JPH03119691A - Thin-film electroluminescence element - Google Patents
Thin-film electroluminescence elementInfo
- Publication number
- JPH03119691A JPH03119691A JP1256869A JP25686989A JPH03119691A JP H03119691 A JPH03119691 A JP H03119691A JP 1256869 A JP1256869 A JP 1256869A JP 25686989 A JP25686989 A JP 25686989A JP H03119691 A JPH03119691 A JP H03119691A
- Authority
- JP
- Japan
- Prior art keywords
- emitting layer
- light
- layer
- light emitting
- reflective 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.)
- Pending
Links
- 239000010409 thin film Substances 0.000 title claims description 32
- 238000005401 electroluminescence Methods 0.000 title 1
- 239000000758 substrate Substances 0.000 claims abstract description 15
- 238000005286 illumination Methods 0.000 abstract 1
- 238000004020 luminiscence type Methods 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 118
- 239000000463 material Substances 0.000 description 22
- 239000010408 film Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 11
- 238000004544 sputter deposition Methods 0.000 description 10
- 238000007740 vapor deposition Methods 0.000 description 8
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 238000000992 sputter etching Methods 0.000 description 6
- 239000011521 glass Substances 0.000 description 5
- 239000007791 liquid phase Substances 0.000 description 5
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000012808 vapor phase Substances 0.000 description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 230000007261 regionalization Effects 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 235000018185 Betula X alpestris Nutrition 0.000 description 1
- 235000018212 Betula X uliginosa Nutrition 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 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
- 239000000284 extract Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- -1 is 2.3 Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
Landscapes
- Electroluminescent Light Sources (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、発光輝度及び発光外部取り出し効率が向上し
た薄膜エレクトロルミネッセンス（以下ＥＬという）素
子に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin-film electroluminescent (hereinafter referred to as EL) element with improved luminance and external extraction efficiency.
￥１ｌｌｌＥＬ素子は、発光中心を少量添加したＺｎＳ
、ＳｒＳ、ＣａＳ等の蛍光体薄膜に電界を印加すること
によりＥＬ現象によって発光を得る発光素子である。￥1llllEL element is made of ZnS with a small amount of luminescent center added.
, SrS, CaS, etc. is a light emitting element that obtains light emission by an EL phenomenon by applying an electric field to a thin film of phosphor such as SrS or CaS.
第１０図は薄膜ＥＬ素子の一般的な構造を示すもので、
ガラス基板等の透明絶縁基板１上にＩＴＯ（インジウム
・ナイン・オキサイド）等の透明電極２、下部絶縁層と
してＳｉ、Ｎａ、Ｓ ｉｏｘ 、Ｔａ＊ Ｏｓ等の絶縁
物、発光中心を少量添加したＺｎＳ、ＳｒＳ％ＣａＳ等
の発光層４、上部絶縁層５としてＳｉ、Ｎ、、ＳｉＯ，
、Ｔａ１Ｏｓ等の絶縁物を藤着又はスパッタリング等に
より順次形成し、最後にＡ１等の背面電極６を形成する
。Figure 10 shows the general structure of a thin film EL element.
On a transparent insulating substrate 1 such as a glass substrate, a transparent electrode 2 such as ITO (indium nine oxide), an insulating material such as Si, Na, Siox, Ta*Os, etc. as a lower insulating layer, and ZnS doped with a small amount of luminescent center. , SrS%CaS, etc., and the upper insulating layer 5 is made of Si, N, , SiO,
, Ta1Os, or the like are sequentially formed by laminating or sputtering, and finally, a back electrode 6 such as A1 is formed.
これらの薄膜ＥＬ素子において、蛍光体の母体材料、発
光中心の材料及び添加量、成膜方法、素子構成等により
発光輝度及び発光外部取り出し効率の向上が計られてい
る。In these thin-film EL devices, improvements in luminance and emission efficiency are attempted by changing the host material of the phosphor, the material for the luminescence center, the amount added, the film formation method, the device configuration, and the like.
Ｃ発明が解決しようとする諜朋〕
しかし、ＩＩＩＥＬ素子をデイスプレィパネルとして使
用する場合、現在量も高い輝度を示すＭｎを少量添加し
たＺｎＳ発光層を用いた二重絶縁構造ＥＬパネルにおい
ても、フレーム周波数６０Ｈｚ程度の線順次走査による
発光表示時その輝度は２０〜３０フートランバードであ
り、ＣＲＴ（カソード・レイ・チューブ）等と比べると
実用的なデイスプレィパネルとしては輝度が低い。C] However, when the IIIEL element is used as a display panel, even in a double insulation structure EL panel using a ZnS light-emitting layer doped with a small amount of Mn, which shows high brightness even at present, When displaying light by line sequential scanning with a frame frequency of about 60 Hz, the luminance is 20 to 30 foot lumbards, which is lower than a CRT (cathode ray tube) or the like for a practical display panel.
本発明は、発光輝度及び発光外部取り出し効率を向上さ
せた薄膜ＥＬ素子を提供するものである。The present invention provides a thin film EL element with improved luminance and efficiency of emitting light to the outside.
本発明は、透明絶縁基板上に、透明電極と背面電極で挟
んだ発光層を形成した薄膜エレクトロルミネッセンス素
子に於いて、発光層が画素部分のみの島状又は画素を含
む様にストライプ状に形成した発光層であり、発光層の
端面に隣接して光を一部又は全部反射する反射層を配置
したことを特徴とするものである。The present invention relates to a thin film electroluminescent device in which a light emitting layer is sandwiched between a transparent electrode and a back electrode on a transparent insulating substrate. The light-emitting layer is characterized in that a reflective layer that reflects part or all of the light is disposed adjacent to the end face of the light-emitting layer.
第９図に示す樺に発光層４からの発光はｘ、ｙ、ｚ軸の
成分をもっている０通常、薄膜ＥＬ素子を表示素子とし
て用いる場合、発光はガラス基板１側又は背面電極６側
から取り出され、それを表示に用いている。これは、膜
に垂直な成分つまりｙ軸方向の光を取り出しているのに
すぎず、展延面方向の成分つまりＸ軸方向の光、ｙ軸方
向の光はほとんど表示には寄与していない。そのため表
示に使用されている光は、発光層４での発光の一部でし
かなく、この展延面方向の光を表示として効果的に取り
出すことができれば、発光輝度及び発光外部取り出し効
率の向上を計り、また展延面方向の光によるハレーショ
ンを防ぎ、コントラストの向上も計ることができる。The light emitted from the light emitting layer 4 in the birch shown in FIG. and is used for display. This only extracts the light component perpendicular to the film, that is, the light in the y-axis direction, and the components in the direction of the spreading surface, that is, the light in the X-axis direction and the light in the y-axis direction, hardly contribute to the display. . Therefore, the light used for display is only a part of the light emitted from the light-emitting layer 4, and if this light in the direction of the spread surface can be effectively extracted as a display, the luminance of the light and the efficiency of extracting the light to the outside can be improved. It also prevents halation caused by light in the direction of the spread surface and improves contrast.
本発明は、この展延面方向の光を反射し表示に利用する
ようにするため、薄膜ＥＬ素子の発光層を第６図（ａ）
（ｂ）（ｃ）に示す様に画素部分のみ島状に形成するか
又は第７図（ａ）（ｂ）（ｃ）に示す様に画素を含む様
にストライプ状に形成し、その発光層の端部に隣接して
光を一部又は全部反射する反射層を配置するようにした
ものである。In the present invention, in order to reflect the light in the direction of the spread surface and use it for display, the light emitting layer of the thin film EL element is shown in FIG. 6(a).
(b) As shown in (c), only the pixel portion is formed in an island shape, or as shown in FIG. A reflective layer that reflects some or all of the light is disposed adjacent to the end of the light.
反射層として、発光層材料より屈折率の低い物質が使用
できる。屈折率ｎｌの第１媒質から屈折率ｎ、の第２媒
質に入射角θ、で入射した場合、第２媒質での屈折角を
θ、とすると、一般にｎ、Ｓｉｎθ、−ｎ、５ｉｎｏｔ
となる、第１媒質の屈折率ｎ、が第２媒質の屈折率ｎ、
より大きいとき、つまり、ｎ、＞ｎ、のとき、
ｎｔ ” −ｎｌ ” Ｓｉｎ’ Ｌ ＜０を満たす入
射角θ、で屈折角θ８が９０°以上となり入射光は全反
射し、入射光の一部を反射することになる。このように
発光層材料より屈折率の低い物質を反射層として用いる
ことができる。As the reflective layer, a substance having a lower refractive index than the material of the emissive layer can be used. When light enters a second medium with a refractive index n from a first medium with a refractive index nl at an incident angle θ, and the refraction angle in the second medium is θ, generally n, Sin θ, -n, 5 inot. , the refractive index n of the first medium is the refractive index n of the second medium,
When the angle of incidence θ satisfies nt ” −nl ” Sin′ L < 0, the refraction angle θ8 becomes 90° or more, and the incident light is totally reflected, and one part of the incident light is This will reflect the area. In this way, a material having a lower refractive index than the material of the light emitting layer can be used as the reflective layer.
代表的な発光母材であるＺｎＳの屈折率は２．３であり
それより屈折率の低い物質としては、Ｓｔｏｗ（屈折率
１．４６）
Ａｌオ０．（屈折率１．６３ ）
ＴａｔＯｓ（屈折率２．１）
Ｙ□０．（屈折率１．８７ ）
Ｓｉ！Ｎｎ（屈折率２．２）
等がある。The refractive index of ZnS, which is a typical light-emitting base material, is 2.3, and materials with lower refractive index include Stow (refractive index 1.46), AlO 0. (Refractive index 1.63) TatOs (Refractive index 2.1) Y□0. (Refractive index 1.87) Si! Examples include Nn (refractive index 2.2).
また金属等の光を反射する物質も使用可能である。たと
えばＡＩ（アルミニウム）の場合、可視光を９０％程度
反射し、展延面方向に対して厚さ１０Ａ程度で光を反射
する膜とすることができる。It is also possible to use materials that reflect light, such as metals. For example, in the case of AI (aluminum), it is possible to form a film that reflects about 90% of visible light and has a thickness of about 10 A in the direction of the spread surface.
このように、金属等の光を反射する物質は、この反射層
として用いることができる。In this way, a substance that reflects light, such as metal, can be used as this reflective layer.
第１図は本発明による薄膜ＥＬ素子の一実施例を示す断
面図で、ガラス基板等の透明基板１上に透明電極２、下
部絶縁層３、発光層４、反射層１０、上部絶縁層５、背
面電極６を順次形成した交流型薄膜ＥＬ素子である。透
明電極２としてＩＴＯ（インジューム・ティン・オキサ
イド）膜を蒸着又はスパッタリング法により形成し、下
部絶縁層３にはＳ ｉｓ Ｎ４ 、Ｓ ｉｏｔ 、Ｔａ
ｔＯｓ等の単層又は多層膜をスパッタリング法等により
形成した０発光層４には発光中心としてＭｎを少量添加
したＺｎＳ膜を蒸着又はスパッタリング法により形成し
、第６図に示す様に画素部分のみ島状又は第７図に示す
様に画素を含む様にストライプ状にパターン形成する。FIG. 1 is a sectional view showing an embodiment of a thin film EL element according to the present invention, in which a transparent electrode 2, a lower insulating layer 3, a light emitting layer 4, a reflective layer 10, an upper insulating layer 5 are disposed on a transparent substrate 1 such as a glass substrate. This is an AC thin film EL device in which back electrodes 6 are sequentially formed. An ITO (indium tin oxide) film is formed as the transparent electrode 2 by vapor deposition or sputtering, and the lower insulating layer 3 is made of Sis N4, Siot, Ta.
For the light-emitting layer 4, which is a single-layer or multilayer film of tOs or the like formed by sputtering or the like, a ZnS film doped with a small amount of Mn as a light-emitting center is formed by vapor deposition or sputtering, and as shown in FIG. A pattern is formed in an island shape or in a stripe shape so as to include pixels as shown in FIG.
この発光層４のパターン形成には、発光層４成膜時にメ
タルマスクによりパターン形成する方法又はフォトリソ
グラフを用いたパターン形成する方法等がある。Patterning of the light-emitting layer 4 includes a method of forming a pattern using a metal mask when forming the light-emitting layer 4, a method of forming a pattern using photolithography, and the like.
第２図（ａ）ないしくｆ）は発光層４のパターン形成並
びに反射層１０形成について説明するものである。FIGS. 2(a) to 2(f) illustrate pattern formation of the light emitting layer 4 and formation of the reflective layer 10.
ＺｎＳ：Ｍｎ発光層４成形後、発光層４上に第６図、第
７図の所定のパターンのレジスト１１をたて（第２図（
ａ））硝酸等の液相又はスパッタエツチング、ＲＩＢ（
リアクティブ・エツチング）等の気相によりＺｎＳ：Ｍ
ｎ発光１ｉ４の不要部分をエツチングする（第２図（ｂ
））、その後反射層１０を発光層４端部に隣接して配置
する。この反射層１０として、ＺｎＳ：Ｍｎ発光層４よ
り屈折率の低い物質の５ｉＯｉを使用した。また光を反
射する物質としてＡＩを反射層１０として用いた。まず
リフトオフ法を用いて反射層１０を形成する場合には、
発光Ｍ４上のレジストを剥離せずそのまま反射層１０材
料Ｓｔｏｗ又はＡＩを蒸着又はスパッタリング法により
成膜しく第２図（Ｃ））、その後レジストと共にレジス
ト上の反射層材料膜を除去して、発光層４端部に隣接し
て反射層１０を第２図（ｆ）に示す様に配置する０次に
、エツチング法により反射層ＩＯを形成する場合は、第
２図０））からレジスト１１を除去し、反射層１０材料
の５ｉＯｉ又はＡＩを蒸着又はスパッタリング法により
形成する（第２図＠）、その後ＺｎＳ：Ｍｎ発光層４の
部分にレジストをたてる（第２図（ｅ））。After forming the ZnS:Mn light-emitting layer 4, a resist 11 with a predetermined pattern as shown in FIGS. 6 and 7 is formed on the light-emitting layer 4 (see FIG. 2).
a)) Liquid phase such as nitric acid or sputter etching, RIB (
ZnS:M by vapor phase such as reactive etching)
Etching unnecessary parts of the n-emitting device 1i4 (Fig. 2(b)
)) Then, the reflective layer 10 is placed adjacent to the end of the light emitting layer 4. As this reflective layer 10, 5iOi, which is a material having a lower refractive index than the ZnS:Mn light emitting layer 4, was used. Furthermore, AI was used as the reflective layer 10 as a material that reflects light. First, when forming the reflective layer 10 using the lift-off method,
Without peeling off the resist on the light emitting layer M4, the reflective layer 10 material Stow or AI is deposited by vapor deposition or sputtering (Fig. 2 (C)), and then the reflective layer material film on the resist is removed together with the resist, and the light emitting layer 10 is removed. The reflective layer 10 is arranged adjacent to the end of the layer 4 as shown in FIG. Then, 5iOi or AI, which is the material of the reflective layer 10, is formed by vapor deposition or sputtering (FIG. 2@), and then a resist is applied to the ZnS:Mn light emitting layer 4 (FIG. 2(e)).
反射層１０が５ｉ０１の場合はスパッタエツチング等の
気相を用い、反射層１０がＡＩの場合は、リン酸、水酸
化ナトリウム等の液相又はスパッタエツチング、ＲＩＥ
等の気相を用い、発光層４上の反射層１０材料膜を除去
して発光層４端部に反射層ｌＯを第２図（ｆ）に示す様
に配置する。このようにＺｎＳ：Ｍｎ発光層４、Ｓ ｉ
Ｏｗ又はＡＩ反射層１０を形成した後、上部絶縁層５
としてＳ ｉｓ Ｎａ 、Ｓ ｆｏｘ 、Ｔａｘ Ｏｓ
等の単層又は多層膜を形成し、その上に背面電極６とし
てＡＩ膜を蒸着又はスパッタリング法により形成し、第
１図に示す構造もつ薄膜ＥＬ素子を得る。このように、
発光層４端部に隣接して反射層１０を配置することによ
り、展延面方向の発光を表示として取り出すことができ
る様になり、輝度向上を計ることができる。When the reflective layer 10 is made of 5i01, a vapor phase such as sputter etching is used, and when the reflective layer 10 is made of AI, a liquid phase such as phosphoric acid, sodium hydroxide, etc. or sputter etching, RIE is used.
The material film of the reflective layer 10 on the light-emitting layer 4 is removed using a vapor phase such as the above, and a reflective layer 1O is placed at the end of the light-emitting layer 4 as shown in FIG. 2(f). In this way, the ZnS:Mn light emitting layer 4, Si
After forming the Ow or AI reflective layer 10, the upper insulating layer 5
As S is Na , S fox , Tax Os
A single layer or multilayer film such as the above is formed, and an AI film is formed thereon as a back electrode 6 by vapor deposition or sputtering to obtain a thin film EL element having the structure shown in FIG. in this way,
By arranging the reflective layer 10 adjacent to the end portion of the light emitting layer 4, it becomes possible to extract light emitted in the direction of the spread surface as a display, and it is possible to improve the brightness.
第３図は、本発明による薄膜ＥＬ素子の他の実施例を示
す断面図である。これは第１図の場合と同様に、ガラス
基板等の透明絶縁基板１上に透明電極２、上部絶縁層３
を順次形成し、発光層４を形成するときのその端部を断
面台形のテーバ状にして、その端部に隣接して反射層１
０を配置したものである。この発光層４のパターン形成
並びに反射層１０形成について第４図（ａ）〜げ）に示
す。FIG. 3 is a sectional view showing another embodiment of the thin film EL device according to the present invention. As in the case of FIG. 1, a transparent electrode 2 and an upper insulating layer 3 are placed on a transparent insulating substrate 1 such as a glass substrate.
are successively formed, and when forming the light emitting layer 4, the end thereof is made into a tapered shape with a trapezoidal cross section, and the reflective layer 1 is formed adjacent to the end.
0 is placed. The pattern formation of the light-emitting layer 4 and the formation of the reflective layer 10 are shown in FIGS.
Ｍｎを少量添加したＺｎＳを発光層４として蒸着又はス
パッタリング法により成膜法、発光層４上に第６図又は
第７図の所定のパターンのレジストをたてる（第４図（
ａ））、これを硝酸等の液相又はスパッタエツチング、
ＲＩＥ等の液相にＺｎＳ：Ｍｎ発光層４の不要部分をエ
ツチングする。このとき第２図山）に示すようにＺｎＳ
：Ｍｎ発光層４端部が断面台形のテーバ状になる様にオ
ーバーエツチングする。リフトオフ法を用いて反射層１
０を形成する場合には、発光Ｎ４上のレジストを除去せ
ずそのままＺｎＳ：Ｍｎ発光層４より屈折率の低いＳｔ
ｏｗ又は光を反射する物質のＡＩを蒸着又はスパッタリ
ング法により成膜する（第４図（Ｃ））、その後、レジ
ストと共にレジスト上の反射層材料膜を除去して、発光
層４端部に隣接して反射層１０を第４図（ｆ）に示す様
に配置する。このリフトオフ法を行う場合には、発光層
４端部を断面台形のテーバ状にし、レジストのひさしを
つくるようにする０次にエツチング法により反射層１０
を形成する場合には、第４図（ａ）からレジストを除去
し反射層１０材料の５ｉＯ１又はＡｌを蒸着又はスパッ
タリング法により形成する（第４図（ｄ））、その後Ｚ
ｎＳ＝Ｍｎ発光層４以外の部分にレジストをたてる（第
４図（ｅ））、反射層ｌＯがＳｉＯオの場合はスパッタ
エツチング等の気相を用い、反射層１０がＡＩの場合に
はリン酸、水酸化ナトリウム等の液相又はスパッタエツ
チング、ＲＩＥ等の気相を用い、発光層４上の反射層１
０材料膜を除去して発光層４端部に隣接して反射層ｌＯ
を第４図（ｆ）の様に配置する。これらの方法でＺｎＳ
：Ｍｎ発光１１４、Ｓｉｎｇ又はＡＩ反射層１０を形成
した後、上部絶縁層５、背面電極６を第１図に示す場合
と同様に形成し、第３図に示す構造をもつ薄膜ＥＬ素子
を得る。このように発光層４端部に隣接して反射層１０
を配置することにより、上述した第１図に示す場合と同
じく、展延面方向の光を表示として取り出すことができ
、輝度向上を計ることができる。A light-emitting layer 4 of ZnS doped with a small amount of Mn is formed by vapor deposition or sputtering, and a resist having a predetermined pattern as shown in FIG. 6 or 7 is formed on the light-emitting layer 4 (see FIG. 4).
a)), using a liquid phase such as nitric acid or sputter etching,
Unnecessary portions of the ZnS:Mn light emitting layer 4 are etched in a liquid phase using RIE or the like. At this time, as shown in Figure 2, ZnS
: Overetching is performed so that the ends of the Mn light-emitting layer 4 have a tapered trapezoidal cross section. Reflective layer 1 using lift-off method
0, the resist on the light emitting layer 4 is not removed and the resist on the ZnS:Mn light emitting layer 4 is formed using St.
A film of AI, which is a material that reflects light or light, is formed by vapor deposition or sputtering (Fig. 4 (C)). After that, the reflective layer material film on the resist is removed together with the resist, and the film adjacent to the end of the light emitting layer 4 is removed. Then, the reflective layer 10 is arranged as shown in FIG. 4(f). When performing this lift-off method, the ends of the light-emitting layer 4 are made into a tapered shape with a trapezoidal cross section, and the reflective layer 10 is etched by a zero-order etching method that creates a resist eaves.
When forming Z, the resist is removed from FIG. 4(a) and 5iO1 or Al, which is the material of the reflective layer 10, is formed by vapor deposition or sputtering (FIG. 4(d)).
A resist is applied to the parts other than the nS=Mn light-emitting layer 4 (FIG. 4(e)). If the reflective layer 10 is made of SiO, use a gas phase such as sputter etching. If the reflective layer 10 is made of AI, use a vapor phase process. The reflective layer 1 on the light emitting layer 4 is etched using a liquid phase such as phosphoric acid or sodium hydroxide or a gas phase such as sputter etching or RIE.
0 material film is removed and a reflective layer 10 is formed adjacent to the end of the light emitting layer 4.
are arranged as shown in FIG. 4(f). With these methods, ZnS
: After forming the Mn light emitting layer 114 and the Sing or AI reflective layer 10, the upper insulating layer 5 and the back electrode 6 are formed in the same manner as shown in FIG. 1 to obtain a thin film EL element having the structure shown in FIG. . In this way, the reflective layer 10 is placed adjacent to the end of the light emitting layer 4.
By arranging this, the light in the direction of the spread surface can be extracted as a display, as in the case shown in FIG. 1 described above, and the brightness can be improved.
第５図に本発明による薄膜ＥＬ素子の更に他の一実施例
の断面図を示す、これは通常薄膜ＥＬ素子の絶縁層に用
いる材料は、発光層材料に比べて屈折率が低いことから
、上部絶縁層で反射層を兼ねる構造の薄膜ＥＬ素子であ
る。ガラス基板等の絶縁基板１上に透明電極２、下部絶
縁層３、発光層４を順次成膜後、発光層４を第６図又は
第７図のように所定のパターンにパターン形成する０発
光層４より屈折率の低い絶縁層材料例えばＳ’１ｓＮａ
を成膜することにより、発光層端部及び発光層４上部に
配置することができ、反射層兼用上部絶縁層２０を同時
に形成できる。その上部に、背面電極６を形成して、第
５図のような構造の交流型薄膜ＥＬ素子を得る。その結
果、発光外部取り出し効率の向上により輝度向上を図る
ことができる。FIG. 5 shows a cross-sectional view of yet another embodiment of the thin film EL device according to the present invention. This is a thin film EL element with a structure in which the upper insulating layer also serves as a reflective layer. After sequentially forming a transparent electrode 2, a lower insulating layer 3, and a light emitting layer 4 on an insulating substrate 1 such as a glass substrate, the light emitting layer 4 is patterned into a predetermined pattern as shown in FIG. 6 or FIG. 7. An insulating layer material having a lower refractive index than layer 4, for example S'1sNa
By forming a film, it can be placed at the end of the light emitting layer and on the top of the light emitting layer 4, and the upper insulating layer 20 which also serves as a reflective layer can be formed at the same time. A back electrode 6 is formed on top of the EL element to obtain an AC thin film EL element having a structure as shown in FIG. As a result, brightness can be improved by improving the efficiency of extracting light to the outside.
本発明の薄膜ＥＬ素子の輝度対印加電圧の関係を第８図
に示す、尚、第８図中Ａ、Ｂは第２図に示した薄膜ＥＬ
素子についての結果であり、ＡはＺｎＳ：Ｍｎ発光層の
端部にＺｎＳ：Ｍｎよりも屈折率の低いＳｉｎ、を反射
層として配置したもの、ＢはＺｎＳ：Ｍｎ発光層の端部
にＡＩを反射層として配置したもので、Ｃは従来の反射
層を設けない薄膜ＥＬ素子の結果である。このように、
反射層を発光層の端部に配置した薄膜ＥＬ素子は、従来
の反射層を配置しない素子の１．５〜２倍程度の輝度向
上を示す
以上発光層と透明電極、背面電極との間に絶縁層を設け
た交流型の薄膜ＥＬ素子について説明したが、本発明の
薄膜ＥＬ素子は、透明絶縁基板上に透明電極、発光層、
背面電極を順次形成する直流型の薄膜ＥＬ素子でも良い
。The relationship between brightness and applied voltage of the thin film EL device of the present invention is shown in FIG. 8. In FIG. 8, A and B are the thin film EL elements shown in FIG.
The results are for devices. A is a device in which Sin, which has a lower refractive index than ZnS:Mn, is placed as a reflective layer at the end of a ZnS:Mn light-emitting layer, and B is a device in which AI is placed at the end of a ZnS:Mn light-emitting layer. C is the result of a conventional thin film EL device without a reflective layer. in this way,
Thin-film EL devices in which a reflective layer is placed at the end of a light-emitting layer show an improvement in brightness of about 1.5 to 2 times that of conventional devices without a reflective layer. Although the AC type thin film EL device provided with an insulating layer has been described, the thin film EL device of the present invention has a transparent electrode, a light emitting layer, and a transparent electrode on a transparent insulating substrate.
A direct current type thin film EL element in which back electrodes are sequentially formed may also be used.
透明絶縁基板としてはガラス基板、透明電極としてはＩ
ＴＯ１発光層としては発光中心を少量含有したＺ ｎ
Ｓ ＳＳ ｒ Ｓ ％ Ｃａ Ｓ 、背面電極としては
ＡＩ、絶縁層としてはＳ １ ｓ Ｎａ 、Ｓ Ｉ Ｏ
＠、Ｔａ、Ｏ，等が好ましくは使用される。A glass substrate is used as the transparent insulating substrate, and I is used as the transparent electrode.
As the TO1 light-emitting layer, Zn containing a small amount of light-emitting center is used.
S SS r S % Ca S , AI as the back electrode, S 1 s Na , S IO as the insulating layer
@, Ta, O, etc. are preferably used.
本発明の、発光層を画素部分のみ島状又は画素を含む様
にストライプ状に形成し、その端部に発光層より屈折率
の低い物質又は金属等の光を反射する物質を配置した薄
膜ＥＬ素子は、従来技術の薄膜ＥＬ素子に比べ発光外部
取り出し効率を高くすることができ、その結果発光輝度
の向上を計ることができ、また展延面方向に濡れる光が
少なくなるためコントラストの向上にも効果がある。さ
らに本発明は発光層の蛍光体母体材料、発光中心材料、
発光層形成法等に関係なく適用でき、カラー化に必要な
赤色、青色とといった現在発光輝度向上が望まれる発光
層についても効果的である。A thin film EL according to the present invention, in which the light-emitting layer is formed in an island shape or in a stripe shape so as to include pixels only in the pixel portion, and a light-reflecting material such as a material having a lower refractive index than the light-emitting layer or a metal is arranged at the end of the light-emitting layer. Compared to conventional thin-film EL devices, the device can increase the efficiency of emitting light to the outside, resulting in improved luminance, and because less light permeates in the direction of the spread surface, contrast can be improved. is also effective. Furthermore, the present invention provides a phosphor matrix material of a luminescent layer, a luminescent center material,
It can be applied regardless of the method of forming the emissive layer, and is also effective for emissive layers for which improvement in luminance is currently desired, such as red and blue necessary for colorization.
第１図、第３図、第５図は、それぞれ本発明の薄膜ＥＬ
素子の断面図、第２図（ａ）〜Ｃｒ）、第４図（ａ）〜
＜ｒ＞はそれぞれ第１図、第３図の薄膜ＥＬ素子の発光
層及び反射層の形成工程のを示す断面図、第６図（ａ）
（ｂ）（ｃ）、第７図（ａ）（ｂ）（ｃ）は発光層の成
パターンを示すそれぞれ平面図、正面図、側面図、第８
図は本発明の薄膜ＥＬ素子の輝度対印加電圧の関係を従
来の輝度対印加電圧の関係を比較して表わすグラフ、第
９図は発光層からの発光の進行を表わした斜視図、第１
０図は一般的な薄膜ＥＬ素子の斜視図である。
符号の説明
１、透明基板 ２．透明電極
３、下部絶縁層 ４９発光層
５、上部絶縁層 ６．背面電極
１０、反射層 １１．レジスト２０、反射層兼
用上部絶縁層FIGS. 1, 3, and 5 show the thin film EL of the present invention, respectively.
Cross-sectional views of the device, Fig. 2(a) to Cr), Fig. 4(a) to
<r> is a cross-sectional view showing the formation process of the light-emitting layer and reflective layer of the thin film EL device in FIGS. 1 and 3, respectively, and FIG. 6(a)
(b), (c), and Fig. 7 (a), (b), and (c) are respectively a plan view, a front view, a side view, and a
The figure is a graph showing the relationship between the brightness and the applied voltage of the thin film EL element of the present invention compared with the relationship between the conventional brightness and the applied voltage.
FIG. 0 is a perspective view of a general thin film EL element. Explanation of symbols 1. Transparent substrate 2. Transparent electrode 3, lower insulating layer 49 light emitting layer 5, upper insulating layer 6. Back electrode 10, reflective layer 11. Resist 20, upper insulating layer that also serves as a reflective layer
Claims (2)
光層を形成した薄膜エレクトロルミネッセンス素子に於
いて、発光層が画素部分のみの島状又は画素を含む様に
ストライプ状に形成した発光層であり、発光層の端面に
隣接して光を一部又は全部反射する反射層を配置したこ
とを特徴とする薄膜エレクトロルミネッセンス素子。1. In a thin film electroluminescent device in which a light emitting layer is formed between a transparent electrode and a back electrode on a transparent insulating substrate, the light emitting layer is formed in the form of an island only in the pixel portion or in the form of a stripe so as to include the pixels. 1. A thin film electroluminescent device, characterized in that a reflective layer that partially or completely reflects light is disposed adjacent to an end face of a light emitting layer.
状に形成した発光層の端面を断面台形のテーパ状に形成
したことを特徴とする請求項１記載の薄膜エレクトロル
ミネッセンス素子。2. 2. The thin film electroluminescent device according to claim 1, wherein the end face of the light emitting layer formed in the form of an island only in the pixel portion or in the form of a stripe so as to include the pixels is formed in a tapered shape with a trapezoidal cross section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1256869A JPH03119691A (en) | 1989-09-30 | 1989-09-30 | Thin-film electroluminescence element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1256869A JPH03119691A (en) | 1989-09-30 | 1989-09-30 | Thin-film electroluminescence element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03119691A true JPH03119691A (en) | 1991-05-22 |
Family
ID=17298549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1256869A Pending JPH03119691A (en) | 1989-09-30 | 1989-09-30 | Thin-film electroluminescence element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03119691A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5525288A (en) * | 1993-06-22 | 1996-06-11 | Toyoda Gosei Co., Ltd. | Method of manufacturing a hose having an expanded portion and a compression formed portion |
-
1989
- 1989-09-30 JP JP1256869A patent/JPH03119691A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5525288A (en) * | 1993-06-22 | 1996-06-11 | Toyoda Gosei Co., Ltd. | Method of manufacturing a hose having an expanded portion and a compression formed portion |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2553696B2 (en) | Multicolor light emitting thin film electroluminescent device | |
| CN100593225C (en) | Electron emission display | |
| JPH01220394A (en) | High-intensity el element | |
| US5400047A (en) | High brightness thin film electroluminescent display with low OHM electrodes | |
| JPH06275381A (en) | Multicolor luminous element and substrate thereof | |
| US6781307B2 (en) | Electroluminescent device and method for manufacturing the same | |
| RU2129344C1 (en) | Luminescent indication board which is visible under day light | |
| JP2842956B2 (en) | Thin film matrix configuration especially for electroluminescent displays | |
| US5521465A (en) | Sunlight viewable thin film electroluminscent display having darkened metal electrodes | |
| KR20020025862A (en) | Organic el display | |
| JPS60180093A (en) | Thin film el element | |
| JPH08509834A (en) | High contrast thin film EL display | |
| JP2001043981A (en) | Display device and manufacture of the same | |
| JP3601289B2 (en) | EL display device | |
| JPH03119691A (en) | Thin-film electroluminescence element | |
| JPH05108014A (en) | Formation of light emitting film for color display of el display panel | |
| US6621215B1 (en) | Front plate of a plasma display panel (PDP) and the method of fabricating the same | |
| US5783904A (en) | High luminescence display | |
| JPS63299092A (en) | Thin film electroluminescent panel | |
| JPH0527996U (en) | EL display element | |
| JPH01186587A (en) | Display device and its manufacture | |
| JPH0527835Y2 (en) | ||
| US5762527A (en) | High luminescence display | |
| JPH0322394A (en) | Thin film el device | |
| JPH0460317B2 (en) |