JP2004091444A - Diazafluorene compound and organic light emitting device using the same - Google Patents

Abstract

（式中、Ｒ_１およびＲ_２は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基、置換あるいは無置換の複素環基、置換あるいは無置換の縮合多環芳香族基、置換あるいは無置換の縮合多環複素環基、置換アミノ基、シアノ基またはハロゲン原子を表わし、同じであっても異なっていてもよい。Ｒ_３およびＲ_４は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基または置換あるいは無置換の複素環基を表わし、異なるフルオレン基に結合するＲ_３同士、Ｒ_４同士は、同じであっても異なっていてもよく、同じフルオレン基に結合するＲ_３およびＲ_４は、同じであっても異なっていてもよい。ｎは、１乃至１０の整数を表す。）
【選択図】　　　なしProvided is a novel diazafluorene compound, and an extremely durable organic light-emitting device having extremely high efficiency, high luminance light output and extremely high efficiency using the compound.
A diazafluorene compound represented by the following general formula [I].
Embedded image

(Wherein, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group A substituted or unsubstituted fused polycyclic heterocyclic group, a substituted amino group, a cyano group or a halogen atom, which may be the same or different, and R ₃ and R ₄ are a hydrogen atom, a substituted or unsubstituted Represents an alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and R ₃ and R ₄ bonded to different fluorene groups may be the same or different, and may be the same or different. R ₃ and R ₄ bonded to the fluorene group may be the same or different, and n represents an integer of 1 to 10.)
[Selection diagram] None

Description

【００１８】
（式中、Ｒ_１およびＲ_２は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基、置換あるいは無置換の複素環基、置換あるいは無置換の縮合多環芳香族基、置換あるいは無置換の縮合多環複素環基、置換アミノ基、シアノ基またはハロゲン原子を表わし、同じであっても異なっていてもよい。Ｒ_３およびＲ_４は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基または置換あるいは無置換の複素環基を表わし、異なるフルオレン基に結合するＲ_３同士、Ｒ_４同士は、同じであっても異なっていてもよく、同じフルオレン基に結合するＲ_３およびＲ_４は、同じであっても異なっていてもよい。
ｎは、１乃至１０の整数を表す。）
【００１９】
【化９】

【００２０】
（式中、Ｒ_５およびＲ_６は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基、置換あるいは無置換の複素環基、置換あるいは無置換の縮合多環芳香族基、置換あるいは無置換の縮合多環複素環基、置換アミノ基、シアノ基またはハロゲン原子を表わし、同じであっても異なっていてもよい。Ｒ_７およびＲ_８は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基または置換あるいは無置換の複素環基を表わし、同じであっても異なっていてもよい。）
【００２１】
【化１０】

【００２２】
（式中、Ｒ_９およびＲ_１０は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基、置換あるいは無置換の複素環基、置換あるいは無置換の縮合多環芳香族基、置換あるいは無置換の縮合多環複素環基、置換アミノ基、シアノ基またはハロゲン原子を表わし、同じであっても異なっていてもよい。
Ｒ_１１およびＲ_１２は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基または置換あるいは無置換の複素環基を表わし、同じであっても異なっていてもよい。）
【００２３】
また、本発明の有機発光素子は、陽極及び陰極からなる一対の電極と、該一対の電極間に挟持された一または複数の有機化合物を含む層を少なくとも有する有機発光素子において、前記有機化合物を含む層の少なくとも一層が上記ジアザフルオレン化合物の少なくとも一種を含有することを特徴とする。
【００２４】
【発明の実施の形態】
以下、本発明を詳細に説明する。
【００２５】
まず、本発明のジアザフルオレン化合物について説明する。
【００２６】
本発明のジアザフルオレン化合物は、上記一般式［Ｉ］〜［ＩＩＩ］で示され、一般式［Ｉ］で示されるジアザフルオレン化合物は、下記一般式［ＩＶ］で示される化合物であることが好ましい。
【００２７】
【化１１】

【００２８】
（式中、Ｒ_１３およびＲ_１４は、置換あるいは無置換の縮合多環芳香族基または置換あるいは無置換の縮合多環複素環基を表わし、同じであっても異なっていてもよい。
Ｒ_１５およびＲ_１６は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基または置換あるいは無置換の複素環基を表わし、同じであっても異なっていてもよい。）
【００２９】
また、一般式［Ｉ］〜［ＩＩＩ］で示されるジアザフルオレン化合物におけるＲ_１、Ｒ_２、Ｒ_５、Ｒ_６、Ｒ_９、Ｒ_１０、Ｒ_１３またはＲ_１４が、下記一般式［Ｖ］〜［Ｘ］のいずれかで示される縮合多環芳香族基であることが好ましい。
【００３０】
【化１２】

【００３１】
（式中、Ｒ_１７は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基、置換あるいは無置換の複素環基、置換アミノ基、シアノ基またはハロゲン原子を表わす。Ｒ_１８およびＲ_１９は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基または置換あるいは無置換の複素環基を表わし、同じであっても異なっていてもよい。）
【００３２】
【化１３】

【００３３】
（式中、Ｒ_２０〜Ｒ_２３は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基、置換あるいは無置換の複素環基、置換アミノ基、シアノ基またはハロゲン原子を表わす。）
【００３４】
【化１４】

【００３５】
（式中、Ｒ_２４およびＲ_２５は、水素原子、置換あるいは無置換のアルキル基、置換あるいは無置換のアリール基、置換あるいは無置換の複素環基、置換アミノ基、シアノ基またはハロゲン原子を表わし、同じであっても異なっていてもよい。）
【００３６】
上記一般式［Ｉ］〜［Ｘ］における置換基の具体例を以下に示す。
【００３７】
アルキル基としては、メチル基、エチル基、ｎ−プロピル基、ｉｓｏ−プロピル基、ｎ−ブチル基、ｔｅｒ−ブチル基、オクチル基などが挙げられる。
【００３８】
アリール基としては、フェニル基、ビフェニル基、ターフェニル基などが挙げられる。
【００３９】
複素環基としては、チエニル基、ピロリル基、ピリジル基、オキサゾリル基、オキサジアゾリル基、チアゾリル基、チアジアゾリル基、ターチエニル基などが挙げられる。
【００４０】
縮合多環芳香族基としては、フルオレニル基、ナフチル基、フルオランテニル基、アンスリル基、フェナンスリル基、ピレニル基、テトラセニル基、ペンタセニル基、トリフェニレニル基、ペリレニル基などが挙げられる。
【００４１】
縮合多環複素環基としては、カルバゾリル基、フェナントロリル基、アクリジニル基などが挙げられる。
【００４２】
置換アミノ基としては、ジメチルアミノ基、ジエチルアミノ基、ジベンジルアミノ基、ジフェニルアミノ基、ジトリルアミノ基、ジアニソリルアミノ基などが挙げられる。
【００４３】
ハロゲン原子としては、フッ素、塩素、臭素、ヨウ素などが挙げられる。
【００４４】
上記置換基が有してもよい置換基としては、メチル基、エチル基、プロピル基などのアルキル基、フェニル基、ビフェニル基などのアリール基、チエニル基、ピロリル基、ピリジル基などの複素環基、ジメチルアミノ基、ジエチルアミノ基、ジベンジルアミノ基、ジフェニルアミノ基、ジトリルアミノ基、ジアニソリルアミノ基などのアミノ基、メトキシル基、エトキシル基、プロポキシル基、フェノキシル基などのアルコキシル基、シアノ基、フッ素、塩素、臭素、ヨウ素などのハロゲン原子などが挙げられる。
【００４５】
次に、本発明のジアザフルオレン化合物の代表例を以下に挙げるが、本発明はこれらに限定されるものではない。
【００４６】
【化１５】

【００４７】
【化１６】

【００４８】
【化１７】

【００４９】
【化１８】

【００５０】
【化１９】

【００５１】
【化２０】

【００５２】
【化２１】

【００５３】
【化２２】

【００５４】
【化２３】

【００５５】
【化２４】

【００５６】
【化２５】

【００５７】
本発明のジアザフルオレン化合物は、一般的に知られている方法で合成でき、例えば、Ｊ．Ａｍ．Ｃｈｅｍ．Ｓｏｃ．，１０６，５８７６−５８７９（１９８４）、Ｊ．Ｏｒｇ．Ｃｈｅｍ．，５０，６６６−６７０，（１９８５）、Ｊ．Ｏｒｇ．Ｃｈｅｍ．，４９，２２０８−２２１２（１９８４）などに記載の方法でジアザフルオレン化合物中間体を得て、さらにパラジウム触媒を用いたｓｕｚｕｋｉ　ｃｏｕｐｌｉｎｇ法（例えばＣｈｅｍ．Ｒｅｖ．１９９５，９５，２４５７−２４８３）などの合成法で得ることができる。
【００５８】
本発明のジアザフルオレン化合物は、従来の化合物に比べ電子輸送性および耐久性の優れた化合物であり、有機発光素子の有機化合物を含む層、特に、電子輸送層および発光層として有用であり、また真空蒸着法や溶液塗布法などによって形成した層は結晶化などが起こりにくく経時安定性に優れている。
【００５９】
次に、本発明の有機発光素子について詳細に説明する。
【００６０】
本発明の有機発光素子は、陽極及び陰極からなる一対の電極と、該一対の電極間に狭持された一または複数の有機化合物を含む層を少なくとも有する有機発光素子において、前記有機化合物を含む層の少なくとも一層が一般式［Ｉ］〜［ＩＩＩ］で示されるジアザフルオレン化合物の少なくとも一種を含有する。
【００６１】
本発明の有機発光素子は、有機化合物を含む層のうち少なくとも電子輸送層または発光層が、前記ジアザフルオレン化合物の少なくとも一種を含有することが好ましい。
【００６２】
本発明の有機発光素子においては、上記一般式［Ｉ］〜［ＩＩＩ］で示されるジアザフルオレン化合物を真空蒸着法や溶液塗布法により陽極及び陰極の間に形成する。その有機層の厚みは１０μｍより薄く、好ましくは０．５μｍ以下、より好ましくは０．０１〜０．５μｍの厚みに薄膜化することが好ましい。
【００６３】
図１〜図６に本発明の有機発光素子の好ましい例を示す。
【００６４】
図１は、本発明の有機発光素子の一例を示す断面図である。図１は、基板１上に、陽極２、発光層３及び陰極４を順次設けた構成のものである。ここで使用する発光素子は、それ自体でホール輸送能、エレクトロン輸送能及び発光性の性能を単一で有している場合や、それぞれの特性を有する化合物を混ぜて使う場合に有用である。
【００６５】
図２は、本発明の有機発光素子における他の例を示す断面図である。図２は、基板１上に、陽極２、ホール輸送層５、電子輸送層６及び陰極４を順次設けた構成のものである。この場合は、発光物質はホール輸送性かあるいは電子輸送性のいずれか、あるいは両方の機能を有している材料をそれぞれの層に用い、発光性の無い単なるホール輸送物質あるいは電子輸送物質と組み合わせて用いる場合に有用である。また、この場合、発光層は、ホール輸送層５あるいは電子輸送層６のいずれかから成る。
【００６６】
図３は、本発明の有機発光素子における他の例を示す断面図である。図３は、基板１上に、陽極２、ホール輸送層５、発光層３，電子輸送層６及び陰極４を順次設けた構成のものである。これは、キャリヤ輸送と発光の機能を分離したものであり、ホール輸送性、電子輸送性、発光性の各特性を有した化合物と適時組み合わせて用いられ、極めて材料選択の自由度が増すとともに、発光波長を異にする種々の化合物が使用できるため、発光色相の多様化が可能になる。さらに、中央の発光層３に各キャリヤあるいは励起子を有効に閉じこめて、発光効率の向上を図ることも可能になる。
【００６７】
図４は、本発明の有機発光素子における他の例を示す断面図である。図４は、図３に対して、ホール注入層７を陽極２側に挿入した構成であり、陽極２とホール輸送層５の密着性改善あるいはホールの注入性改善に効果があり、低電圧化に効果的である。
【００６８】
図５および図６は、本発明の有機発光素子における他の例を示す断面図である。図５および図６は、図３および図４に対してホールあるいは励起子（エキシトン）を陰極４側に抜けることを阻害する層（ホールブロッキング層８）を、発光層３、電子輸送層６間に挿入した構成である。イオン化ポテンシャルの非常に高い化合物をホールブロッキング層８として用いる事により、発光効率の向上に効果的な構成である。
【００６９】
ただし、図１〜図６はあくまで、ごく基本的な素子構成であり、本発明の化合物を用いた有機発光素子の構成はこれらに限定されるものではない。例えば、電極と有機層界面に絶縁性層を設ける、接着層あるいは干渉層を設ける、ホール輸送層がイオン化ポテンシャルの異なる２層から構成される、など多様な層構成をとることができる。
【００７０】
本発明に用いられる一般式［Ｉ］〜［ＩＩＩ］で示されるジアザフルオレン化合物は、従来の化合物に比べ電子輸送性および耐久性の優れた化合物であり、図１〜図６のいずれの形態でも使用することができる。
【００７１】
本発明は、電子輸送層または発光層の構成成分として一般式［Ｉ］〜［ＩＩＩ］で示されるジアザフルオレン化合物を用いるものであるが、これまで知られているホール輸送性化合物、発光性化合物あるいは電子輸送性化合物などを必要に応じて一緒に使用することもできる。
【００７２】
以下にこれらの化合物例を挙げる。
【００７３】
【化２６】

【００７４】
【化２７】

【００７５】
【化２８】

【００７６】
【化２９】

【００７７】
【化３０】

【００７８】
【化３１】

【００７９】
本発明の有機発光素子において、一般式［Ｉ］〜［ＩＩＩ］で示されるジアザフルオレン化合物を含有する層および他の有機化合物を含有する層は、一般には真空蒸着法あるいは、適当な溶媒に溶解させて塗布法により薄膜を形成する。特に塗布法で成膜する場合は、適当な結着樹脂と組み合わせて膜を形成することもできる。
【００８０】
上記結着樹脂としては、広範囲な結着性樹脂より選択でき、たとえばポリビニルカルバゾール樹脂、ポリカーボネート樹脂、ポリエステル樹脂、ポリアリレート樹脂、ポリスチレン樹脂、アクリル樹脂、メタクリル樹脂、ブチラール樹脂、ポリビニルアセタール樹脂、ジアリルフタレート樹脂、フェノール樹脂、エポキシ樹脂、シリコーン樹脂、ポリスルホン樹脂、尿素樹脂等が挙げられるが、これらに限定されるものではない。また、これらは単独または共重合体ポリマーとして１種または２種以上混合してもよい。
【００８１】
陽極材料としては、仕事関数がなるべく大きなものがよく、例えば、金、白金、ニッケル、パラジウム、コバルト、セレン、バナジウム等の金属単体あるいはこれらの合金、酸化錫、酸化亜鉛、酸化錫インジウム（ＩＴＯ），酸化亜鉛インジウム等の金属酸化物が使用できる。また、ポリアニリン、ポリピロール、ポリチオフェン、ポリフェニレンスルフィド等の導電性ポリマーも使用できる。これらの電極物質は単独で用いてもよく、複数併用することもできる。
【００８２】
一方、陰極材料としては、仕事関数の小さなものがよく、リチウム、ナトリウム、カリウム、セシウム、カルシウム、マグネシウム、アルミニウム、インジウム、銀、鉛、錫、クロム等の金属単体あるいは複数の合金として用いることができる。酸化錫インジウム（ＩＴＯ）等の金属酸化物の利用も可能である。また、陰極は一層構成でもよく、多層構成をとることもできる。
【００８３】
本発明で用いる基板としては、特に限定するものではないが、金属製基板、セラミックス製基板等の不透明性基板、ガラス、石英、プラスチックシート等の透明性基板が用いられる。また、基板にカラーフィルター膜、蛍光色変換フィルター膜、誘電体反射膜などを用いて発色光をコントロールする事も可能である。
【００８４】
なお、作成した素子に対して、酸素や水分等との接触を防止する目的で保護層あるいは封止層を設けることもできる。保護層としては、ダイヤモンド薄膜、金属酸化物、金属窒化物等の無機材料膜、フッ素樹脂、ポリパラキシレン、ポリエチレン、シリコーン樹脂、ポリスチレン樹脂等の高分子膜、さらには、光硬化性樹脂等が挙げられる。また、ガラス、気体不透過性フィルム、金属などをカバーし、適当な封止樹脂により素子自体をパッケージングすることもできる。
【００８５】
【実施例】
以下、実施例により本発明をさらに具体的に説明していくが、本発明はこれらに限定されるものではない。
【００８６】
＜合成例１＞［例示化合物Ｎｏ．１の合成］
【００８７】
【化３２】

【００８８】
２００ｍｌ三ツ口フラスコに、４，５−ジアザフルオレン−９−オン［１］１０．０ｇ（５５．０ｍｍｏｌ）およびヒドラジン一水和物１３．４ｍｌ（８０％、２２０ｍｍｏｌ）を入れ、１６０℃で１２時間攪拌した後、水を加え有機層をクロロホルムで抽出し無水硫酸ナトリウムで乾燥後、アルミナカラム（クロロホルム展開溶媒）で精製し、［２］（白色結晶）４．８ｇ（収率５２％）を得た。
【００８９】
次に、２００ｍｌ三ツ口フラスコに、［２］３．０ｇ（１７．８ｍｍｏｌ）およびＤＭＦ７０ｍｌを入れ、窒素雰囲気中、０℃で攪拌下、ナトリウムメトキサイド２．１ｇ（３９．２ｍｍｏｌ）を添加後、ヨウ化メチル４．４ｍｌ（７１．２ｍｍｏｌ）を滴下した。室温で１２時間攪拌した後、水を加え有機層をクロロホルムで抽出し無水硫酸ナトリウムで乾燥後、アルミナカラム（クロロホルム展開溶媒）で精製し、［３］（白色結晶）２．８ｇ（収率８０％）を得た。
【００９０】
さらに、２００ｍｌ三ツ口フラスコに、２−ヨード−９，９−ジメチルフルオレン［４］５．９ｇ（１８．３ｍｍｏｌ）およびジエチルエーテル５０ｍｌを入れ、窒素雰囲気中、−７８℃で攪拌下、ｎ−ブチルリチウム（１５％ヘキサン溶液）１１．９ｍｌ（１８．３ｍｍｏｌ）を滴下した。室温まで昇温し１時間攪拌した後、−２０℃に冷却し［３］１．０ｇ（５．１０ｍｍｏｌ）のトルエン８０ｍｌ分散液を滴下した。室温で１２時間攪拌後、水を加え有機層をクロロホルムで抽出し無水硫酸ナトリウムで乾燥後、アルミナカラム（ヘキサン＋クロロホルム混合展開溶媒）で精製し、例示化合物Ｎｏ．１（黄色結晶）１．６ｇ（収率５４％）を得た。
【００９１】
＜合成例２＞［例示化合物Ｎｏ．２の合成］
【００９２】
【化３３】

【００９３】
２００ｍｌ三ツ口フラスコに、［３］３．０ｇ（１５．３ｍｍｏｌ）およびニトロベンゼン７０ｍｌを入れ、１３０℃で攪拌下、臭素２．４ｍｌ（４５．９ｍｍｏｌ）のニトロベンゼン１０ｍｌ溶液を滴下し、１４０℃で５時間攪拌した。反応液を水に滴下し、有機層をクロロホルムで抽出、チオ硫酸ナトリウム水溶液で洗浄し、無水硫酸ナトリウムで乾燥後、アルミナカラム（ヘキサン＋クロロホルム混合展開溶媒）で精製し、ジブロモ体［５］（白色結晶）１．８ｇ（収率３３％）を得た。
【００９４】
次に、２００ｍｌ三ツ口フラスコに、ジブロモ体［５］０．５ｇ（１．４１ｍｍｏｌ）、ボロン酸［６］１．３ｇ（５．６５ｍｍｏｌ）、トルエン６０ｍｌおよびエタノール３０ｍｌを入れ、窒素雰囲気中、室温で攪拌下、炭酸ナトリウム６ｇ／水３０ｍｌの水溶液を滴下し、次いでテトラキス（トリフェニルホスフィン）パラジウム（０）０．１６ｇ（０．１４ｍｍｏｌ）を添加した。室温で３０分攪拌した後、７７℃に昇温し３時間攪拌した。反応後、有機層をクロロホルムで抽出し無水硫酸ナトリウムで乾燥後、アルミナカラム（クロロホルム展開溶媒）で精製し、例示化合物Ｎｏ．２（黄色結晶）０．７ｇ（収率８５％）を得た。
【００９５】
＜合成例３＞［例示化合物Ｎｏ．４１の合成］
【００９６】
【化３４】

【００９７】
２００ｍｌ三ツ口フラスコに、［７］^＊）３．０ｇ（１１．１ｍｍｏｌ）およびＤＭＦ７０ｍｌを入れ、窒素雰囲気中、０℃で攪拌下、ナトリウムメトキサイド１．３ｇ（２４．４ｍｍｏｌ）を添加後、ヨウ化メチル２．１ｍｌ（３３．３ｍｍｏｌ）を滴下した。室温で１２時間攪拌した後、水を加え有機層をクロロホルムで抽出し無水硫酸ナトリウムで乾燥後、アルミナカラム（クロロホルム展開溶媒）で精製し、［８］（黄色結晶）２．５ｇ（収率７６％）を得た。
【００９８】
さらに、２００ｍｌ三ツ口フラスコに、２−ヨード−９，９−ジメチルフルオレン［４］３．９ｇ（１２．１ｍｍｏｌ）およびジエチルエーテル５０ｍｌを入れ、窒素雰囲気中、−７８℃で攪拌下、ｎ−ブチルリチウム（１５％ヘキサン溶液）７．８ｍｌ（１２．１ｍｍｏｌ）を滴下した。室温まで昇温し１時間攪拌した後、−２０℃に冷却し［８］１．０ｇ（３．３６ｍｍｏｌ）のトルエン８０ｍｌ分散液を滴下した。室温で１２時間攪拌後、水を加え有機層をクロロホルムで抽出し無水硫酸ナトリウムで乾燥後、アルミナカラム（ヘキサン＋クロロホルム混合展開溶媒）で精製し、例示化合物Ｎｏ．４１（黄色結晶）１．１ｇ（収率４８％）を得た。
【００９９】
＜実施例１＞
図３に示す構造の素子を作成した。
【０１００】
基板１としてのガラス基板上に、陽極２としての酸化錫インジウム（ＩＴＯ）をスパッタ法にて１２０ｎｍの膜厚で成膜したものを透明導電性支持基板として用いた。これをアセトン、イソプロピルアルコール（ＩＰＡ）で順次超音波洗浄し、次いでＩＰＡで煮沸洗浄後、乾燥した。さらに、ＵＶ／オゾン洗浄したものを透明導電性支持基板として使用した。
【０１０１】
透明導電性支持基板上に下記構造式で示される化合物のクロロホルム溶液をスピンコート法により３０ｎｍの膜厚で成膜し、ホール輸送層５を形成した。
【０１０２】
【化３５】

【０１０３】
さらに下記構造式で示されるＩｒ錯体および例示化合物Ｎｏ．１で示されるジアザフルオレン化合物（重量比５：１００）を真空蒸着法により２０ｎｍの膜厚で成膜し、発光層３を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１０４】
【化３６】

【０１０５】
さらにアルミニウムトリスキノリノールを真空蒸着法により４０ｎｍの膜厚で成膜し、電子輸送層６を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１０６】
次に、陰極４として、アルミニウムとリチウム（リチウム濃度１原子％）からなる蒸着材料を用いて、上記有機層の上に真空蒸着法により厚さ５０ｎｍの金属層膜を形成し、さらに真空蒸着法により厚さ１５０ｎｍのアルミニウム層を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は１．０〜１．２ｎｍ／ｓｅｃの条件で成膜した。
【０１０７】
さらに、窒素雰囲気中で保護用ガラス板をかぶせ、アクリル樹脂系接着材で封止した。
【０１０８】
この様にして得られた素子に、ＩＴＯ電極（陽極２）を正極、Ａｌ−Ｌｉ電極（陰極４）を負極にして、１０Ｖの直流電圧を印加すると２１．０ｍＡ／ｃｍ^２の電流密度で電流が素子に流れ、６０００ｃｄ／ｍ^２の輝度で緑色の発光が観測された。
【０１０９】
さらに、電流密度を１０．０ｍＡ／ｃｍ^２に保ち１００時間電圧を印加したところ、初期輝度２０００ｃｄ／ｍ２から１００時間後１５００ｃｄ／ｍ^２と輝度劣化は小さかった。
【０１１０】
＜実施例２〜１０＞
例示化合物Ｎｏ．１に代えて、表１に示す例示化合物を用いた他は実施例１と同様に素子を作成し、同様な評価を行った。結果を表１に示す。
【０１１１】
＜比較例１〜３＞
例示化合物Ｎｏ．１に代えて、下記構造式で示される化合物を用いた他は実施例１と同様に素子を作成し、同様な評価を行った。結果を表１に示す。
【０１１２】
【化３７】

【０１１３】
【表１】

【０１１４】
＜実施例１１＞
図３に示す構造の素子を作成した。
【０１１５】
実施例１と同様に、透明導電性支持基板上にホール輸送層５を形成した。
【０１１６】
さらに下記構造式で示されるアリールアミノ化合物および例示化合物Ｎｏ．４で示されるジアザフルオレン化合物（重合比１：２０）を真空蒸着法により２０ｎｍの膜厚で成膜し、発光層３を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１１７】
【化３８】

【０１１８】
さらにアルミニウムトリスキノリノールを真空蒸着法により４０ｎｍの膜厚で成膜し、電子輸送層６を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１１９】
次に、実施例１と同様にして陰極４を形成した後に封止した。
【０１２０】
この様にして得られた素子に、ＩＴＯ電極（陽極２）を正極、Ａｌ−Ｌｉ電極（陰極４）を負極にして、６Ｖの直流電圧を印加すると１２０ｍＡ／ｃｍ^２の電流密度で電流が素子に流れ、９５００ｃｄ／ｍ^２の輝度で青色の発光が観測された。
【０１２１】
さらに、電流密度を１００ｍＡ／ｃｍ^２に保ち１００時間電圧を印加したところ、初期輝度７５００ｃｄ／ｍ^２から１００時間後６０００ｃｄ／ｍ^２と輝度劣化は小さかった。
【０１２２】
＜実施例１２〜２５＞
例示化合物Ｎｏ．４に代えて、表２に示す例示化合物を用いた他は実施例１１と同様に素子を作成し、同様な評価を行った。結果を表２に示す。
【０１２３】
＜比較例４〜６＞
例示化合物Ｎｏ．４に代えて、比較化合物Ｎｏ．１〜３を用いた他は実施例１１と同様に素子を作成し、同様な評価を行った。結果を表２に示す。
【０１２４】
【表２】

【０１２５】
＜実施例２６＞
図３に示す構造の素子を作成した。
【０１２６】
実施例１と同様に、透明導電性支持基板上にホール輸送層５を形成した。
【０１２７】
さらにクマリンおよびアルミニウムトリスキノリノール（重合比１：２０）を真空蒸着法により２０ｎｍの膜厚で成膜し、発光層３を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１２８】
さらに例示化合物Ｎｏ．１で示されるジアザフルオレン化合物を４０ｎｍの膜厚で成膜し、電子輸送層６を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１２９】
次に、実施例１と同様にして陰極４を形成した後に封止した。
【０１３０】
この様にして得られた素子に、ＩＴＯ電極（陽極２）を正極、Ａｌ−Ｌｉ電極（陰極４）を負極にして、６Ｖの直流電圧を印加すると１９０ｍＡ／ｃｍ^２の電流密度で電流が素子に流れ、１７０００ｃｄ／ｍ^２の輝度で緑色の発光が観測された。
【０１３１】
さらに、電流密度を１５０ｍＡ／ｃｍ^２に保ち１００時間電圧を印加したところ、初期輝度８０００ｃｄ／ｍ^２から１００時間後６０００ｃｄ／ｍ^２と輝度劣化は小さかった。
【０１３２】
＜実施例２７〜４０＞
例示化合物Ｎｏ．１に代えて、表３に示す例示化合物を用いた他は実施例２６と同様に素子を作成し、同様な評価を行った。結果を表３に示す。
【０１３３】
＜比較例７〜９＞
例示化合物Ｎｏ．１に代えて、比較化合物Ｎｏ．１〜３を用いた他は実施例２６と同様に素子を作成し、同様な評価を行った。結果を表３に示す。
【０１３４】
【表３】

【０１３５】
＜実施例４１＞
図３に示す構造の素子を作成した。
【０１３６】
実施例１と同様な透明導電性支持基板上に、下記構造式で示されるアリールアミン化合物を真空蒸着法により４０ｎｍの膜厚で成膜し、ホール輸送層５を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１３７】
【化３９】

【０１３８】
さらに下記構造式で示されるＩｒ錯体および下記構造式で示されるカルバゾール化合物（重合比５：１００）を真空蒸着法により２０ｎｍの膜厚で成膜し、発光層３を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１３９】
【化４０】

【０１４０】
【化４１】

【０１４１】
さらに例示化合物Ｎｏ．１１で示されるジアザフルオレン化合物を４０ｎｍの膜厚で成膜し電子輸送層６を形成した。蒸着時の真空度は１．０×１０^−４Ｐａ、成膜速度は０．２〜０．３ｎｍ／ｓｅｃの条件で成膜した。
【０１４２】
次に、実施例１と同様にして陰極４を形成した後に封止した。
【０１４３】
この様にして得られた素子に、ＩＴＯ電極（陽極２）を正極、Ａｌ−Ｌｉ電極（陰極４）を負極にして、１０Ｖの直流電圧を印加すると２４．０ｍＡ／ｃｍ^２の電流密度で電流が素子に流れ、９０００ｃｄ／ｍ^２の輝度で緑色の発光が観測された。
【０１４４】
さらに、電流密度を１０．０ｍＡ／ｃｍ^２に保ち１００時間電圧を印加したところ、初期輝度３５００ｃｄ／ｍ^２から１００時間後２５００ｃｄ／ｍ^２と輝度劣化は小さかった。
【０１４５】
＜実施例４２〜５５＞
例示化合物Ｎｏ．１１に代えて、表４に示す例示化合物を用いた他は実施例４１と同様に素子を作成し、同様な評価を行った。結果を表４に示す。
【０１４６】
＜比較例１０〜１２＞
例示化合物Ｎｏ．１１に代えて、比較化合物Ｎｏ．１〜３を用いた他は実施例４１と同様に素子を作成し、同様な評価を行った。結果を表４に示す。
【０１４７】
【表４】

【０１４８】
＜実施例５６＞
図１に示す構造の素子を作成した。
【０１４９】
実施例１と同様な透明導電性支持基板上に、例示化合物Ｎｏ．２５で示されるジアザフルオレン化合物を０．０５０ｇおよびポリ−Ｎ−ビニルカルバゾール（重量平均分子量＝６３，０００）１．００ｇをクロロホルム８０ｍｌに溶解した溶液をスピンコート法（回転数＝２０００ｒｐｍ）により１２０ｎｍの膜厚に成膜し、有機層（発光層３）を形成した。
【０１５０】
次に、実施例１と同様にして陰極４を形成した後に封止した。
【０１５１】
この様にして得られた素子に、ＩＴＯ電極（陽極２）を正極、Ａｌ−Ｌｉ電極（陰極４）を負極にして、１０Ｖの直流電圧を印加すると８．５ｍＡ／ｃｍ^２の電流密度で電流が素子に流れ、１５００ｃｄ／ｍ^２の輝度で青色の発光が観測された。
【０１５２】
さらに、窒素雰囲気下で電流密度を８．０ｍＡ／ｃｍ^２に保ち１００時間電圧を印加したところ、初期輝度１３００ｃｄ／ｍ^２から１００時間後１１００ｃｄ／ｍ^２と輝度劣化は小さかった。
【０１５３】
＜実施例５７〜６０＞
例示化合物Ｎｏ．２５に代えて、表５に示す例示化合物を用いた他は実施例５６と同様に素子を作成し、同様な評価を行った。結果を表５に示す。
【０１５４】
＜比較例１３〜１５＞
例示化合物Ｎｏ．２５に代えて、比較化合物Ｎｏ．１〜３を用いた他は実施例５６と同様に素子を作成し、同様な評価を行った。結果を表５に示す。
【０１５５】
【表５】

【０１５６】
【発明の効果】
以上説明のように、一般式［Ｉ］〜［ＩＩＩ］で示されるジアザフルオレン化合物を用いた有機発光素子は、低い印加電圧で高輝度な発光が得られ、耐久性にも優れている。特に本発明のジアザフルオレン化合物を含有する有機層は、電子輸送層として優れ、かつ発光層としても優れている。
【０１５７】
さらに、素子の作成も真空蒸着あるいはキャステイング法等を用いて作成可能であり、比較的安価で大面積の素子を容易に作成できる。
【図面の簡単な説明】
【図１】本発明における有機発光素子の一例を示す断面図である。
【図２】本発明における有機発光素子の他の例を示す断面図である。
【図３】本発明における有機発光素子の他の例を示す断面図である。
【図４】本発明における有機発光素子の他の例を示す断面図である。
【図５】本発明における有機発光素子の他の例を示す断面図である。
【図６】本発明における有機発光素子の他の例を示す断面図である。
【符号の説明】
１　基板
２　陽極
３　発光層
４　陰極
５　ホール輸送層
６　電子輸送層
７　ホール注入層
８　ホール／エキシトンブロッキング層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a novel organic compound and an organic light emitting device using the same.
[0002]
[Prior art]
An organic light-emitting device has a thin film containing a fluorescent organic compound or a phosphorescent organic compound sandwiched between an anode and a cathode, and injects electrons and holes (holes) from each electrode to form a fluorescent compound or a phosphorescent compound. Is an element utilizing light emitted when the exciton returns to the ground state.
[0003]
In 1987, a study by Kodak Company (Non-patent Document 1) stated that an ITO was used for the anode, an alloy of magnesium and silver was used for the cathode, an aluminum quinolinol complex was used as the electron transporting material and the luminescent material, and a triphenylamine derivative was used as the hole transporting material. Emission of about 1000 cd / m ^{2 at} an applied voltage of about 10 V has been reported for the used device having a function-separated type two-layer structure. Related patents include Patent Documents 1-3.
[0004]
In addition, by changing the type of the fluorescent organic compound, light emission from ultraviolet to infrared is possible, and various compounds have been actively studied recently. For example, it is described in Patent Documents 4 to 11 and the like.
[0005]
In recent years, many studies have been made to use a phosphorescent compound as a light emitting material and use triplet energy for EL light emission. A group at Princeton University reports that an organic light-emitting element using an iridium complex as a light-emitting material exhibits high luminous efficiency (Non-Patent Document 2).
[0006]
Further, in addition to the organic light-emitting device using the above low-molecular material, an organic light-emitting device using a conjugated polymer has been reported by a group of Cambridge University (Non-Patent Document 3). In this report, light emission was confirmed in a single layer by forming a film of polyphenylenevinylene (PPV) in a coating system.
[0007]
Patents related to organic light-emitting devices using a conjugated polymer include Patent Documents 12 to 16.
[0008]
As described above, recent advances in organic light-emitting devices are remarkable, and their characteristics are wide-ranging applications because they can be made into high-brightness, diversified emission wavelengths, high-speed response, thin and lightweight light-emitting devices at low applied voltage. Suggests the possibility to.
[0009]
However, at present, an even higher luminance light output or higher conversion efficiency is required. Further, there are still many problems in terms of durability such as a change with time due to long-term use and deterioration due to an atmospheric gas containing oxygen or moisture. Further, in consideration of application to a full-color display or the like, emission of blue, green, and red with good color purity is required, but these problems are not yet sufficient.
[0010]
On the other hand, phenanthroline compounds, oxadiazole compounds or triazole compounds are known as electron transport materials. Patent Literatures 17 to 19 are examples of the use of these compounds in organic light-emitting devices, but the characteristics when used as an electron transport layer or a light-emitting layer are not sufficient.
[0011]
[Patent Document 1]
US Patent No. 4,539,507 [Patent Document 2]
US Patent No. 4,720,432 [Patent Document 3]
US Patent No. 4,885,211 [Patent Document 4]
US Patent No. 5,151,629 [Patent Document 5]
US Patent No. 5,409,783 [Patent Document 6]
US Patent No. 5,382,477 [Patent Document 7]
JP-A-2-247278 [Patent Document 8]
JP-A-3-255190 [Patent Document 9]
JP-A-5-202356 [Patent Document 10]
Japanese Patent Application Laid-Open No. 9-202878 [Patent Document 11]
JP-A-9-227576 [Patent Document 12]
US Patent No. 5,247,190 [Patent Document 13]
US Patent No. 5,514,878 [Patent Document 14]
US Patent No. 5,672,678 [Patent Document 15]
JP-A-4-145192 [Patent Document 16]
JP-A-5-247460 [Patent Document 17]
Japanese Patent Application Laid-Open No. 5-331559 [Patent Document 18]
JP-A-4-363891,
[Patent Document 19]
Japanese Patent Application Laid-Open No. 7-41759 [Non-Patent Document 1]
Appl. Phys. Lett. 51, 913 (1987)
[Non-patent document 2]
Nature, 395, 151 (1998).
[Non-Patent Document 3]
Nature, 347, 539 (1990)
[0012]
[Problems to be solved by the invention]
An object of the present invention is to provide a novel diazafluorene compound.
[0013]
Another object of the present invention is to provide an organic light-emitting device using a specific diazafluorene compound and having extremely high efficiency and high luminance light output.
[0014]
Another object of the present invention is to provide an extremely durable organic light emitting device.
[0015]
It is still another object of the present invention to provide an organic light emitting device that can be easily manufactured and can be manufactured at relatively low cost.
[0016]
[Means for Solving the Problems]
That is, the diazafluorene compound of the present invention is characterized by being represented by the following general formulas [I] to [III].
[0017]
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[0018]
(Wherein, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group A substituted or unsubstituted fused polycyclic heterocyclic group, a substituted amino group, a cyano group or a halogen atom, which may be the same or different, and R ₃ and R ₄ are a hydrogen atom, a substituted or unsubstituted Represents an alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and R ₃ and R ₄ bonded to different fluorene groups may be the same or different, and may be the same or different. R ₃ and R ₄ attached to the fluorene group may be the same or different.
n represents an integer of 1 to 10. )
[0019]
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[0020]
(Wherein R ₅ and R ₆ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group Represents a substituted or unsubstituted fused polycyclic heterocyclic group, a substituted amino group, a cyano group or a halogen atom, and may be the same or different, and R ₇ and R ₈ are a hydrogen atom, a substituted or unsubstituted An alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, which may be the same or different.)
[0021]
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[0022]
(Wherein R ₉ and R ₁₀ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group , A substituted or unsubstituted fused polycyclic heterocyclic group, a substituted amino group, a cyano group or a halogen atom, which may be the same or different.
R ₁₁ and R ₁₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and may be the same or different. )
[0023]
Further, the organic light-emitting element of the present invention is a pair of electrodes including an anode and a cathode, and an organic light-emitting element having at least a layer containing one or more organic compounds sandwiched between the pair of electrodes; At least one of the layers containing at least one of the above diazafluorene compounds.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
[0025]
First, the diazafluorene compound of the present invention will be described.
[0026]
The diazafluorene compound of the present invention is represented by the general formulas [I] to [III], and the diazafluorene compound represented by the general formula [I] is a compound represented by the following general formula [IV] Is preferred.
[0027]
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[0028]
(Wherein, R ₁₃ and R ₁₄ represent a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group, and may be the same or different.
R ₁₅ and R ₁₆ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and may be the same or different. )
[0029]
In the diazafluorene compounds represented by the general formulas [I] to [III], R ₁ , R ₂ , R ₅ , R ₆ , R ₉ , R ₁₀ , R ₁₃ or R ₁₄ are represented by the following general formula [V] It is preferably a condensed polycyclic aromatic group represented by any one of [X] to [X].
[0030]
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[0031]
(Wherein, R ₁₇ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, .R ₁₈ of a cyano group or a halogen atom And R ₁₉ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, which may be the same or different.)
[0032]
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[0033]
(Wherein, R _{20 to} R ₂₃ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom. .)
[0034]
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[0035]
(Wherein R ₂₄ and R ₂₅ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group or a halogen atom. , May be the same or different.)
[0036]
Specific examples of the substituents in the general formulas [I] to [X] are shown below.
[0037]
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a ter-butyl group, and an octyl group.
[0038]
Examples of the aryl group include a phenyl group, a biphenyl group, and a terphenyl group.
[0039]
Examples of the heterocyclic group include a thienyl group, a pyrrolyl group, a pyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, and a terthienyl group.
[0040]
Examples of the condensed polycyclic aromatic group include a fluorenyl group, a naphthyl group, a fluoranthenyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a tetracenyl group, a pentacenyl group, a triphenylenyl group and a perylenyl group.
[0041]
Examples of the condensed polycyclic heterocyclic group include a carbazolyl group, a phenanthrolyl group, and an acridinyl group.
[0042]
Examples of the substituted amino group include a dimethylamino group, a diethylamino group, a dibenzylamino group, a diphenylamino group, a ditolylamino group, and a dianisolylamino group.
[0043]
Examples of the halogen atom include fluorine, chlorine, bromine and iodine.
[0044]
Examples of the substituent which the above substituent may have include an alkyl group such as a methyl group, an ethyl group and a propyl group; an aryl group such as a phenyl group and a biphenyl group; a heterocyclic group such as a thienyl group, a pyrrolyl group and a pyridyl group. , An amino group such as dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, ditolylamino group, dianisolylamino group, methoxyl group, ethoxyl group, propoxyl group, alkoxyl group such as phenoxyl group, cyano group And halogen atoms such as fluorine, chlorine, bromine and iodine.
[0045]
Next, typical examples of the diazafluorene compound of the present invention are shown below, but the present invention is not limited to these.
[0046]
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[0047]
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[0048]
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[0049]
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[0050]
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[0051]
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[0052]
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[0053]
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[0054]
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[0055]
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[0056]
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[0057]
The diazafluorene compound of the present invention can be synthesized by a generally known method. Am. Chem. Soc. , 106, 5876-5879 (1984); Org. Chem. , 50, 666-670, (1985); Org. Chem. , 49, 2208-2212 (1984), etc. to obtain a diazafluorene compound intermediate, and further to a method such as a suzuki coupling method using a palladium catalyst (for example, Chem. Rev. 1995, 95, 2457-2483). It can be obtained by a synthetic method.
[0058]
The diazafluorene compound of the present invention is a compound having excellent electron transportability and durability as compared with conventional compounds, and is useful as a layer containing an organic compound of an organic light emitting device, particularly, as an electron transport layer and a light emitting layer, In addition, a layer formed by a vacuum evaporation method, a solution coating method, or the like is less likely to be crystallized and has excellent stability over time.
[0059]
Next, the organic light emitting device of the present invention will be described in detail.
[0060]
The organic light-emitting element of the present invention includes a pair of electrodes including an anode and a cathode, and an organic light-emitting element including at least a layer including one or more organic compounds sandwiched between the pair of electrodes, including the organic compound. At least one of the layers contains at least one of the diazafluorene compounds represented by the general formulas [I] to [III].
[0061]
In the organic light emitting device of the present invention, it is preferable that at least the electron transporting layer or the light emitting layer among the layers containing the organic compound contains at least one of the diazafluorene compounds.
[0062]
In the organic light-emitting device of the present invention, the diazafluorene compounds represented by the above general formulas [I] to [III] are formed between the anode and the cathode by a vacuum evaporation method or a solution coating method. The thickness of the organic layer is thinner than 10 μm, preferably 0.5 μm or less, more preferably 0.01 to 0.5 μm.
[0063]
1 to 6 show preferred examples of the organic light emitting device of the present invention.
[0064]
FIG. 1 is a sectional view showing an example of the organic light emitting device of the present invention. FIG. 1 shows a structure in which an anode 2, a light emitting layer 3 and a cathode 4 are sequentially provided on a substrate 1. The light emitting element used here is useful when it has a single hole transporting ability, electron transporting ability, and luminous performance by itself, or when it is used by mixing compounds having the respective properties.
[0065]
FIG. 2 is a sectional view showing another example of the organic light emitting device of the present invention. FIG. 2 shows a configuration in which an anode 2, a hole transport layer 5, an electron transport layer 6, and a cathode 4 are sequentially provided on a substrate 1. In this case, a luminescent material having either a hole-transporting property or an electron-transporting property, or both, is used for each layer and combined with a simple hole-transporting substance or an electron-transporting substance having no light-emitting property. This is useful when used. In this case, the light emitting layer is composed of either the hole transport layer 5 or the electron transport layer 6.
[0066]
FIG. 3 is a sectional view showing another example of the organic light emitting device of the present invention. FIG. 3 shows a configuration in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. It separates the functions of carrier transport and luminescence, and is used in a timely combination with a compound having each of hole transportability, electron transportability, and luminescent properties, which greatly increases the degree of freedom in material selection, Since various compounds having different emission wavelengths can be used, the emission hue can be diversified. Further, it is possible to effectively confine each carrier or exciton in the central light emitting layer 3 to improve the luminous efficiency.
[0067]
FIG. 4 is a sectional view showing another example of the organic light emitting device of the present invention. FIG. 4 shows a configuration in which the hole injection layer 7 is inserted on the anode 2 side with respect to FIG. 3, which is effective for improving the adhesion between the anode 2 and the hole transport layer 5 or for improving the hole injection property. It is effective for
[0068]
5 and 6 are cross-sectional views illustrating another example of the organic light emitting device of the present invention. FIGS. 5 and 6 show a layer (a hole blocking layer 8) that prevents holes or excitons (excitons) from leaking to the cathode 4 side between the light emitting layer 3 and the electron transport layer 6 in FIGS. It is the structure inserted in. By using a compound having an extremely high ionization potential as the hole blocking layer 8, the structure is effective for improving the luminous efficiency.
[0069]
However, FIGS. 1 to 6 show only very basic device configurations, and the configuration of the organic light-emitting device using the compound of the present invention is not limited thereto. For example, various layer configurations such as providing an insulating layer at an interface between an electrode and an organic layer, providing an adhesive layer or an interference layer, and forming a hole transport layer from two layers having different ionization potentials can be employed.
[0070]
The diazafluorene compounds represented by the general formulas [I] to [III] used in the present invention are compounds having more excellent electron transportability and durability than conventional compounds, and have any of the configurations shown in FIGS. But can be used.
[0071]
In the present invention, the diazafluorene compounds represented by the general formulas [I] to [III] are used as components of the electron transporting layer or the light emitting layer. A compound or an electron transporting compound can be used together if necessary.
[0072]
Examples of these compounds will be described below.
[0073]
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[0074]
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[0075]
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[0076]
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[0077]
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[0078]
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[0079]
In the organic light emitting device of the present invention, the layer containing the diazafluorene compound represented by any one of the general formulas [I] to [III] and the layer containing another organic compound are generally formed by a vacuum evaporation method or an appropriate solvent. After dissolution, a thin film is formed by a coating method. In particular, when the film is formed by a coating method, the film can be formed in combination with an appropriate binder resin.
[0080]
The binder resin can be selected from a wide range of binder resins, for example, polyvinyl carbazole resin, polycarbonate resin, polyester resin, polyarylate resin, polystyrene resin, acrylic resin, methacrylic resin, butyral resin, polyvinyl acetal resin, diallyl phthalate Examples include, but are not limited to, resins, phenolic resins, epoxy resins, silicone resins, polysulfone resins, urea resins, and the like. These may be used alone or in combination of two or more as a copolymer.
[0081]
The anode material preferably has a work function as large as possible. For example, simple metals such as gold, platinum, nickel, palladium, cobalt, selenium, and vanadium or alloys thereof, tin oxide, zinc oxide, and indium tin oxide (ITO) And metal oxides such as indium zinc oxide. Further, conductive polymers such as polyaniline, polypyrrole, polythiophene, and polyphenylene sulfide can also be used. These electrode substances may be used alone or in combination.
[0082]
On the other hand, as the cathode material, a material having a small work function is preferable, and it can be used as a single metal or a plurality of alloys such as lithium, sodium, potassium, cesium, calcium, magnesium, aluminum, indium, silver, lead, tin, and chromium. it can. It is also possible to use a metal oxide such as indium tin oxide (ITO). The cathode may have a single-layer structure or a multilayer structure.
[0083]
The substrate used in the present invention is not particularly limited, but an opaque substrate such as a metal substrate or a ceramic substrate, or a transparent substrate such as glass, quartz, or a plastic sheet is used. Further, it is also possible to control the emitted light by using a color filter film, a fluorescent color conversion filter film, a dielectric reflection film or the like on the substrate.
[0084]
Note that a protective layer or a sealing layer can be provided on the manufactured element for the purpose of preventing contact with oxygen, moisture, or the like. As the protective layer, an inorganic material film such as a diamond thin film, a metal oxide, or a metal nitride, a polymer film such as a fluororesin, polyparaxylene, polyethylene, a silicone resin, and a polystyrene resin, and a photocurable resin, etc. No. Further, the device itself can be covered with glass, a gas impermeable film, a metal, or the like, and packaged with an appropriate sealing resin.
[0085]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto.
[0086]
<Synthesis Example 1> [Exemplified Compound No. Synthesis of 1]
[0087]
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[0088]
In a 200 ml three-necked flask, 10.0 g (55.0 mmol) of 4,5-diazafluoren-9-one [1] and 13.4 ml (80%, 220 mmol) of hydrazine monohydrate were placed, and the mixture was heated at 160 ° C. for 12 hours. After stirring, water was added, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and then purified with an alumina column (chloroform developing solvent) to obtain 4.8 g (yield: 52%) of [2] (white crystals). Was.
[0089]
Next, 3.0 g (17.8 mmol) of [2] and 70 ml of DMF were placed in a 200 ml three-necked flask, and 2.1 g (39.2 mmol) of sodium methoxide was added thereto while stirring at 0 ° C. in a nitrogen atmosphere. 4.4 ml (71.2 mmol) of methyl chloride were added dropwise. After stirring at room temperature for 12 hours, water was added, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and then purified on an alumina column (chloroform developing solvent) to obtain 2.8 g of [3] (white crystals) (yield: 80). %).
[0090]
Further, 5.9 g (18.3 mmol) of 2-iodo-9,9-dimethylfluorene [4] and 50 ml of diethyl ether were placed in a 200 ml three-necked flask, and n-butyllithium was stirred in a nitrogen atmosphere at -78 ° C. 11.9 ml (18.3 mmol) of (15% hexane solution) was added dropwise. After the temperature was raised to room temperature and stirred for 1 hour, the mixture was cooled to −20 ° C., and a dispersion of 1.0 g (5.10 mmol) of [3] in 80 ml of toluene was added dropwise. After stirring at room temperature for 12 hours, water was added, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with an alumina column (hexane / chloroform mixed developing solvent). 1.6 g (yield 54%) of 1 (yellow crystal) was obtained.
[0091]
<Synthesis Example 2> [Exemplified Compound No. Synthesis of 2]
[0092]
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[0093]
In a 200 ml three-necked flask, 3.0 g (15.3 mmol) of [3] and 70 ml of nitrobenzene were put, and a solution of 2.4 ml (45.9 mmol) of bromine in 10 ml of nitrobenzene was added dropwise at 130 ° C. with stirring, and the mixture was stirred at 140 ° C. for 5 hours. Stirred. The reaction solution was added dropwise to water, and the organic layer was extracted with chloroform, washed with an aqueous solution of sodium thiosulfate, dried over anhydrous sodium sulfate, and then purified on an alumina column (hexane / chloroform mixed developing solvent) to obtain a dibromo compound [5] ( 1.8 g (yield 33%) of white crystals were obtained.
[0094]
Next, 0.5 g (1.41 mmol) of the dibromo compound [5], 1.3 g (5.65 mmol) of boronic acid [6], 60 ml of toluene and 30 ml of ethanol were placed in a 200 ml three-necked flask, and the mixture was heated at room temperature in a nitrogen atmosphere. Under stirring, an aqueous solution of 6 g of sodium carbonate / 30 ml of water was added dropwise, and then 0.16 g (0.14 mmol) of tetrakis (triphenylphosphine) palladium (0) was added. After stirring at room temperature for 30 minutes, the mixture was heated to 77 ° C. and stirred for 3 hours. After the reaction, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and then purified on an alumina column (chloroform developing solvent). 0.7 g (yield 85%) of 2 (yellow crystals) was obtained.
[0095]
<Synthesis Example 3> [Exemplified Compound No. Synthesis of 41]
[0096]
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[0097]
In a 200 ml three-necked flask, 3.0 g (11.1 mmol) of [7] ^*) and 70 ml of DMF were added, and 1.3 g (24.4 mmol) of sodium methoxide was added thereto while stirring at 0 ° C. in a nitrogen atmosphere. 2.1 ml (33.3 mmol) of methyl was added dropwise. After stirring at room temperature for 12 hours, water was added, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with an alumina column (chloroform developing solvent) to obtain 2.5 g of [8] (yellow crystals) (yield 76). %).
[0098]
Further, 3.9 g (12.1 mmol) of 2-iodo-9,9-dimethylfluorene [4] and 50 ml of diethyl ether were put into a 200 ml three-necked flask, and n-butyllithium was stirred in a nitrogen atmosphere at -78 ° C. (15% hexane solution) 7.8 ml (12.1 mmol) was added dropwise. After heating to room temperature and stirring for 1 hour, the mixture was cooled to −20 ° C., and a dispersion of 1.0 g (3.36 mmol) of [8] in 80 ml of toluene was added dropwise. After stirring at room temperature for 12 hours, water was added, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with an alumina column (hexane / chloroform mixed developing solvent). 1.1 g (yield 48%) of 41 (yellow crystals) was obtained.
[0099]
<Example 1>
An element having the structure shown in FIG. 3 was produced.
[0100]
A transparent conductive support substrate formed by depositing indium tin oxide (ITO) as an anode 2 with a thickness of 120 nm on a glass substrate as a substrate 1 by a sputtering method was used. This was ultrasonically washed with acetone and isopropyl alcohol (IPA) sequentially, then washed with boiling IPA and dried. Further, a substrate subjected to UV / ozone cleaning was used as a transparent conductive support substrate.
[0101]
A hole transport layer 5 was formed on a transparent conductive support substrate by spin-coating a chloroform solution of a compound represented by the following structural formula to a thickness of 30 nm.
[0102]
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[0103]
Further, an Ir complex represented by the following structural formula and Exemplified Compound No. The diazafluorene compound (weight ratio 5: 100) represented by No. 1 was formed into a film having a thickness of 20 nm by a vacuum evaporation method to form a light emitting layer 3. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0104]
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[0105]
Further, aluminum trisquinolinol was formed into a film with a thickness of 40 nm by a vacuum evaporation method to form an electron transport layer 6. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0106]
Next, as the cathode 4, a metal layer film having a thickness of 50 nm is formed on the organic layer by a vacuum deposition method using a deposition material composed of aluminum and lithium (lithium concentration: 1 atomic%). To form an aluminum layer having a thickness of 150 nm. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 1.0 to 1.2 nm / sec.
[0107]
Further, a protective glass plate was covered in a nitrogen atmosphere and sealed with an acrylic resin-based adhesive.
[0108]
When a DC voltage of 10 V is applied to the device thus obtained by using an ITO electrode (anode 2) as a positive electrode and an Al—Li electrode (cathode 4) as a negative electrode, a current density of 21.0 mA / cm ² is obtained. Flowed through the device, and green light emission was observed at a luminance of 6000 cd / m ² .
[0109]
Furthermore, when a voltage was applied for 100 hours while maintaining the current density at 10.0 mA / cm ² , the luminance degradation was small, from the initial luminance of 2000 cd / m ² to 1500 cd / m ² after 100 hours.
[0110]
<Examples 2 to 10>
Exemplified Compound No. A device was prepared in the same manner as in Example 1 except for using the exemplified compounds shown in Table 1 in place of 1, and the same evaluation was performed. Table 1 shows the results.
[0111]
<Comparative Examples 1 to 3>
Exemplified Compound No. A device was prepared in the same manner as in Example 1 except that a compound represented by the following structural formula was used instead of 1, and the same evaluation was performed. Table 1 shows the results.
[0112]
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[0113]
[Table 1]

[0114]
<Example 11>
An element having the structure shown in FIG. 3 was produced.
[0115]
As in Example 1, the hole transport layer 5 was formed on the transparent conductive support substrate.
[0116]
Further, an arylamino compound represented by the following structural formula and Exemplified Compound No. A diazafluorene compound represented by No. 4 (polymerization ratio 1:20) was formed into a film having a thickness of 20 nm by a vacuum evaporation method to form a light emitting layer 3. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0117]
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[0118]
Further, aluminum trisquinolinol was formed into a film with a thickness of 40 nm by a vacuum evaporation method to form an electron transport layer 6. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0119]
Next, after forming the cathode 4 in the same manner as in Example 1, sealing was performed.
[0120]
When a direct current voltage of 6 V is applied to the device thus obtained with the ITO electrode (anode 2) serving as a positive electrode and the Al-Li electrode (cathode 4) serving as a negative electrode, a current is applied at a current density of 120 mA / cm ^2. And blue light emission was observed at a luminance of 9500 cd / m ² .
[0121]
Further, when a voltage was applied for 100 hours while maintaining the current density at 100 mA / cm ² , the luminance degradation was small, from initial luminance of 7500 cd / m ² to 6000 cd / m ² after 100 hours.
[0122]
<Examples 12 to 25>
Exemplified Compound No. A device was prepared in the same manner as in Example 11 except for using the exemplified compounds shown in Table 2 in place of 4, and the same evaluation was performed. Table 2 shows the results.
[0123]
<Comparative Examples 4 to 6>
Exemplified Compound No. In place of Comparative Compound No. 4, A device was prepared in the same manner as in Example 11 except that Samples 1 to 3 were used, and the same evaluation was performed. Table 2 shows the results.
[0124]
[Table 2]

[0125]
<Example 26>
An element having the structure shown in FIG. 3 was produced.
[0126]
As in Example 1, the hole transport layer 5 was formed on the transparent conductive support substrate.
[0127]
Further, coumarin and aluminum trisquinolinol (polymerization ratio 1:20) were formed into a film having a thickness of 20 nm by a vacuum evaporation method to form the light emitting layer 3. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0128]
Further, the exemplified compound No. The electron transport layer 6 was formed by forming a film of the diazafluorene compound represented by No. 1 with a thickness of 40 nm. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0129]
Next, after forming the cathode 4 in the same manner as in Example 1, sealing was performed.
[0130]
When a DC voltage of 6 V is applied to the thus obtained device with the ITO electrode (anode 2) serving as a positive electrode and the Al—Li electrode (cathode 4) serving as a negative electrode, a current density of 190 mA / cm ² results. And green light emission was observed at a luminance of 17000 cd / m ² .
[0131]
Further, when a voltage was applied for 100 hours with the current density kept to 150 mA / cm ^2, after the initial luminance 8000 cd / ^{m 2} 100 hours 6000 cd / ^{m 2} and luminance degradation was small.
[0132]
<Examples 27 to 40>
Exemplified Compound No. A device was prepared in the same manner as in Example 26 except that the exemplified compounds shown in Table 3 were used instead of 1, and the same evaluation was performed. Table 3 shows the results.
[0133]
<Comparative Examples 7 to 9>
Exemplified Compound No. In place of Comparative Compound No. 1, A device was prepared in the same manner as in Example 26 except that the devices Nos. 1 to 3 were used, and the same evaluation was performed. Table 3 shows the results.
[0134]
[Table 3]

[0135]
<Example 41>
An element having the structure shown in FIG. 3 was produced.
[0136]
On the same transparent conductive support substrate as in Example 1, an arylamine compound represented by the following structural formula was formed into a film having a thickness of 40 nm by a vacuum evaporation method to form a hole transport layer 5. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0137]
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[0138]
Further, an Ir complex represented by the following structural formula and a carbazole compound represented by the following structural formula (polymerization ratio: 5: 100) were formed into a film having a thickness of 20 nm by a vacuum evaporation method, so that the light-emitting layer 3 was formed. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0139]
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[0140]
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[0141]
Further, the exemplified compound No. A diazafluorene compound represented by No. 11 was formed into a film having a thickness of 40 nm to form an electron transport layer 6. The film was formed under the conditions that the degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation speed was 0.2 to 0.3 nm / sec.
[0142]
Next, after forming the cathode 4 in the same manner as in Example 1, sealing was performed.
[0143]
When a DC voltage of 10 V is applied to the device thus obtained with the ITO electrode (anode 2) serving as a positive electrode and the Al-Li electrode (cathode 4) serving as a negative electrode, a current density of 24.0 mA / cm ² is obtained. Flowed through the device, and green light emission was observed at a luminance of 9000 cd / m ² .
[0144]
Further, when a voltage was applied for 100 hours while the current density was kept at 10.0 mA / cm ² , the luminance was small from initial luminance of 3500 cd / m ² to 2500 cd / m ² after 100 hours.
[0145]
<Examples 42 to 55>
Exemplified Compound No. A device was prepared in the same manner as in Example 41 except that the exemplified compounds shown in Table 4 were used instead of 11, and the same evaluation was performed. Table 4 shows the results.
[0146]
<Comparative Examples 10 to 12>
Exemplified Compound No. In place of Comparative Compound No. 11, Comparative Compound No. A device was prepared in the same manner as in Example 41 except that the devices Nos. 1 to 3 were used, and the same evaluation was performed. Table 4 shows the results.
[0147]
[Table 4]

[0148]
<Example 56>
An element having the structure shown in FIG. 1 was produced.
[0149]
On the same transparent conductive support substrate as in Example 1, Exemplified Compound No. A solution prepared by dissolving 0.050 g of the diazafluorene compound represented by 25 and 1.00 g of poly-N-vinylcarbazole (weight average molecular weight = 63,000) in 80 ml of chloroform was subjected to spin coating (rotational number = 2000 rpm) at 120 nm. To form an organic layer (light-emitting layer 3).
[0150]
Next, after forming the cathode 4 in the same manner as in Example 1, sealing was performed.
[0151]
When a DC voltage of 10 V is applied to the device thus obtained with the ITO electrode (anode 2) serving as a positive electrode and the Al-Li electrode (cathode 4) serving as a negative electrode, a current density of 8.5 mA / cm ² is obtained. Flowed into the device, and blue light emission was observed at a luminance of 1500 cd / m ² .
[0152]
Further, when a voltage was applied for 100 hours while maintaining the current density at 8.0 mA / cm ² in a nitrogen atmosphere, the luminance was small from initial luminance of 1300 cd / m ² to 1100 cd / m ² after 100 hours.
[0153]
<Examples 57 to 60>
Exemplified Compound No. A device was prepared in the same manner as in Example 56 except that the exemplified compounds shown in Table 5 were used instead of 25, and the same evaluation was performed. Table 5 shows the results.
[0154]
<Comparative Examples 13 to 15>
Exemplified Compound No. 25 in place of Comparative Compound No. 25 A device was prepared in the same manner as in Example 56 except that the devices Nos. 1 to 3 were used, and the same evaluation was performed. Table 5 shows the results.
[0155]
[Table 5]

[0156]
【The invention's effect】
As described above, the organic light-emitting element using the diazafluorene compound represented by any one of the general formulas [I] to [III] can emit light with high luminance at a low applied voltage and has excellent durability. In particular, the organic layer containing the diazafluorene compound of the present invention is excellent as an electron transporting layer and also excellent as a light emitting layer.
[0157]
Furthermore, the device can be prepared by using a vacuum deposition method or a casting method, and a relatively inexpensive and large-area device can be easily prepared.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example of an organic light emitting device according to the present invention.
FIG. 2 is a cross-sectional view illustrating another example of the organic light emitting device according to the present invention.
FIG. 3 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.
FIG. 4 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.
FIG. 5 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.
FIG. 6 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Light emitting layer 4 Cathode 5 Hole transport layer 6 Electron transport layer 7 Hole injection layer 8 Hole / exciton blocking layer

Claims (7)

A diazafluorene compound represented by the following general formula [I]:

(Wherein, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group A substituted or unsubstituted fused polycyclic heterocyclic group, a substituted amino group, a cyano group or a halogen atom, which may be the same or different, and R ₃ and R ₄ are a hydrogen atom, a substituted or unsubstituted Represents an alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and R ₃ and R ₄ bonded to different fluorene groups may be the same or different, and may be the same or different. R ₃ and R ₄ attached to the fluorene group may be the same or different.
n represents an integer of 1 to 10. ) A diazafluorene compound represented by the following general formula [II]:

(Wherein R ₅ and R ₆ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group Represents a substituted or unsubstituted fused polycyclic heterocyclic group, a substituted amino group, a cyano group or a halogen atom, and may be the same or different, and R ₇ and R ₈ are a hydrogen atom, a substituted or unsubstituted An alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, which may be the same or different.) A diazafluorene compound represented by the following general formula [III]:

(Wherein R ₉ and R ₁₀ are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group Represents a substituted or unsubstituted fused polycyclic heterocyclic group, substituted amino group, cyano group or halogen atom, which may be the same or different.
R ₁₁ and R ₁₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and may be the same or different. ) The diazafluorene compound according to claim 1, which is represented by the following general formula [IV].

(Wherein, R ₁₃ and R ₁₄ represent a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group, and may be the same or different.
R ₁₅ and R ₁₆ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and may be the same or different. ) R ₁ , R ₂ , R ₅ , R ₆ , R ₉ , R ₁₀ , R ₁₃ or R ₁₄ is a condensed polycyclic aromatic group represented by any of the following formulas [V] to [X]. The diazafluorene compound according to claim 1, wherein:

(Wherein, R ₁₇ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, .R ₁₈ of a cyano group or a halogen atom And R ₁₉ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, which may be the same or different.)

(Wherein, R _{20 to} R ₂₃ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom. .)

(Wherein R ₂₄ and R ₂₅ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group or a halogen atom. , May be the same or different.) A pair of electrodes consisting of an anode and a cathode, and an organic light-emitting element having at least a layer containing one or more organic compounds sandwiched between the pair of electrodes, wherein at least one of the layers containing the organic compounds is at least one layer. 5. An organic light-emitting device comprising at least one of the diazafluorene compounds according to any one of 5. The organic light emitting device according to claim 6, wherein at least one of the electron transport layer and the light emitting layer among the layers containing the organic compound contains at least one of the diazafluorene compounds.

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