JP2003229279A - Organic electroluminescent element - Google Patents
Organic electroluminescent elementInfo
- Publication number
- JP2003229279A JP2003229279A JP2002026746A JP2002026746A JP2003229279A JP 2003229279 A JP2003229279 A JP 2003229279A JP 2002026746 A JP2002026746 A JP 2002026746A JP 2002026746 A JP2002026746 A JP 2002026746A JP 2003229279 A JP2003229279 A JP 2003229279A
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- Japan
- Prior art keywords
- anode
- layer
- thin film
- organic
- film layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、各種の表示装置と
して広範囲に利用される発光素子であって、連続駆動耐
久性に優れた有機電界発光素子に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device which is widely used as various display devices and has excellent continuous driving durability.
【０００２】[0002]
【従来の技術】電界発光素子は、自己発光のために液晶
素子にくらべて明るく、鮮明な表示が可能であるため、
古くから多くの研究者によって研究されてきた。現在実
用レベルに達した電界発光素子としては、無機材料のＺ
ｎＳを用いた素子がある。しかし、この様な無機の電界
発光素子は、発光のための駆動電圧として５０Ｖ以上が
必要であるため、広く使用されるには至っていない。2. Description of the Related Art An electroluminescent device is brighter and clearer than a liquid crystal device due to self-luminous display.
It has been studied by many researchers since ancient times. As an electroluminescent device that has reached a practical level, Z, which is an inorganic material, is currently used.
There is an element using nS. However, such an inorganic electroluminescent device requires a driving voltage of 50 V or higher for light emission, and thus has not been widely used.
【０００３】これに対して有機材料を用いた電界発光素
子である有機電界発光素子は、従来実用的なレベルから
はほど遠いものであったが、１９８７年にイーストマン
・コダック社のシー・ダブリュ・タン（Ｃ．Ｗ．Ｔａｎ
ｇ）らによって開発された積層構造素子によりその特性
が飛躍的に進歩した。彼らは蒸着膜の構造が安定で電子
を輸送することのできる蛍光体からなる層（電子輸送性
発光層）と、正孔を輸送することのできる有機物からな
る層（正孔輸送層）とを積層し、正孔と電子を蛍光体中
に注入して発光させることに成功した。これによって有
機電界発光素子の発光効率が向上し、１０Ｖ以下の電圧
で１０００ｃｄ／ｍ2以上の発光が得られる様になっ
た。その後、電子輸送性発光層を発光層と電子輸送層に
分けるなど、素子を構成する層の機能分離が進められた
結果、現在では１００００ｃｄ／ｍ 2以上の発光特性が
得られている。On the other hand, an electroluminescent element using an organic material
The organic electroluminescent device, which is a child
It was far from, but in 1987 Eastman
・ CW Tan of Kodak Company
g) The characteristics of the laminated structure element developed by
Has made great strides. They have a stable vapor-deposited film structure
Layer consisting of a phosphor that can transport
Light emitting layer) and an organic substance capable of transporting holes.
Layer (hole-transporting layer) to stack holes and electrons in the phosphor.
It was succeeded in injecting into and making it emit light. By this
The luminous efficiency of the electroluminescent device is improved and the voltage is 10 V or less.
1000 cd / m2The above light emission can be obtained
It was After that, the electron-transporting light-emitting layer was formed into a light-emitting layer and an electron-transporting layer.
The functional separation of the layers that make up the device was promoted.
As a result, at present 10,000 cd / m 2The above emission characteristics
Has been obtained.
【０００４】有機電界発光素子の発光効率をさらに向上
させるため、陽極と正孔輸送層の間に正孔注入層を挿入
することが検討されている。正孔注入層として検討され
ている材料としては、特開昭６３−２９５６９５号公報
に記載のフタロシアニン、特開平８−３２５５６４号公
報に記載のキナクリドン誘導体、特開２０００−１５０
１６７号公報に記載のアンサンスロン誘導体などがあげ
られる。In order to further improve the luminous efficiency of the organic electroluminescent device, it has been studied to insert a hole injection layer between the anode and the hole transport layer. Examples of materials being studied for the hole injection layer include phthalocyanine described in JP-A-63-295695, quinacridone derivative described in JP-A-8-325564, and JP-A-2000-150.
Ansanthuron derivatives described in Japanese Patent No. 167 and the like can be mentioned.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、このよ
うな有機電界発光素子は、素子作製直後においては高い
発光特性を有しているものの、駆動時の安定性が充分で
はないこと、および具体的には連続駆動するにつれて輝
度が低下したり駆動電圧が上昇するといった現象がみら
れ、実用化にあたっての課題となっている。However, although such an organic electroluminescent device has a high light emitting property immediately after the device is manufactured, it does not have sufficient stability during driving. Phenomenon such as a decrease in brightness and an increase in drive voltage with continuous driving is seen, which is a problem for practical use.
【０００６】本発明の目的は、有機電界発光素子の素子
構成を改良することによって、駆動耐久性の改善された
有機電界発光素子を実現することにある。An object of the present invention is to realize an organic electroluminescent device having improved driving durability by improving the device structure of the organic electroluminescent device.
【０００７】[0007]
【課題を解決するための手段】本発明の有機電界発光素
子は、陽極と陰極からなる一対の電極とその間に挟まれ
た少なくとも一層以上の有機物からなる層を有し、かつ
陽極と有機層との間にある特定の化合物または、特定の
性質を有する材料からなる陽極界面薄膜層を有している
ものである。本発明により、従来のものに比べて駆動耐
久性、具体的には連続駆動時の輝度低下および駆動電圧
の上昇が抑制された有機電界発光素子が得られる。An organic electroluminescent device of the present invention has a pair of electrodes composed of an anode and a cathode and at least one layer composed of an organic material sandwiched therebetween, and an anode and an organic layer. Between the anode and the anode interfacial thin film layer made of a specific compound or a material having a specific property. According to the present invention, it is possible to obtain an organic electroluminescence device in which driving durability, specifically, reduction in luminance and increase in driving voltage during continuous driving are suppressed as compared with conventional ones.
【０００８】[0008]
【発明の実施の形態】請求項１から３に記載の発明は、
陽極と陰極からなる一対の電極と、その間に正孔輸送層
を含む少なくとも二層以上の有機物からなる層を有し、
かつ前記陽極と有機層との間にカルバゾール環を有する
化合物から構成される陽極界面薄膜層を設けたことを特
徴とした有機電界発光素子であり、本発明により連続駆
動時の輝度低下を抑制することができる。BEST MODE FOR CARRYING OUT THE INVENTION The invention described in claims 1 to 3 is
A pair of electrodes consisting of an anode and a cathode, and a layer made of at least two or more organic substances including a hole transport layer therebetween,
An organic electroluminescence device characterized in that an anode interfacial thin film layer composed of a compound having a carbazole ring is provided between the anode and the organic layer, and the present invention suppresses a decrease in luminance during continuous driving. be able to.
【０００９】請求項４から６に記載の発明は、陽極と陰
極からなる一対の電極と、その間に正孔輸送層を含む少
なくとも二層以上の有機物からなる層を有し、かつ前記
陽極と有機層との間にイミダゾール化合物、オキサジン
化合物、フェナントロリン化合物のいずれかから構成さ
れる陽極界面薄膜層を設けたことを特徴とした有機電界
発光素子であり、本発明により連続駆動時の駆動電圧上
昇を抑制することができる。The inventions according to claims 4 to 6 have a pair of electrodes composed of an anode and a cathode, and a layer composed of at least two layers of organic materials including a hole transport layer between them, and the anode and the organic material. An OLED compound, an oxazine compound, an organic electroluminescent device characterized by providing an anode interface thin film layer composed of any of a phenanthroline compound between layers, according to the present invention to increase the driving voltage during continuous driving. Can be suppressed.
【００１０】請求項７に記載の発明は、前記請求項１か
ら６のいずれかに記載の電界発光素子において、正孔輸
送層にトリフェニルアミン誘導体を用いたことを特徴と
したものであり、本発明によりより高効率の素子を得る
ことができる。The invention according to claim 7 is characterized in that, in the electroluminescent device according to any one of claims 1 to 6, a triphenylamine derivative is used in the hole transport layer. According to the present invention, a device with higher efficiency can be obtained.
【００１１】請求項８に記載の発明は、陽極と陰極から
なる一対の電極と、その間に挟まれた少なくとも一層以
上の有機物からなる層を有し、かつ前記陽極と有機層の
間に陽極界面薄膜層を有しており、前記陽極界面薄膜層
を構成する材料のイオン化ポテンシャルまたは仕事関数
が、前記陽極および前記陽極界面薄膜層と接する有機層
を構成する材料のイオン化ポテンシャルまたは仕事関数
よりも大きいことを特徴とした有機電界発光素子であ
り、本発明により連続駆動時の駆動電圧上昇を大幅に抑
制することができる。According to an eighth aspect of the present invention, there is provided a pair of electrodes composed of an anode and a cathode and at least one layer made of an organic material sandwiched between the electrodes, and an anode interface is provided between the anode and the organic layer. Having a thin film layer, the ionization potential or work function of the material forming the anode interface thin film layer is greater than the ionization potential or work function of the material forming the organic layer in contact with the anode and the anode interface thin film layer. According to the present invention, it is possible to significantly suppress an increase in driving voltage during continuous driving.
【００１２】請求項９に記載の発明は、陽極と陰極から
なる一対の電極と、その間に挟まれた少なくとも一層以
上の有機物からなる層を有し、かつ前記陽極と有機層の
間に陽極界面薄膜層を有しており、前記陽極界面薄膜層
を構成する材料の正孔易動度が前記陽極界面薄膜層と接
する有機層の正孔易動度よりも小さいことを特徴とした
有機電界発光素子であり、本発明により連続駆動時の駆
動電圧上昇を抑制することができる。The invention according to claim 9 has a pair of electrodes composed of an anode and a cathode, and a layer composed of at least one organic material sandwiched between the electrodes, and the anode interface is provided between the anode and the organic layer. Organic electroluminescence having a thin film layer, characterized in that the hole mobility of the material forming the anode interface thin film layer is smaller than the hole mobility of the organic layer in contact with the anode interface thin film layer. This is an element, and the present invention can suppress an increase in drive voltage during continuous driving.
【００１３】以下、本発明の実施の形態について、図面
を用いて説明する。図１は本発明による有機電界発光素
子の概略構成を示す断面図である。ガラス基板１上に陽
極２を形成し、その上に陽極界面薄膜層３、正孔輸送層
４、発光層５、電子輸送層６、陰極７を形成したもので
ある。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic structure of an organic electroluminescent device according to the present invention. An anode 2 is formed on a glass substrate 1, and an anode interface thin film layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6 and a cathode 7 are formed on the anode 2.
【００１４】陽極２には透明電極としてインジウム錫酸
化物（ＩＴＯ）や半透明電極としての金薄膜を用いるこ
とができる。For the anode 2, indium tin oxide (ITO) as a transparent electrode or a gold thin film as a semitransparent electrode can be used.
【００１５】正孔輸送層４と電子輸送層６により電荷輸
送層が構成され、それぞれ、電極からの電荷の注入を容
易にし、注入された電荷を発光領域まで輸送するという
働きをする。正孔輸送層４としては、正孔輸送性の強い
材料が使用され、具体的にはＮ、Ｎ‘−ジフェニル−
Ｎ、Ｎ’−ビス(３−メチルフェニル)１，１‘-ビフェ
ニル−４，４’−ジアミン（ＴＰＤ）、４、４‘−ビス
［Ｎ−（１−ナフチル）−Ｎ−フェニル−アミノ］ビフ
ェニル（α−ＮＰＤ）などのトリフェニルアミン誘導体
やチオフェン誘導体、スチルベン誘導体などを用いるこ
とができる。一方、電子輸送層６としては電子輸送性の
強い材料が用いることができ、具体的にはフェナントロ
リン誘導体，オキサジアゾール誘導体やトリス（８−ヒ
ドロキシキノリノール）アルミニウム（Ａｌｑ）などに
代表されるキノリノール金属錯体などの使用が検討され
ている。The hole-transporting layer 4 and the electron-transporting layer 6 constitute a charge-transporting layer, which facilitates the injection of charges from the electrodes and transports the injected charges to the light-emitting region. As the hole transport layer 4, a material having a strong hole transport property is used, and specifically, N, N′-diphenyl-
N, N'-bis (3-methylphenyl) 1,1'-biphenyl-4,4'-diamine (TPD), 4,4'-bis [N- (1-naphthyl) -N-phenyl-amino] A triphenylamine derivative such as biphenyl (α-NPD), a thiophene derivative, or a stilbene derivative can be used. On the other hand, a material having a strong electron transporting property can be used for the electron transporting layer 6, and specifically, a quinolinol metal typified by a phenanthroline derivative, an oxadiazole derivative, tris (8-hydroxyquinolinol) aluminum (Alq), or the like. The use of complexes and the like is being considered.
【００１６】発光層５としては数多くの化合物群が検討
されているが、基本的には電子・正孔の注入が可能でか
つ蛍光・りん光を有する物質であれば使用できる。ま
た、成膜性に優れた材料の中に色素を少量分散させた膜
を発光層として用いることにより、素子の高効率化、長
寿命化および発光色の調整をすることも検討されてい
る。この手法は、単独では結晶化しやすい、あるいは濃
度消光を起こしやすい蛍光色素に対して非常に有効であ
る。A large number of compounds have been studied for the light emitting layer 5, but basically any substance capable of injecting electrons / holes and having fluorescence / phosphorescence can be used. In addition, it has been studied to use a film in which a small amount of a dye is dispersed in a material having excellent film-forming properties as a light emitting layer to improve the efficiency of the device, prolong the life of the device, and adjust the emission color. This method is very effective for fluorescent dyes that are easily crystallized or cause concentration quenching by themselves.
【００１７】陰極７は有機膜に電子が注入できることが
必要であり、アルカリ金属またはアルカリ土類金属また
はその化合物を構成材料の一つとして用いることが多
い。具体的にはリチウム、マグネシウムやカルシウム、
あるいはこれらの金属や化合物を他の金属と組み合わせ
て用いることができる。The cathode 7 needs to be capable of injecting electrons into the organic film, and an alkali metal, an alkaline earth metal or a compound thereof is often used as one of the constituent materials. Specifically, lithium, magnesium and calcium,
Alternatively, these metals and compounds can be used in combination with other metals.
【００１８】本実施の形態によれば、陽極２と正孔輸送
層４との間に陽極界面薄膜層３を設けることにより、連
続駆動時の輝度低下あるいは駆動電圧上昇を抑制するこ
とができ、駆動耐久性を大きく向上させることができ
る。According to the present embodiment, by providing the anode interface thin film layer 3 between the anode 2 and the hole transport layer 4, it is possible to suppress the decrease in brightness or the increase in drive voltage during continuous driving, The driving durability can be greatly improved.
【００１９】この陽極界面薄膜層３を構成する主な材料
として、（化４）(化５) (化６）で表されるカルバゾー
ル環を有する化合物、特に（化７）(化９)で表される化
合物を用いることができる。As a main material constituting the anode interface thin film layer 3, a compound having a carbazole ring represented by the following formulas (4), (5) and (6), particularly represented by (7) and (9) The compound can be used.
【００２０】[0020]
【化４】
（Ａｒは次の（Ａ）から（Ｈ）で表される２価基を表
す。）[Chemical 4] (Ar represents a divalent group represented by the following (A) to (H).)
【００２１】[0021]
【化５】
（式中、Ｒ1は水素原子、アルキル基、アルコキシ基、
ハロゲン原子を表し、ｎは１〜５の整数を表す。）[Chemical 5] (In the formula, R 1 is a hydrogen atom, an alkyl group, an alkoxy group,
It represents a halogen atom, and n represents an integer of 1 to 5. )
【００２２】[0022]
【化６】
（式中、Ｒ2は水素原子、アルキル基、アルコキシ基、
ハロゲン原子を表し、Ａは窒素原子、炭素原子、置換ま
たは無置換の芳香族炭化水素環を表し、ｍは３または４
を示す。）[Chemical 6] (In the formula, R 2 is a hydrogen atom, an alkyl group, an alkoxy group,
Represents a halogen atom, A represents a nitrogen atom, a carbon atom, a substituted or unsubstituted aromatic hydrocarbon ring, and m represents 3 or 4
Indicates. )
【００２３】カルバゾール環は他のカルバゾール環と会
合状態を作りやすいため、薄膜にした際に緻密な膜を形
成しやすいと考えられる。有機膜中には電荷を輸送する
ために強い電界が発生しているため、素子中にイオン性
の不純物が含まれる場合、これらの不純物が膜中を移動
し蓄積する可能性がある。しかし、このような緻密な膜
を陽極界面に挿入することにより、ＩＴＯ表面のイオン
性不純物、特に連続駆動時の輝度低下の一要因としてあ
げられるインジウムイオンの膜中への拡散を抑制するこ
とができる。さらに、イミダゾール化合物、オキサジン
化合物、フェナントロリン化合物を用いることによって
も同様な効果が得られる。Since the carbazole ring easily forms an association state with other carbazole rings, it is considered that it is easy to form a dense film when formed into a thin film. Since a strong electric field is generated in the organic film for transporting charges, when the element contains ionic impurities, these impurities may move and accumulate in the film. However, by inserting such a dense film at the interface of the anode, it is possible to suppress the diffusion of ionic impurities on the ITO surface, particularly indium ions, which is one of the factors that causes a decrease in brightness during continuous driving, into the film. it can. Further, the same effect can be obtained by using an imidazole compound, an oxazine compound or a phenanthroline compound.
【００２４】また、陽極界面薄膜層３を構成する主な材
料として、イオン化ポテンシャルまたは仕事関数が陽極
２および陽極界面薄膜層３と接する有機層を構成する材
料のイオン化ポテンシャルまたは仕事関数よりも大きい
材料を用いることができる。このような材料を陽極界面
薄膜層３に用いると、陽極界面付近に強い電界が形成さ
れる。このことにより、陽極２から有機層への正孔の注
入が容易になり、連続駆動による陽極界面状態の変化の
影響を受けにくくなると考えられる。陽極界面薄膜層３
に陽極界面薄膜層３と接する有機層の正孔易動度よりも
小さい正孔易動度を有する材料を用いることによって
も、同様の効果を得ることができる。As a main material for forming the anode interface thin film layer 3, a material having an ionization potential or work function larger than the ionization potential or work function of the material forming the organic layer in contact with the anode 2 and the anode interface thin film layer 3. Can be used. When such a material is used for the anode interface thin film layer 3, a strong electric field is formed near the anode interface. It is considered that this facilitates injection of holes from the anode 2 into the organic layer, and makes it less susceptible to changes in the anode interface state due to continuous driving. Anode interface thin film layer 3
The same effect can be obtained by using a material having a hole mobility lower than the hole mobility of the organic layer in contact with the anode interface thin film layer 3.
【００２５】この陽極界面薄膜層３は適当な２種類以上
の材料を混合して用いてもよい。製膜は一般的に用いら
れる手法、具体的には真空蒸着法（抵抗加熱・電子ビー
ム・スパッタリングなど）や湿式の製膜法（キャスト法
・スピンコート法など）を用いることができる。The anode interface thin film layer 3 may be a mixture of two or more suitable materials. For the film formation, a generally used method, specifically, a vacuum vapor deposition method (resistance heating, electron beam, sputtering, etc.) or a wet film formation method (cast method, spin coating method, etc.) can be used.
【００２６】本発明による陽極界面薄膜層３は１〜５０
ｎｍの膜厚のものが使用できるが、より高い効果を得る
ためには1〜１０ｎｍの膜厚にするのが望ましい。The anode interface thin film layer 3 according to the present invention has a thickness of 1 to 50.
A film having a film thickness of nm can be used, but a film thickness of 1 to 10 nm is preferable in order to obtain a higher effect.
【００２７】なお、ここでは有機層が正孔輸送層４、発
光層５、電子輸送層６の３層から構成される場合につい
て説明したが、２つの層の有する機能を１つの層で兼ね
る場合や、各層が複数の材料から構成される場合も同様
に実施可能である。また、新たな機能を有する層を挿入
する事も可能である。Although the case where the organic layer is composed of the three layers of the hole transport layer 4, the light emitting layer 5 and the electron transport layer 6 has been described here, the case where one layer also has the function of two layers is described. Alternatively, when each layer is composed of a plurality of materials, it can be similarly implemented. It is also possible to insert a layer having a new function.
【００２８】[0028]
【実施例】次に、本発明の具体例を説明する。
（実施例１）基板にはガラス上に透明な陽極としてイン
ジウム錫酸化膜（ＩＴＯ 仕事関数４．８ｅＶ）をあら
かじめ形成し、電極の形にパターニングしたもの用い
た。この基板を充分に洗浄した後、蒸着する材料と一緒
に真空装置内にセットし、１０-4Ｐａまで排気した。そ
の後、陽極界面薄膜層として（化７）に示す化合物
（１）（イオン化ポテンシャル ６．０ｅＶ）を５ｎｍ
製膜した。さらにその上に正孔輸送層としてＮ，Ｎ’−
ビス［４’−（Ｎ，Ｎ−ジフェニルアミノ）−４−ビフ
ェニリル］−Ｎ，Ｎ’−ジフェニルベンジジン（ＴＰＴ
イオン化ポテンシャル ５．４ｅＶ）を５０ｎｍ製膜
した。その後、発光層兼電子輸送層として（化８）に示
すＡｌｑを５０ｎｍ製膜した。その後、陰極としてＡｌ
/Ｌｉ混合膜を１５０ｎｍの厚さで製膜し、素子を作成
した。これらの製膜は一度も真空を破ることなく、連続
して行った。なお、膜厚は水晶振動子によってモニター
した。素子作製後、直ちに乾燥窒素中で電極の取り出し
を行い、引き続き特性測定を行った。得られた素子に電
圧を印加したところ、均一な黄緑色の発光が見られた。
この素子を乾燥窒素中において、電流密度５０ｍＡ／ｃ
ｍ2で駆動したところ、輝度１３６０ｃｄ/ｍ2、電圧
６．３Ｖであった。さらに電流密度５０ｍＡ／ｃｍ 2で
５００時間定電流駆動した時の輝度は７５０ｃｄ／
ｍ2、電圧は６．５Ｖであった。EXAMPLES Next, specific examples of the present invention will be described.
(Example 1) As a transparent anode on a glass substrate,
Coat a tin-tin oxide film (ITO work function 4.8 eV)
Used by caulking and patterning in the shape of electrodes
It was After cleaning this substrate thoroughly, put it together with the material to be evaporated.
Set in the vacuum device at-FourExhausted to Pa. So
And then the compound shown in (Chemical Formula 7) as a thin film layer at the anode interface.
(1) (Ionization potential 6.0 eV) at 5 nm
The film was formed. Further thereon, N, N'- as a hole transport layer is formed.
Bis [4 '-(N, N-diphenylamino) -4-bif
[Enyryl] -N, N'-diphenylbenzidine (TPT
Ionization potential 5.4eV) 50nm film formation
did. After that, as a light emitting layer and an electron transport layer
Alq was formed into a film of 50 nm. Then Al as the cathode
/ Li mixed film is formed with a thickness of 150 nm to create a device
did. These films are continuous without breaking the vacuum.
I went. The film thickness is monitored by a crystal oscillator.
did. Immediately after manufacturing the device, take out the electrode in dry nitrogen.
Then, the characteristics were measured. The device obtained is charged.
When pressure was applied, uniform yellow-green light emission was observed.
In this device, the current density was 50 mA / c in dry nitrogen.
m2When driven at a brightness of 1360 cd / m2,Voltage
It was 6.3V. Further current density 50mA / cm 2so
The luminance when driven with a constant current for 500 hours is 750 cd /
m2The voltage was 6.5V.
【００２９】[0029]
【化７】 [Chemical 7]
【００３０】[0030]
【化８】 [Chemical 8]
【００３１】（実施例２）陽極界面薄膜層に（化９）に
示す化合物（２）を用いること以外は実施例１と同様に
素子を作製した。この素子を電流密度５０ｍＡ／ｃｍ2
で駆動したところ，輝度１５５０ｃｄ／ｍ2、電圧６．
８Ｖであった。さらに電流密度５０ｍＡ／ｃｍ2で５０
０時間定電流駆動した時の輝度は７８０ｃｄ／ｍ2、電
圧は７．１Ｖであった。Example 2 An element was prepared in the same manner as in Example 1 except that the compound (2) shown in (Chemical Formula 9) was used for the anode interface thin film layer. This element is used at a current density of 50 mA / cm 2
When driven at a luminance of 1550 cd / m 2 , a voltage of 6.
It was 8V. 50 at a current density of 50 mA / cm 2
The luminance when driven with a constant current for 0 hours was 780 cd / m 2 , and the voltage was 7.1V.
【００３２】[0032]
【化９】 [Chemical 9]
【００３３】（実施例３）陽極界面薄膜層として（化１
０）に示す化合物（３）を用いること以外は実施例１と
同様に素子を作製した。この素子を電流密度５０ｍＡ／
ｃｍ2で駆動したところ、輝度１３９０ｃｄ／ｍ2、電圧
６．５Ｖであった。さらに電流密度５０ｍＡ／ｃｍ2で
５００時間定電流駆動したときの輝度は７５０ｃｄ／ｍ
2、電圧は６．８Ｖであった。Example 3 As an anode interface thin film layer (Chemical formula 1)
A device was produced in the same manner as in Example 1 except that the compound (3) shown in 0) was used. Current density of this device is 50mA /
When driven at cm 2 , the luminance was 1390 cd / m 2 and the voltage was 6.5V. Furthermore, the brightness when driven at a constant current for 500 hours at a current density of 50 mA / cm 2 is 750 cd / m 2.
2 , the voltage was 6.8V.
【００３４】[0034]
【化１０】 [Chemical 10]
【００３５】（実施例４）陽極界面薄膜層としてレーザ
ー色素のナイルレッドを用いること以外は実施例１と同
様に素子を作製した。この素子を電流密度５０ｍＡ／ｃ
ｍ2で駆動したところ、輝度１３１０ｃｄ／ｍ2、電圧
６．４Ｖであった。さらに電流密度５０ｍＡ／ｃｍ2で
５００時間定電流駆動したときの輝度は６８０ｃｄ／ｍ
2、電圧は６．６Ｖであった。Example 4 An element was prepared in the same manner as in Example 1 except that Nile Red which was a laser dye was used as the anode interface thin film layer. This device has a current density of 50 mA / c
When driven at m 2 , the brightness was 1310 cd / m 2 and the voltage was 6.4V. Furthermore, the brightness when driven with a constant current for 500 hours at a current density of 50 mA / cm 2 is 680 cd / m 2.
2 , the voltage was 6.6V.
【００３６】（実施例５）陽極界面薄膜層として（化１
１）に示すバソクプロインを用いること以外は実施例１
と同様に素子を作製した。この素子を電流密度５０ｍＡ
／ｃｍ2で駆動したところ、輝度１４００ｃｄ／ｍ2、電
圧６．２Ｖであった。さらに電流密度５０ｍＡ／ｃｍ2
で５００時間定電流駆動したときの輝度は７２０ｃｄ／
ｍ2、電圧は６．６Ｖであった。Example 5 As an anode interface thin film layer (Chemical formula 1)
Example 1 except that bathocuproin shown in 1) was used.
A device was prepared in the same manner as in. Current density of this device is 50mA
When driven at / cm 2 , the luminance was 1400 cd / m 2 and the voltage was 6.2V. Furthermore, the current density is 50 mA / cm 2
The brightness when driven with a constant current for 500 hours at 720 cd /
m 2 and voltage were 6.6V.
【００３７】[0037]
【化１１】 [Chemical 11]
【００３８】（実施例６）基板にはガラス上に透明な陽
極としてインジウム錫酸化膜（ＩＴＯ）をあらかじめ形
成し、電極の形にパターニングしたもの用いた。この基
板を充分に洗浄した後、蒸着する材料と一緒に真空装置
内にセットし、１０-4Ｐａまで排気した。その後、陽極
界面薄膜層として化合物（１）を５ｎｍ製膜した。さら
にその上に正孔輸送層としてＴＰＴを５０ｎｍ製膜し
た。その後、発光層としてＡｌｑにレーザー色素である
ＤＣＭを１ｍｏｌ％添加した混合層を２５ｎｍ、電子輸
送層としてＡｌｑを２５ｎｍ製膜した。ＡｌｑとＤＣＭ
の混合層は２種類の材料をそれぞれ独立な蒸着元から蒸
発させる共蒸着法によって作製した。これらの製膜は一
度も真空を破ることなく、連続して行った。なお、膜厚
は水晶振動子によってモニターした。素子作製後、直ち
に乾燥窒素中で電極の取り出しを行い、引き続き特性測
定を行った。得られた素子に電圧を印加したところ、均
一な橙色の発光が得られた。この素子を電流密度５０ｍ
Ａ／ｃｍ2で駆動したところ、輝度２０７０ｃｄ／ｍ2、
電圧６．４Ｖであった。さらに電流密度５０ｍＡ／ｃｍ
2で５００時間定電流駆動したときの輝度は１１３０ｃ
ｄ／ｍ2、電圧は６．５Ｖであった。(Example 6) As a substrate, an indium tin oxide film (ITO) was previously formed on a glass as a transparent anode and patterned into an electrode shape. After thoroughly washing this substrate, it was set in a vacuum apparatus together with the material to be vapor-deposited and evacuated to 10 −4 Pa. Then, the compound (1) was formed into a film of 5 nm as an anode interface thin film layer. Further, TPT having a thickness of 50 nm was formed thereon as a hole transport layer. Then, a mixed layer in which 1 mol% of DCM as a laser dye was added to Alq as a light emitting layer with a thickness of 25 nm and Alq as an electron transport layer with a thickness of 25 nm was formed. Alq and DCM
The mixed layer of was prepared by a co-evaporation method in which two kinds of materials are evaporated from independent evaporation sources. These film formations were continuously performed without breaking the vacuum even once. The film thickness was monitored by a crystal oscillator. Immediately after the device was manufactured, the electrode was taken out in dry nitrogen, and then the characteristics were measured. When a voltage was applied to the obtained device, uniform orange light emission was obtained. Current density of this element is 50m
When driven at A / cm 2 , the brightness was 2070 cd / m 2 ,
The voltage was 6.4V. Further current density 50mA / cm
Brightness of 2 500 hours constant current when driven 1130c
The d / m 2 and the voltage were 6.5V.
【００３９】（実施例７）ガラス上に透明な陽極として
インジウム錫酸化膜（ＩＴＯ）をあらかじめ形成し、電
極の形にパターニングした基板を充分に洗浄した後、蒸
着する材料と一緒に真空装置内にセットし、１０-4Ｐａ
まで排気した。その後、陽極界面薄膜層として（化１
２）に示す化合物（４）（正孔易動度 ５×１０-6ｃｍ
2／Ｖ・ｓｅｃ）を５ｎｍ製膜した。さらにその上に正
孔輸送層として（化１３）に示す化合物（５）（正孔易
動度 ３×１０-5ｃｍ2／Ｖ・ｓｅｃ）を５０ｎｍ製膜
した。その後、電子輸送性発光層としてＡｌｑを製膜し
た。その後、陰極としてＡｌ／Ｌｉ混合膜を１５０ｎｍ
の厚さで製膜し、素子を作製した。これらの製膜は一度
も真空を破ることなく、連続して行った。なお、膜厚は
水晶振動子によってモニターした。素子作製後、直ちに
乾燥窒素中で電極の取り出しを行い、引き続き特性測定
を行った。得られた素子に電圧を印加したところ、均一
な黄緑色の発光が得られた。この素子を電流密度５０ｍ
Ａ／ｃｍ2で駆動したところ、輝度１３００ｃｄ／ｍ2、
電圧６．１Ｖであった。さらに電流密度５０ｍＡ／ｃｍ
2で５００時間定電流駆動したときの輝度は７３０ｃｄ
／ｍ2、電圧は６．３Ｖであった。Example 7 An indium tin oxide film (ITO) was formed in advance as a transparent anode on glass, and a substrate patterned in the shape of an electrode was thoroughly washed, and then it was placed in a vacuum apparatus together with a material to be deposited. Set to 10 -4 Pa
Exhausted to. Then, as an anode interface thin film layer (Chemical formula 1
Compound (4) shown in 2) (hole mobility 5 × 10 −6 cm
2 / V · sec) was formed into a film of 5 nm. Further, a compound (5) (hole mobility: 3 × 10 −5 cm 2 / V · sec) shown in (Chemical Formula 13) as a hole transport layer was formed thereon to a thickness of 50 nm. Then, Alq was formed as an electron transporting light emitting layer. After that, an Al / Li mixed film as a cathode is formed to a thickness of 150 nm.
A film was formed with a thickness of 1 to prepare a device. These film formations were continuously performed without breaking the vacuum even once. The film thickness was monitored by a crystal oscillator. Immediately after the device was manufactured, the electrode was taken out in dry nitrogen, and then the characteristics were measured. When a voltage was applied to the obtained device, uniform yellow-green light emission was obtained. Current density of this element is 50m
When driven at A / cm 2 , the brightness was 1300 cd / m 2 ,
The voltage was 6.1V. Further current density 50mA / cm
The brightness when driven with constant current for 2 hours at 730 cd
/ M 2 and the voltage was 6.3V.
【００４０】[0040]
【化１２】 [Chemical 12]
【００４１】[0041]
【化１３】 [Chemical 13]
【００４２】（比較例１）比較例１として、陽極界面薄
膜層を設けなかったこと以外は実施例1と同様に素子を
作製した。この素子に電圧を印加したところ、均一な黄
緑色の発光が得られた。この素子を電流密度５０ｍＡ／
ｃｍ2で駆動したところ、輝度１１７０ｃｄ／ｍ2、電圧
６．５Ｖであった。さらに電流密度５０ｍＡ／ｃｍ2で
５００時間定電流駆動したときの輝度は５００ｃｄ／ｍ
2、電圧は７．２Ｖであった。Comparative Example 1 As Comparative Example 1, an element was prepared in the same manner as in Example 1 except that the anode interface thin film layer was not provided. When a voltage was applied to this device, uniform yellow-green light emission was obtained. Current density of this device is 50mA /
When driven at cm 2 , the luminance was 1170 cd / m 2 and the voltage was 6.5V. Furthermore, the brightness when driven with a constant current for 500 hours at a current density of 50 mA / cm 2 is 500 cd / m 2.
2 , the voltage was 7.2V.
【００４３】（比較例２）比較例２として、陽極界面薄
膜層を設けなかったこと以外は実施例５と同様に素子を
作製した。この素子に電圧を印加したところ、均一な橙
色の発光が得られた。この素子を電流密度５０ｍＡ／ｃ
ｍ2で駆動したところ、輝度１８８０ｃｄ／ｍ2、電圧
６．６Ｖであった。さらに電流密度５０ｍＡ／ｃｍ2で
５００時間定電流駆動したときの輝度は１０４０ｃｄ／
ｍ2、電圧は７．１Ｖであった。(Comparative Example 2) As Comparative Example 2, an element was prepared in the same manner as in Example 5 except that the anode interface thin film layer was not provided. When a voltage was applied to this device, uniform orange light emission was obtained. This device has a current density of 50 mA / c
When it was driven at m 2 , the brightness was 1880 cd / m 2 and the voltage was 6.6 V. Further, the luminance when driven at a constant current for 500 hours at a current density of 50 mA / cm 2 is 1040 cd /
m 2 and voltage were 7.1V.
【００４４】実施例１から５および比較例１、２に示し
た結果より、本実施例で得られた素子は連続駆動時の輝
度低下および電圧上昇が抑制されていることが分かっ
た。From the results shown in Examples 1 to 5 and Comparative Examples 1 and 2, it was found that the element obtained in this example was suppressed in the decrease in luminance and the increase in voltage during continuous driving.
【００４５】[0045]
【発明の効果】以上のように本発明によれば、連続駆動
時の耐久性を向上させることが可能になるという効果が
得られる。As described above, according to the present invention, it is possible to improve the durability during continuous driving.
【図１】本発明の実施の形態における電界発光素子の構
成の断面図FIG. 1 is a cross-sectional view of a structure of an electroluminescent device according to an embodiment of the present invention.
１ 基板 ２ 陽極 ３ 陽極界面薄膜層 ４ 正孔輸送層 ５ 発光層 ６ 電子輸送層 ７ 陰極 1 substrate 2 anode 3 Anode interface thin film layer 4 Hole transport layer 5 Light emitting layer 6 Electron transport layer 7 cathode
Claims (9)
間に正孔輸送層を含む少なくとも二層以上の有機物から
なる層を有した有機電界発光素子において、前記陽極と
正孔輸送層との間に陽極界面薄膜層を有しており、前記
陽極界面薄膜層がカルバゾール環を有する化合物である
ことを特徴とした有機電界発光素子。1. An organic electroluminescence device having a pair of electrodes composed of an anode and a cathode and a layer composed of at least two layers including an organic material containing a hole transport layer therebetween, wherein the anode and the hole transport layer are An organic electroluminescence device having an anode interfacial thin film layer in between, wherein the anode interfacial thin film layer is a compound having a carbazole ring.
る化合物であることを特徴とした請求項１に記載の有機
電界発光素子。 【化１】 （Ａｒは次の（Ａ）から（Ｈ）で表される２価基を表
す。） 【化２】 （式中、Ｒ1は水素原子、アルキル基、アルコキシ基、
ハロゲン原子を表し、ｎは１〜５の整数を表す。）2. The organic electroluminescence device according to claim 1, wherein the anode interface thin film layer is a compound represented by the formula (1). [Chemical 1] (Ar represents a divalent group represented by the following (A) to (H).) (In the formula, R 1 is a hydrogen atom, an alkyl group, an alkoxy group,
It represents a halogen atom, and n represents an integer of 1 to 5. )
れることを特徴とした請求項１に記載の有機電界発光素
子。 【化３】 （式中、Ｒ2は水素原子、アルキル基、アルコキシ基、
ハロゲン原子を表し、Ａは窒素原子、炭素原子、置換ま
たは無置換の芳香族炭化水素環を表し、ｍは３または４
を示す。）3. The organic electroluminescent device according to claim 1, wherein the anode interface thin film layer is represented by the following general formula. [Chemical 3] (In the formula, R 2 is a hydrogen atom, an alkyl group, an alkoxy group,
Represents a halogen atom, A represents a nitrogen atom, a carbon atom, a substituted or unsubstituted aromatic hydrocarbon ring, and m represents 3 or 4
Indicates. )
間に正孔輸送層を含む少なくとも二層以上の有機物から
なる層を有した有機電界発光素子において、前記陽極と
正孔輸送層との間に陽極界面薄膜層を有しており、前記
陽極界面薄膜層がイミダゾール化合物であることを特徴
とした有機電界発光素子。4. An organic electroluminescence device having a pair of electrodes composed of an anode and a cathode and at least two or more layers containing an organic material including a hole transport layer between the electrodes, wherein the anode and the hole transport layer are An organic electroluminescent device having an anode interface thin film layer between the anode interface thin film layer and the anode interface thin film layer being an imidazole compound.
間に正孔輸送層を含む少なくとも二層以上の有機物から
なる層を有した有機電界発光素子において、前記陽極と
正孔輸送層との間に陽極界面薄膜層を有しており、前記
陽極界面薄膜層がオキサジン化合物であることを特徴と
した有機電界発光素子。5. An organic electroluminescence device having a pair of electrodes composed of an anode and a cathode, and a layer composed of at least two organic layers including a hole transport layer between them, wherein the anode and the hole transport layer are An organic electroluminescent device comprising an anode interfacial thin film layer between the anode interfacial thin film layer and an oxazine compound.
間に正孔輸送層を含む少なくとも二層以上の有機物から
なる層を有した有機電界発光素子において、前記陽極と
正孔輸送層との間に陽極界面薄膜層を有しており、前記
陽極界面薄膜層がフェナントロリン化合物であることを
特徴とした有機電界発光素子。6. An organic electroluminescence device having a pair of electrodes composed of an anode and a cathode and a layer composed of at least two organic layers including a hole transport layer therebetween, wherein the anode and the hole transport layer are An organic electroluminescent device having an anode interface thin film layer between the anode and the anode interface thin film layer being a phenanthroline compound.
がトリフェニルアミン誘導体であることを特徴とした請
求項１から６のいずれかに記載の有機電界発光素子。7. The organic electroluminescent device according to claim 1, wherein the hole transport layer in contact with the anode interface thin film layer is a triphenylamine derivative.
間に挟まれた少なくとも一層以上の有機物からなる層を
有した有機電界発光素子において、前記陽極と有機層と
の間に陽極界面薄膜層を有しており、前記陽極界面薄膜
層を構成する材料のイオン化ポテンシャルまたは仕事関
数が、前記陽極および前記陽極界面薄膜層と接する有機
層を構成する材料のイオン化ポテンシャルまたは仕事関
数よりも大きいことを特徴とした有機電界発光素子。8. An organic electroluminescent device having a pair of electrodes composed of an anode and a cathode and at least one layer made of an organic material sandwiched between the electrodes, wherein an anode interface thin film layer is provided between the anode and the organic layer. And the ionization potential or work function of the material forming the anode interface thin film layer is larger than the ionization potential or work function of the material forming the organic layer in contact with the anode and the anode interface thin film layer. Characterized organic electroluminescent device.
間に挟まれた少なくとも一層以上の有機物からなる層を
有した有機電界発光素子において、前記陽極と有機層と
の間に陽極界面薄膜層を有しており、前記陽極界面薄膜
層を構成する材料の正孔易動度が前記陽極界面薄膜層と
接する有機層の正孔易動度よりも小さいことを特徴とし
た有機電界発光素子。9. An organic electroluminescent device having a pair of electrodes composed of an anode and a cathode and at least one layer made of an organic material sandwiched therebetween, wherein an anode interface thin film layer is provided between the anode and the organic layer. And a hole mobility of a material forming the anode interface thin film layer is smaller than a hole mobility of an organic layer in contact with the anode interface thin film layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002026746A JP2003229279A (en) | 2002-02-04 | 2002-02-04 | Organic electroluminescent element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002026746A JP2003229279A (en) | 2002-02-04 | 2002-02-04 | Organic electroluminescent element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003229279A true JP2003229279A (en) | 2003-08-15 |
Family
ID=27748481
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002026746A Withdrawn JP2003229279A (en) | 2002-02-04 | 2002-02-04 | Organic electroluminescent element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003229279A (en) |
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|---|---|---|---|---|
| JP2005085599A (en) * | 2003-09-09 | 2005-03-31 | Toyo Ink Mfg Co Ltd | Organic electroluminescent element |
| JP2005104971A (en) * | 2003-09-05 | 2005-04-21 | Qinghua Univ | Carbazole derivative and its use for organic el element |
| WO2005082851A2 (en) * | 2004-02-20 | 2005-09-09 | E.I. Dupont De Nemours And Company | Charge transport compounds and electronic devices made with such compounds |
| WO2009041635A1 (en) * | 2007-09-28 | 2009-04-02 | Idemitsu Kosan Co., Ltd. | Organic el device |
| JP2009170820A (en) * | 2008-01-18 | 2009-07-30 | Mitsui Chemicals Inc | Triphenyl methane derivative and organic electroluminescent element containing the same |
| US7763364B2 (en) | 2006-01-23 | 2010-07-27 | Fujifilm Corporation | Organic electroluminescence device |
| US8617720B2 (en) | 2009-12-21 | 2013-12-31 | E I Du Pont De Nemours And Company | Electroactive composition and electronic device made with the composition |
| JP2015212276A (en) * | 2007-12-27 | 2015-11-26 | 出光興産株式会社 | Nitrogen-containing heterocyclic derivative and organic electroluminescent element using the same |
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2002
- 2002-02-04 JP JP2002026746A patent/JP2003229279A/en not_active Withdrawn
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005104971A (en) * | 2003-09-05 | 2005-04-21 | Qinghua Univ | Carbazole derivative and its use for organic el element |
| JP2005085599A (en) * | 2003-09-09 | 2005-03-31 | Toyo Ink Mfg Co Ltd | Organic electroluminescent element |
| JP4581355B2 (en) * | 2003-09-09 | 2010-11-17 | 東洋インキ製造株式会社 | Organic electroluminescence device |
| WO2005082851A2 (en) * | 2004-02-20 | 2005-09-09 | E.I. Dupont De Nemours And Company | Charge transport compounds and electronic devices made with such compounds |
| WO2005082851A3 (en) * | 2004-02-20 | 2005-10-20 | Du Pont | Charge transport compounds and electronic devices made with such compounds |
| US7763364B2 (en) | 2006-01-23 | 2010-07-27 | Fujifilm Corporation | Organic electroluminescence device |
| WO2009041635A1 (en) * | 2007-09-28 | 2009-04-02 | Idemitsu Kosan Co., Ltd. | Organic el device |
| JPWO2009041635A1 (en) * | 2007-09-28 | 2011-01-27 | 出光興産株式会社 | Organic EL device |
| US8106391B2 (en) | 2007-09-28 | 2012-01-31 | Idemitsu Kosan Co., Ltd. | Organic EL device |
| KR101332953B1 (en) | 2007-09-28 | 2013-11-25 | 이데미쓰 고산 가부시키가이샤 | Organic el device |
| JP2015212276A (en) * | 2007-12-27 | 2015-11-26 | 出光興産株式会社 | Nitrogen-containing heterocyclic derivative and organic electroluminescent element using the same |
| JP2009170820A (en) * | 2008-01-18 | 2009-07-30 | Mitsui Chemicals Inc | Triphenyl methane derivative and organic electroluminescent element containing the same |
| US8617720B2 (en) | 2009-12-21 | 2013-12-31 | E I Du Pont De Nemours And Company | Electroactive composition and electronic device made with the composition |
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