JPS63299096A - Thin film el element - Google Patents
Thin film el elementInfo
- Publication number
- JPS63299096A JPS63299096A JP62135782A JP13578287A JPS63299096A JP S63299096 A JPS63299096 A JP S63299096A JP 62135782 A JP62135782 A JP 62135782A JP 13578287 A JP13578287 A JP 13578287A JP S63299096 A JPS63299096 A JP S63299096A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- light emission
- light
- insulating
- thin film
- 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
Links
- 239000010409 thin film Substances 0.000 title claims description 16
- 239000012212 insulator Substances 0.000 claims description 16
- 239000010408 film Substances 0.000 description 10
- CMIHHWBVHJVIGI-UHFFFAOYSA-N gadolinium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Gd+3].[Gd+3] CMIHHWBVHJVIGI-UHFFFAOYSA-N 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 229910001936 tantalum oxide Inorganic materials 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 239000005083 Zinc sulfide Substances 0.000 description 3
- 229910001938 gadolinium oxide Inorganic materials 0.000 description 3
- 229940075613 gadolinium oxide Drugs 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 3
- 229910052984 zinc sulfide Inorganic materials 0.000 description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- XLIXIZFRMFEDKT-UHFFFAOYSA-N [O-2].[Ta+5].[Gd+3].[O-2].[O-2].[O-2] Chemical compound [O-2].[Ta+5].[Gd+3].[O-2].[O-2].[O-2] XLIXIZFRMFEDKT-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005283 ground state Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、薄膜ＥＬ素子に係り、特に輝度の向上のため
の構造に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film EL device, and particularly to a structure for improving brightness.
（従来技術およびその問題点）
輝度の面での問題が多く照明用光源としての開発を断念
せざるを得なかった、硫化亜鉛（ＺｎＳ）系蛍光体粉末
を用いた分散型ＥＬ素子に代わって、薄膜蛍光体層を用
いた薄膜型Ｅし素子が島輝度を得られることから近年注
目されてきている。(Prior art and its problems) This technology replaces the dispersion type EL element using zinc sulfide (ZnS)-based phosphor powder, which had many problems with brightness and had to be abandoned for development as a light source for lighting. In recent years, thin-film type E elements using a thin-film phosphor layer have been attracting attention because they can obtain island brightness.
薄１１ＥＬ素子は、発光層が透明な薄膜で構成されてい
て粒状性がないため、外部から入射する光および発光層
内部で発光した光が散乱されてハレーションやにじみを
生じることがなく、鮮明でコントラストが高いことから
、車両への搭載用：コンピュータ端末等の表示装置ある
いは照明用として脚光を浴びている。Thin 11EL elements have a light-emitting layer made of a transparent thin film and have no graininess, so light incident from the outside and light emitted inside the light-emitting layer are not scattered, causing halation or blurring, and are clear. Due to its high contrast, it is in the spotlight for use in vehicles, display devices such as computer terminals, and lighting.
従来簿膜ＥＬ素子の基本ＩＩ造は、第３図に示す如く透
光性の基板１上に酸化錫（ＳｎＯ２）層等からなる透明
電極２と第１の絶縁体層３と、ＺｎＳ：Ｍｎ薄膜等から
なる発光層４と、第２の絶縁体層５と、アルミニウム（
Ａオ）層等からなる背面電極６とが順次ｖ４層せしめら
れた２重絶縁体構造をなしている。The basic structure of a conventional film EL device is as shown in FIG. A light emitting layer 4 made of a thin film or the like, a second insulator layer 5, and an aluminum (
It has a double insulator structure in which the back electrode 6 consisting of A) layers and the like are sequentially formed into V4 layers.
そして、発光の過程は、以下に示す如くである。The process of light emission is as shown below.
前記透明電極と前記背面電極との間に電圧を印加すると
、発光層内に誘起された電界によって界面単位にトラッ
プされていた電子が引き出されて加速され充分なエネル
ギーを得、この電子がＭｎ（発光中心）の軌道電子に衝
突しこれを励起する。When a voltage is applied between the transparent electrode and the back electrode, the electric field induced in the light-emitting layer pulls out the electrons trapped at each interface and accelerates them to obtain sufficient energy, and these electrons become Mn( It collides with the orbital electrons of the luminescent center) and excites them.
そしてこの励起された発光中心が基底状態に戻る際に発
光を行なう。Then, when this excited luminescent center returns to the ground state, it emits light.
しかし、発光層からの電子の放出は少なく、そのため発
光に際して高電圧をかけて電子放出性を高めるようにし
なければならず発光効率が悪いという問題があった。However, the emission of electrons from the light-emitting layer is small, and therefore, when emitting light, a high voltage must be applied to increase the electron-emitting property, resulting in a problem of poor light-emitting efficiency.
本発明は、前記実情に鑑みてなされたもので、発光効率
の高いＷＩＷｉ！ＥＬ素子を提供することを目的とする
。The present invention has been made in view of the above-mentioned circumstances, and is based on the WIWi! which has high luminous efficiency! The purpose is to provide an EL element.
そこで本発明では、基板上に、透明電極と、第１の絶縁
体層と、発光層と、第２の絶縁体層と、背面電極とを順
次１ａ層せしめた薄膜ＥＬ素子において、第１又は第２
の絶縁体層と発光層との間にそれぞれ第１又は第２の絶
縁体層よりも仕事関数の低い第３又は第４の絶縁体層を
介在せしめるようにしている。Therefore, in the present invention, in a thin film EL element in which a transparent electrode, a first insulating layer, a light emitting layer, a second insulating layer, and a back electrode are sequentially formed on a substrate, the first or Second
A third or fourth insulating layer having a lower work function than the first or second insulating layer is interposed between the insulating layer and the light emitting layer.
すなわち、本発明によれば、通常用いられている酸化シ
リコン層や酸化タンタル層からなる絶縁膜の仕事関数が
５〜１０ｅＶであるのに対し、これよりも仕事関数が低
い（３〜４ｅＶ程度）絶縁膜を介在させるようにしてい
る。That is, according to the present invention, while the work function of the normally used insulating film made of a silicon oxide layer or a tantalum oxide layer is 5 to 10 eV, the work function is lower (about 3 to 4 eV). An insulating film is interposed.
従って、上記構成によれば、発光層と絶縁体層との間に
仕事関数の低い、すなわち電子放出性の高い絶縁体層を
介在せしめることにより、透明電極と背面電極との間に
電圧をかけたとき、電子放出は、発光層からだけでなく
、この電子放出性の絶縁体層からも起る。Therefore, according to the above structure, a voltage is applied between the transparent electrode and the back electrode by interposing an insulating layer with a low work function, that is, a high electron emitting property, between the light emitting layer and the insulating layer. In this case, electron emission occurs not only from the light-emitting layer but also from this electron-emitting insulator layer.
このため全体として電子の放出量が増大し、発光層にお
ける発光中心への電子の衝突確率が高められる。その結
果、発光効率が高められる。Therefore, the amount of electrons emitted increases as a whole, and the probability of electrons colliding with the luminescent center in the luminescent layer increases. As a result, luminous efficiency is increased.
以下、本発明の実施例について、図面を参照しつつ詳細
に説明する。Embodiments of the present invention will be described in detail below with reference to the drawings.
第１図は、本発明実施例のｗＩ膜ＥＬ素子を示す図であ
る。FIG. 1 is a diagram showing a wI film EL device according to an embodiment of the present invention.
この＠ＩＩＩＥＬ素子は、厚さ１ＪｗｌＩの透光性のガ
ラス基板１１上にｇ！膜厚、３μｍの酸化錫（ＳｎＯ２
）層からなる透明電極１２、膜厚０．５μ乳の酸化タン
タル（ＴａｚＯ５）層から−なる第１の絶縁体層１３、
ｇ！膜厚００人の酸化ガドリウム（Ｇｄ２０３）層から
なる第３の絶縁体層１４、膜厚０．５μｍの硫化亜鉛（
ＺｎＯ）：マンガン（Ｍｎ）層からなる発光層１５、Ｗ
Ａ厚５ｏｏＡ、の酸化ガドリウム（Ｇｄ２０３）層から
なる第４の絶縁体１１１６．１１！？０．５μｍの酸化
タンタル層からなる第２の絶縁体層からなる第２の絶縁
体層１７、Ｉ！膜厚、５μｍのアルミニウム層からなる
背面電極１８が順次積層せしめられて構成されている。This @IIIEL element is placed on a translucent glass substrate 11 with a thickness of 1 JwlI. Tin oxide (SnO2) with a film thickness of 3 μm
) layer, a first insulator layer 13 consisting of a tantalum oxide (TazO5) layer with a thickness of 0.5μ,
g! The third insulator layer 14 consists of a gadolinium oxide (Gd203) layer with a thickness of 0.00 μm, and a zinc sulfide layer with a thickness of 0.5 μm.
ZnO): light-emitting layer 15 made of manganese (Mn) layer, W
A fourth insulator 1116.11 made of a gadolinium oxide (Gd203) layer with a thickness of 5ooA! ? A second insulator layer 17 consisting of a second insulator layer consisting of a 0.5 μm tantalum oxide layer, I! A back electrode 18 made of an aluminum layer having a thickness of 5 μm is sequentially laminated.
この３１ｇ１ＥＬ素子について電極と輝度との関係を測
定した結果を第２図に曲Ｉａａで示す。この図中で曲線
すは、第３および第４の絶縁層を有しない点のみが異な
る他は全て上記実施例の薄膜ＥＬ素子と同一構造を有す
る従来のＨＷＡＥＬ素子の電圧と輝度との関係を示す比
較のための曲線である。The results of measuring the relationship between electrodes and brightness for this 31g1EL element are shown in FIG. 2 by curve Iaa. The curved line in this figure represents the relationship between the voltage and luminance of a conventional HWAEL element, which has the same structure as the thin film EL element of the above embodiment except that it does not have the third and fourth insulating layers. The curve shown is for comparison.
これらの曲＠ａ、ｂの比較からも明らかなように、本発
明の薄膜ＥＬ素子によれば、従来では１４０ｖであった
駆！ｌＪ電圧を１１０■にすることができる。As is clear from the comparison of these songs @a and b, according to the thin film EL device of the present invention, the current voltage is 140v! The lJ voltage can be set to 110■.
従って、駆動回路に用いるドライバー素子等への負担も
小さくなり、信頼性が高められる上設計においても自由
度が高くなる。Therefore, the burden on the driver elements used in the drive circuit is reduced, reliability is increased, and the degree of freedom in design is increased.
また、製造に際しては、順次、各層を通常の如く積層し
ていけばよいため、極めて容易に製造可能である。Further, during manufacturing, each layer may be laminated in sequence in the usual manner, so manufacturing is extremely easy.
このように、低電圧駆動で信頼性の高い薄膜ＥＬ素子を
得ることガできる。In this way, it is possible to obtain a highly reliable thin film EL element driven at low voltage.
なお実施例では、発光層の両側に電子放出性の絶縁膜を
設けたが、片側のみでもよい。また、この電子放出性の
絶縁膜としては、両側で膜厚あるいは材賀の異なるもの
、−例えば酸化ガドリウムと酸化ガドリウムタンタル（
Ｇ ａ Ｔ ａ Ｏ）等−を用いてもよい。In the example, the electron-emitting insulating film was provided on both sides of the light-emitting layer, but it may be provided on only one side. In addition, this electron-emitting insulating film may have different film thicknesses or materials on both sides, such as gadolinium oxide and gadolinium tantalum oxide (
G a T a O) etc. may be used.
更に、両電極側に設ける第１および第２の絶縁膜として
は、酸化タンタルの他、酸化シリコン（Ｓｉ０２）、窒
化シリコン（Ｓｉ３Ｎ４）、酸化アルミニウム（ＡＪ２
０３）等、他の材料を用いてもよいことはいうまでもな
い。Furthermore, the first and second insulating films provided on both electrode sides include tantalum oxide, silicon oxide (Si02), silicon nitride (Si3N4), and aluminum oxide (AJ2).
It goes without saying that other materials such as 03) may also be used.
また、発光層および各電極の構成材料についても、実施
例に限定されることなく、適宜変更可能である。加えて
、この薄膜ＥＬ素子は、表示装置以外に照明用として、
実施例に限定されることなく、適宜変更可能である。加
えて、このｉ％ＩＷｉ！ＥＬ素子は、表示装置以外に照
明用として、光記録媒体への信丹の出き込み、読み出し
、消去用の光源としても使用可能である。Further, the constituent materials of the light emitting layer and each electrode are not limited to the examples, and can be changed as appropriate. In addition, this thin film EL element can be used for lighting purposes in addition to display devices.
It is not limited to the embodiments and can be modified as appropriate. In addition, this i%IWi! In addition to display devices, EL elements can be used for illumination, and as light sources for reading, reading, and erasing light from optical recording media.
以上説明してきたように、本発明のＷｒｔｉ！ＥＬ素子
によれば、発光層と絶縁体層との間に、仕事関数の低い
絶縁体層を介在させるようにしているため、電子の放出
量が増大せしめられ、発光効率が向上せしめられる。As explained above, the Wrti! of the present invention! According to the EL element, since the insulating layer with a low work function is interposed between the light emitting layer and the insulating layer, the amount of electron emission is increased and the luminous efficiency is improved.
第１図は、本発明実施例の薄膜ＥＬ素子を示す図、第２
図は、同薄膜ＥＬ素子と従来のＳ膜ＥＬ素子との輝度−
電圧特性の比較図、第３図は、従来例の薄膜ＥＬ素子を
示す図である。
１・・・基板、２・・・透明電極、３・・・第１の絶縁
体層、４・・・発光層、５・・・第２の絶縁体層、６・
・・背面電極、１１・・・ガラス基板、１２・・・透明
電極、１３・・・第１の絶縁体層、１４・・・第３の絶
縁体層、１５・・・発光層、１６・・・第４の絶縁体層
、１７・・・第２の絶縁体層、１８・・・背面電極。FIG. 1 is a diagram showing a thin film EL device according to an embodiment of the present invention, and FIG.
The figure shows the luminance difference between the thin film EL element and the conventional S film EL element.
A comparison diagram of voltage characteristics, FIG. 3, is a diagram showing a conventional thin film EL element. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Transparent electrode, 3... First insulator layer, 4... Light emitting layer, 5... Second insulator layer, 6...
... Back electrode, 11... Glass substrate, 12... Transparent electrode, 13... First insulator layer, 14... Third insulator layer, 15... Light emitting layer, 16... ... Fourth insulator layer, 17... Second insulator layer, 18... Back electrode.
Claims (1)
の絶縁体層を介して発光層を挟持してなる薄膜ＥＬ素子
において、 前記発光層と前記第１又は第２の絶縁体層との間に、夫
々前記第１又は第２の絶縁体層よりも仕事関数の低い第
３の絶縁体層を介在せしめたことを特徴とする薄膜ＥＬ
素子。[Claims] First and second electrodes are provided between the transparent electrode and the back electrode, respectively.
In a thin film EL device having a light-emitting layer sandwiched between the light-emitting layer and the first or second insulator layer, there is a layer between the light-emitting layer and the first or second insulator layer, respectively. A thin film EL characterized by interposing a third insulating layer with a low work function.
element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62135782A JPS63299096A (en) | 1987-05-29 | 1987-05-29 | Thin film el element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62135782A JPS63299096A (en) | 1987-05-29 | 1987-05-29 | Thin film el element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63299096A true JPS63299096A (en) | 1988-12-06 |
Family
ID=15159725
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62135782A Pending JPS63299096A (en) | 1987-05-29 | 1987-05-29 | Thin film el element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63299096A (en) |
-
1987
- 1987-05-29 JP JP62135782A patent/JPS63299096A/en active Pending
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