27.
[0233]
Next, when driving was performed at room temperature 22 ° C. for 1000 hours under these driving conditions, the blue pixel was 6 cd / m 2.²(Assuming that the initial value is 1, the ratio is 0.55), and the green pixel is 16 cd / m.²(Assuming that the initial value is 1, the ratio is 0.48), and the red pixel is 6 cd / m.²(Assuming that the initial value is 1, the ratio is 0.50), and the luminance of the organic EL element is 84 cd / m 2.²(Assuming that the initial value is 1, the ratio was 0.56).
[0234]
When the organic EL element was sealed with a normal inert gas such as dry nitrogen, the luminance degradation of the organic EL element was 0.58, assuming that the initial value was 1. .
[0235]
From the above results, it can be understood that, when the surface protection layer 102 is formed on the IZO, which is the anode 16 of the CCM substrate 124, the light emission luminance for the same voltage is increased for each color as compared with the case where the film is not formed. Like. That is, according to the present example, it was confirmed that the luminous efficiency was improved.
[0236]
In addition, it can be understood that, even in the case of continuous driving, the progress speed of the deterioration of the emission luminance is suppressed when the surface protective layer 102 is formed as compared with the case where the film is not formed.
[0237]
As described above, it was found that when the surface protective layer 102 was formed on the anode 16, the light emitting performance was improved, and the stability (that is, the life) of the panel during continuous driving was improved.
[0238]
Embodiment 2 Example in which TFT is included in the structure
In the example shown in FIG. 1, the anode 16 is shown on the CCM layer 14. In FIG. 1, the driving method of the anode 16 is not particularly shown. For example, it is preferable to drive the anode 16 by using a thin film transistor (TFT). Such an arrangement is shown in FIG. FIG. 4 is a schematic cross-sectional view of one color portion in one pixel shown in FIG. That is, a portion corresponding to any one of red, blue, and green in FIG. 1 is shown.
[0239]
As shown in this figure, in the present embodiment, a CCM layer 14 is provided on a substrate 12. The overcoat layer 210 and the passivation film 212 are provided on the CCM layer 14. On the passivation film 212, a gate 226 of the thin film transistor 220 is provided, and an insulating film 230 is further laminated so as to cover the gate.
[0240]
On the insulating film 230, the anode 16 and the drain 224 and the source 222 of the thin film transistor 220 for driving the anode 16 are formed. Further, the drain 224 is electrically connected to the anode 16.
[0241]
A characteristic feature of the second embodiment is that the anode 16 is driven by a thin film transistor (TFT). The power supply to the anode 16 is controlled by the potential applied to the gate 226 of the thin film transistor 220. The thin film transistor 220 corresponds to an example of a “driving element” in the claims.
[0242]
One of the features of the present invention is that the surface protective layer 102 is provided on the anode 16. However, the present embodiment is not limited to the case where the thin film transistor 220 may be provided on the same layer as the anode. Form 2 is shown.
[0243]
In other words, the second embodiment is essentially different from FIG. 2 only in that the anode 16 is driven by the thin film transistor 220. That is, the surface protection layer 102 is provided on the anode and the thin film transistor 220 as in FIG. This surface protective layer is the same as the surface protective layer 102 described above.
[0244]
1, the organic material layer 18 and the cathode 20 are provided on the surface protective layer 102, and the organic EL display device 200 is constituted as a whole.
[0245]
In the second embodiment, the use of the thin film transistor 220 as the driving method of the anode 16 has been described. However, it is needless to say that various other driving elements and driving methods can be appropriately used.
[0246]
【The invention's effect】
As described above, according to the electrode substrate of the present invention, since the electrode with the reduced number of defective surface layers is used, the electrical stability is improved. Therefore, when this electrode substrate is used, for example, as an anode of an organic EL element, the effect of extending the life of the element can be obtained. Further, there is an effect that a rise in the driving voltage of the organic EL element can be suppressed. Further, the heat resistance of the organic EL device can be improved.
[0247]
Further, according to the present invention, since a driving element for driving an electrode on the electrode substrate is provided, it is possible to provide an electrode substrate suitable for manufacturing a display device of, for example, a TFT system.
[0248]
In addition, when an organic EL display device is configured by using the electrode substrate of the present invention as an electrode of an organic EL device, it is possible to obtain an organic EL display device in which unevenness in light emission and variation in luminance are reduced and image quality is improved. Further, it is possible to improve the reliability over time of the image quality of the organic EL display device.
[0249]
Further, according to the electrode substrate manufacturing method of the present invention, it is possible to manufacture an electrode substrate having the above effects.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view illustrating a configuration of a preferred organic EL display device of the present invention.
FIG. 2 is a schematic diagram of a graph showing a spectrum when an In-containing compound is inspected by XPS.
FIG. 3 is a schematic sectional view illustrating a configuration of an organic EL display device according to a second embodiment.
FIG. 4 is a schematic sectional view of a conventional CCM type organic EL display device.
[Explanation of symbols]
10, 100, 200 organic EL display device
12mm board
14 CCM layer
14B blue CCM layer
14R red CCM layer
14G green CCM layer
16mm anode
18 Organic layer
20 cathode
22, 122} Organic EL device
24, 124 CCM board
102 surface protective layer
210 overcoat layer
212 passivation film
220 thin film transistor
222 gate
224 drain
226 gate

Claims (16)

Board and
An electrode comprising an In atom-containing compound,
A layer located between the electrode and the substrate, a fluorescence conversion layer for converting the wavelength of light incident on this layer,
An electrode substrate comprising:
An electrode substrate, wherein a surface protective layer made of an inorganic compound is formed on a surface of the electrode opposite to a surface facing the fluorescence conversion layer. The electrode substrate according to claim 1, wherein a constituent material of the substrate and / or the electrode is a transparent material. The electrode substrate according to claim 1, wherein the electrode is an electrode subjected to reverse sputtering. 4. The electrode substrate according to claim 3, wherein the reverse sputtering process is a reverse sputtering process using inductively coupled RF plasma-assisted magnetron sputtering. The inorganic compound constituting the surface protective layer is made of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, K, Cd, Mg, Si, Ta, Ge, Sb, Zn, Cs, Eu, Y. , Ce, W, Zr, La, Sc, Rb, Lu, Ti, Cr, Ho, Cu, Er, Sm, W, Co, Se, Hf, Tm, Fe, Nb The electrode substrate according to any one of claims 1 to 4, wherein the electrode substrate is any one of an oxide, a nitride, a composite oxide, a sulfide, and a fluoride. The electrode substrate according to claim 5, wherein the surface protection layer is formed by a sputtering method. The electrode substrate according to claim 6, wherein the surface protective layer is formed by a sputtering method using inductively coupled RF plasma-assisted magnetron sputtering. The electrode substrate according to any one of claims 1 to 7, wherein the thickness of the surface protective layer is in a range of 5 to 100 °. The electrode substrate according to any one of claims 1 to 8, wherein the electrode is made of indium tin oxide (ITO) or indium zinc oxide (IZO). The electrode substrate according to claim 9, wherein the electrode is an amorphous oxide. The electrode substrate according to claim 1, further comprising: a driving element that drives the electrode. Board and
An electrode comprising an In atom-containing compound,
A layer located between the electrode and the substrate, a fluorescence conversion layer for converting the wavelength of light incident on this layer,
In a method of manufacturing an electrode substrate comprising:
Forming the fluorescence conversion layer on the substrate,
Forming the electrode on the formed fluorescence conversion layer,
Performing a reverse sputtering process on the formed electrode surface;
Including
In the step of performing a reverse sputtering process on the electrode surface,
A method for manufacturing an electrode substrate, comprising: forming a surface protective layer made of an inorganic compound after performing a reverse sputtering process or when performing a reverse sputtering process. The method of claim 12, wherein the reverse sputtering is performed using inductively coupled RF plasma assisted magnetron sputtering. In the reverse sputtering process,
A high frequency power of 50 to 200 W and a frequency of 13.56 to 100 MHz is applied to the helical coil of the inductively coupled RF plasma assisted magnetron sputtering,
A high frequency power of 200 to 500 W and a frequency of 13.56 to 100 MHz is applied to the cathode of the inductively coupled RF plasma-assisted magnetron sputtering to cause plasma discharge,
14. The method of claim 13, wherein the intensity of the magnetron magnetic field of the inductively coupled RF plasma assisted magnetron sputtering is set to a value within a range of 200 to 300 Gauss. The electrode substrate according to claim 1, wherein
When the half width of the peak of the 3d _5/2 orbital spectrum of the In atom measured on the surface facing the surface protective layer by X-ray photoelectron spectroscopy is represented by [In3d5 _{/ 2} ] _n ,
An electrode substrate, wherein a value of [In3d5 / ₂ ] _h / [In3d5 _{/ 2} ] _n, which is a ratio of each half-value width, is in a range of 0.9 to 1.2. The electrode substrate according to claim 1, wherein
The peak value of the 3d _5/2 orbital spectrum of the In atom measured at the electrode by X-ray photoelectron spectroscopy is represented by Inpeak,
The peak value of the 3d _5/2 orbital spectrum of Sn atoms measured at the electrode by X-ray photoelectron spectroscopy is represented by Snpeak,
The ratio of each peak measured on the electrode surface is represented by (Inpeak / Snpeak) _h ,
When the ratio of each peak measured inside the electrode is represented by (Inpeak / Snpeak) _n ,
An electrode substrate, wherein ((Snpeak / Inpeak) _h / (Snpeak / Inpeak) _n ) <1.5.

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