JP4255635B2 - Light emitting device - Google Patents

Description

【００５３】
次に、格子B1を形成する金属錯体の形態について、図５、図６および図７を用いて述べる。まず図５に示すように、sp³混成軌道により４つの結合手を持つ原子Sp（具体的には第１４族元素）を中心に持ち、四面体501の頂点方向に配位できる配位子Xを選ぶことにより、クリストバライト型の格子（図５(a)）が可能となると考えられる。
【００５４】
図５(a)の例を図５(b)に示す。配位子Xとして好ましくは、四面体の頂点方向に８−キノリノール骨格を有する下記構造式（２）のような配位子を用いればよい（Aは、パラフェニレン基を含む置換基、または複素環を含む置換基、または縮合環を含む置換基、などの剛直な置換基である。）なお下記構造式（３）に示すように、Aはなくても良い。ただしこの場合、中心金属Mとしては平面配位可能な金属を選択することが望ましい（四面体配位の場合、格子が大きくねじれてしまう）。
【００５５】
【化６】

【化７】

【００５６】
また、格子B1を形成する金属錯体の形態としては、図６(a)のように、ベンゼン環を中心に持ち、正三角形の頂点方向に配位できる配位子Xを選ぶことにより、六角形の格子も可能となると考えられる。また、図６(b)に示すように、配位子Xと同じかあるいは異なる配位子Zを導入することにより、擬似的なハニカム状の格子（六方格子）が可能となると考えられる。
【００５７】
図６(b)の例を図７に示す。配位子Xとして好ましくは、ベンゼン環の１，３，および５位にキノリノール骨格を有する下記構造式（４）のような配位子を用いればよい（Aは、パラフェニレン基を含む置換基、または複素環を含む置換基、または縮合環を含む置換基、などの剛直な置換基である。）なお下記構造式（５）に示すように、Aはなくても良い。また、配位子Zとしては、両端に非共有電子対を持つ配位子（例えばピラジン）を用いればよい。ただしこの場合、中心金属Mとしては八面体配位可能な金属を選択する必要がある。なお、図７における配位状態は、図示簡略化のため、紙面手前の金属原子のみ描いてある。
【００５８】
【化８】

【化９】

【００５９】
次に、格子A2を形成する複核構造の金属錯体の形態について、図８および図９を用いて述べる。図８に示すように、配位子Xの形態に関わらず、複核構造M₂が平面配位801であれば平方格子（図８(a)）になると考えられる。さらに、複核構造M₂が八面体配位802できるのであれば、配位子Xと同じかあるいは異なる配位子Zを導入することにより、立方格子または正方格子が可能となると考えられる（図８(b)）。
【００６０】
ここで、図８(b)の例を図９に示す。配位子Xとして好ましくは、下記一般式（６）〜（８）で表されるような両端にカルボキシル基を有する、ジカルボン酸イオンを用いればよい（ただしaは、パラフェニレン基を含む置換基、または複素環を含む置換基、または縮合環を含む置換基、を表す。bは、一つもしくは複数のシクロアルキレン基を表し、前記bは置換基を有していても良い。nは、１以上の整数を表す。）。配位子Zとしては、両端に非共有電子対を持つ配位子（例えばピラジン）を用いればよい。このようにして、図９のような構造が可能となる。
【００６１】
【化１０】

【化１１】

【化１２】

【００６２】
さらに、下記一般式（９）を配位子とする複核錯体に、両端に非共有電子対を持つ配位子（例えばピラジン）を配位させた場合にも、格子構造を形成することができる（cは、アリール基を含む置換基、または複素環を含む置換基、または縮合環を含む置換基、を表す。）。
【００６３】
【化１３】

【００６４】
なお、本実施の形態で述べたようなA2型の格子構造を形成する金属錯体（一般式（６）〜（９）を配位子とする複核錯体）に関しては、以下の文献に記載されている（文献６：高見澤聡、「分子を取り込む金属錯体」、化学と工業、第５３巻、第２号(2000)、p.136-139）。
【００６５】
最後に、格子B2を形成する複核構造の金属錯体の形態について、図１０を用いて述べる。図１０(a)のように、ベンゼン環を中心に持ち、正三角形の頂点方向に配位できる配位子Xを選ぶことにより、六角形の格子が可能となると考えられる。また、図１０(b)に示すように、配位子Xと同じかあるいは異なる配位子Zを導入することにより、擬似的なハニカム状の格子（六方格子）が可能となると考えられる。
【００６６】
図１０(b)の例を図１１に示す。配位子Xとして好ましくは、下記一般式（１０）で表されるようなベンゼン環の１，３，および５位にホルミルサリチル酸骨格を有する配位子か、あるいは下記一般式（１１）で表されるようなベンゼン環の１，３，および５位にカルボキシサリチリデンアミン骨格を有する配位子を用いればよい（Aは、パラフェニレン基を含む置換基、または複素環を含む置換基、または縮合環を含む置換基、などの剛直な置換基である。）なお下記一般式（１２）、（１３）に示すように、Aはなくても良い。また、配位子Zとしては、中心金属が２価の場合は両端に非共有電子対を持つ配位子（例えばピラジン）を、中心金属が３価の場合はジカルボン酸イオンを用いればよい。図１１では、上記一般式（９）で表される配位子Xと、ジカルボン酸イオンである配位子Zを用いた。なお、図１１における配位状態は、図示簡略化のため、紙面手前の金属原子のみ描いてある。
【００６７】
【化１４】

【化１５】

【化１６】

【化１７】

【００６８】
ところで、以上の実施の形態の中で最も好ましい形態は、A2型の格子構造を形成できる金属錯体であると言える。その理由としては、既に合成法がある程度確立されており、なおかつその合成法が比較的簡便なためである。下記の文献７によれば、一般式（６）においてaがフェニレン基である配位子（すなわち、テレフタル酸イオン）と銅(II)イオンからなる複核錯体（すなわち、テレフタル酸銅(II)）の合成方法は、蟻酸銅(II)四水和物とテレフタル酸のそれぞれのメタノール溶液を混合するだけであり、極めて簡便であることがわかる（文献７：森和亮、高見澤聡、「新しいマイクロポアー物質」、化学と工業、第５１巻、第２号(1998)、p.210-212）。
【００６９】
ここで、文献６に記載されている配位子の中で、一般式（６）〜（９）に該当するものを下記表１にまとめた。複核構造を形成する中心金属としては、Cu、Cr、Mo、W、Rh、Re、Ruなどが挙げられている。なお、下記表１中のNo.7の配位子を用い、中心金属をRhとした複核錯体に関しては、ピラジンを用いて架橋することにより三次元構造を形成できることが示されている。
【００７０】
【表１】

【００７１】
これらの容易な合成法が確立されている金属錯体を有機EL素子の発光層として適用することにより、本発明を実施することが比較的容易となるため、本発明に好適である。
【００７２】
【実施例】
以下では、発明の実施の形態において述べた各構成を具体的に例示する。なお、実施例１から実施例７までの有機EL素子構造は、図１２に示した。
［実施例１］
本実施例では、発明の実施の形態において図３(b)で述べたような金属錯体を用いた有機EL素子を、具体的に例示する。中心金属Mとして２価の平面配位可能な金属であるCu(II)を、配位子Xとして下記式（１４）で表される化合物を用いる。
【化１８】

【００７３】
まず、透明な陽極1202であるITOが成膜されたガラス基板1201上に、スルホン酸をドープして導電性を向上させたポリエチレンジオキシチオフェン（以下、「PEDOT」と記す）の水溶液をスピンコーティングにより成膜し、水分を蒸発させることにより正孔注入層1203とする。膜厚は30nm程度が望ましい。
【００７４】
次に、中心金属MであるCu(II)と、配位子Xである上記式（１４）で表される配位子と、からなる平方格子構造の金属錯体1204a、およびトリス（８−キノリノラト）アルミニウム（以下、「Alq₃」と記す）からなる発光材料1204bを同一の有機溶媒に溶解させる。この溶液をスピンコーティングによりPEDOT上に塗布し、溶媒を蒸発させることにより電子輸送性発光層1204とする。膜厚は50nm程度が望ましい。
【００７５】
なお、上記平方格子構造の金属錯体1204aの作製法であるが、Cu(II)を含む金属塩と配位子とを混合させることで作製できると考えられる。この時、中心金属Mと配位子Xとの存在比は、M：X＝１：２となるように調整する必要がある。
【００７６】
最後に、電子注入層1205としてリチウムアセチルアセトネート錯体（以下、「Li(acac)」と記す）を2nm程度、陰極1206としてAlを100nm程度成膜することにより、有機EL素子とする。
【００７７】
［実施例２］
本実施例では、発明の実施の形態において図５(b)で述べたような金属錯体を用いた有機EL素子を、具体的に例示する。中心金属Mとして２価の平面配位可能な金属であるNi(II)を、配位子Xとして下記式（１５）で表される化合物を用いる。
【化１９】

【００７８】
まず、透明な陽極1202であるITOが成膜されたガラス基板1201上に、スルホン酸をドープして導電性を向上させたPEDOTの水溶液をスピンコーティングにより成膜し、水分を蒸発させることにより正孔注入層1203とする。膜厚は30nm程度が望ましい。
【００７９】
次に、中心金属MであるNi(II)と、配位子Xである上記式（１５）で表される配位子と、からなるクリストバライト型格子構造の金属錯体1204a、およびAlq₃からなる発光材料1204bを同一の有機溶媒に溶解させる。この溶液をスピンコーティングによりPEDOT上に塗布し、溶媒を蒸発させることにより電子輸送性発光層1204とする。膜厚は50nm程度が望ましい。
【００８０】
なお、上記クリストバライト型格子構造の金属錯体1204aの作製法であるが、Ni(II)を含む金属塩と配位子とを混合させることで作製できると考えられる。この時、中心金属Mと配位子Xとの存在比は、M：X＝２：１となるように調整する必要がある。
【００８１】
最後に、電子注入層1205としてLi(acac)を2nm程度、陰極1206としてAlを100nm程度成膜することにより、有機EL素子とする。
【００８２】
［実施例３］
本実施例では、発明の実施の形態において図７で述べたような金属錯体を用いた有機EL素子を、具体的に例示する。中心金属Mとして２価の八面体配位可能な金属であるCo(II)を、配位子Xとして下記式（１６）で表される化合物を、配位子Zとしてピラジンを用いる。
【化２０】

【００８３】
まず、透明な陽極1202であるITOが成膜されたガラス基板1201上に、スルホン酸をドープして導電性を向上させたPEDOTの水溶液をスピンコーティングにより成膜し、水分を蒸発させることにより正孔注入層1203とする。膜厚は30nm程度が望ましい。
【００８４】
次に、中心金属MであるCo(II)と、配位子Xである上記式（１６）で表される配位子と、配位子Zであるピラジンと、からなる六方格子構造の金属錯体1204a、およびAlq₃からなる発光材料1204bを同一の有機溶媒に溶解させる。この溶液をスピンコーティングによりPEDOT上に塗布し、溶媒を蒸発させることにより電子輸送性発光層1204とする。膜厚は50nm程度が望ましい。
【００８５】
なお、上記六方格子構造の金属錯体1204aの作製法であるが、Co(II)を含む金属塩と配位子とを混合させることで作製できると考えられる。この時、中心金属Mと配位子Xと配位子Zとの存在比は、M：X：Z＝３：２：３となるように調整する必要がある。
【００８６】
最後に、電子注入層1205としてLi(acac)を2nm程度、陰極1206としてAlを100nm程度成膜することにより、有機EL素子とする。
【００８７】
［実施例４］
本実施例では、発明の実施の形態において図９で述べたような複核錯体を用いた有機EL素子を、具体的に例示する。中心金属Mとして２価の金属であるMo(II)を、配位子Xとして下記式（１７）で表される化合物を、配位子Zとしてピラジンを用いる。
【化２１】

【００８８】
まず、透明な陽極1202であるITOが成膜されたガラス基板1201上に、スルホン酸をドープして導電性を向上させたPEDOTの水溶液をスピンコーティングにより成膜し、水分を蒸発させることにより正孔注入層1203とする。膜厚は30nm程度が望ましい。
【００８９】
次に、中心金属MであるMo(II)と、配位子Xである上記式（１７）で表される配位子と、配位子Zであるピラジンと、からなる正方格子構造の複核錯体1204a、およびAlq₃からなる発光材料1204bを同一の有機溶媒に溶解させる。この溶液をスピンコーティングによりPEDOT上に塗布し、溶媒を蒸発させることにより電子輸送性発光層1204とする。膜厚は50nm程度が望ましい。
【００９０】
なお、上記正方格子構造の複核錯体1204aの作製法であるが、酢酸銅一水和物型の複核Mo(II)錯体と配位子とを混合させる、配位子置換反応で作製できると考えられる。この時、中心金属Mと配位子Xと配位子Zとの存在比は、M：X：Z＝２：２：１となるように調整する必要がある。
【００９１】
最後に、電子注入層1205としてLi(acac)を2nm程度、陰極1206としてAlを100nm程度成膜することにより、有機EL素子とする。
【００９２】
［実施例５］
本実施例では、発明の実施の形態において図１１で述べたような複核錯体を用いた有機EL素子を、具体的に例示する。中心金属Mとして３価の金属であるMn (III)を、配位子Xとして下記式（１８）で表される化合物を、配位子Zとしてテレフタル酸を用いる。
【化２２】

【００９３】
まず、透明な陽極1202であるITOが成膜されたガラス基板1201上に、スルホン酸をドープして導電性を向上させたPEDOTの水溶液をスピンコーティングにより成膜し、水分を蒸発させることにより正孔注入層1203とする。膜厚は30nm程度が望ましい。
【００９４】
次に、中心金属MであるMn(III)と、配位子Xである上記式（１８）で表される配位子と、配位子Zであるテレフタル酸と、からなる六方格子構造の複核錯体1204a、およびAlq₃からなる発光材料1204bを同一の有機溶媒に溶解させる。この溶液をスピンコーティングによりPEDOT上に塗布し、溶媒を蒸発させることにより電子輸送性発光層1204とする。膜厚は50nm程度が望ましい。
【００９５】
なお、上記六方格子構造の複核錯体1204aの作製法であるが、Mn(III)を含む金属塩と配位子とを混合させることで作製できると考えられる。この時、中心金属Mと配位子Xと配位子Zとの存在比は、M：X：Z＝６：２：３となるように調整する必要がある。
【００９６】
最後に、電子注入層1205としてLi(acac)を2nm程度、陰極1206としてAlを100nm程度成膜することにより、有機EL素子とする。
【００９７】
［実施例６］
本実施例では、発明の実施の形態における表１で示された配位子を用いた複核錯体を具体的に例示し、これを用いた有機発光素子の作製法を示す。ここでは、表１におけるNo,1（テレフタル酸イオン；下記式（１９））を用いた銅複核錯体を用いる。
【００９８】
【化２３】

【００９９】
まず、透明な陽極1202であるITOが成膜されたガラス基板1201上に、スルホン酸をドープして導電性を向上させたPEDOTの水溶液をスピンコーティングにより成膜し、水分を蒸発させることにより正孔注入層1203とする。膜厚は30nm程度が望ましい。
【０１００】
次に、中心金属Cuの原料である蟻酸銅四水和物のメタノール溶液と、配位子の原料であるテレフタル酸のメタノール溶液と、Alq3のメタノール溶液とを、混合すると同時にスピンコーティングによりPEDOT上に塗布し、溶媒を蒸発させることにより電子輸送性発光層1204とする。文献６に示される通り、蟻酸銅四水和物とテレフタル酸は反応して格子構造の複核錯体1204aを形成する。Alq₃からなる発光材料1204bは格子中に取り込まれると考えられる。膜厚は50nm程度が望ましい。
【０１０１】
最後に、電子注入層1205としてLi(acac)を2nm程度、陰極1206としてAlを100nm程度成膜することにより、有機EL素子とする。
【０１０２】
［実施例７］
本実施例では、発明の実施の形態における表１で示された配位子を用いた複核錯体を具体的に例示し、これを用いた有機発光素子の作製法を示す。ここでは、表１におけるNo,7（安息香酸イオン；下記式（２０））を用いたロジウム複核錯体を用いる。
【０１０３】
【化２４】

【０１０４】
まず、透明な陽極1202であるITOが成膜されたガラス基板1201上に、スルホン酸をドープして導電性を向上させたPEDOTの水溶液をスピンコーティングにより成膜し、水分を蒸発させることにより正孔注入層1203とする。膜厚は30nm程度が望ましい。
【０１０５】
次に、文献６で示されている安息香酸ロジウム複核錯体をピラジンに溶解させ、この溶液とAlq₃とを混合した後、スピンコーティングによりPEDOT上に塗布し、溶媒を減圧下にて蒸発させることにより電子輸送性発光層1204とする。この場合、文献６に示されるような、安息香酸ロジウム複核錯体とピラジンからなる格子構造の複核錯体1204aが形成され、Alq₃からなる発光材料1204bは格子中に取り込まれると考えられる。膜厚は50nm程度が望ましい。
【０１０６】
最後に、電子注入層1205としてLi(acac)を2nm程度、陰極1206としてAlを100nm程度成膜することにより、有機EL素子とする。
【０１０７】
［実施例８］
本実施例では、本発明で開示した有機EL素子を含む発光装置について説明する。図１３は本発明の有機EL素子を用いたアクティブマトリクス型発光装置の断面図である。なお、能動素子としてここでは薄膜トランジスタ（以下、「TFT」と記す）を用いているが、MOSトランジスタを用いてもよい。
【０１０８】
また、TFTとしてトップゲート型TFT（具体的にはプレーナ型TFT）を例示するが、ボトムゲート型TFT（典型的には逆スタガ型TFT）を用いることもできる。
【０１０９】
図１３において、1301は基板であり、ここでは可視光を透過する基板を用いる。具体的には、ガラス基板、石英基板、結晶化ガラス基板もしくはプラスチック基板（プラスチックフィルムを含む）を用いればよい。なお、基板1301には、基板の表面に設けた絶縁膜も含めるものとする。
【０１１０】
基板1301の上には画素部1311および駆動回路1312が設けられている。まず、画素部1311について説明する。
【０１１１】
画素部1311は画像表示を行う領域であり、複数の画素を有し、各画素には有機EL素子に流れる電流を制御するためのTFT（以下、「電流制御TFT」と記す）1302、画素電極（陽極）1303、有機EL層1304および陰極1305が設けられている。なお、図１３では電流制御TFTしか図示していないが、電流制御TFTのゲートに加わる電圧を制御するためのTFT（以下、「スイッチングTFT」と記す）を設けている。
【０１１２】
電流制御TFT1302は、ここではpチャネル型TFTを用いることが好ましい。nチャネル型TFTとすることも可能であるが、図１３のように有機EL素子の陽極に電流制御TFTを接続する場合は、pチャネル型TFTの方が消費電力を押さえることができる。ただし、スイッチングTFTはnチャネル型TFTでもpチャネル型TFTでもよい。
【０１１３】
また、電流制御TFT1302のドレインには画素電極1303が電気的に接続されている。本実施例では、画素電極1303の材料として仕事関数が4.5〜5.5eVの導電性材料を用いるため、画素電極1303は有機EL素子の陽極として機能する。画素電極1303として代表的には、酸化インジウム、酸化錫、酸化亜鉛もしくはこれらの化合物（ITOなど）を用いればよい。画素電極1303の上には有機EL層1304が設けられている。
【０１１４】
さらに、有機EL層1304の上には陰極1305が設けられている。陰極1305の材料としては、仕事関数が2.5〜3.5eVの導電性材料を用いることが望ましい。陰極1305として代表的には、アルカリ金属元素もしくはアルカリ度類金属元素を含む導電膜、あるいはその導電膜にアルミニウム合金を積層したものを用いればよい。
【０１１５】
また、画素電極1303、有機EL膜1304、および陰極1305からなる層は、保護膜1306で覆われている。保護膜1306は、有機EL素子を酸素および水から保護するために設けられている。保護膜1306の材料としては、窒化珪素、窒化酸化珪素、酸化アルミニウム、酸化タンタル、もしくは炭素（具体的にはダイヤモンドライクカーボン）を用いる。
【０１１６】
次に、駆動回路1312について説明する。駆動回路1312は画素部1311に伝送される信号（ゲート信号およびデータ信号）のタイミングを制御する領域であり、シフトレジスタ、バッファ、ラッチ、アナログスイッチ（トランスファゲート）もしくはレベルシフタが設けられている。図１３では、これらの回路の基本単位としてnチャネル型TFT1307およびpチャネル型TFT1308からなるCMOS回路を示している。
【０１１７】
なお、シフトレジスタ、バッファ、ラッチ、アナログスイッチ（トランスファゲート）もしくはレベルシフタの回路構成は、公知のものでよい。また図１３では、同一の基板上に画素部1311および駆動回路1312を設けているが、駆動回路1312を設けずにICやLSIを電気的に接続することもできる。
【０１１８】
また、図１３では電流制御TFT1302に画素電極（陽極）1303が電気的に接続されているが、陰極が電流制御TFTに接続された構造をとることもできる。その場合、画素電極を陰極1305と同様の材料で形成し、陰極を画素電極（陽極）1303と同様の材料で形成すればよい。その場合、電流制御TFTはnチャネル型TFTとすることが好ましい。
【０１１９】
ここで、図１３に示したアクティブマトリクス型発光装置の外観を図１４に示す。なお、図１４(a)には上面図を示し、図１４(b)には図１４(a)をP−P'で切断した時の断面図を示す。また、図１３の符号を引用する。
【０１２０】
図１４(a)において、1401は画素部、1402はゲート信号側駆動回路、1403はデータ信号側駆動回路である。また、ゲート信号側駆動回路1402およびデータ信号側駆動回路1403に伝送される信号は、入力配線1404を介してTAB（Tape Automated Bonding）テープ1405から入力される。なお、図示しないが、TABテープ1405の代わりに、TABテープにIC（集積回路）を設けたTCP（Tape Carrier Package）を接続してもよい。
【０１２１】
このとき、1406は図１３に示した有機EL素子の上方に設けられるカバー材であり、樹脂からなるシール材1407により接着されている。カバー材1406は酸素および水を透過しない材質であれば、いかなるものを用いてもよい。本実施例では、カバー材1406は図１４(b)に示すように、プラスチック材1406aと、前記プラスチック材1406aの表面および裏面に設けられた炭素膜（具体的にはダイヤモンドライクカーボン膜）1406b、1406cからなる。
【０１２２】
さらに、図１４(b)に示すように、シール材1407は樹脂からなる封止材1408で覆われ、有機EL素子を完全に密閉空間1409に封入するようになっている。密閉空間1409は不活性ガス（代表的には窒素ガスや希ガス）、樹脂または不活性液体（例えばパーフルオロアルカンに代表される液状のフッ素化炭素）を充填しておけばよい。さらに、吸湿剤や脱酸素剤を設けることも有効である。
【０１２３】
また、本実施例に示した発光装置の表示面（画像を観測する面）に偏光板をもうけてもよい。この偏光板は、外部から入射した光の反射を押さえ、観測者が表示面に映り込むことを防ぐ効果がある。一般的には、円偏光板が用いられている。ただし、有機EL膜から発した光が偏光板により反射されて内部に戻ることを防ぐため、屈折率を調節して内部反射の少ない構造とすることが好ましい。
【０１２４】
なお、本実施例の発光装置に含まれる有機EL素子には、本発明で開示した有機EL素子のいずれを用いてもよい。
［実施例９］
【０１２５】
本実施例では、本発明で開示した有機EL素子を含む発光装置の例として、パッシブマトリクス型発光装置を例示する。図１５(a)にはその上面図を示し、図１５(b)には図１５(a)をP−P'で切断した時の断面図を示す。
【０１２６】
図１５(a)において、1501は基板であり、ここではプラスチック材を用いる。プラスチック材としては、ポリイミド、ポリアミド、アクリル樹脂、エポキシ樹脂、PES（ポリエチレンサルファイル）、PC（ポリカーボネート）、PET（ポリエチレンテレフタレート）もしくはPEN（ポリエチレンナフタレート）を板状、もしくはフィルム上にしたものが使用できる。
【０１２７】
1502は酸化導電膜からなる走査線（陽極）であり、本実施例では酸化亜鉛に酸化ガリウムを添加した酸化物導電膜を用いる。また、1503は金属膜からなるデータ線（陰極）であり、本実施例ではビスマス膜を用いる。また、1504はアクリル樹脂からなるバンクであり、データ線1503を分断するための隔壁として機能する。走査線1502とデータ線1503は両方とも、ストライプ状に複数形成されており、互いに直交するように設けられている。なお、図１５(a)では図示していないが、走査線1502とデータ線1503の間には有機EL層が挟まれており、交差部1505が画素となる。
【０１２８】
そして、走査線1502およびデータ線1503はTABテープ1507を介して外部の駆動回路に接続される。なお、1508は走査線1502が集合してなる配線群を表しており、1509はデータ線1503に接続された接続配線1506の集合からなる配線群を表す。また、図示していないが、TABテープ1507の代わりに、TABテープにICを設けたTCPを接続してもよい。
【０１２９】
また、図１５(b)において、1510はシール材、1511はシール材1510によりプラスチック材1501に貼り合わされたカバー材である。シール材1510としては光硬化樹脂を用いていればよく、脱ガスが少なく、吸湿性の低い材料が望ましい。カバー材としては基板1501と同一の材料が好ましく、ガラス（石英ガラスを含む）もしくはプラスチックを用いることができる。ここではプラスチック材を用いる。
【０１３０】
次に、画素領域の構造の拡大図を図１５(c)に示す。1513は有機EL層である。なお、図１５(c)に示すように、バンク1504は下層の幅が上層の幅よりも狭い形状になっており、データ線1503を物理的に分断できる。また、シール材1510で囲まれた画素部1514は、樹脂からなる封止材1515により外気から遮断され、有機EL層の劣化を防ぐ構造となっている。
【０１３１】
以上のような構成からなる本発明の発光装置は、画素部1514が走査線1502、データ線1503、バンク1504および有機EL層1513で形成されるため、非常に簡単なプロセスで作製することができる。
【０１３２】
また、本実施例に示した発光装置の表示面（画像を観測する面）に偏光板をもうけてもよい。この偏光板は、外部から入射した光の反射を押さえ、観測者が表示面に映り込むことを防ぐ効果がある。一般的には、円偏光板が用いられている。ただし、有機EL膜から発した光が偏光板により反射されて内部に戻ることを防ぐため、屈折率を調節して内部反射の少ない構造とすることが好ましい。
【０１３３】
なお、本実施例の発光装置に含まれる有機EL素子には、本発明で開示した有機EL素子のいずれを用いてもよい。
【０１３４】
［実施例１０］
本実施例では、実施例９で示した発光装置にプリント配線板を設けてモジュール化した例を示す。
【０１３５】
図１６(a)に示すモジュールは、基板1601（ここでは、画素部1602、配線1603a、 1603bを含む）にTABテープ1604が取り付けられ、前記TABテープ1604を介してプリント配線板1605が取り付けられている。
【０１３６】
ここで、プリント配線板1605の機能ブロック図を図１６(b)に示す。プリント配線板1605の内部には少なくともI/Oポート（入力もしくは出力部）1606、 1609、データ信号側駆動回路1607およびゲート信号側回路1608として機能するICが設けられている。
【０１３７】
このように、基板面に画素部が形成された基板にTABテープが取り付けられ、そのTABテープを介して駆動回路としての機能を有するプリント配線版が取り付けられた構成のモジュールを、本明細書では特に駆動回路外付け型モジュールと呼ぶことにする。
【０１３８】
なお、本実施例の発光装置に含まれる有機EL素子には、本発明で開示した有機EL素子のいずれを用いてもよい。
【０１３９】
［実施例１１］
本実施例では、実施例８もしくは実施例９に示した発光装置にプリント配線板を設けてモジュール化した例を示す。
【０１４０】
図１７(a)に示すモジュールは、基板1701（ここでは、画素部1702、データ信号側駆動回路1703、ゲート信号側駆動回路1704、配線1703a、 1704aを含む）にTABテープ1705が取り付けられ、そのTABテープ1705を介してプリント配線板1706が取り付けられている。プリント配線板1706の機能ブロック図を図１７(b)に示す。
【０１４１】
図１７(b)に示すように、プリント配線板1706の内部には少なくともI/Oポート1707、 1710、コントロール部1708として機能するICが設けられている。なお、ここではメモリ部1709を設けてあるが、必ずしも必要ではない。またコントロール部1708は、駆動回路の制御、映像データの補正などをコントロールするための機能を有した部位である。
【０１４２】
このように、有機EL素子の形成された基板にコントローラーとしての機能を有するプリント配線板が取り付けられた構成のモジュールを、本明細書では特にコントローラー外付け型モジュールと呼ぶことにする。
【０１４３】
なお、本実施例の発光装置に含まれる有機EL素子には、本発明で開示した有機EL素子のいずれを用いてもよい。
【０１４４】
[実施例１２]
上記実施例で述べた本発明の発光装置は、明るく低消費電力であるという利点を有する。したがって、前記発光装置が表示部等として含まれる電気器具は、従来よりも低い消費電力で動作可能な電気器具となる。特に電源としてバッテリーを使用する携帯機器のような電気器具に関しては、低消費電力化が便利さに直結する（電池切れが起こりにくい）ため、極めて有用である。
【０１４５】
また、前記発光装置は、自発光型であることから液晶表示装置のようなバックライトは必要なく、有機EL膜の厚みも１μmに満たないため、薄型軽量化が可能である。したがって、前記発光装置が表示部等として含まれる電気器具は、従来よりも薄型軽量な電気器具となる。このことも、特に携帯機器のような電気器具に関して、便利さ（持ち運びの際の軽さやコンパクトさ）に直結するため、極めて有用である。さらに、電気器具全般においても、薄型である（かさばらない）ことは運送面（大量輸送が可能）、設置面（部屋などのスペース確保）からみても有用であることは疑いない。
【０１４６】
なお、前記発光装置は自発光型であるために、液晶表示装置に比べて明るい場所での視認性に優れ、しかも視野角が広いという特徴を持つ。したがって、前記発光装置を表示部として有する電気器具は、表示の見やすさの点でも大きなメリットがある。
【０１４７】
すなわち、本発明の発光装置を用いた電気器具は、低消費電力・薄型軽量・高視認性といった長所を持っている。さらに前記発光装置は、安価で入手できる従来の蛍光色素を用いて燐光を促進させる構成であるため、前記発光装置を用いた電気器具は従来に比べて安価になるというメリットも持つ。
【０１４８】
本実施例では、本発明の発光装置を表示部として含む電気器具を例示する。その具体例を図１８および図１９に示す。なお、本実施例の電気器具に含まれる有機EL素子には、本発明で開示した金属錯体のいずれを用いても良い。また、本実施例の電気器具に含まれる発光装置の形態は、図１３〜図１７のいずれの形態を用いても良い。
【０１４９】
図１８(a)は有機ELディスプレイであり、筐体1801a、支持台1802a、表示部1803aを含む。本発明の発光装置を表示部1803aとして用いたディスプレイを作製することにより、薄く軽量なディスプレイを実現できる。よって、輸送が簡便になり、さらに設置の際の省スペースが可能となる。
【０１５０】
図１８(b)はビデオカメラであり、本体1801b、表示部1802b、音声入力部1803b、操作スイッチ1804b、バッテリー1805b、受像部1806bを含む。本発明の発光装置を表示部1802bとして用いたビデオカメラを作製することにより、消費電力が少なく、軽量なビデオカメラを実現できる。よって、電池の消費量が少なくなり、持ち運びも簡便になる。
【０１５１】
図１８(c)はデジタルカメラであり、本体1801c、表示部1802c、接眼部1803c、操作スイッチ1804cを含む。本発明の発光装置を表示部1802cとして用いたデジタルカメラを作製することにより、消費電力が少なく、軽量なデジタルカメラを実現できる。よって、電池の消費量が少なくなり、持ち運びも簡便になる。
【０１５２】
図１８(d)は記録媒体を備えた画像再生装置であり、本体1801d、記録媒体（CD、LD、またはDVDなど）1802d、操作スイッチ1803d、表示部(A)1804d、表示部(B)1805dを含む。表示部(A)1804dは主として画像情報を表示し、表示部(B)1805dは主として文字情報を表示する。本発明の発光装置をこれら表示部(A)1804dや表示部(B)1805dとして用いた前記画像再生装置を作製することにより、消費電力が少なく、軽量な前記画像再生装置を実現できる。なお、この記録媒体を備えた画像再生装置には、CD再生装置、ゲーム機器なども含む。
【０１５３】
図１８(e)は携帯型（モバイル）コンピュータであり、本体1801e、表示部1802e、受像部1803e、操作スイッチ1804e、メモリスロット1805eを含む。本発明の発光装置を表示部1802eとして用いた携帯型コンピュータを作製することにより、消費電力が少なく、薄型軽量な携帯型コンピュータを実現できる。よって、電池の消費量が少なくなり、持ち運びも簡便になる。なお、この携帯型コンピュータはフラッシュメモリや不揮発性メモリを集積化した記録媒体に情報を記録したり、それを再生したりすることができる。
【０１５４】
図１８(f)はパーソナルコンピュータであり、本体1801f、筐体1802f、表示部1803f、キーボード1804fを含む。本発明の発光装置を表示部1803fとして用いたパーソナルコンピュータを作製することにより、消費電力が少なく、薄型軽量なパーソナルコンピュータを実現できる。特に、ノートパソコンのように持ち歩く用途が必要な場合、電池の消費量や軽さの点で大きなメリットとなる。
【０１５５】
なお、上記電気器具はインターネットなどの電子通信回線や電波などの無線通信を通じて配信される情報を表示することが多くなってきており、特に動画情報を表示する機会が増えている。有機EL素子の応答速度は非常に速く、そのような動画表示に好適である。
【０１５６】
次に、図１９(a)は携帯電話であり、本体1901a、音声出力部1902a、音声入力部1903a、表示部1904a、操作スイッチ1905a、アンテナ1906aを含む。本発明の発光装置を表示部1904aとして用いた携帯電話を作製することにより、消費電力が少なく、薄型軽量な携帯電話を実現できる。よって、電池の消費量が少なくなり、持ち運びも楽になる上にコンパクトな本体にできる。
【０１５７】
図１９(b)は音響機器（具体的には車載用オーディオ）であり、本体1901b、表示部1902b、操作スイッチ1903b、1904bを含む。本発明の発光装置を表示部1902bとして用いた音響機器を作製することにより、消費電力が少なく、軽量な音響機器を実現できる。また、本実施例では車載用オーディオを例として示すが、家庭用オーディオに用いても良い。
【０１５８】
なお、図１８〜図１９で示したような電気器具において、さらに光センサを内蔵させ、使用環境の明るさを検知する手段を設けることで、使用環境の明るさに応じて発光輝度を変調させるような機能を持たせることは有効である。使用者は、使用環境の明るさに比べてコントラスト比で100〜150の明るさを確保できれば、問題なく画像もしくは文字情報を認識できる。すなわち、使用環境が明るい場合は画像の輝度を上げて見やすくし、使用環境が暗い場合は画像の輝度を抑えて消費電力を抑えるといったことが可能となる。
【０１５９】
また、本発明の発光装置を光源として用いた様々な電気器具も、低消費電力での動作や薄型軽量化が可能であるため、非常に有用と言える。代表的には、液晶表示装置のバックライトもしくはフロントライトといった光源、または照明機器の光源として本発明の発光装置を含む電気器具は、低消費電力の実現や薄型軽量化が可能である。
【０１６０】
したがって、本実施例に示した図１８〜図１９の電気器具の表示部を、全て液晶ディスプレイにする場合においても、その液晶ディスプレイのバックライトもしくはフロントライトとして本発明の発光装置を用いた電気器具を作製することにより、消費電力が少なく、薄くて軽量な電気器具が達成できる。
【０１６１】
【発明の効果】
本発明を実施することで、明るく消費電力が少ない上に、発光色が多彩でコスト的にも優れた発光装置を得ることができる。さらに、そのような発光装置を光源もしくは表示部に用いることで、明るく消費電力が少ない上に、発光色が多彩で安価な電気器具を得ることができる。
【図面の簡単な説明】
【図１】格子を形成する金属錯体の概念を示す図。
【図２】格子を形成する金属錯体の概念を示す図。
【図３】格子を形成する金属錯体の構成を示す図。
【図４】格子を形成する金属錯体の構成を示す図。
【図５】格子を形成する金属錯体の構成を示す図。
【図６】格子を形成する金属錯体の構成を示す図。
【図７】格子を形成する金属錯体の構成を示す図。
【図８】格子を形成する金属錯体の構成を示す図。
【図９】格子を形成する金属錯体の構成を示す図。
【図１０】格子を形成する金属錯体の構成を示す図。
【図１１】格子を形成する金属錯体の構成を示す図。
【図１２】有機EL素子の構造を示す図。
【図１３】発光装置の断面構造を示す図。
【図１４】発光装置の上面構造および断面構造を示す図。
【図１５】発光装置の上面構造および断面構造を示す図。
【図１６】発光装置の構成を示す図。
【図１７】発光装置の構成を示す図。
【図１８】電気器具の具体例を示す図。
【図１９】電気器具の具体例を示す図。[0001]
[Field of the Invention]
The present invention includes an element having an anode layer, a cathode layer, and a film (hereinafter referred to as “organic EL layer”) containing an organic compound from which EL (Electro Luminescence; luminescence generated by applying an electric field) is obtained ( Hereinafter, the present invention relates to a light emitting device using “organic EL element”. EL in organic compounds includes light emission (fluorescence) when returning from the singlet excited state to the ground state and light emission (phosphorescence) when returning from the triplet excited state to the ground state. Alternatively, the present invention relates to a light-emitting device that can promote phosphorescence by arranging a light-emitting material in the pores by applying a metal complex capable of forming pores resulting from a three-dimensional network structure to the light-emitting layer. Note that the light emitting device in this specification refers to an image display device or a light emitting device using an organic EL element as a light emitting element. Also, a module with a TAB (Tape Automated Bonding) tape or TCP (Tape Carrier Package) attached to an organic EL element, a module with a printed wiring board provided at the end of a TAB tape or TCP, or a COG (Chip All modules on which an IC (integrated circuit) is directly mounted by the On Glass method are also included in the light emitting device.
[0002]
[Prior art]
An organic EL element emits light when an electric field is applied. The light emission mechanism is an excited state in which an electron injected from the cathode and a hole injected from the anode are recombined at the emission center in the organic EL layer by applying a voltage with the organic EL layer sandwiched between the electrodes. It is said that this molecule emits light by releasing energy when the molecular exciton returns to the ground state (hereinafter referred to as “molecular exciton”).
[0003]
In a normal organic EL element, the organic EL layer is formed with a thin film having a thickness of less than 1 μm. Further, since the organic EL element itself is a self-luminous element, a backlight as used in a conventional liquid crystal display is not necessary. Therefore, it is a great advantage that the organic EL element can be manufactured to be extremely thin and light.
[0004]
For example, in an organic EL layer of about 100 to 200 nm, the time from carrier injection to recombination is about several tens of nanoseconds considering the carrier mobility of the organic EL layer, and light emission from recombination Even including the process up to, light emission occurs on the order of microseconds or less. Therefore, one of the features is that the response speed is very fast.
[0005]
Furthermore, since the organic EL element is a carrier injection type light emitting element, it can be driven with a DC voltage and noise is hardly generated. With respect to the driving voltage, driving in the order of several volts is possible by selecting an electrode material that reduces the carrier injection barrier or introducing a heterostructure (laminated structure) (Reference 1: CW Tang). and SA VanSlyke, "Organic electroluminescent diodes", Applied Physics Letters, vol. 51, No. 12, 913-915 (1987)). In Reference 1, an Mg: Ag alloy is used as a cathode, a diamine compound and tris (8-quinolinolato) -aluminum (hereinafter “Alq”). _Three DC low voltage drive is realized by adopting a heterostructure in which the above are stacked.
[0006]
Due to these thin, lightweight, high-speed response, and direct current low voltage drive characteristics, organic EL devices are attracting attention as next-generation flat panel display devices. Further, since it is a self-luminous type and has a wide viewing angle, the visibility is relatively good, and it is considered effective as an element used for a display screen of a portable device.
[0007]
By the way, as described above, organic EL is a phenomenon in which molecular excitons emit light when returning to the ground state, but the excited state of molecular excitons formed by organic compounds is a singlet excited state (S ^* ) And triplet excited states (T ^* Is possible. The statistical generation ratio of organic EL elements is S ^* : T ^* = 1: 3 (Reference 2: Tetsuo Tsutsui, “Applied Physics Society of Organic Molecules and Bioelectronics Subcommittee, 3rd Workshop Text”, P.31 (1993)).
[0008]
However, common organic compounds are triplet excited states (T ^* ) (Phosphorescence) is not observed and is usually singlet excited (S ^* Only the light emission (fluorescence) from is observed. The ground state of an organic compound is usually a singlet ground state (S ₀ ) Because T ^* → S ₀ Transition is a forbidden transition, S ^* → S ₀ This is because the transition is an allowable transition.
[0009]
That is, the singlet excited state (S ^* ) Usually contributes to light emission, and this also applies to organic EL elements. Therefore, the theoretical limit of internal quantum efficiency (ratio of photons generated with respect to injected carriers) in organic EL devices is S ^* : T ^* = 25% based on 1: 3.
[0010]
Further, not all of the generated light is emitted to the outside, and part of the light cannot be extracted due to the refractive index inherent to the organic EL element constituent material (organic EL layer material, electrode material) and the substrate material. The ratio of the generated light that is extracted to the outside is called light extraction efficiency. In an organic EL element having a glass substrate, the extraction efficiency is said to be about 20%.
[0011]
For the above reasons, even if all the injected carriers form molecular excitons, the theoretical limit of the proportion of photons that can be finally extracted outside the number of injected carriers (hereinafter referred to as “external quantum efficiency”) Was said to be 25% x 20% = 5%. That is, even if all the carriers are recombined, only 5% of them can be extracted as light.
[0012]
Recently, however, triplet excited states (T ^* Organic EL devices that can convert the energy released when returning to the ground state (hereinafter referred to as “triplet excitation energy”) to light emission have been announced one after another, and the high luminous efficiency has attracted attention ( Reference 3: DF O'Brien, MA Baldo, ME Thompson and SR Forrest, "Improved energy transfer in electrophosphorescent devices", Applied Physics Letters, vol. 74, No. 3, 442-444 (1999)) (Reference 4: Tetsuo Tsutsui, Moon-Jae Yang, Masayuki Yahiro, Kenji Nakamura, Teruichi Watanabe, Taishi Tsuji, Yoshinori Fukuda, Takeo Wakimoto and Satoshi Miyaguchi, "High Quantum Efficiency in Organic Light-Emitting Devices with Iridium-Complex as a Triplet Emissive Center", Japanese Journal of Applied Physics, Vol. 38, L1502-L1504 (1999)).
[0013]
Document 3 uses a metal complex with platinum as the central metal (hereinafter referred to as “platinum complex”), and Document 4 uses a metal complex with iridium as the central metal (hereinafter referred to as “iridium complex”). It can be said that this metal complex is also characterized by introducing a third transition series element as a central metal. Among them, there are those that far exceed the theoretical limit of 5% of the external quantum efficiency described above.
[0014]
As shown in Literature 3 and Literature 4, the organic EL element capable of converting triplet excitation energy into light emission can achieve higher external quantum efficiency than conventional ones. And if external quantum efficiency becomes high, light emission brightness will also improve. Therefore, an organic EL device capable of converting triplet excitation energy into light emission is considered to occupy a large weight in future development as a method for achieving high luminance light emission and high light emission efficiency.
[0015]
[Problems to be solved by the invention]
However, since both platinum and iridium are so-called noble metals, platinum complexes and iridium complexes using them are also expensive, and it is expected that they will be an adverse effect of cost reduction in the future.
[0016]
Further, the emission color of the iridium complex is green, that is, a wavelength located in the middle in the visible light region. The platinum complex emits red light with relatively good color purity when used as a dopant. However, when the concentration is low, the host material also shines, resulting in poor color purity. When the concentration is high, light emission occurs due to concentration quenching. There is a disadvantage that efficiency is reduced. That is, high-efficiency light emission of red or blue with high color purity has not been obtained from an organic EL element that can convert triplet excitation energy into light emission.
[0017]
Therefore, in the future, considering the production of full-color flat panel displays using red, green, and blue light emission colors, red light emission with high external quantum efficiency and high color purity, as well as iridium complexes and platinum complexes, and Blue emission must be achieved using as cheap a material as possible.
[0018]
From such a background, in addition to the organic EL element using the existing iridium complex or platinum complex, development of an organic EL element capable of converting triplet excitation energy into light emission is desired. The simplest method is to develop a new organic compound that emits phosphorescence at room temperature. However, a clear molecular design policy has not yet been established, and there are many difficult aspects.
[0019]
Therefore, it is important to develop a new phosphorescent material, but it is desirable to design an organic EL layer configuration that promotes phosphorescence emission compared to the light-emitting materials that have been used in conventional organic EL devices. . This is because various luminescent colors have already been obtained with luminescent materials conventionally used in organic EL elements, so that various luminescent colors may be exhibited and many inexpensive materials exist.
[0020]
Therefore, in the present invention, an organic EL element capable of converting triplet excitation energy into light emission is achieved by devising the configuration of the light emitting layer while using the light emitting material conventionally used in organic EL elements. To do. Accordingly, it is an object to provide an organic EL element that has high luminous efficiency and exhibits various emission colors by using a conventional organic compound and can be manufactured at low cost.
[0021]
It is another object of the present invention to provide a light-emitting device that is bright and consumes less power and exhibits various emission colors using the organic EL element disclosed in the present invention at low cost. Furthermore, by using such a light-emitting device, it is an object to provide an inexpensive electric appliance that is bright and consumes less power and exhibits various emission colors.
[0022]
[Means for Solving the Problems]
The inventor paid attention to the heavy atom effect known in the field of PL (Photo Luminescence; luminescence generated by irradiating light). The heavy atom effect means that by introducing a heavy atom (atom having many nuclear loads) into a molecule or solvent, a spin-orbit interaction is increased and phosphorescence emission is promoted. . The nuclear load corresponds to the atomic number, that is, the number of positive charges in the nucleus.
[0023]
There are two types of heavy atom effects: internal heavy atom effects and external heavy atom effects. The internal heavy atom effect means that phosphorescence emission is promoted when a heavy atom is contained in the molecule of the light emitting material. On the other hand, even when heavy atoms are present in the solvent containing the luminescent material as a solute, the phosphorescent emission of the luminescent material is sometimes promoted, and this phenomenon is called the external heavy atom effect.
[0024]
Therefore, it is considered that phosphorescence may be obtained if the external heavy atom effect can be expressed also in the organic EL element. In other words, this is a technique for promoting phosphorescence emission by allowing a material containing heavy atoms to exist around the light emitting material.
[0025]
A simple method is to disperse a metal as a heavy atom in the light emitting layer of the organic EL layer, but in that case, it is considered difficult to function as the light emitting layer. For example, if the organic EL layer is doped with an alkali metal (such as cesium), the doped layer has improved conductivity and can exhibit an excellent function as a carrier transport layer. However, since the doped metal becomes a material that deactivates excitation energy and prevents light emission (hereinafter referred to as “quencher”), the doped layer does not emit light. Therefore, it is usually difficult to use such a doped layer as the light emitting layer, and it is impossible to introduce the heavy atom effect.
[0026]
Therefore, in short, an insulator containing heavy atoms may be disposed around the light emitting material, not the metal itself. That is, by using an insulator having a large band gap as a material containing heavy atoms, energy transfer and deactivation from the light emitting material are prevented, and a quencher is prevented. Thereby, promotion of phosphorescence emission by the heavy atom effect can be expected.
[0027]
For example, there is a report on PL characteristics of an organic material dispersed in pores of an insulating zeolite (Reference 5: V. Ramamurthy, J. V Caspar, DF Eaton, Erica W. Kuo, and DR Corbin, "Heavy-Atom-Induced Phosphorescence of Aromatics and Olefins Included within Zeolites", Journal of American Chemical Society, Vol. 114, No. 10, 3882-3892 (1992)). According to the literature 5, about the PL of the organic material contained in the pores of the zeolite, when the zeolite cations (Li, Na, K, Rb, Cs, and Tl) are replaced, the cations become heavier atoms. The result that phosphorescence emission is accelerated | stimulated by the heavy atom effect has been obtained.
[0028]
Here, in particular, as in Document 5, the insulator containing heavy atoms is used in the form of a porous body (with a uniform pore size distribution as much as possible), and a method of introducing a light emitting material into the pores of the porous body The inventor believes that this is desirable. This is because the light emitting material has a structure surrounded by the porous body, so that the interaction between the heavy atoms contained in the porous body and the light emitting material is increased, and the phosphorescence emission is facilitated by the heavy atom effect. This is because it is expected. In addition, since the luminescent material is confined in the pores and the pores are regularly arranged, a pseudo-like superlattice structure is formed, stable molecular excitons are generated, and the emission characteristics are improved. There is also a possibility of improving.
[0029]
However, in an organic EL device, there are some problems in driving the device by containing a light emitting material in zeolite. First, when zeolite is provided on the electrode, injection of carriers into the organic EL layer is hindered, and there is a possibility that the emission characteristics are rather deteriorated. In addition, a technique for forming a zeolite film as a thin film of about 100 to 200 nm is also necessary. Furthermore, it is mentioned that a light emitting material cannot be contained in zeolite by vacuum deposition (it is possible by a wet method).
[0030]
Considering these electrical characteristics and process problems, it can be said that promotion of phosphorescence emission using zeolite as shown in Reference 5 is an easy technique because it is PL. That is, it is relatively difficult to apply to an EL element.
[0031]
Therefore, the present inventor has devised a technique that makes use of the concept of containing a light-emitting material in the pores of a porous body containing heavy atoms and that is less likely to cause problems in electrical characteristics and processes. That is, a metal complex that forms a network structure is used as a host for a light emitting material, and the light emitting material is dispersed in the network of the host. The schematic diagram is shown in FIG.
[0032]
As a network formed by a metal complex (hereinafter, simply referred to as “lattice”), a form as shown in FIG. 1A in which a metal atom 101a is located at a lattice point and a ligand 102a is bridged (hereinafter, “ 1 (b) ”(hereinafter referred to as“ lattice B1 ”) in which the ligand 102b is positioned at a lattice point and the metal atom 101b is bridged. Note that the shape of the lattice is not limited to the quadrangle as shown in FIG. 1, and various polygons (such as hexagons) are possible. The lattice can have both a two-dimensional (planar) structure and a three-dimensional (three-dimensional) structure.
[0033]
Then, at the time of synthesizing or forming a metal complex having such a lattice structure, the light emitting material 103 having an appropriate molecular size can be mixed to introduce the light emitting material into the interstitial position of the lattice structure.
[0034]
Therefore, in the present invention, in a light emitting device having an organic EL element including a light emitting layer composed of an organic compound from which EL can be obtained, and a metal complex, the metal complex is a lattice in which metal atoms and ligands are alternately arranged. A structure is formed, wherein the metal atom is a lattice point and the ligand bridges the lattice point (lattice A1).
[0035]
In the present invention, in the light-emitting device having an organic EL element including a light-emitting layer composed of an organic compound capable of obtaining EL and a metal complex, the metal complex has metal atoms and ligands arranged alternately. A lattice structure is formed, wherein the ligand is a lattice point and the metal atom bridges the lattice point (lattice B1).
[0036]
Although most metal atoms are thought to be able to cause more or less heavy atom effects, in the field of PL, heavy atom effects occur especially when they contain atoms that are heavier than bromine (Br; atomic number 35). Is noticeable. Therefore, the metal atom contained in the metal complex is preferably a metal atom heavier than rubidium (Rb; atomic number 37).
[0037]
Therefore, in the present invention, in a light-emitting device having an organic EL element including a light-emitting layer composed of an organic compound from which EL can be obtained, and a metal complex, the metal complex is a lattice in which metal atoms and ligands are alternately arranged. A lattice structure of A1 or lattice B1 is formed, and the metal atom has an atomic number greater than or equal to rubidium.
[0038]
By the way, the heavy atom effect means that the introduction of heavy atoms increases the spin-orbit interaction and promotes phosphorescence. Therefore, even when no heavy atom is used, triplet excitation energy can be converted into light emission if a molecular structure having a large spin-orbit interaction can be introduced.
[0039]
One possible method is to introduce a molecular structure that exhibits ferromagnetism or antiferromagnetism. Therefore, the present inventor has focused on a binuclear complex (a metal complex having two metal atoms as a nucleus). The reason for this is that in a multinuclear complex having a paramagnetic metal ion, a ferromagnetic or antiferromagnetic interaction is often observed in the complex. If a heavy metal is selected as the metal atom, the phosphorescence emission can be further promoted because a heavy atom effect is added.
[0040]
Therefore, in particular, a metal complex in which the metal atom in FIG. 1 is replaced with a binuclear structure composed of two metal atoms is more preferable (FIG. 2). In this case, a configuration as shown in FIG. 2A (hereinafter referred to as “lattice A2”) in which the ligand 201a is bridged by the site 201a of the binuclear structure positioned at the lattice point, and the ligand 202b is the lattice point. A configuration as shown in FIG. 2B (hereinafter referred to as “lattice B2”) in which the portion 201b of the binuclear structure is bridged is considered. Note that the shape of the lattice is not limited to the quadrangle as shown in FIG. 2, and various polygons (such as hexagons) are possible. The lattice can have both a two-dimensional (planar) structure and a three-dimensional (three-dimensional) structure.
[0041]
Then, at the time of synthesizing or forming a metal complex having such a lattice structure, a light emitting material can be introduced into the interstitial position of the lattice structure by mixing the light emitting material 203 having an appropriate molecular size.
[0042]
Furthermore, when a metal complex having a binuclear structure is used in the present invention, the lattice is easy to take a rectangular shape, so that there is an advantage that a regular structure such as a cubic lattice or a square lattice can be produced relatively easily. For this reason, as described above, since the pores are regularly arranged, a state like a superlattice structure is formed in a pseudo manner, and stable molecular excitons are generated, which may lead to improvement of the light emission characteristics. is there.
[0043]
As described above, in the present invention, in the light-emitting device having an organic EL element including a light-emitting layer composed of an organic compound capable of obtaining EL and a metal complex having a binuclear structure having two metal atoms as nuclei, the metal The complex has a lattice structure in which the site of the multinuclear structure and the ligand are alternately arranged, the site of the binuclear structure is a lattice point, and the ligand bridges the lattice point. (Lattice A2).
[0044]
Further, in the present invention, in a light-emitting device having an organic EL element comprising a light-emitting layer comprising an organic compound from which EL can be obtained and a metal complex having a binuclear structure having two metal atoms as nuclei, the metal complex comprises: Forming a lattice structure in which the site of the binuclear structure and the ligand are alternately arranged, the ligand being a lattice point, and the site of the binuclear structure is a structure that bridges the lattice point (Lattice B2).
[0045]
In addition, as a metal seed | species, since the metal element from a 5th group to a 11th group among transition series elements tends to form a binuclear structure, it is suitable for this invention. Among these, niobium, tantalum, molybdenum, and tungsten are more preferable because they are higher in atomic number than bromine in which the heavy atom effect is noticeable and are inexpensive materials among transition series elements.
[0046]
Therefore, in the present invention, in a light-emitting device having an organic EL element including a light-emitting layer composed of an organic compound from which EL can be obtained, a metal complex having a binuclear structure having two metal atoms as nuclei, A lattice structure of lattice A2 or lattice B2 in which a portion of a binuclear structure and a ligand are alternately arranged is formed, and the metal atom is composed of any element of Group 5 to Group 11 elements. To do.
[0047]
By implementing the invention as described above, it is possible to provide a light-emitting device that is bright and consumes less power and exhibits various emission colors at low cost. Furthermore, by using such a light-emitting device, it is possible to provide an inexpensive electric appliance that is bright and consumes less power and exhibits various emission colors.
[0048]
DETAILED DESCRIPTION OF THE INVENTION
In practicing the present invention, it is important to select a metal complex having a rigid group as a ligand. In other words, when a ligand having a chain portion such as an alkyl group as the main chain is used, the lattice is twisted during crosslinking (or when lattice points are formed), and pores having a uniform distribution are formed. become unable. Therefore, it is desirable to introduce an aromatic ring (specifically, a substituent containing a paraphenylene group, a substituent containing a heterocyclic ring, or a substituent containing a condensed ring) as a rigid group.
[0049]
The rigid group may have some substituent as a side chain, but it is preferable that the substituent does not participate in complex formation. That is, for example, when having a hydroxyl group or the like as a side chain, a complex may be formed there, and the expected lattice may not be formed. Therefore, an alkyl group, an alkoxyl group, etc. can be considered as a preferable substituent as a side chain of the rigid group.
[0050]
First, the form of the metal complex forming the lattice A1 will be described with reference to FIGS. As shown in FIG. 3, regardless of the form of the ligand X, if the central metal M is a tetrahedral coordination 301, a three-dimensional structure such as a cristobalite type lattice (FIG. 3 (a)) is formed, and the central metal M If is a planar configuration 302, a square lattice (FIG. 3B) is obtained. Further, if the central metal M can be octahedrally coordinated 303, a cubic or square lattice can be formed by introducing a ligand Z that is the same as or different from the ligand X (FIG. 3 (c)). ).
[0051]
Here, an example of FIG. 3C is shown in FIG. A metal capable of bivalent octahedral coordination as the central metal M, and a ligand X preferably has a phenolic anion and a 4-pyridyl group at both ends as represented by the following general formula (1). It is considered that a structure as shown in FIG. 4 can be obtained by using a ligand having a lone pair as a ligand Z (for example, pyrazine) at both ends (A is a paraphenylene group). Or a substituent containing a heterocyclic ring, or a rigid substituent such as a substituent containing a condensed ring).
[0052]
[Chemical formula 5]

[0053]
Next, the form of the metal complex forming the lattice B1 will be described with reference to FIGS. First, as shown in FIG. ^Three By selecting a ligand X that has an atom Sp (specifically, a group 14 element) having four bonds due to the hybrid orbital and can coordinate in the apex direction of the tetrahedron 501, a cristobalite-type lattice ( It is considered that FIG. 5 (a)) becomes possible.
[0054]
An example of FIG. 5A is shown in FIG. The ligand X is preferably a ligand represented by the following structural formula (2) having an 8-quinolinol skeleton in the apex direction of the tetrahedron (A is a substituent containing a paraphenylene group or a complex It is a rigid substituent such as a substituent containing a ring or a substituent containing a condensed ring.) As shown in the following structural formula (3), A may not be present. However, in this case, it is desirable to select a metal capable of planar coordination as the central metal M (in the case of tetrahedral coordination, the lattice is greatly twisted).
[0055]
[Chemical 6]

[Chemical 7]

[0056]
As the form of the metal complex forming the lattice B1, as shown in FIG. 6 (a), by selecting a ligand X having a benzene ring at the center and capable of coordination in the apex direction of an equilateral triangle, It is thought that the lattice of is also possible. Further, as shown in FIG. 6B, it is considered that a pseudo honeycomb lattice (hexagonal lattice) can be realized by introducing a ligand Z that is the same as or different from the ligand X.
[0057]
An example of FIG. 6B is shown in FIG. The ligand X is preferably a ligand represented by the following structural formula (4) having a quinolinol skeleton at the 1,3, and 5 positions of the benzene ring (A is a substituent containing a paraphenylene group). Or a substituent containing a heterocyclic ring or a substituent containing a condensed ring, etc.) As shown in the following structural formula (5), A may not be present. Further, as the ligand Z, a ligand having unshared electron pairs at both ends (for example, pyrazine) may be used. However, in this case, it is necessary to select a metal capable of octahedral coordination as the central metal M. Note that the coordination state in FIG. 7 shows only metal atoms in front of the paper for the sake of simplicity.
[0058]
[Chemical 8]

[Chemical 9]

[0059]
Next, the form of the metal complex having a binuclear structure forming the lattice A2 will be described with reference to FIGS. As shown in FIG. 8, regardless of the form of the ligand X, the binuclear structure M ₂ If the plane configuration is 801, it is considered that a square lattice (FIG. 8A) is obtained. In addition, the multinuclear structure M ₂ Can be octahedrally coordinated 802, it is considered that a cubic lattice or a tetragonal lattice can be formed by introducing the same or different ligand Z as the ligand X (FIG. 8 (b)).
[0060]
Here, an example of FIG. 8B is shown in FIG. The ligand X is preferably a dicarboxylate ion having carboxyl groups at both ends as represented by the following general formulas (6) to (8) (where a is a substituent containing a paraphenylene group). Or a substituent containing a heterocyclic ring or a substituent containing a condensed ring, b represents one or more cycloalkylene groups, and b may have a substituent, and n is Represents an integer of 1 or more). As the ligand Z, a ligand having an unshared electron pair at both ends (for example, pyrazine) may be used. In this way, a structure as shown in FIG. 9 is possible.
[0061]
[Chemical Formula 10]

Embedded image

Embedded image

[0062]
Furthermore, a lattice structure can also be formed when a ligand having an unshared electron pair at both ends (for example, pyrazine) is coordinated to a binuclear complex having the following general formula (9) as a ligand. (C represents a substituent containing an aryl group, a substituent containing a heterocyclic ring, or a substituent containing a condensed ring).
[0063]
Embedded image

[0064]
Note that the metal complex (a binuclear complex having the general formulas (6) to (9) as a ligand) that forms an A2-type lattice structure as described in this embodiment is described in the following documents. (Reference 6: Jun Takamizawa, “Metal Complexes Incorporating Molecules”, Chemistry and Industry, Vol. 53, No. 2 (2000), p. 136-139).
[0065]
Finally, the form of the metal complex having a binuclear structure forming the lattice B2 will be described with reference to FIG. As shown in FIG. 10 (a), it is considered that a hexagonal lattice can be realized by selecting a ligand X having a benzene ring at the center and capable of coordinating in the apex direction of an equilateral triangle. Further, as shown in FIG. 10B, it is considered that a pseudo honeycomb lattice (hexagonal lattice) can be realized by introducing a ligand Z that is the same as or different from the ligand X.
[0066]
An example of FIG. 10B is shown in FIG. Ligand X is preferably a ligand having a formylsalicylic acid skeleton at positions 1, 3, and 5 of the benzene ring as represented by the following general formula (10), or represented by the following general formula (11). A ligand having a carboxysalicylideneamine skeleton at the 1,3, and 5 positions of the benzene ring may be used (A is a substituent containing a paraphenylene group or a substituent containing a heterocyclic ring, Or a rigid substituent such as a substituent containing a condensed ring.) As shown in the following general formulas (12) and (13), A may not be present. As the ligand Z, a ligand having an unshared electron pair at both ends (for example, pyrazine) may be used when the central metal is divalent, and a dicarboxylate ion may be used when the central metal is trivalent. In FIG. 11, the ligand X represented by the general formula (9) and the ligand Z which is a dicarboxylic acid ion are used. Note that the coordination state in FIG. 11 shows only metal atoms in front of the paper for the sake of simplicity.
[0067]
Embedded image

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Embedded image

[0068]
By the way, it can be said that the most preferable form among the above embodiments is a metal complex capable of forming an A2 type lattice structure. This is because a synthesis method has already been established to some extent, and the synthesis method is relatively simple. According to the following document 7, a binuclear complex (that is, copper (II) terephthalate) composed of a ligand (that is, terephthalate ion) in which a is a phenylene group in general formula (6) and a copper (II) ion. The synthesis method is simply mixed with each methanol solution of copper (II) formate tetrahydrate and terephthalic acid, which proves extremely simple (Reference 7: Ryo Mori, Akira Takamizawa, “New Micro Pore substances ", Chemistry and Industry, Vol. 51, No. 2 (1998), p.210-212).
[0069]
Here, among the ligands described in Document 6, those corresponding to the general formulas (6) to (9) are summarized in Table 1 below. Cu, Cr, Mo, W, Rh, Re, Ru etc. are mentioned as a central metal which forms a binuclear structure. In addition, it is shown that a three-dimensional structure can be formed by crosslinking using a pyrazine with respect to a binuclear complex in which the No. 7 ligand in Table 1 below is used and the central metal is Rh.
[0070]
[Table 1]

[0071]
By applying a metal complex for which an easy synthesis method has been established as a light emitting layer of an organic EL device, it is relatively easy to carry out the present invention, which is preferable for the present invention.
[0072]
【Example】
Hereinafter, each configuration described in the embodiment of the invention will be specifically exemplified. The organic EL element structures from Example 1 to Example 7 are shown in FIG.
[Example 1]
In this example, an organic EL element using the metal complex described in FIG. 3B in the embodiment of the invention is specifically exemplified. As the central metal M, Cu (II) which is a metal capable of bivalent planar coordination is used, and as the ligand X, a compound represented by the following formula (14) is used.
Embedded image

[0073]
First, spin coating of an aqueous solution of polyethylene dioxythiophene (hereinafter referred to as “PEDOT”) doped with sulfonic acid to improve conductivity on a glass substrate 1201 on which ITO is formed as a transparent anode 1202 Then, a hole injection layer 1203 is formed by evaporating moisture. The film thickness is desirably about 30 nm.
[0074]
Next, a metal complex 1204a having a square lattice structure composed of Cu (II) as a central metal M and a ligand represented by the above formula (14) as a ligand X, and tris (8-quinolinolato) ) Aluminum (hereinafter “Alq _Three The light emitting material 1204b made up of “)” is dissolved in the same organic solvent. This solution is applied onto PEDOT by spin coating, and the solvent is evaporated to form an electron transporting light emitting layer 1204. The film thickness is desirably about 50 nm.
[0075]
Note that this is a method for manufacturing the metal complex 1204a having the above-mentioned square lattice structure, but it is considered that the metal complex 1204a can be manufactured by mixing a metal salt containing Cu (II) and a ligand. At this time, it is necessary to adjust the abundance ratio between the central metal M and the ligand X so that M: X = 1: 2.
[0076]
Finally, a lithium acetylacetonate complex (hereinafter referred to as “Li (acac)”) is formed to have a thickness of about 2 nm as the electron injection layer 1205, and Al is formed to have a thickness of about 100 nm as the cathode 1206, thereby obtaining an organic EL device.
[0077]
[Example 2]
In this example, an organic EL element using a metal complex as described in FIG. 5B in the embodiment of the invention is specifically exemplified. As the central metal M, Ni (II) which is a metal capable of bivalent planar coordination is used, and as the ligand X, a compound represented by the following formula (15) is used.
Embedded image

[0078]
First, on a glass substrate 1201 on which ITO, which is a transparent anode 1202, is formed, an aqueous solution of PEDOT doped with sulfonic acid to improve conductivity is formed by spin coating, and water is evaporated to evaporate the water. The hole injection layer 1203 is used. The film thickness is desirably about 30 nm.
[0079]
Next, a metal complex 1204a having a cristobalite type lattice structure composed of Ni (II) as a central metal M and a ligand represented by the above formula (15) as a ligand X, and Alq _Three The light emitting material 1204b made of is dissolved in the same organic solvent. This solution is applied onto PEDOT by spin coating, and the solvent is evaporated to form an electron transporting light emitting layer 1204. The film thickness is desirably about 50 nm.
[0080]
Note that this is a method for manufacturing the metal complex 1204a having the cristobalite-type lattice structure, but it can be prepared by mixing a metal salt containing Ni (II) and a ligand. At this time, the abundance ratio between the central metal M and the ligand X needs to be adjusted so that M: X = 2: 1.
[0081]
Finally, a film of Li (acac) of about 2 nm as the electron injection layer 1205 and a film of Al of about 100 nm as the cathode 1206 are formed into an organic EL element.
[0082]
[Example 3]
In this example, an organic EL element using the metal complex described in FIG. 7 in the embodiment of the invention is specifically exemplified. Co (II), which is a divalent octahedrally coordinated metal, is used as the central metal M, a compound represented by the following formula (16) is used as the ligand X, and pyrazine is used as the ligand Z.
Embedded image

[0083]
First, on a glass substrate 1201 on which ITO, which is a transparent anode 1202, is formed, an aqueous solution of PEDOT doped with sulfonic acid to improve conductivity is formed by spin coating, and water is evaporated to evaporate the water. The hole injection layer 1203 is used. The film thickness is desirably about 30 nm.
[0084]
Next, a metal having a hexagonal lattice structure comprising Co (II) as the central metal M, a ligand represented by the above formula (16) as the ligand X, and pyrazine as the ligand Z. Complex 1204a, and Alq _Three The light emitting material 1204b made of is dissolved in the same organic solvent. This solution is applied onto PEDOT by spin coating, and the solvent is evaporated to form an electron transporting light emitting layer 1204. The film thickness is desirably about 50 nm.
[0085]
Note that this is a method for manufacturing the metal complex 1204a having the above hexagonal lattice structure, but it can be manufactured by mixing a metal salt containing Co (II) and a ligand. At this time, the abundance ratio of the central metal M, the ligand X, and the ligand Z needs to be adjusted so that M: X: Z = 3: 2: 3.
[0086]
Finally, a film of Li (acac) of about 2 nm as the electron injection layer 1205 and a film of Al of about 100 nm as the cathode 1206 are formed into an organic EL element.
[0087]
[Example 4]
In this example, an organic EL element using the binuclear complex described in FIG. 9 in the embodiment of the invention is specifically exemplified. Mo (II) which is a divalent metal is used as the central metal M, a compound represented by the following formula (17) is used as the ligand X, and pyrazine is used as the ligand Z.
Embedded image

[0088]
First, on a glass substrate 1201 on which ITO, which is a transparent anode 1202, is formed, an aqueous solution of PEDOT doped with sulfonic acid to improve conductivity is formed by spin coating, and water is evaporated to evaporate the water. The hole injection layer 1203 is used. The film thickness is desirably about 30 nm.
[0089]
Next, a dinuclear having a square lattice structure comprising Mo (II) as the central metal M, a ligand represented by the above formula (17) as the ligand X, and pyrazine as the ligand Z. Complex 1204a, and Alq _Three The light emitting material 1204b made of is dissolved in the same organic solvent. This solution is applied onto PEDOT by spin coating, and the solvent is evaporated to form an electron transporting light emitting layer 1204. The film thickness is desirably about 50 nm.
[0090]
In addition, although it is the preparation method of the binuclear complex 1204a of the above-mentioned square lattice structure, it is considered that it can be prepared by a ligand substitution reaction in which a copper acetate monohydrate type binuclear Mo (II) complex and a ligand are mixed. It is done. At this time, the abundance ratio of the central metal M, the ligand X, and the ligand Z needs to be adjusted so that M: X: Z = 2: 2: 1.
[0091]
Finally, a film of Li (acac) of about 2 nm as the electron injection layer 1205 and a film of Al of about 100 nm as the cathode 1206 are formed into an organic EL element.
[0092]
[Example 5]
In this example, an organic EL element using the binuclear complex as described in FIG. 11 in the embodiment of the invention is specifically exemplified. A trivalent metal Mn (III) is used as the central metal M, a compound represented by the following formula (18) is used as the ligand X, and terephthalic acid is used as the ligand Z.
Embedded image

[0093]
First, on a glass substrate 1201 on which ITO, which is a transparent anode 1202, is formed, an aqueous solution of PEDOT doped with sulfonic acid to improve conductivity is formed by spin coating, and water is evaporated to evaporate the water. The hole injection layer 1203 is used. The film thickness is desirably about 30 nm.
[0094]
Next, a hexagonal lattice structure comprising Mn (III) as the central metal M, a ligand represented by the above formula (18) as the ligand X, and terephthalic acid as the ligand Z. Binuclear complex 1204a, and Alq _Three The light emitting material 1204b made of is dissolved in the same organic solvent. This solution is applied onto PEDOT by spin coating, and the solvent is evaporated to form an electron transporting light emitting layer 1204. The film thickness is desirably about 50 nm.
[0095]
Note that the method for producing the above hexagonal lattice-structured binuclear complex 1204a is considered to be produced by mixing a metal salt containing Mn (III) and a ligand. At this time, it is necessary to adjust the abundance ratio of the central metal M, the ligand X, and the ligand Z to be M: X: Z = 6: 2: 3.
[0096]
Finally, a film of Li (acac) of about 2 nm as the electron injection layer 1205 and a film of Al of about 100 nm as the cathode 1206 are formed into an organic EL element.
[0097]
[Example 6]
In this example, a binuclear complex using the ligand shown in Table 1 in the embodiment of the invention is specifically exemplified, and a method for manufacturing an organic light-emitting element using the complex is shown. Here, a copper binuclear complex using No, 1 (terephthalate ion; the following formula (19)) in Table 1 is used.
[0098]
Embedded image

[0099]
First, on a glass substrate 1201 on which ITO, which is a transparent anode 1202, is formed, an aqueous solution of PEDOT doped with sulfonic acid to improve conductivity is formed by spin coating, and water is evaporated to evaporate the water. The hole injection layer 1203 is used. The film thickness is desirably about 30 nm.
[0100]
Next, the methanol solution of copper formate tetrahydrate, which is the raw material of the central metal Cu, the methanol solution of terephthalic acid, which is the raw material of the ligand, and the methanol solution of Alq3 are mixed and simultaneously spin-coated on the PEDOT. The electron-transporting light-emitting layer 1204 is formed by coating the substrate and evaporating the solvent. As shown in Reference 6, copper formate tetrahydrate and terephthalic acid react to form a binuclear complex 1204a having a lattice structure. Alq _Three The light emitting material 1204b made of is considered to be taken into the lattice. The film thickness is desirably about 50 nm.
[0101]
Finally, a film of Li (acac) of about 2 nm as the electron injection layer 1205 and a film of Al of about 100 nm as the cathode 1206 are formed into an organic EL element.
[0102]
[Example 7]
In this example, a binuclear complex using the ligand shown in Table 1 in the embodiment of the invention is specifically exemplified, and a method for manufacturing an organic light-emitting element using the complex is shown. Here, a rhodium binuclear complex using No. 7 (benzoate ion; the following formula (20)) in Table 1 is used.
[0103]
Embedded image

[0104]
First, on a glass substrate 1201 on which ITO, which is a transparent anode 1202, is formed, an aqueous solution of PEDOT doped with sulfonic acid to improve conductivity is formed by spin coating, and water is evaporated to evaporate the water. The hole injection layer 1203 is used. The film thickness is desirably about 30 nm.
[0105]
Next, the rhodium benzoate binuclear complex shown in Reference 6 is dissolved in pyrazine, and this solution is mixed with Alq. _Three Are mixed on the PEDOT by spin coating, and the solvent is evaporated under reduced pressure to form an electron transporting light emitting layer 1204. In this case, as shown in Reference 6, a binuclear complex 1204a having a lattice structure composed of a rhodium benzoate binuclear complex and pyrazine is formed, and Alq _Three The light emitting material 1204b made of is considered to be taken into the lattice. The film thickness is desirably about 50 nm.
[0106]
Finally, a film of Li (acac) of about 2 nm as the electron injection layer 1205 and a film of Al of about 100 nm as the cathode 1206 are formed into an organic EL element.
[0107]
[Example 8]
In this example, a light-emitting device including the organic EL element disclosed in the present invention will be described. FIG. 13 is a cross-sectional view of an active matrix light-emitting device using the organic EL element of the present invention. Note that although a thin film transistor (hereinafter referred to as “TFT”) is used here as an active element, a MOS transistor may be used.
[0108]
Further, although a top gate TFT (specifically, a planar TFT) is exemplified as the TFT, a bottom gate TFT (typically an inverted staggered TFT) can also be used.
[0109]
In FIG. 13, reference numeral 1301 denotes a substrate. Here, a substrate that transmits visible light is used. Specifically, a glass substrate, a quartz substrate, a crystallized glass substrate, or a plastic substrate (including a plastic film) may be used. Note that the substrate 1301 includes an insulating film provided on the surface of the substrate.
[0110]
A pixel portion 1311 and a driver circuit 1312 are provided over the substrate 1301. First, the pixel portion 1311 will be described.
[0111]
The pixel portion 1311 is an area for displaying an image and has a plurality of pixels. Each pixel has a TFT (hereinafter referred to as “current control TFT”) 1302 for controlling a current flowing through the organic EL element, a pixel electrode An (anode) 1303, an organic EL layer 1304, and a cathode 1305 are provided. Although only the current control TFT is shown in FIG. 13, a TFT (hereinafter referred to as “switching TFT”) for controlling the voltage applied to the gate of the current control TFT is provided.
[0112]
As the current control TFT 1302, a p-channel TFT is preferably used here. Although an n-channel TFT can be used, when a current control TFT is connected to the anode of the organic EL element as shown in FIG. 13, the p-channel TFT can reduce power consumption. However, the switching TFT may be an n-channel TFT or a p-channel TFT.
[0113]
Further, the pixel electrode 1303 is electrically connected to the drain of the current control TFT 1302. In this embodiment, since a conductive material having a work function of 4.5 to 5.5 eV is used as the material of the pixel electrode 1303, the pixel electrode 1303 functions as an anode of the organic EL element. As the pixel electrode 1303, typically, indium oxide, tin oxide, zinc oxide, or a compound thereof (ITO or the like) may be used. An organic EL layer 1304 is provided on the pixel electrode 1303.
[0114]
Further, a cathode 1305 is provided on the organic EL layer 1304. As a material for the cathode 1305, it is desirable to use a conductive material having a work function of 2.5 to 3.5 eV. As the cathode 1305, a conductive film containing an alkali metal element or an alkalinity metal element, or a layer in which an aluminum alloy is stacked over the conductive film may be used.
[0115]
Further, a layer including the pixel electrode 1303, the organic EL film 1304, and the cathode 1305 is covered with a protective film 1306. The protective film 1306 is provided to protect the organic EL element from oxygen and water. As a material for the protective film 1306, silicon nitride, silicon nitride oxide, aluminum oxide, tantalum oxide, or carbon (specifically, diamond-like carbon) is used.
[0116]
Next, the drive circuit 1312 will be described. The driver circuit 1312 is an area for controlling the timing of signals (gate signal and data signal) transmitted to the pixel portion 1311, and is provided with a shift register, a buffer, a latch, an analog switch (transfer gate), or a level shifter. In FIG. 13, a CMOS circuit including an n-channel TFT 1307 and a p-channel TFT 1308 is shown as a basic unit of these circuits.
[0117]
The circuit configuration of the shift register, buffer, latch, analog switch (transfer gate) or level shifter may be a known one. In FIG. 13, the pixel portion 1311 and the drive circuit 1312 are provided over the same substrate, but an IC or an LSI can be electrically connected without providing the drive circuit 1312.
[0118]
In FIG. 13, the pixel electrode (anode) 1303 is electrically connected to the current control TFT 1302, but a structure in which the cathode is connected to the current control TFT can also be adopted. In that case, the pixel electrode may be formed using the same material as the cathode 1305 and the cathode may be formed using the same material as the pixel electrode (anode) 1303. In that case, the current control TFT is preferably an n-channel TFT.
[0119]
Here, an appearance of the active matrix light-emitting device shown in FIG. 13 is shown in FIG. 14A shows a top view, and FIG. 14B shows a cross-sectional view when FIG. 14A is cut along PP ′. Further, reference is made to the reference numerals in FIG.
[0120]
In FIG. 14A, reference numeral 1401 denotes a pixel portion, 1402 denotes a gate signal side driving circuit, and 1403 denotes a data signal side driving circuit. Signals transmitted to the gate signal side drive circuit 1402 and the data signal side drive circuit 1403 are input from a TAB (Tape Automated Bonding) tape 1405 through the input wiring 1404. Although not shown, instead of the TAB tape 1405, a TCP (Tape Carrier Package) provided with an IC (integrated circuit) may be connected to the TAB tape.
[0121]
At this time, reference numeral 1406 denotes a cover material provided above the organic EL element shown in FIG. 13, and is bonded by a sealing material 1407 made of resin. Any material may be used as the cover material 1406 as long as it does not transmit oxygen and water. In this embodiment, as shown in FIG. 14 (b), the cover material 1406 includes a plastic material 1406a and a carbon film (specifically, a diamond-like carbon film) 1406b provided on the front and back surfaces of the plastic material 1406a. 1406c.
[0122]
Further, as shown in FIG. 14B, the sealing material 1407 is covered with a sealing material 1408 made of resin so that the organic EL element is completely enclosed in the sealed space 1409. The sealed space 1409 may be filled with an inert gas (typically nitrogen gas or a rare gas), a resin, or an inert liquid (for example, liquid fluorinated carbon typified by perfluoroalkane). It is also effective to provide a hygroscopic agent or oxygen scavenger.
[0123]
Further, a polarizing plate may be provided on the display surface (the surface on which an image is observed) of the light emitting device shown in this embodiment. This polarizing plate has an effect of suppressing reflection of light incident from the outside and preventing an observer from being reflected on the display surface. Generally, a circularly polarizing plate is used. However, in order to prevent light emitted from the organic EL film from being reflected by the polarizing plate and returning to the inside, it is preferable to adjust the refractive index so that the structure has less internal reflection.
[0124]
Note that any of the organic EL elements disclosed in the present invention may be used as the organic EL element included in the light emitting device of this example.
[Example 9]
[0125]
In this example, a passive matrix light-emitting device is illustrated as an example of a light-emitting device including the organic EL element disclosed in the present invention. FIG. 15 (a) shows a top view thereof, and FIG. 15 (b) shows a cross-sectional view of FIG. 15 (a) taken along PP ′.
[0126]
In FIG. 15A, reference numeral 1501 denotes a substrate, and here a plastic material is used. Plastic materials include polyimide, polyamide, acrylic resin, epoxy resin, PES (polyethylene sulfide), PC (polycarbonate), PET (polyethylene terephthalate) or PEN (polyethylene naphthalate) in plate form or on film Can be used.
[0127]
Reference numeral 1502 denotes a scanning line (anode) made of an oxide conductive film. In this embodiment, an oxide conductive film obtained by adding gallium oxide to zinc oxide is used. Reference numeral 1503 denotes a data line (cathode) made of a metal film. In this embodiment, a bismuth film is used. Reference numeral 1504 denotes a bank made of acrylic resin, which functions as a partition for dividing the data line 1503. A plurality of scanning lines 1502 and data lines 1503 are both formed in a stripe shape, and are provided so as to be orthogonal to each other. Although not shown in FIG. 15A, an organic EL layer is sandwiched between the scanning line 1502 and the data line 1503, and the intersection 1505 is a pixel.
[0128]
The scanning line 1502 and the data line 1503 are connected to an external drive circuit via the TAB tape 1507. Note that 1508 represents a wiring group formed by aggregating the scanning lines 1502, and 1509 represents a wiring group formed by a set of connection wirings 1506 connected to the data line 1503. Further, although not shown, instead of the TAB tape 1507, a TCP provided with an IC on the TAB tape may be connected.
[0129]
In FIG. 15B, reference numeral 1510 denotes a sealing material, and 1511 denotes a cover material bonded to the plastic material 1501 by the sealing material 1510. As the sealing material 1510, a photo-curing resin may be used, and a material with low degassing and low hygroscopicity is desirable. The cover material is preferably the same material as that of the substrate 1501, and glass (including quartz glass) or plastic can be used. Here, a plastic material is used.
[0130]
Next, an enlarged view of the structure of the pixel region is shown in FIG. Reference numeral 1513 denotes an organic EL layer. As shown in FIG. 15C, the bank 1504 has a shape in which the width of the lower layer is narrower than the width of the upper layer, and the data line 1503 can be physically divided. Further, the pixel portion 1514 surrounded by the sealing material 1510 has a structure in which the organic EL layer is prevented from being deteriorated by being blocked from the outside air by a sealing material 1515 made of resin.
[0131]
The light-emitting device of the present invention having the above structure can be manufactured by a very simple process because the pixel portion 1514 is formed of the scanning line 1502, the data line 1503, the bank 1504, and the organic EL layer 1513. .
[0132]
Further, a polarizing plate may be provided on the display surface (the surface on which an image is observed) of the light emitting device shown in this embodiment. This polarizing plate has an effect of suppressing reflection of light incident from the outside and preventing an observer from being reflected on the display surface. Generally, a circularly polarizing plate is used. However, in order to prevent light emitted from the organic EL film from being reflected by the polarizing plate and returning to the inside, it is preferable to adjust the refractive index so that the structure has less internal reflection.
[0133]
Note that any of the organic EL elements disclosed in the present invention may be used as the organic EL element included in the light emitting device of this example.
[0134]
[Example 10]
In this embodiment, an example in which a printed wiring board is provided in the light emitting device shown in Embodiment 9 to form a module is shown.
[0135]
In the module shown in FIG. 16A, a TAB tape 1604 is attached to a substrate 1601 (here, including a pixel portion 1602, wirings 1603a and 1603b), and a printed wiring board 1605 is attached via the TAB tape 1604. Yes.
[0136]
Here, a functional block diagram of the printed wiring board 1605 is shown in FIG. Inside the printed wiring board 1605, at least ICs functioning as I / O ports (input or output units) 1606 and 1609, a data signal side drive circuit 1607, and a gate signal side circuit 1608 are provided.
[0137]
In this specification, a module having a configuration in which a TAB tape is attached to a substrate having a pixel portion formed on the substrate surface and a printed wiring plate having a function as a drive circuit is attached via the TAB tape is described in this specification. In particular, it will be called a drive circuit external module.
[0138]
Note that any of the organic EL elements disclosed in the present invention may be used as the organic EL element included in the light emitting device of this example.
[0139]
[Example 11]
In this embodiment, an example in which a light-emitting device shown in Embodiment 8 or Embodiment 9 is provided with a printed wiring board to form a module will be described.
[0140]
In the module shown in FIG. 17A, a TAB tape 1705 is attached to a substrate 1701 (including a pixel portion 1702, a data signal side driving circuit 1703, a gate signal side driving circuit 1704, wirings 1703a and 1704a). A printed wiring board 1706 is attached via a TAB tape 1705. A functional block diagram of the printed wiring board 1706 is shown in FIG.
[0141]
As shown in FIG. 17 (b), at least ICs functioning as I / O ports 1707 and 1710 and a control unit 1708 are provided inside the printed wiring board 1706. Although the memory unit 1709 is provided here, it is not always necessary. The control unit 1708 is a part having a function for controlling control of the driving circuit, correction of video data, and the like.
[0142]
In this specification, a module having a configuration in which a printed wiring board having a function as a controller is attached to a substrate on which an organic EL element is formed is particularly referred to as a controller external module.
[0143]
Note that any of the organic EL elements disclosed in the present invention may be used as the organic EL element included in the light emitting device of this example.
[0144]
[Example 12]
The light-emitting device of the present invention described in the above embodiment has an advantage of being bright and low power consumption. Therefore, an electric appliance in which the light-emitting device is included as a display unit or the like is an electric appliance that can operate with lower power consumption than before. In particular, an electric appliance such as a portable device that uses a battery as a power source is extremely useful because low power consumption is directly linked to convenience (battery is unlikely to run out).
[0145]
Further, since the light-emitting device is a self-luminous type, a backlight like a liquid crystal display device is not necessary, and the thickness of the organic EL film is less than 1 μm, so that it can be thin and light. Therefore, an electric appliance in which the light emitting device is included as a display unit or the like is an electric appliance that is thinner and lighter than conventional ones. This is also extremely useful because it is directly connected to convenience (lightness and compactness when carrying), especially with respect to electric appliances such as portable devices. Furthermore, there is no doubt that the thinness (not bulky) of electrical appliances in general is also useful from the viewpoint of transportation (capable of mass transportation) and installation (serving space such as rooms).
[0146]
Note that since the light-emitting device is a self-luminous type, the light-emitting device is superior in visibility in a bright place as compared with a liquid crystal display device and has a wide viewing angle. Therefore, an electric appliance having the light-emitting device as a display portion has a great merit in terms of easy viewing.
[0147]
That is, an electric appliance using the light emitting device of the present invention has advantages such as low power consumption, thin weight, and high visibility. Furthermore, since the light-emitting device is configured to promote phosphorescence using a conventional fluorescent dye that can be obtained at low cost, an electric appliance using the light-emitting device has an advantage that it is less expensive than the conventional one.
[0148]
In this embodiment, an electric appliance including the light emitting device of the present invention as a display portion is illustrated. Specific examples thereof are shown in FIGS. Note that any of the metal complexes disclosed in the present invention may be used for the organic EL element included in the electric appliance of this example. Moreover, any form of FIGS. 13-17 may be used for the form of the light-emitting device contained in the electric appliance of a present Example.
[0149]
FIG. 18A shows an organic EL display, which includes a housing 1801a, a support stand 1802a, and a display portion 1803a. By manufacturing a display using the light-emitting device of the present invention as the display portion 1803a, a thin and lightweight display can be realized. Therefore, transportation becomes simple and further space saving at the time of installation becomes possible.
[0150]
FIG. 18B shows a video camera, which includes a main body 1801b, a display portion 1802b, an audio input portion 1803b, operation switches 1804b, a battery 1805b, and an image receiving portion 1806b. By manufacturing a video camera using the light-emitting device of the present invention as the display portion 1802b, a lightweight video camera with low power consumption can be realized. Therefore, the consumption of the battery is reduced and the carrying becomes easy.
[0151]
FIG. 18C shows a digital camera, which includes a main body 1801c, a display portion 1802c, an eyepiece portion 1803c, and an operation switch 1804c. By manufacturing a digital camera using the light-emitting device of the present invention as the display portion 1802c, a lightweight digital camera with low power consumption can be realized. Therefore, the consumption of the battery is reduced and the carrying becomes easy.
[0152]
FIG. 18D shows an image reproducing device provided with a recording medium, which includes a main body 1801d, a recording medium (such as a CD, LD, or DVD) 1802d, an operation switch 1803d, a display unit (A) 1804d, and a display unit (B) 1805d. including. The display portion (A) 1804d mainly displays image information, and the display portion (B) 1805d mainly displays character information. By manufacturing the image reproducing device using the light emitting device of the present invention as the display portion (A) 1804d and the display portion (B) 1805d, the image reproducing device with low power consumption and light weight can be realized. Note that the image reproducing device provided with the recording medium includes a CD reproducing device, a game machine, and the like.
[0153]
FIG. 18E shows a portable (mobile) computer, which includes a main body 1801e, a display portion 1802e, an image receiving portion 1803e, an operation switch 1804e, and a memory slot 1805e. By manufacturing a portable computer using the light-emitting device of the present invention as the display portion 1802e, a thin and light portable computer with low power consumption can be realized. Therefore, the consumption of the battery is reduced and the carrying becomes easy. The portable computer can record information on a recording medium in which flash memory or nonvolatile memory is integrated, and can reproduce the information.
[0154]
FIG. 18F shows a personal computer, which includes a main body 1801f, a housing 1802f, a display portion 1803f, and a keyboard 1804f. By manufacturing a personal computer using the light-emitting device of the present invention as the display portion 1803f, a thin and lightweight personal computer with low power consumption can be realized. In particular, when a portable application such as a notebook computer is required, it is a great advantage in terms of battery consumption and lightness.
[0155]
In addition, the electric appliances often display information distributed through an electronic communication line such as the Internet or wireless communication such as radio waves, and in particular, opportunities for displaying moving image information are increasing. The response speed of the organic EL element is very fast and is suitable for such moving image display.
[0156]
Next, FIG. 19A shows a mobile phone, which includes a main body 1901a, an audio output unit 1902a, an audio input unit 1903a, a display unit 1904a, an operation switch 1905a, and an antenna 1906a. By manufacturing a mobile phone using the light-emitting device of the present invention as the display portion 1904a, a thin and lightweight mobile phone with low power consumption can be realized. Therefore, the battery consumption is reduced, the carrying becomes easier and the body can be made compact.
[0157]
FIG. 19B shows an audio device (specifically, an on-vehicle audio), which includes a main body 1901b, a display portion 1902b, and operation switches 1903b and 1904b. By manufacturing an acoustic device using the light-emitting device of the present invention as the display portion 1902b, a lightweight acoustic device with low power consumption can be realized. In the present embodiment, in-vehicle audio is shown as an example, but it may be used for home audio.
[0158]
In addition, in the electric appliances as shown in FIGS. 18 to 19, the light emission luminance is modulated according to the brightness of the usage environment by further incorporating a photosensor and providing means for detecting the brightness of the usage environment. It is effective to have such a function. The user can recognize the image or the character information without any problem if the brightness of 100 to 150 can be secured in the contrast ratio as compared with the brightness of the usage environment. That is, when the usage environment is bright, it is possible to increase the brightness of the image for easy viewing, and when the usage environment is dark, the brightness of the image can be suppressed to reduce power consumption.
[0159]
Various electric appliances using the light-emitting device of the present invention as a light source can be said to be very useful because they can operate with low power consumption and can be thin and light. Typically, an electrical appliance including the light-emitting device of the present invention as a light source such as a backlight or a front light of a liquid crystal display device or a light source of a lighting device can achieve low power consumption and be thin and lightweight.
[0160]
Therefore, even when the display units of the electric appliances shown in FIGS. 18 to 19 shown in this embodiment are all liquid crystal displays, the electric appliances using the light emitting device of the present invention as the backlight or the front light of the liquid crystal display. By producing a thin, lightweight electric appliance with low power consumption can be achieved.
[0161]
【The invention's effect】
By implementing the present invention, it is possible to obtain a light-emitting device that is bright and consumes less power, has various emission colors, and is excellent in cost. Further, by using such a light-emitting device for a light source or a display portion, it is possible to obtain an electric appliance that is bright and consumes less power and has various emission colors and is inexpensive.
[Brief description of the drawings]
FIG. 1 is a diagram showing the concept of a metal complex that forms a lattice.
FIG. 2 is a view showing the concept of a metal complex forming a lattice.
FIG. 3 shows a structure of a metal complex forming a lattice.
FIG. 4 is a diagram showing a configuration of a metal complex forming a lattice.
FIG. 5 shows a structure of a metal complex that forms a lattice.
FIG. 6 shows a structure of a metal complex forming a lattice.
FIG. 7 shows a structure of a metal complex forming a lattice.
FIG. 8 shows a structure of a metal complex that forms a lattice.
FIG. 9 shows a structure of a metal complex forming a lattice.
FIG. 10 shows a structure of a metal complex forming a lattice.
FIG. 11 shows a structure of a metal complex forming a lattice.
FIG. 12 shows a structure of an organic EL element.
FIG 13 illustrates a cross-sectional structure of a light-emitting device.
FIGS. 14A and 14B illustrate a top structure and a cross-sectional structure of a light-emitting device. FIGS.
FIGS. 15A and 15B illustrate a top structure and a cross-sectional structure of a light-emitting device. FIGS.
FIG 16 illustrates a structure of a light-emitting device.
FIG 17 illustrates a structure of a light-emitting device.
FIG. 18 is a diagram showing a specific example of an electric appliance.
FIG. 19 shows a specific example of an electric appliance.

Claims (4)

Luminescence generated an organic compound consisting of Alq ₃ which EL is obtained, the two copper atoms have a dinuclear structure core, and a metal complex consisting of terephthalic acid copper (II), a phosphorescent formed by mixing A light emitting device comprising an organic EL element including a layer. Luminescence generated an organic compound consisting of Alq ₃ which EL is obtained, the two copper atoms have a dinuclear structure core, and a metal complex consisting of terephthalic acid copper (II), a phosphorescent formed by mixing In a light emitting device having an organic EL element including a layer,
The metal complex forms a lattice structure in which the site of the binuclear structure and a ligand composed of terephthalate ions are alternately arranged, the site of the binuclear structure is a lattice point, and the ligand is the lattice. A light-emitting device having a structure that bridges dots. Formed by mixing an organic compound composed of Alq ₃ from which EL can be obtained and a metal complex having a lattice structure in which a rhodium benzoate binuclear complex is bridged with pyrazine having a binuclear structure having two rhodium atoms as nuclei A light-emitting device having an organic EL element including a light-emitting layer that generates phosphorescent light. Appliance, characterized in that the light-emitting device according to any one of claims 1 to 3.

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