JPH07230881A - Organic electroluminescent element - Google Patents

Organic electroluminescent element

Info

Publication number
JPH07230881A
JPH07230881A JP6019412A JP1941294A JPH07230881A JP H07230881 A JPH07230881 A JP H07230881A JP 6019412 A JP6019412 A JP 6019412A JP 1941294 A JP1941294 A JP 1941294A JP H07230881 A JPH07230881 A JP H07230881A
Authority
JP
Japan
Prior art keywords
thin film
organic electroluminescent
layer
light emitting
polyimide thin
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.)
Pending
Application number
JP6019412A
Other languages
Japanese (ja)
Inventor
Shinji Nakagawa
信治 中川
Tatsuo Nakano
辰夫 中野
Kazuo Kato
和男 加藤
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.)
Denka Co Ltd
Original Assignee
Denki Kagaku Kogyo KK
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 Denki Kagaku Kogyo KK filed Critical Denki Kagaku Kogyo KK
Priority to JP6019412A priority Critical patent/JPH07230881A/en
Publication of JPH07230881A publication Critical patent/JPH07230881A/en
Pending legal-status Critical Current

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

Abstract

PURPOSE:To enhance heat resistance and light emitting brightness characteristics by forming an electron hole transporting layer to form an organic electroluminescent element as a prescribed thin film. CONSTITUTION:A positive electrode A of a transparent electrode, an electron hole transporting layer B, a light emitting layer C and a negative electrode D are layered on a transparent board E, and an organic electroluminescent element is formed. This layer B is composed of a thermal decomposition polyimide thin film containing Si in a structure formed by thermal decomposition after a polyimide thin film is formed. Thereby, an organic electroluminescent element whose heat resistance and light emitting brightness characteristics are enhanced more than a luminescent element having a hole transporting layer composed of a polyimide thin film, is formed.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、平面光源や表示装置に
利用される有機電界発光素子に関し、特にその正孔輸送
層において、耐熱性及び正孔輸送能の優れた有機材料を
用い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 element used for a flat light source or a display device, and particularly to an organic electroluminescent element using an organic material excellent in heat resistance and hole transporting ability in its hole transporting layer. The present invention relates to an electroluminescent device.

【0002】[0002]

【従来の技術】従来、有機化合物を原料とした電界発光
素子は、安価な大面積のフルカラー表示装置を実現する
ものとして注目を集めている。例えば、アントラセンや
ペリレン等の縮合多環芳香族系化合物を原料として、L
B膜法や真空蒸着法で薄膜化した有機電界発光素子が開
発され、その発光特性が注目されている。最近、App
l.Phys.Lett、Vol.51、p.913、
(1987)にて、有機薄膜層を正孔輸送層と発光層の
2層構造にした新しいタイプの有機電界発光素子が報告
され、駆動電圧6〜7Vで、数100cd/m2の輝度
が得られることが示されている。この2層構造型有機電
界発光素子の正孔輸送層には、正孔輸送能の大きいトリ
フェニルアミン誘導体がよく用いられている。しかしな
がら、トリフェニルアミン誘導体は、正孔輸送能は大き
いが、ガラス転移温度が90℃以下であるため、耐熱性
が小さく、このため有機電界発光素子の発光時に生じる
発熱により、素子劣化が起こり、素子寿命が短いという
問題があった。特開平4−93389号公報に、有機電
界発光素子の耐熱性を向上させるために、正孔輸送層に
耐熱性の優れたポリイミドを使用した例が開示されてい
るが、ポリイミド自体は正孔輸送能が小さいため、ポリ
イミド膜を正孔輸送層に用いた有機電界発光素子は、発
光輝度特性が印加電圧25Vで約500cd/m2と低
く、実用上問題があった。
2. Description of the Related Art Conventionally, an electroluminescent device made of an organic compound as a raw material has been attracting attention as an inexpensive and large-area full-color display device. For example, using a condensed polycyclic aromatic compound such as anthracene or perylene as a raw material, L
Organic electroluminescent devices thinned by the B film method or the vacuum deposition method have been developed, and their light emitting characteristics have been attracting attention. Recently, App
l. Phys. Lett, Vol. 51, p. 913,
(1987), a new type of organic electroluminescent device in which an organic thin film layer has a two-layer structure of a hole transport layer and a light emitting layer was reported, and a luminance of several hundred cd / m 2 was obtained at a driving voltage of 6 to 7V. It is shown that A triphenylamine derivative having a large hole-transporting ability is often used in the hole-transporting layer of the two-layer structure organic electroluminescent device. However, the triphenylamine derivative has a high hole-transporting ability, but has a low glass transition temperature of 90 ° C. and thus has low heat resistance. Therefore, heat generated during light emission of the organic electroluminescent element causes element deterioration, There is a problem that the device life is short. Japanese Unexamined Patent Publication (Kokai) No. 4-93389 discloses an example in which a polyimide having excellent heat resistance is used for the hole transport layer in order to improve the heat resistance of the organic electroluminescent device. Since the organic electroluminescent device using the polyimide film for the hole transport layer has a low light emitting property, it has a practical problem that the emission luminance characteristic is as low as about 500 cd / m 2 at the applied voltage of 25V.

【0003】[0003]

【発明が解決しようとする課題】本発明は、有機電界発
光素子において、耐熱性及び発光輝度特性の優れた有機
電界発光素子を提供することを目的とするものである。
本発明者らは、電極間に、少なくとも正孔輸送層及び発
光層を含む有機電界発光素子において、前記正孔輸送層
の耐熱性及び正孔輸送能を向上させるべく、鋭意検討し
た結果、正孔輸送層としてポリイミド薄膜を真空中で加
熱処理した薄膜、すなわち、熱分解ポリイミド薄膜を用
いること、さらに、この熱分解ポリイミド薄膜がその構
造中にSiを含有している熱分解ポリイミド薄膜から構
成されることによって、耐熱性及び発光輝度特性の優れ
た有機電界発光素子が得られることを見いだし、本発明
に到達した。
SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic electroluminescent device having excellent heat resistance and emission luminance characteristics.
In the organic electroluminescent device including at least the hole transport layer and the light emitting layer between the electrodes, the present inventors have earnestly studied to improve the heat resistance and the hole transport ability of the hole transport layer. A thin film obtained by heat-treating a polyimide thin film in a vacuum as a hole transport layer, that is, a thermally decomposed polyimide thin film is used, and this thermally decomposed polyimide thin film is composed of a thermally decomposed polyimide thin film containing Si in its structure. It was found that an organic electroluminescent device having excellent heat resistance and emission luminance characteristics can be obtained by the above process, and the present invention has been accomplished.

【0004】[0004]

【課題を解決する手段】すなわち、本発明の第1の発明
は、少なくとも一方が透明電極からなる陽極と陰極の間
に、少なくとも正孔輸送層及び発光層を含む有機電界発
光素子において、前記正孔輸送層が、熱分解ポリイミド
薄膜からなることを特徴とする有機電界発光素子であ
り、本発明の第2の発明は、正孔輸送層が、その構造中
にSiを含有している熱分解ポリイミド薄膜であること
を特徴とする請求項1記載の有機電界発光素子である。
That is, the first invention of the present invention is directed to an organic electroluminescent device including at least a hole transport layer and a light emitting layer between an anode and a cathode, at least one of which is a transparent electrode. The hole transporting layer is an organic electroluminescent device characterized by comprising a pyrolyzed polyimide thin film, and the second invention of the present invention is the pyrolysis wherein the hole transporting layer contains Si in its structure. It is a polyimide thin film, It is an organic electroluminescent element of Claim 1 characterized by the above-mentioned.

【0005】以下、本発明を詳細に説明する。本発明の
有機電界発光素子は、少なくとも陽極、有機化合物から
なる正孔輸送層、有機化合物からなる発光層、及び陰極
を基本構成としている。本発明の有機電界発光素子の構
成は、必要に応じて、陽極と正孔輸送層との間に正孔注
入層を設けても良い。また、必要に応じて、発光層と陰
極との間に電子輸送層を設けても良い。更に、上記各層
間に、上記組合せからなる物質の混合層または該組合せ
からなる物質の成分が連続して変化する濃度傾斜層を設
けても良い。
The present invention will be described in detail below. The organic electroluminescent element of the present invention basically has at least an anode, a hole transport layer made of an organic compound, a light emitting layer made of an organic compound, and a cathode. In the structure of the organic electroluminescent element of the present invention, a hole injection layer may be provided between the anode and the hole transport layer, if necessary. Moreover, you may provide an electron carrying layer between a light emitting layer and a cathode as needed. Further, a mixed layer of the substances of the combination or a concentration gradient layer in which the components of the substances of the combination continuously change may be provided between the layers.

【0006】次に、図1に示した本発明の有機電界発光
素子の断面構造を用いて、具体的に説明する。ガラス、
透明プラスチック等の透明基板の上に、陽極となる透明
電極を形成する。この透明電極の材料としては導電性の
金属酸化物、半透明の金属薄膜が用いられる。具体的に
は金、白金、パラジウム等の金属薄膜または錫、錫・ド
ープ・酸化インジウム等の酸化物薄膜が用いらる。薄膜
の形成方法としては、真空蒸着法、スパッタリング法、
メッキ法などが用いられる。ついで、必要に応じて、こ
の上に正孔注入層を設けても良い。正孔注入層に用いら
れる正孔注入材料の代表的な具体例としては、銅フタロ
シアニン、1×10 -3torr程度の真空中において8
00℃程度の温度で熱処理を行ったエポキシ薄膜等があ
るが、これらに限られるものではない。
Next, the organic electroluminescence of the present invention shown in FIG.
A specific description will be given using the cross-sectional structure of the element. Glass,
On a transparent substrate such as transparent plastic, a transparent anode
Form electrodes. The material of this transparent electrode is conductive
A metal oxide or a semitransparent metal thin film is used. Specifically
Is a metal thin film of gold, platinum, palladium, etc. or tin, tin
An oxide thin film of indium oxide or the like is used. Thin film
As a method of forming, a vacuum deposition method, a sputtering method,
A plating method or the like is used. Then, if necessary,
A hole injection layer may be provided on the above. Used for hole injection layer
A typical example of the hole injection material used is copper phthalate.
Cyanine, 1 x 10 -38 in a vacuum of about torr
There is an epoxy thin film etc. that has been heat treated at a temperature of about 00 ° C.
However, it is not limited to these.

【0007】ついで、この上に正孔輸送層である熱分解
ポリイミド薄膜層を形成するが、この熱分解ポリイミド
薄膜はポリイミド薄膜を形成した後、熱分解することに
より形成される。ポリイミド薄膜は、テトラカルボン酸
二無水物とジアミン化合物が反応して生成したポリアミ
ド酸薄膜を、硬化したものが好ましい。ポリアミド酸薄
膜の形成方法としては、テトラカルボン酸二無水物とジ
アミン化合物を真空共蒸着法を用いて製膜する方法、或
いは、テトラカルボン酸二無水物とジアミン化合物とを
混合した溶液をスピンコーティング法、キャスティング
法、ディッピング法等を用いて製膜する方法がある。広
い面積に均一な薄膜を形成するという点において真空共
蒸着法が特に好ましい。ポリアミド酸薄膜中のテトラカ
ルボン酸二無水物とジアミン化合物の重量比は30:1
〜1:30の範囲が好ましく、特に10:1〜1:10
の範囲が好ましい。ポリアミド酸薄膜形成後、硬化処理
を行い、ポリイミド薄膜を形成するが、硬化処理は空気
中、250℃〜450℃で行うことが好ましい。以上に
より、ポリイミド薄膜層が形成される。
Next, a thermally decomposed polyimide thin film layer which is a hole transport layer is formed on this, and this thermally decomposed polyimide thin film is formed by forming a polyimide thin film and then thermally decomposing it. The polyimide thin film is preferably a cured polyamic acid thin film formed by the reaction of a tetracarboxylic dianhydride and a diamine compound. As a method for forming a polyamic acid thin film, a method of forming a film of a tetracarboxylic acid dianhydride and a diamine compound using a vacuum co-evaporation method, or a solution obtained by mixing a tetracarboxylic acid dianhydride and a diamine compound by spin coating There is a method of forming a film by using a method, a casting method, a dipping method, or the like. The vacuum co-evaporation method is particularly preferable in terms of forming a uniform thin film over a wide area. The weight ratio of tetracarboxylic dianhydride and diamine compound in the polyamic acid thin film is 30: 1.
The range of from 1 to 30 is preferable, and particularly from 10: 1 to 1:10.
Is preferred. After forming the polyamic acid thin film, a curing process is performed to form a polyimide thin film, and the curing process is preferably performed in air at 250 ° C to 450 ° C. As described above, the polyimide thin film layer is formed.

【0008】次に、ポリイミド薄膜を真空中で熱分解す
ることにより、熱分解ポリイミド薄膜が形成される。熱
分解の温度は、500℃〜1000℃が好ましい。熱分
解ポリイミド薄膜の膜厚としては、好ましくは10Å〜
1μmであり、特に好ましくは20Å〜2000Åの範
囲である。熱分解ポリイミドの構造についてはChe
m.Eng.News,July26,p.37(19
65)に言及されているとおり、ポリイミド薄膜の熱分
解によって、環化が進み、π電子雲が二次元的に広が
り、半導体の性質が増加する構造と考えられる。本発明
に使用するテトラカルボン酸二無水物の具体例として
は、下記化学式に示すものを挙げることができるが、こ
れらの化合物は代表的な例であり、本発明はこれらに限
定されるものではない。
Next, the polyimide thin film is thermally decomposed in vacuum to form a thermally decomposed polyimide thin film. The temperature of thermal decomposition is preferably 500 ° C to 1000 ° C. The thickness of the pyrolyzed polyimide thin film is preferably 10Å ~
It is 1 μm, and particularly preferably in the range of 20Å to 2000Å. Che for the structure of pyrolytic polyimide
m. Eng. News, July 26, p. 37 (19
As mentioned in (65), it is considered that the structure is such that cyclization proceeds due to thermal decomposition of the polyimide thin film, the π electron cloud spreads two-dimensionally, and the properties of the semiconductor increase. Specific examples of the tetracarboxylic dianhydride used in the present invention include those represented by the following chemical formulas, but these compounds are representative examples, and the present invention is not limited to these. Absent.

【0009】[0009]

【化1】 本発明において、ジアミン化合物の具体例としては、下
記化学式に示すものを挙げることができるが、これらの
化合物は代表的な例であり、本発明はこれらに限定され
るものではない。
[Chemical 1] In the present invention, specific examples of the diamine compound include those represented by the following chemical formulas, but these compounds are representative examples and the present invention is not limited thereto.

【0010】[0010]

【化2】 [Chemical 2]

【0011】本発明において、熱分解ポリイミド薄膜
は、テトラカルボン酸二無水物及びジアミン化合物を用
いて形成されたものも用いられるが、特に好ましくは、
少なくとも前記化合物の一部又は全部として、その構造
中にSiを含有するテトラカルボン酸二無水物及び/ま
たはジアミン化合物を用いて形成され、その構造中にS
iを含有した熱分解ポリイミド薄膜である。薄膜形成に
おける、このSiを含有したテトラカルボン酸二無水物
及び/またはジアミン化合物の含有量は、使用する原材
料全体に対して1モル%以上、特に好ましくは5モル%
以上である。1モル%未満では、本発明の効果が得られ
ない。本発明に使用するSiを含有するテトラカルボン
酸二無水物の具体例としては、下記化学式に示すものを
挙げることができるが、これらの化合物は代表的な例で
あり、本発明はこれらに限定されるものではない。
In the present invention, the thermally decomposed polyimide thin film may be formed by using a tetracarboxylic dianhydride and a diamine compound, but particularly preferably,
It is formed by using a tetracarboxylic dianhydride and / or diamine compound containing Si in the structure as at least a part or all of the compound, and S in the structure is formed.
It is a pyrolytic polyimide thin film containing i. The content of the tetracarboxylic dianhydride containing Si and / or the diamine compound in the thin film formation is 1 mol% or more, particularly preferably 5 mol% with respect to the entire raw materials used.
That is all. If it is less than 1 mol%, the effect of the present invention cannot be obtained. Specific examples of the tetracarboxylic dianhydride containing Si used in the present invention include those represented by the following chemical formulas, but these compounds are representative examples, and the present invention is not limited to these. It is not something that will be done.

【0012】[0012]

【化3】 [Chemical 3]

【0013】本発明において、Siを含有するジアミン
化合物の具体例としては、下記化学式に示すものを挙げ
ることができるが、これらの化合物は代表的な例であ
り、本発明はこれらに限定されるものではない。
In the present invention, specific examples of the Si-containing diamine compound include those represented by the following chemical formulas, but these compounds are typical examples, and the present invention is not limited thereto. Not a thing.

【0014】[0014]

【化4】 [Chemical 4]

【0015】ついで、熱分解ポリイミド薄膜層の上に、
発光層を形成する。発光層に用いられる発光材料ついて
は、特に制限されることはなく、従来公知の化合物の中
から任意のものを選択し使用できる。電子輸送層を設け
ない場合は、発光層には電子輸送能を有する発光材料を
用いることが好ましい。電子輸送能を有する発光材料の
具体例としては、トリス(8−オキシキノリネート)ア
ルミニウム(Alq3と略す)等が挙げられる。発光材
料の電子輸送能が乏しい場合は、電子輸送能を持つ有機
または無機半導体の電子輸送材料を電子注入輸送層とし
てこの発光層上に設けることが好ましい。電子輸送材料
としては従来公知の物から選択し使用できる。よく用い
られる電子輸送材料にオキサジアゾール誘導体、無定形
n型シリコン等があり、具体的には、下記の化学式に示
すPBD及びOXDが挙げられる。
Then, on the pyrolytic polyimide thin film layer,
A light emitting layer is formed. The light emitting material used for the light emitting layer is not particularly limited, and any one of conventionally known compounds can be selected and used. When the electron transport layer is not provided, it is preferable to use a light emitting material having an electron transport ability for the light emitting layer. Specific examples of the light emitting material having an electron transporting property include tris (8-oxyquinolinate) aluminum (abbreviated as Alq3) and the like. When the light emitting material has a poor electron transporting ability, it is preferable to provide an organic or inorganic semiconductor electron transporting material having an electron transporting ability as an electron injecting and transporting layer on the light emitting layer. The electron transporting material can be selected and used from conventionally known materials. Commonly used electron transport materials include oxadiazole derivatives and amorphous n-type silicon, and specific examples thereof include PBD and OXD represented by the following chemical formulas.

【0016】[0016]

【化5】 [Chemical 5]

【0017】前記発光層及び前記電子輸送層の形成方法
としては、真空蒸着法、スピンコーティング法、キャス
ティング法、ディッピング法等がある。なお、均一な薄
膜を形成するという点において、真空蒸着法が好まし
い。また、前記発光層及び前記電子輸送層は、少なくと
もピンホールが発生しないような膜厚である必要がある
反面、余り厚いと、高い駆動電圧が必要となり好ましく
ない。従って、前記発光層及び前記電子輸送層の膜厚
は、好ましくは10Å〜1μm、特に好ましくは50Å
〜2000Åである。ついで、前記発光層もしくは前記
電子輸送層の上に陰極を設けるが、陰極を形成する物質
の具体例としてはAl、In、Mg等の金属、Mg−A
g合金、In−Ag合金、Mg−In合金、グラファイ
ト薄膜等が挙げられる。真空蒸着やスパッタ膜が形成で
きる固体金属であれば、単独金属薄膜でも共蒸着合金で
も用いられる。この中で仕事関数が小さいものが特に好
ましい。このようにして本発明の有機電界発光素子を製
造する。
As a method for forming the light emitting layer and the electron transport layer, there are a vacuum vapor deposition method, a spin coating method, a casting method, a dipping method and the like. The vacuum vapor deposition method is preferable in terms of forming a uniform thin film. Further, the light emitting layer and the electron transporting layer need to have a film thickness such that at least pinholes are not generated. Therefore, the thickness of the light emitting layer and the electron transporting layer is preferably 10Å to 1 μm, particularly preferably 50Å.
It is ~ 2000Å. Next, a cathode is provided on the light emitting layer or the electron transporting layer. Specific examples of the material forming the cathode include metals such as Al, In and Mg, and Mg-A.
Examples thereof include g alloys, In-Ag alloys, Mg-In alloys, and graphite thin films. A solid metal thin film or a co-deposited alloy can be used as long as it is a solid metal capable of forming a vacuum deposition or sputtered film. Among these, those having a low work function are particularly preferable. Thus, the organic electroluminescent device of the present invention is manufactured.

【0018】[0018]

【実施例】以下、実施例にて、更に詳細に説明する。EXAMPLES The present invention will be described in more detail below with reference to examples.

【0019】実施例1 1000ÅのITO(錫・ドープ・酸化インジウム)膜
が形成された透明電極付きガラス透明基板E(松崎真空
社製)を用い、この基板をアセトン中で超音波洗浄し、
次いで、オーブン中、500℃で加熱処理し、陽極Aと
した。この表面処理した透明電極付きガラス基板を真空
装置にセットし、1×10-5torrの真空中で、ITO膜
上に、テトラカルボン酸二無水物として無水ピロメリッ
ト酸(半井化学薬品(株)製)とジアミン化合物として
ビス(4−ジアミノジフェニル)ジフェニルシラン(有
機合成薬品工業(株)製)を蒸着速度比で1:1にて、
650Å共蒸着した。その後、真空装置から取り出し、
オーブン中、350℃で1時間、硬化処理し、ポリイミ
ド薄膜を形成した。更に、このポリイミド薄膜を1×1
-3torrの真空中800℃で1時間加熱し、熱分解ポリ
イミド薄膜層Bを形成した。
Example 1 A glass transparent substrate E with a transparent electrode (made by Matsuzaki Vacuum Co., Ltd.) having a 1000 liter ITO (tin-doped indium oxide) film formed thereon was used, and the substrate was ultrasonically cleaned in acetone.
Then, heat treatment was performed at 500 ° C. in an oven to obtain an anode A. This surface-treated glass substrate with a transparent electrode was set in a vacuum apparatus, and pyromellitic dianhydride as tetracarboxylic acid dianhydride was prepared on the ITO film in a vacuum of 1 × 10 −5 torr (Hanui Chemical Co., Ltd.). ) And bis (4-diaminodiphenyl) diphenylsilane (manufactured by Organic Synthetic Chemical Industry Co., Ltd.) as a diamine compound at a vapor deposition rate ratio of 1: 1.
Co-deposited with 650Å. After that, remove from the vacuum device,
Curing treatment was performed in an oven at 350 ° C. for 1 hour to form a polyimide thin film. Furthermore, this polyimide thin film is 1 × 1
The film was heated in a vacuum of 0 −3 torr at 800 ° C. for 1 hour to form a pyrolytic polyimide thin film layer B.

【0020】この熱分解ポリイミド薄膜層を設けた透明
電極付きガラス基板を真空装置にセットし、8×10-6
torrの真空度で発光材料のトリス(8−オキシキノリ
ネート)アルミニウム(Alq3)を650Å蒸着し,
発光層Cとした。更に、マグネシウム(Mg)と銀(A
g)を10:1の原子比で2870Å共蒸着し陰極Dと
し有機電界発光素子を作成した。この有機電界発光素子
を直流で駆動した結果、緑色の発光が観察された。駆動
電圧12Vにおいて発光輝度は3500cd/m2であ
った。また、発光表面も均一であった。
The glass substrate with a transparent electrode provided with this pyrolyzed polyimide thin film layer was set in a vacuum device, and 8 × 10 -6
Tris (8-oxyquinolinate) aluminum (Alq3), which is a light emitting material, is deposited at a vacuum of torr by 650Å,
The light emitting layer C was used. Furthermore, magnesium (Mg) and silver (A
2870Å was co-deposited with g) in an atomic ratio of 10: 1 to prepare a cathode D to prepare an organic electroluminescence device. As a result of driving this organic electroluminescent device with direct current, green light emission was observed. The emission luminance was 3500 cd / m 2 at a driving voltage of 12V. The light emitting surface was also uniform.

【0021】比較例1 実施例1において、ポリイミド薄膜の真空中での熱分解
を行わないこと以外は同様の操作で有機電界発光素子を
作成した。この操作により、熱分解ポリイミド薄膜層の
替わりに、ポリイミド薄膜層を設けた有機電界発光素子
が形成された。この有機電界発光素子を直流で駆動した
結果、緑色の発光が観察された。駆動電圧19Vにおい
て発光輝度は290cd/m2であった。
Comparative Example 1 An organic electroluminescent device was prepared in the same manner as in Example 1, except that the polyimide thin film was not thermally decomposed in vacuum. By this operation, an organic electroluminescence device provided with a polyimide thin film layer instead of the pyrolytic polyimide thin film layer was formed. As a result of driving this organic electroluminescent device with direct current, green light emission was observed. The emission luminance was 290 cd / m 2 at a driving voltage of 19V.

【0022】[0022]

【発明の効果】以上説明したように、有機電界発光素子
の正孔輸送層に本発明の熱分解ポリイミド薄膜を用いる
ことにより、更に、前記熱分解ポリイミド薄膜として、
その構造中にSiを含有している熱分解ポリイミド薄膜
を用いることにより、従来の有機電界発光素子に比較し
て、耐熱性及び発光輝度特性を向上することができた。
As described above, by using the pyrolytic polyimide thin film of the present invention in the hole transport layer of the organic electroluminescent device, further, as the pyrolytic polyimide thin film,
By using the pyrolyzed polyimide thin film containing Si in its structure, it was possible to improve heat resistance and emission luminance characteristics as compared with the conventional organic electroluminescent device.

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

【図1】本発明の有機電界発光素子の断面構造を示す。FIG. 1 shows a cross-sectional structure of an organic electroluminescence device of the present invention.

【符号の説明】[Explanation of symbols]

A :陽極(透明電極) B :熱分解ポリイミド薄膜層 C :発光層 D :陰極 E :透明基板 A: Anode (transparent electrode) B: Pyrolytic polyimide thin film layer C: Light emitting layer D: Cathode E: Transparent substrate

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 少なくとも一方が透明電極からなる陽極
と陰極の間に、少なくとも正孔輸送層及び発光層を含む
有機電界発光素子において、前記正孔輸送層が、熱分解
ポリイミド薄膜からなることを特徴とする有機電界発光
素子。
1. An organic electroluminescent device comprising at least a hole transport layer and a light emitting layer between an anode and a cathode, at least one of which is a transparent electrode, wherein the hole transport layer comprises a pyrolytic polyimide thin film. A characteristic organic electroluminescent device.
【請求項2】 正孔輸送層が、その構造中にSiを含有
している熱分解ポリイミド薄膜であることを特徴とする
請求項1記載の有機電界発光素子。
2. The organic electroluminescence device according to claim 1, wherein the hole transport layer is a pyrolytic polyimide thin film containing Si in its structure.
JP6019412A 1994-02-16 1994-02-16 Organic electroluminescent element Pending JPH07230881A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6019412A JPH07230881A (en) 1994-02-16 1994-02-16 Organic electroluminescent element

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6019412A JPH07230881A (en) 1994-02-16 1994-02-16 Organic electroluminescent element

Publications (1)

Publication Number Publication Date
JPH07230881A true JPH07230881A (en) 1995-08-29

Family

ID=11998547

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6019412A Pending JPH07230881A (en) 1994-02-16 1994-02-16 Organic electroluminescent element

Country Status (1)

Country Link
JP (1) JPH07230881A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6497969B2 (en) 1997-09-05 2002-12-24 Nessdisplay Co., Ltd. Electroluminescent device having an organic layer including polyimide
KR100644168B1 (en) * 1999-11-24 2006-11-13 고등기술연구원연구조합 Organic electroluminescent device containing electro-active organic complex thin layers
US7935433B2 (en) 2003-12-25 2011-05-03 Fujifilm Corporation Organic EL element, organic EL display apparatus, method for manufacturing organic EL element, and apparatus for manufacturing organic EL element

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6497969B2 (en) 1997-09-05 2002-12-24 Nessdisplay Co., Ltd. Electroluminescent device having an organic layer including polyimide
KR100644168B1 (en) * 1999-11-24 2006-11-13 고등기술연구원연구조합 Organic electroluminescent device containing electro-active organic complex thin layers
US7935433B2 (en) 2003-12-25 2011-05-03 Fujifilm Corporation Organic EL element, organic EL display apparatus, method for manufacturing organic EL element, and apparatus for manufacturing organic EL element

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