JPH10255974A - Bidirectional field drive type organic electroluminescent element - Google Patents

Bidirectional field drive type organic electroluminescent element

Info

Publication number
JPH10255974A
JPH10255974A JP9052014A JP5201497A JPH10255974A JP H10255974 A JPH10255974 A JP H10255974A JP 9052014 A JP9052014 A JP 9052014A JP 5201497 A JP5201497 A JP 5201497A JP H10255974 A JPH10255974 A JP H10255974A
Authority
JP
Japan
Prior art keywords
light
host
light emitting
organic electroluminescent
electric field
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.)
Withdrawn
Application number
JP9052014A
Other languages
Japanese (ja)
Inventor
Koichi Yamashita
浩一 山下
Tatsuo Mori
竜雄 森
Terukichi Mizutani
照吉 水谷
Koji Ohata
功治 尾畑
Kaname Imaizumi
要 今泉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Chemical and Materials Co Ltd
Original Assignee
Nippon Steel Chemical Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Steel Chemical Co Ltd filed Critical Nippon Steel Chemical Co Ltd
Priority to JP9052014A priority Critical patent/JPH10255974A/en
Publication of JPH10255974A publication Critical patent/JPH10255974A/en
Withdrawn legal-status Critical Current

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Classifications

    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00Organic light-emitting devices
    • H10K50/10OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/841Applying alternating current [AC] during manufacturing or treatment

Landscapes

  • Electroluminescent Light Sources (AREA)
  • Luminescent Compositions (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a bidirectional field drive type organic electroluminescent element in which light emission is possible to a single element in the case where a field is applied in an inverse direction as well as the case of a normal direction, and in two different colors can be emitted in the cases where the field is applied in the normal and the inverse directions. SOLUTION: This element is provided with a pair of electrodes at least one of which is transparent or translucent, a host light emission layer 4 positioned between the electrodes and composed of organic fluorescent material to emit light by recombination of holes with electrons injected from the respective electrodes, and a pair of carrier transport layers 3, 5 positioned between the host light emission layer 4 and each electrode which transport the holes and electrons injected from the electrodes, which efficiently enclose the holes and electrons in the host light emission layer 4, and which are light-transmitting in a light emission maximum range of emitted light, where guest light emission material comprising pigment compound is doped to both surface sides or either surface side of the host light emission layer 4 and capable of emitting two-color light.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】この発明は、新規な有機電界
発光素子に係り、更に詳しくは、一つの素子に順方向及
び逆方向の電界を印加することによって、互いに異なる
色若しくは同じ色の光を発光することができる双方向電
界駆動型有機電界発光素子に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel organic electroluminescent device, and more particularly, to applying a forward and a reverse electric field to one device to emit light of different colors or the same color. The present invention relates to a bidirectional electric field driven organic electroluminescent device capable of emitting light.

【0002】従来のブラウン管に代わるフラットパネル
ディスプレイの需要の急増に伴い、各種表示素子の開発
及び実用化が精力的に進められている。電界発光素子も
こうしたニーズに応えるものであり、特に全体が固体の
自発光素子であって他のディスプレイにはない高解像度
及び高視認性を有することから注目を集めている。
With the rapid increase in demand for flat panel displays replacing conventional CRTs, various display elements have been developed and put into practical use. Electroluminescent devices also meet these needs, and are particularly attracting attention because they are solid self-luminous devices and have high resolution and high visibility that other displays do not have.

【0003】そして、現在実用化されているものとして
は、発光層にZnS/ Mn系の無機材料を用いた無機エ
レクトロルミネッセンス素子(無機EL素子)が知られ
ている。しかしながら、この種の無機EL素子において
は、発光に必要な駆動電圧が100V以上と高く、この
ために駆動方法が複雑になって製造コストが高くなると
う問題があるほか、青色発光の効率が低くてフルカラー
化が困難であるという問題もある。
[0003] As an element currently in practical use, an inorganic electroluminescence element (inorganic EL element) using a ZnS / Mn-based inorganic material for a light emitting layer is known. However, this type of inorganic EL element has a problem that the driving voltage required for light emission is as high as 100 V or more, which complicates the driving method and increases the manufacturing cost. In addition, the efficiency of blue light emission is low. Therefore, it is difficult to achieve full color.

【0004】これに対して、有機材料を用いた薄膜有機
電界発光素子は、その発光に必要な駆動電圧を大幅に低
くすることができ、また、各種の発光材料の適用により
フルカラー化の可能性も充分にあり、近年その研究が活
発化している。中でも、フルカラー化に際し、色の同調
方法は素子応用への大きな研究課題となっている。
On the other hand, a thin-film organic electroluminescent device using an organic material can drastically reduce the driving voltage required for its light emission, and the possibility of full color by applying various light-emitting materials. The research has been active recently. Above all, the color tuning method has become a major research topic for device application in full color.

【0005】ところで、従来の有機電界発光素子は、あ
る一定の方向に電界が印加された場合にのみ発光し、1
つの素子からは1つの色の光が発光するにすぎない(特
開平5−198378号公報等)。このため、フルカラ
ーディスプレイにおいて、必要な色の3原色である赤、
緑、及び青を発光させるためには、それぞれの色の素子
を微細にかつ規則正しく並べることが必須になり、従来
の素子によっては必要な色の画素数分だけ微細にかつ規
則正しく並べることは非常に困難なことであった。
The conventional organic electroluminescent device emits light only when an electric field is applied in a certain direction, and emits light only when the electric field is applied.
One element emits only one color of light (Japanese Patent Laid-Open No. 5-198378). For this reason, in a full-color display, red, which is the three primary colors required,
In order to emit green and blue light, it is necessary to arrange the elements of each color finely and regularly, and it is very difficult to arrange the elements of each color finely and regularly by the number of pixels of the required color depending on the conventional element. It was difficult.

【0006】[0006]

【発明が解決しようとする課題】本発明は、かかる観点
に基づいて創案されたものであり、その目的とするとこ
ろは、1つの素子に対して電界を順方向に印加した場合
に限らず、電界を逆方向に印加した場合にも発光するこ
とができる双方向電界駆動型有機電界発光素子を提供す
ることにある。
SUMMARY OF THE INVENTION The present invention has been made based on such a viewpoint, and its object is not limited to the case where an electric field is applied to one element in the forward direction. An object of the present invention is to provide a bidirectional electric field driving type organic electroluminescent device which can emit light even when an electric field is applied in a reverse direction.

【0007】また、本発明は、順方向に電界を印加した
場合と逆方向に電界を印加した場合とによって、互いに
異なる光を発光することができる2色発光可能な双方向
電界駆動型有機電界発光素子を提供することにある。
The present invention is also directed to a bidirectional electric field driven organic electric field capable of emitting two colors of light, which can emit different light depending on whether an electric field is applied in a forward direction or an electric field is applied in a reverse direction. It is to provide a light emitting element.

【0008】[0008]

【課題を解決するための手段】本発明は、少なくとも一
方が透明又は半透明である一対の電極と、これら一対の
電極間に位置し、各電極から注入される正孔及び電子の
再結合により発光する有機蛍光性物質で形成されたホス
ト発光層と、このホスト発光層と上記各電極と間に位置
し、各電極から注入される正孔及び電子を輸送できると
共にこれらの正孔及び電子を上記ホスト発光層内に効率
よく閉じ込めることができ、かつ、発光した光の発光極
大領域において光透過性である一対のキャリヤ輸送層と
を備えている双方向電界駆動型有機電界発光素子であ
る。
According to the present invention, a pair of electrodes, at least one of which is transparent or translucent, is provided between the pair of electrodes and recombination of holes and electrons injected from each electrode. A host light-emitting layer formed of an organic fluorescent substance that emits light, and is located between the host light-emitting layer and each of the electrodes, and can transport holes and electrons injected from each of the electrodes and dissipate these holes and electrons. A bidirectional electric-field-driven organic electroluminescence device comprising a pair of carrier transport layers that can be efficiently confined in the host light-emitting layer and that are light-transmissive in the maximum region of emitted light.

【0009】また、本発明は、このような層構成の有機
電界発光素子において、そのホスト発光層は、キャリヤ
輸送層と接するその両面側に又はそのいずれか一方の面
側に色素化合物からなるゲスト発光材料がドープされて
いる双方向電界駆動型有機電界発光素子である。
Further, according to the present invention, in the organic electroluminescent device having such a layer structure, the host light emitting layer has a guest comprising a dye compound on both sides or one of the sides in contact with the carrier transport layer. This is a bidirectional electric field driven organic electroluminescent device doped with a light emitting material.

【0010】更に、本発明は、このような層構成の有機
電界発光素子において、そのホスト発光層の両面側にド
ープされたゲスト発光材料が、互いに異なる色の色素化
合物であり、駆動させる電界の方向により互いに異なる
色の光を発光する双方向電界駆動型有機電界発光素子で
ある。
Further, according to the present invention, in the organic electroluminescent device having such a layer structure, the guest light emitting materials doped on both sides of the host light emitting layer are dye compounds of different colors from each other. This is a bidirectional electric field driven organic electroluminescent device that emits light of different colors depending on directions.

【0011】本発明において、素子を構成する積層構造
については、一般に下記のものが挙げられる。 透明電極/キャリヤ輸送層/ホスト発光層/キャリ
ヤ輸送層/背面電極 透明電極/キャリヤ輸送層/(ゲスト発光材料ドー
プ)ホスト発光層/キャリヤ輸送層/背面電極 透明電極/キャリヤ輸送層/ホスト発光層(ゲスト
発光材料ドープ)/キャリヤ輸送層/背面電極 透明電極/キャリヤ輸送層/(ゲスト発光材料Aド
ープ)ホスト発光層(ゲスト発光材料Aドープ)/キャ
リヤ輸送層/背面電極 透明電極/キャリヤ輸送層/(ゲスト発光材料Aド
ープ)ホスト発光層(ゲスト発光材料Bドープ)/キャ
リヤ輸送層/背面電極 (但し、上記ゲスト発光材料Aとゲスト発光材料Bとは
互いに異なる種類のゲスト発光材料であることを示
す。)
In the present invention, the following are generally mentioned as the laminated structure constituting the element. Transparent electrode / Carrier transport layer / Host light emitting layer / Carrier transport layer / Back electrode Transparent electrode / Carrier transport layer / (Guest light emitting material doped) Host light emitting layer / Carrier transport layer / Back electrode Transparent electrode / Carrier transport layer / Host light emitting layer (Guest light emitting material doped) / Carrier transport layer / Back electrode Transparent electrode / Carrier transport layer / (Guest light emitting material A doped) Host light emitting layer (Guest light emitting material A doped) / Carrier transport layer / Back electrode Transparent electrode / Carrier transport layer / (Guest luminescent material A doped) host luminescent layer (guest luminescent material B doped) / carrier transporting layer / back electrode (however, guest luminescent material A and guest luminescent material B are different types of guest luminescent materials from each other) Is shown.)

【0012】本発明において、上記透明電極は、ホスト
発光層で放射された光を効率良く透過するものであるの
が好ましく、例えば金、ニッケル等の半透膜や、インジ
ウムスズ酸化物(ITO)、酸化スズ、酸化インジウ
ム、酸化亜鉛アルミニウム、ポリピロール等の透明導電
膜等で形成され、抵抗加熱蒸着法、電子ビーム蒸着法、
スパッタリング法、電解重合法、化学重合法等の方法で
形成される。
In the present invention, it is preferable that the transparent electrode efficiently transmits light emitted from the host light-emitting layer. For example, a semipermeable film of gold, nickel or the like, or indium tin oxide (ITO) , Formed of a transparent conductive film such as tin oxide, indium oxide, zinc aluminum oxide, polypyrrole, etc .; resistance heating evaporation method, electron beam evaporation method,
It is formed by a method such as a sputtering method, an electrolytic polymerization method, and a chemical polymerization method.

【0013】そして、この透明電極は、一般に、光透過
性の良好なガラス、金属又は樹脂製の板材で形成され、
素子の支持板となる透明基板の上に積層される。このよ
うな透明基板としては、具体的には、ソーダガラス、無
蛍光ガラス、燐酸系ガラス等のガラス板や、石英、アル
ミナ等の金属板や、アクリル系樹脂、スチレン系樹脂、
ポリカーボネート系樹脂、エポキシ系樹脂、ポリエチレ
ン系樹脂、ポリエステル系樹脂、シリコーン系樹脂等の
樹脂板等が挙げられる
The transparent electrode is generally formed of a plate made of glass, metal or resin having good light transmittance.
It is laminated on a transparent substrate serving as a support plate of the element. As such a transparent substrate, specifically, a glass plate such as soda glass, non-fluorescent glass, phosphoric acid glass, quartz, a metal plate such as alumina, an acrylic resin, a styrene resin,
Resin plates such as polycarbonate resin, epoxy resin, polyethylene resin, polyester resin, silicone resin, etc.

【0014】また、本発明の素子を構成する背面電極と
しては、一般的には、仕事関数の小さいLi、Na、M
g、Sr、Ag、In、Sn、Zn、Zr、Ca、A
l、Mo、Bi等の単独金属薄膜や、2成分、3成分の
積層、共蒸着、合金等が用いられるが、正孔及び電子を
効率良く有機層に注入できるものであれば、これに限ら
ず、種々のものを用いることができる。この背面電極の
成膜方法としては、一般的には、抵抗加熱蒸着法、電子
ビーム蒸着法、スパッタリング法、イオンプレーティン
グ法等が挙げられるが、薄膜化できる方法であれば、こ
れに限らず種々の方法を採用することができる。
The back electrode constituting the device of the present invention is generally made of Li, Na, M having a small work function.
g, Sr, Ag, In, Sn, Zn, Zr, Ca, A
Single metal thin films such as l, Mo, Bi, etc., two-component, three-component lamination, co-evaporation, alloys, and the like are used. Instead, various types can be used. Examples of the method for forming the back electrode include a resistance heating evaporation method, an electron beam evaporation method, a sputtering method, and an ion plating method. Various methods can be employed.

【0015】更に、本発明で用いるキャリア輸送層は、
正孔及び電子を各電極から注入できかつ輸送することの
できる物質であって、正孔又は電子からなるキャリアを
ホスト発光層内に効率良く閉じ込めることのできるエネ
ルギーレベルを持つ物質であるのが好ましい。このキュ
リヤ輸送層には、一般的には、アミン化合物、ヒドラゾ
ン化合物、ピラゾリン化合物、シラン化合物、ポルフィ
リン誘導体、フタロシアニン、ポリビニルカルバゾー
ル、その他芳香族化合物、ポリシラン、無定形p型シリ
コン、無定形p型炭化シリコン等が用いられるが、正孔
及び電子を効率良く注入・輸送し、かつ、発光した光の
発光極大領域においてできるだけ透明なものであればよ
く、これらに限定されるものではない。成膜方法として
は、蒸着法、スピンコート、キャスティング、LB法、
電子ビーム蒸着、分子線エピタキシ、化学気相蒸着法等
が挙げられるが、薄膜化できる方法であればこれらに制
限されない。
Further, the carrier transporting layer used in the present invention comprises:
It is a substance capable of injecting and transporting holes and electrons from each electrode, and preferably having an energy level capable of efficiently confining carriers composed of holes or electrons in the host light emitting layer. . The carrier transport layer generally includes an amine compound, a hydrazone compound, a pyrazoline compound, a silane compound, a porphyrin derivative, phthalocyanine, polyvinyl carbazole, other aromatic compounds, polysilane, amorphous p-type silicon, amorphous p-type carbon, Silicon or the like is used, but is not limited thereto, as long as it is capable of efficiently injecting and transporting holes and electrons, and is as transparent as possible in the region where the emitted light has a maximum light emission. As a film forming method, a vapor deposition method, spin coating, casting, LB method,
Examples include electron beam evaporation, molecular beam epitaxy, and chemical vapor deposition, but are not limited to these as long as they can be thinned.

【0016】本発明で用いるホスト発光層は、キャリア
輸送層から注入された正孔と電子とがこの層内で効率良
く再結合し、生成した励起子のエネルギ−を光として発
光できる有機蛍光性物質であればよく、一般的には、ニ
トロ置換フルオレノン誘導体、アントラキノン誘導体、
ジオキサゾール誘導体、チオピランジオキシド誘導体、
フルオレニリデンメタン誘導体、アントロン誘導体、ペ
リレン誘導体、ジオキサン誘導体、オキサジアゾール化
合物、オキサトリアゾール化合物、無定形n型シリコ
ン、その他有機化合物、無機半導体等が挙げられ、好ま
しくは8−オキシキノリンのアルミニウム錯体等の芳香
族化合物が用いられる。
The host light emitting layer used in the present invention is an organic fluorescent material which can efficiently recombine holes and electrons injected from the carrier transport layer in this layer, and emit energy of excitons generated as light. Any substance can be used, and in general, nitro-substituted fluorenone derivatives, anthraquinone derivatives,
Dioxazole derivatives, thiopyran dioxide derivatives,
Examples include fluorenylidenemethane derivatives, anthrone derivatives, perylene derivatives, dioxane derivatives, oxadiazole compounds, oxatriazole compounds, amorphous n-type silicon, other organic compounds, inorganic semiconductors, and the like. Preferably, 8-oxyquinoline aluminum complex And the like.

【0017】このホスト発光層としては、好ましくは生
成した励起子のエネルギ−をゲスト発光材料へ効率良く
エネルギー移動する化合物であり、これによってホスト
発光層にゲスト発光材料をドープした場合にこのドープ
されたゲスト発光材料のもつ色の光を効率良く発光させ
ることができ、ドープされたゲスト発光材料の量に応じ
てゲスト発光材料のもつ色の光やこのゲスト発光材料が
発光する色とホスト発光層が発光する色との混合色の光
を発光させることができる。
The host light emitting layer is preferably a compound which efficiently transfers the energy of the generated excitons to the guest light emitting material. When the host light emitting layer is doped with the guest light emitting material, the compound is preferably doped. The light of the color of the guest light-emitting material can be efficiently emitted, and the light of the color of the guest light-emitting material and the color of the light emitted by the guest light-emitting material and the host light-emitting layer according to the amount of the doped guest light-emitting material. Can emit light of a mixed color with the color that emits light.

【0018】上記ホスト発光層の成膜方法としては、抵
抗加熱蒸着、スピンコート、キャスティング、LB法、
電子ビーム蒸着、分子線エピタキシー等の方法を挙げる
ことができるが、薄膜化できる方法であれば特にこれら
に方法に限られるものではない。
As the method for forming the host light emitting layer, resistance heating evaporation, spin coating, casting, LB method,
Examples of the method include electron beam evaporation and molecular beam epitaxy. However, the method is not particularly limited to these methods as long as the method can reduce the thickness.

【0019】本発明において、上記ホスト発光層には、
キャリヤ輸送層と接するその両面側に又はそのいずれか
一方の面側に色素化合物からなるゲスト発光材料をドー
プし、ホスト発光層が発光する色の光を強調したり、あ
るいは、このホスト発光層による色の光とは別の色のゲ
スト発光材料に基づく色の光を発光させたり、更には、
ホスト発光層が発光する色とゲスト発光材料が発光する
色の混合色を発光せしめることができる。
In the present invention, the host light emitting layer includes:
A guest light-emitting material made of a dye compound is doped on both sides of the carrier transport layer or on either one of the sides to enhance the light emitted by the host light-emitting layer, or by the host light-emitting layer. It emits light of a color based on the guest light emitting material of a different color from the light of the color, and furthermore,
A mixed color of a color emitted from the host light emitting layer and a color emitted from the guest light emitting material can be emitted.

【0020】このような目的でホスト発光層の両面側若
しくはそのいずれか一方の面側にドープされるゲスト発
光材料としては、それがホスト発光層で生成した励起子
のエネルギーを効率良く受け取るエネルギーレベルを持
ち、かつ、効率良く発光する色素化合物であることが好
ましく、具体的には、ニトロ置換フルオレノン誘導体、
アントラキノン誘導体、ジオキサゾール誘導体、チオピ
ランジオキシド誘導体、フルオレニリデンメタン誘導
体、アントロン誘導体、ペリレン誘導体、ジオキサン誘
導体、オキサジアゾール化合物、オキサトリアゾール化
合物、その他有機化合物等を挙げることができる。
The guest light emitting material doped on both sides of the host light emitting layer or at least one of the surfaces for such a purpose may be an energy level at which it efficiently receives exciton energy generated in the host light emitting layer. Is preferably a dye compound that emits light efficiently, specifically, a nitro-substituted fluorenone derivative,
Examples include anthraquinone derivatives, dioxazole derivatives, thiopyrandioxide derivatives, fluorenylidenemethane derivatives, anthrone derivatives, perylene derivatives, dioxane derivatives, oxadiazole compounds, oxatriazole compounds, and other organic compounds.

【0021】このゲスト発光材料として特に好ましいの
は、4−ジシアノメチレン−6−(p−ジメチルアミノ
スチリル)−2−メチル−4H−ピラン(DCM、4-di
cyanomethylene-6-(p-dimethylaminostylyl)-2-methyl-
4H-pylan)等のピラン誘導体や、3−(2−ベンゾチア
ゾリル)−7−ジメチルアミノクマリン(C540、3-
(2-benzothiazoyl)-7-diethylaminocoumarin)等のクマ
リン誘導体や、その他キナクリドン誘導体、スクアリリ
ウム誘導体、ペリレン誘導体、ピレン誘導体等である。
Particularly preferred as this guest light emitting material is 4-dicyanomethylene-6- (p-dimethylaminostyryl) -2-methyl-4H-pyran (DCM, 4-di
cyanomethylene-6- (p-dimethylaminostylyl) -2-methyl-
Pyran derivatives such as 4H-pylan) and 3- (2-benzothiazolyl) -7-dimethylaminocoumarin (C540, 3-
Coumarin derivatives such as (2-benzothiazoyl) -7-diethylaminocoumarin) and other quinacridone derivatives, squarylium derivatives, perylene derivatives, pyrene derivatives and the like.

【0022】これらのゲスト発光材料をホスト発光層の
両面側若しくはそのいずれか一方の面側にドープする方
法については、特に制限されるものではなく従来より知
られている方法を採用することができ、例えば、比較的
低分子化合物の場合に一般的に採用される共蒸着方法
や、比較的高分子化合物の場合に一般的に採用される混
合方法等が挙げられる。
The method of doping these guest light-emitting materials on both sides of the host light-emitting layer or any one of them is not particularly limited, and a conventionally known method can be employed. For example, a co-evaporation method generally used for a relatively low molecular weight compound and a mixing method generally used for a relatively high molecular weight compound can be used.

【0023】更に、本発明においては、上で説明した各
層の一部又は全部あるいはこれらの層を形成する構成材
料の一部又は全部の化合物について、適当な重合性置換
基を1つ以上導入し、成膜前、成膜中、あるいは成膜後
にポリマー化して使用してもよく、これによって形成さ
れる一部又は全部の層の耐熱性を改善することができ
る。
Further, in the present invention, one or more suitable polymerizable substituents are introduced into a part or all of the above-described layers or a part or all of the constituent materials forming these layers. Before, during, or after the film formation, the film may be polymerized and used, whereby the heat resistance of some or all of the layers formed can be improved.

【0024】[0024]

【発明の実施の形態】以下、添付図面に基づいて、本発
明の好適な実施の形態を具体的に説明する。図1に本発
明の典型的な双方向電界駆動型有機電界発光素子が示さ
れている。この図1において、透明基板1の上には透明
電極2が積層されており、更にこの透明電極2の上に順
次キャリヤ輸送層3、ホスト発光層4、キャリヤ輸送層
5及び金属電極(背面電極)6がそれぞれ積層されてい
る。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 shows a typical bidirectional electric field driven organic electroluminescent device of the present invention. In FIG. 1, a transparent electrode 2 is laminated on a transparent substrate 1, and a carrier transport layer 3, a host light emitting layer 4, a carrier transport layer 5 and a metal electrode (back electrode) are successively formed on the transparent electrode 2. 6) are laminated.

【0025】この図1の双方向電界駆動型有機電界発光
素子において、上記ホスト発光層4には、キャリヤ輸送
層3及び5と接するその両面側に、それぞれゲスト発光
材料がドープされた発光材料ドープ領域4a,4bが形
成されている。
In the organic electroluminescent device of the bidirectional electric field driving type shown in FIG. 1, the host light emitting layer 4 is provided with a light emitting material doped with a guest light emitting material on both sides thereof in contact with the carrier transport layers 3 and 5, respectively. Regions 4a and 4b are formed.

【0026】この図1の双方向電界駆動型有機電界発光
素子によれば、透明電極2を陽極とする順方向に電界を
印加すると、透明電極2側の発光材料ドープ領域4aに
ドープされたゲスト発光材料に基づいてその色の光が発
光し、反対に、金属電極6を陽極とする逆方向に電界を
印加すると、透明電極2側の発光材料ドープ領域4bに
ドープされたゲスト発光材料に基づいてその色の光が発
光するようになっている。
According to the bidirectional electric field driving type organic electroluminescent device of FIG. 1, when an electric field is applied in the forward direction with the transparent electrode 2 as the anode, the guest doped in the luminescent material doped region 4a on the transparent electrode 2 side. The light of that color is emitted based on the light emitting material, and conversely, when an electric field is applied in the reverse direction with the metal electrode 6 as the anode, the light is emitted based on the guest light emitting material doped in the light emitting material doped region 4b on the transparent electrode 2 side. Light of that color is emitted.

【0027】従って、この図1の双方向電界駆動型有機
電界発光素子において、発光材料ドープ領域4a,4b
にそれぞれドープされるゲスト発光材料として、例えば
ホスト発光層4が発光する色と同じ色の光を発光する材
料を用いれば、順方向及び逆方向の双方向に印加される
電界に基づいて同じ色の光が強調されて発光し、また、
例えば発光材料ドープ領域4a,4bにそれぞれ別の色
のゲスト発光材料をドープすれば、順方向には発光材料
ドープ領域4aにドープされたゲスト発光材料の色の光
が発光し、逆方向には発光材料ドープ領域4bにドープ
されたゲスト発光材料の色の光が発光し、更に、これら
発光材料ドープ領域4a,4bにドープするゲスト発光
材料の量を調整することにより、ドープされたゲスト発
光材料に基づく色とホスト発光層4に基づく色との混合
色を発光させることもできる。
Therefore, in the bidirectional electric field driving type organic electroluminescent device of FIG. 1, the light emitting material doped regions 4a, 4b
For example, if a material that emits light of the same color as that emitted by the host light emitting layer 4 is used as the guest light emitting material that is doped with the same color, the same color is applied based on the electric field applied in both the forward and reverse directions. Light is emphasized and emits light,
For example, if the light emitting material doped regions 4a and 4b are doped with guest light emitting materials of different colors, light of the guest light emitting material doped in the light emitting material doped region 4a emits light in the forward direction, and light in the reverse direction. The light of the color of the guest light emitting material doped in the light emitting material doped region 4b emits light, and the amount of the guest light emitting material doped in the light emitting material doped regions 4a and 4b is adjusted, so that the doped guest light emitting material is doped. And a color mixed with the color based on the host light emitting layer 4 can be emitted.

【0028】[0028]

【実施例】以下、実施例及び比較例に基づいて、本発明
の双方向電界駆動型有機電界発光素子をより具体的に説
明する。
Hereinafter, the bidirectional electric field driven organic electroluminescent device of the present invention will be described more specifically based on examples and comparative examples.

【0029】実施例1 電子ビーム蒸着法によりガラス基板上に透明電極として
ITOを積層した抵抗率15Ω/□及び電極面積2×2
mm2 のITO付ガラス基板(ミクロ技研製)を用い、
また、ターボ分子ポンプによる真空蒸着装置を用いて昇
華金属用のモリブデンボードを用いた抵抗加熱方式によ
り、蒸着速度をアルバック製の水晶振動子型膜厚コント
ローラーで制御しながら、蒸着中の真空度2〜3×10
-7トル(torr)の条件で上記ITO付ガラス基板のIT
O層の上に以下の有機薄膜を積層し、更に、その上に背
面電極として蒸着法によりアルミニウム(Al)を積層
し金属電極を設け、図1に示す積層構造を有する双方向
電界駆動型有機電界発光素子を構成した。
Example 1 ITO was laminated as a transparent electrode on a glass substrate by an electron beam evaporation method with a resistivity of 15 Ω / □ and an electrode area of 2 × 2.
Using a glass substrate with ITO of mm 2 (manufactured by Micro Giken),
In addition, using a vacuum evaporation apparatus with a turbo molecular pump, a resistance heating method using a molybdenum board for sublimation metal, while controlling the evaporation rate with a quartz crystal type film thickness controller made by ULVAC, the degree of vacuum during evaporation was 2 mm. ~ 3 × 10
Under the condition of -7 torr (torr), the IT
The following organic thin film is laminated on the O layer, and further, aluminum (Al) is laminated thereon by vapor deposition as a back electrode, and a metal electrode is provided thereon. An electroluminescent device was constructed.

【0030】形成された有機薄膜の積層構造は、ITO
上のキャリア輸送層がN,N−ジフェニル−N,N−ビ
ス−(3−メチルフェニル)−ジフェニル−4,4−ジ
アミン(TPD、N,N-diphenyl-N,N-bis-(3-methyl-phe
nyl)-1,1-diphenyl-4,4-diamine )30nmであり、そ
の上のホスト発光層がトリス(8−ヒドロキシキノリ
ン)アルミニウム(Alq3 、tris(8-hydroxyquinolin
e)aluminum)60nmであり、このAlq3 層にはゲス
ト発光材料としてそのITO電極側にDCMが、また、
金属電極側にC540がそれぞれ1モル%の濃度で20
nmの深さまでドープされ、更にこのホスト発光層の上
のキャリヤ輸送層がTPD30nmであった。
The laminated structure of the formed organic thin film is made of ITO.
The upper carrier transport layer is N, N-diphenyl-N, N-bis- (3-methylphenyl) -diphenyl-4,4-diamine (TPD, N, N-diphenyl-N, N-bis- (3- methyl-phe
nyl) -1,1-diphenyl-4,4-diamine) 30 nm, and the host light-emitting layer thereon is tris (8-hydroxyquinoline) aluminum (Alq3, tris (8-hydroxyquinolin)
e) aluminum) 60 nm, and the Alq3 layer has DCM as a guest light emitting material on its ITO electrode side,
On the metal electrode side, C540 was added at a concentration of 1 mol% to 20
nm, and the carrier transport layer on top of this host emissive layer was 30 nm TPD.

【0031】得られた双方向電界駆動型有機電界発光素
子について、透明電極を陽極とし、金属電極を陰極とす
る順方向に26.4V、1.0mAの電界を印加したと
き、この素子はDCMに基づく橙色の光を発光し、ま
た、金属電極を陽極とし、透明電極を陰極とする逆方向
に26.0V、10.0μAの電界を印加したとき、こ
の素子はC540に基づく緑色の光が放射された。これ
らの発光スペクトルを図2に示す。
When an electric field of 26.4 V and 1.0 mA was applied to the obtained bidirectional electric field driven organic electroluminescent device in the forward direction using the transparent electrode as the anode and the metal electrode as the cathode, this device was DCM. When an electric field of 26.0 V and 10.0 μA is applied in the opposite direction with the metal electrode as the anode and the transparent electrode as the cathode, this device emits green light based on C540. Radiated. These emission spectra are shown in FIG.

【0032】実施例2 ホスト発光層のAlq3 層にゲスト発光材料をドープし
なかった以外は、上記実施例1と同様にして双方向電界
駆動型有機電界発光素子を作製した。この素子につい
て、実施例1の場合と同様に順方向及び逆方向にそれぞ
れ電界を印加したところ、この素子は双方向共にAlq
3 層に基づく緑色の光を放射した。
Example 2 A bidirectional electric field driven organic electroluminescent device was produced in the same manner as in Example 1 except that the guest light emitting material was not doped into the Alq3 layer of the host light emitting layer. When an electric field was applied to this element in the forward direction and the reverse direction in the same manner as in Example 1, the element was Alq in both directions.
Emit green light based on three layers.

【0033】比較例1 有機薄膜の積層構造として、ITO上のキャリア輸送層
(TPD)30nm及びその上の発光層(Alq3 )6
0nmの2層構造とした以外は、上記実施例と同様にし
て有機電界発光素子を作製した。この有機電界発光素子
について、上記実施例と同様にそれぞれ順方向及び逆方
向の電界を印加したところ、順方向ではAlq3 層に基
づく緑色の光が放射されたが、逆方向の場合には発光の
放射は確認されなかった。
COMPARATIVE EXAMPLE 1 As a laminated structure of an organic thin film, a carrier transport layer (TPD) 30 nm on ITO and a light emitting layer (Alq 3) 6 thereon
An organic electroluminescent device was produced in the same manner as in the above example, except that a two-layer structure of 0 nm was used. When an electric field in a forward direction and an electric field in a reverse direction were applied to the organic electroluminescent device in the same manner as in the above embodiment, green light based on the Alq3 layer was emitted in the forward direction. No radiation was observed.

【0034】[0034]

【発明の効果】本発明によれば、1つの素子に対して電
界を順方向に印加した場合に限らず、電界を逆方向に印
加した場合にも発光させることができ、順方向及び逆方
向の双方向に同じ色の発光をさせることができる双方向
電界駆動型有機電界発光素子を提供することができる。
According to the present invention, light can be emitted not only when an electric field is applied to one element in the forward direction but also when an electric field is applied in the reverse direction. It is possible to provide a bidirectional electric field driving type organic electroluminescent device which can emit light of the same color in both directions.

【0035】また、本発明によれば、そのホスト発光層
にゲスト発光材料をドープしておくことにより、順方向
に電界を印加した場合と逆方向に電界を印加した場合と
によって互いに異なる光を発光させることができる2色
発光可能な双方向電界駆動型有機電界発光素子を提供す
ることができる。
Further, according to the present invention, the host light emitting layer is doped with a guest light emitting material, so that light different from each other differs depending on whether an electric field is applied in a forward direction or a reverse direction. It is possible to provide a bidirectional electric field driving type organic electroluminescent element capable of emitting light of two colors capable of emitting light.

【図面の簡単な説明】[Brief description of the drawings]

【図1】 図1は、本発明の双方向電界駆動型有機電界
発光素子の積層構造の一例を示す説明図である。
FIG. 1 is an explanatory view showing an example of a laminated structure of a bidirectional electric field driving type organic electroluminescent device of the present invention.

【図2】 図2は、実施例1の双方向電界駆動型有機電
界発光素子の電界発光スペクトルを示すグラフ図であ
る。
FIG. 2 is a graph showing an electroluminescence spectrum of the bidirectional electric field driving type organic electroluminescence device of Example 1.

【符号の説明】[Explanation of symbols]

1…透明基板、2…透明電極、3,5…キャリヤ輸送
層、4…ホスト発光層、4a,4b…発光材料ドープ領
域、6…金属電極(背面電極)。
DESCRIPTION OF SYMBOLS 1 ... Transparent substrate, 2 ... Transparent electrode, 3, 5 ... Carrier transport layer, 4 ... Host light emitting layer, 4a, 4b ... Light emitting material doping area, 6 ... Metal electrode (back electrode).

───────────────────────────────────────────────────── フロントページの続き (72)発明者 森 竜雄 愛知県名古屋市中川区西日置1−5−6 (72)発明者 水谷 照吉 愛知県名古屋市千種区北千種2−1−43 (72)発明者 尾畑 功治 岐阜県羽島市足近町7丁目606番地 (72)発明者 今泉 要 愛知県安城市赤松町大北71、キングスコー ト安城赤松1301 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuo Mori 1-5-6, Nishihioki, Nakagawa-ku, Nagoya-shi, Aichi (72) Inventor Terokichi Mizutani 2-1-43, Kitaseki-shi, Chikusa-ku, Nagoya-shi, Aichi (72) Inventor Koji Obata 7-606, Ashikaga-cho, Hashima-shi, Gifu (72) Inventor Kaname Imaizumi 71, Ohkita, Akamatsu-cho, Aki, Aichi, 1301 Kingscoat Anjo Akamatsu

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 少なくとも一方が透明又は半透明である
一対の電極と、これら一対の電極間に位置し、各電極か
ら注入される正孔及び電子の再結合により発光する有機
蛍光性物質で形成されたホスト発光層と、このホスト発
光層と上記各電極と間に位置し、各電極から注入される
正孔及び電子を輸送できると共にこれらの正孔及び電子
を上記ホスト発光層内に効率よく閉じ込めることがで
き、かつ、発光した光の発光極大領域において光透過性
である一対のキャリヤ輸送層とを備えていることを特徴
とする双方向電界駆動型有機電界発光素子。
1. A pair of electrodes, at least one of which is transparent or translucent, and an organic fluorescent substance located between the pair of electrodes and emitting light by recombination of holes and electrons injected from each electrode. The host light-emitting layer, located between the host light-emitting layer and each of the electrodes, capable of transporting holes and electrons injected from each electrode and efficiently transporting these holes and electrons into the host light-emitting layer. A bidirectional electric-field-driven organic electroluminescent device, comprising: a pair of carrier transport layers that can be confined and are light-transmissive in a region where light emission is maximum.
【請求項2】 ホスト発光層は、キャリヤ輸送層と接す
るその両面側に又はそのいずれか一方の面側に色素化合
物からなるゲスト発光材料がドープされている請求項1
に記載の双方向電界駆動型有機電界発光素子。
2. The host light-emitting layer is doped with a guest light-emitting material comprising a dye compound on both surface sides thereof in contact with the carrier transport layer or on either one of the surfaces.
4. The bidirectional electric field driven organic electroluminescent device according to item 1.
【請求項3】 ホスト発光層の両面側にドープされたゲ
スト発光材料は、互いに異なる色の色素化合物であり、
駆動させる電界の方向により互いに異なる色の光を発光
する請求項2に記載の双方向電界駆動型有機電界発光素
子。
3. The guest light emitting materials doped on both sides of the host light emitting layer are dye compounds of different colors from each other,
3. The bidirectional electric field driven organic electroluminescent device according to claim 2, wherein light of different colors is emitted depending on the direction of the electric field to be driven.
JP9052014A 1997-03-06 1997-03-06 Bidirectional field drive type organic electroluminescent element Withdrawn JPH10255974A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9052014A JPH10255974A (en) 1997-03-06 1997-03-06 Bidirectional field drive type organic electroluminescent element

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9052014A JPH10255974A (en) 1997-03-06 1997-03-06 Bidirectional field drive type organic electroluminescent element

Publications (1)

Publication Number Publication Date
JPH10255974A true JPH10255974A (en) 1998-09-25

Family

ID=12902970

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JPH10255974A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20020087714A (en) * 2001-05-16 2002-11-23 강명구 Organic Light Emitting Diodes(OLEDs) with Guard Ring
KR20040009348A (en) * 2002-07-23 2004-01-31 삼성 엔이씨 모바일 디스플레이 주식회사 Dual-type organic electro luminesence display and the method for manufacturing the same
US7034452B2 (en) 2002-09-19 2006-04-25 Samsung Sdi Co., Ltd. Dual-type organic electroluminescence display and manufacturing method thereof
JP2010267413A (en) * 2009-05-12 2010-11-25 Hitachi Displays Ltd Organic el element, and organic el display device
WO2017031265A1 (en) * 2015-08-18 2017-02-23 Wake Forest University Frequency dependent light emitting devices
CN109698284A (en) * 2018-12-26 2019-04-30 上海晶合光电科技有限公司 A kind of Organic Light Emitting Diode and preparation method thereof

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20020087714A (en) * 2001-05-16 2002-11-23 강명구 Organic Light Emitting Diodes(OLEDs) with Guard Ring
KR20040009348A (en) * 2002-07-23 2004-01-31 삼성 엔이씨 모바일 디스플레이 주식회사 Dual-type organic electro luminesence display and the method for manufacturing the same
US7106001B2 (en) 2002-07-23 2006-09-12 Samsung Sdi Co., Ltd. Dual-type organic electroluminescent display device and method for manufacturing the same
US7034452B2 (en) 2002-09-19 2006-04-25 Samsung Sdi Co., Ltd. Dual-type organic electroluminescence display and manufacturing method thereof
JP2010267413A (en) * 2009-05-12 2010-11-25 Hitachi Displays Ltd Organic el element, and organic el display device
WO2017031265A1 (en) * 2015-08-18 2017-02-23 Wake Forest University Frequency dependent light emitting devices
CN109698284A (en) * 2018-12-26 2019-04-30 上海晶合光电科技有限公司 A kind of Organic Light Emitting Diode and preparation method thereof

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