JPH10149884A - Electrode for light emitting element, manufacture thereof, and manufacture of element having this electrode - Google Patents
Electrode for light emitting element, manufacture thereof, and manufacture of element having this electrodeInfo
- Publication number
- JPH10149884A JPH10149884A JP8308077A JP30807796A JPH10149884A JP H10149884 A JPH10149884 A JP H10149884A JP 8308077 A JP8308077 A JP 8308077A JP 30807796 A JP30807796 A JP 30807796A JP H10149884 A JPH10149884 A JP H10149884A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- layer
- cathode
- samarium
- electron injection
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 229910052772 Samarium Inorganic materials 0.000 claims abstract description 44
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 claims abstract description 44
- 239000010409 thin film Substances 0.000 claims abstract description 32
- 238000007740 vapor deposition Methods 0.000 claims abstract description 23
- 229910052783 alkali metal Inorganic materials 0.000 claims abstract description 16
- 150000001340 alkali metals Chemical class 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims description 39
- 238000002347 injection Methods 0.000 claims description 34
- 239000007924 injection Substances 0.000 claims description 34
- 238000001704 evaporation Methods 0.000 claims description 10
- 230000008020 evaporation Effects 0.000 claims description 8
- 230000008018 melting Effects 0.000 claims description 6
- 238000002844 melting Methods 0.000 claims description 6
- 239000007772 electrode material Substances 0.000 claims description 5
- 238000010549 co-Evaporation Methods 0.000 claims description 3
- 238000010030 laminating Methods 0.000 claims 1
- 239000010410 layer Substances 0.000 abstract description 68
- 239000000758 substrate Substances 0.000 abstract description 26
- 239000012044 organic layer Substances 0.000 abstract description 16
- 239000011521 glass Substances 0.000 abstract description 6
- 230000006866 deterioration Effects 0.000 abstract description 3
- KLCLIOISYBHYDZ-UHFFFAOYSA-N 1,4,4-triphenylbuta-1,3-dienylbenzene Chemical compound C=1C=CC=CC=1C(C=1C=CC=CC=1)=CC=C(C=1C=CC=CC=1)C1=CC=CC=C1 KLCLIOISYBHYDZ-UHFFFAOYSA-N 0.000 abstract description 2
- 230000003647 oxidation Effects 0.000 abstract description 2
- 238000007254 oxidation reaction Methods 0.000 abstract description 2
- IEQIEDJGQAUEQZ-UHFFFAOYSA-N phthalocyanine Chemical class N1C(N=C2C3=CC=CC=C3C(N=C3C4=CC=CC=C4C(=N4)N3)=N2)=C(C=CC=C2)C2=C1N=C1C2=CC=CC=C2C4=N1 IEQIEDJGQAUEQZ-UHFFFAOYSA-N 0.000 abstract description 2
- 239000012780 transparent material Substances 0.000 abstract description 2
- 150000003852 triazoles Chemical class 0.000 abstract description 2
- 238000002513 implantation Methods 0.000 abstract 3
- 238000005275 alloying Methods 0.000 abstract 2
- 238000010314 arc-melting process Methods 0.000 abstract 2
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 abstract 1
- 239000010408 film Substances 0.000 description 29
- 238000000151 deposition Methods 0.000 description 25
- 230000008021 deposition Effects 0.000 description 24
- 239000000463 material Substances 0.000 description 24
- -1 8-quinolinol aluminum Chemical compound 0.000 description 14
- 229910052751 metal Inorganic materials 0.000 description 14
- 239000002184 metal Substances 0.000 description 14
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 13
- 229910052744 lithium Inorganic materials 0.000 description 13
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 12
- 230000005525 hole transport Effects 0.000 description 12
- 150000001875 compounds Chemical class 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 7
- AYEKOFBPNLCAJY-UHFFFAOYSA-O thiamine pyrophosphate Chemical compound CC1=C(CCOP(O)(=O)OP(O)(O)=O)SC=[N+]1CC1=CN=C(C)N=C1N AYEKOFBPNLCAJY-UHFFFAOYSA-O 0.000 description 7
- 239000000126 substance Substances 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 239000010453 quartz Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 4
- 229910052721 tungsten Inorganic materials 0.000 description 4
- 239000010937 tungsten Substances 0.000 description 4
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000011109 contamination Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910052750 molybdenum Inorganic materials 0.000 description 3
- 239000011733 molybdenum Substances 0.000 description 3
- YNHJECZULSZAQK-UHFFFAOYSA-N tetraphenylporphyrin Chemical compound C1=CC(C(=C2C=CC(N2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3N2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 YNHJECZULSZAQK-UHFFFAOYSA-N 0.000 description 3
- HAUGRYOERYOXHX-UHFFFAOYSA-N Alloxazine Chemical compound C1=CC=C2N=C(C(=O)NC(=O)N3)C3=NC2=C1 HAUGRYOERYOXHX-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 238000004020 luminiscence type Methods 0.000 description 2
- 150000004866 oxadiazoles Chemical class 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 238000006862 quantum yield reaction Methods 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- 238000004506 ultrasonic cleaning Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- UWRZIZXBOLBCON-VOTSOKGWSA-N (e)-2-phenylethenamine Chemical class N\C=C\C1=CC=CC=C1 UWRZIZXBOLBCON-VOTSOKGWSA-N 0.000 description 1
- VERMWGQSKPXSPZ-BUHFOSPRSA-N 1-[(e)-2-phenylethenyl]anthracene Chemical class C=1C=CC2=CC3=CC=CC=C3C=C2C=1\C=C\C1=CC=CC=C1 VERMWGQSKPXSPZ-BUHFOSPRSA-N 0.000 description 1
- MNCMBBIFTVWHIP-UHFFFAOYSA-N 1-anthracen-9-yl-2,2,2-trifluoroethanone Chemical group C1=CC=C2C(C(=O)C(F)(F)F)=C(C=CC=C3)C3=CC2=C1 MNCMBBIFTVWHIP-UHFFFAOYSA-N 0.000 description 1
- SULWTXOWAFVWOY-PHEQNACWSA-N 2,3-bis[(E)-2-phenylethenyl]pyrazine Chemical class C=1C=CC=CC=1/C=C/C1=NC=CN=C1\C=C\C1=CC=CC=C1 SULWTXOWAFVWOY-PHEQNACWSA-N 0.000 description 1
- YTJWSLOARYEEOS-UHFFFAOYSA-N 4-methyl-n-(4-methylphenyl)-n-[4-[2,3,4-trimethyl-6-[4-(4-methyl-n-(4-methylphenyl)anilino)phenyl]-5-propan-2-ylphenyl]phenyl]aniline Chemical group C=1C=C(N(C=2C=CC(C)=CC=2)C=2C=CC(C)=CC=2)C=CC=1C=1C(C(C)C)=C(C)C(C)=C(C)C=1C(C=C1)=CC=C1N(C=1C=CC(C)=CC=1)C1=CC=C(C)C=C1 YTJWSLOARYEEOS-UHFFFAOYSA-N 0.000 description 1
- ZOKIJILZFXPFTO-UHFFFAOYSA-N 4-methyl-n-[4-[1-[4-(4-methyl-n-(4-methylphenyl)anilino)phenyl]cyclohexyl]phenyl]-n-(4-methylphenyl)aniline Chemical compound C1=CC(C)=CC=C1N(C=1C=CC(=CC=1)C1(CCCCC1)C=1C=CC(=CC=1)N(C=1C=CC(C)=CC=1)C=1C=CC(C)=CC=1)C1=CC=C(C)C=C1 ZOKIJILZFXPFTO-UHFFFAOYSA-N 0.000 description 1
- 239000005725 8-Hydroxyquinoline Substances 0.000 description 1
- 229910001316 Ag alloy Inorganic materials 0.000 description 1
- 229910017073 AlLi Inorganic materials 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- 241000284156 Clerodendrum quadriloculare Species 0.000 description 1
- 241000511976 Hoya Species 0.000 description 1
- 229910000733 Li alloy Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910000573 alkali metal alloy Inorganic materials 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
- 150000001412 amines Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- 150000004982 aromatic amines Chemical class 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052792 caesium Inorganic materials 0.000 description 1
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 125000000332 coumarinyl group Chemical class O1C(=O)C(=CC2=CC=CC=C12)* 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- ZSWFCLXCOIISFI-UHFFFAOYSA-N cyclopentadiene Chemical class C1C=CC=C1 ZSWFCLXCOIISFI-UHFFFAOYSA-N 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 125000006575 electron-withdrawing group Chemical group 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000005357 flat glass Substances 0.000 description 1
- 150000008376 fluorenones Chemical class 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229940083761 high-ceiling diuretics pyrazolone derivative Drugs 0.000 description 1
- 150000007857 hydrazones Chemical class 0.000 description 1
- 150000002460 imidazoles Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229940079865 intestinal antiinfectives imidazole derivative Drugs 0.000 description 1
- 229910052747 lanthanoid Inorganic materials 0.000 description 1
- 150000002602 lanthanoids Chemical class 0.000 description 1
- 150000002605 large molecules Chemical class 0.000 description 1
- 239000001989 lithium alloy Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- XKGUKYPCHPHAJL-UHFFFAOYSA-N methanetetracarbonitrile Chemical compound N#CC(C#N)(C#N)C#N XKGUKYPCHPHAJL-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 150000005054 naphthyridines Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- AHLBNYSZXLDEJQ-FWEHEUNISA-N orlistat Chemical compound CCCCCCCCCCC[C@H](OC(=O)[C@H](CC(C)C)NC=O)C[C@@H]1OC(=O)[C@H]1CCCCCC AHLBNYSZXLDEJQ-FWEHEUNISA-N 0.000 description 1
- 150000007978 oxazole derivatives Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 229960003540 oxyquinoline Drugs 0.000 description 1
- DGBWPZSGHAXYGK-UHFFFAOYSA-N perinone Chemical class C12=NC3=CC=CC=C3N2C(=O)C2=CC=C3C4=C2C1=CC=C4C(=O)N1C2=CC=CC=C2N=C13 DGBWPZSGHAXYGK-UHFFFAOYSA-N 0.000 description 1
- 125000002080 perylenyl group Chemical group C1(=CC=C2C=CC=C3C4=CC=CC5=CC=CC(C1=C23)=C45)* 0.000 description 1
- 150000004986 phenylenediamines Chemical class 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- JEXVQSWXXUJEMA-UHFFFAOYSA-N pyrazol-3-one Chemical class O=C1C=CN=N1 JEXVQSWXXUJEMA-UHFFFAOYSA-N 0.000 description 1
- 150000003219 pyrazolines Chemical class 0.000 description 1
- 150000005255 pyrrolopyridines Chemical class 0.000 description 1
- MCJGNVYPOGVAJF-UHFFFAOYSA-N quinolin-8-ol Chemical compound C1=CN=C2C(O)=CC=CC2=C1 MCJGNVYPOGVAJF-UHFFFAOYSA-N 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 229910052701 rubidium Inorganic materials 0.000 description 1
- IGLNJRXAVVLDKE-UHFFFAOYSA-N rubidium atom Chemical compound [Rb] IGLNJRXAVVLDKE-UHFFFAOYSA-N 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 150000003384 small molecules Chemical class 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- PJANXHGTPQOBST-UHFFFAOYSA-N stilbene Chemical class C=1C=CC=CC=1C=CC1=CC=CC=C1 PJANXHGTPQOBST-UHFFFAOYSA-N 0.000 description 1
- 238000000859 sublimation Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- QKTRRACPJVYJNU-UHFFFAOYSA-N thiadiazolo[5,4-b]pyridine Chemical class C1=CN=C2SN=NC2=C1 QKTRRACPJVYJNU-UHFFFAOYSA-N 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/805—Electrodes
- H10K50/82—Cathodes
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Electroluminescent Light Sources (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、発光素子用電極お
よびその製造方法ならびにその電極を有するＥＬ素子に
関し、詳しくは、ＥＬ素子として高輝度・高効率、かつ
安定な発光が得られる陰極ならびにその製造方法に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for a light emitting device, a method for manufacturing the same, and an EL device having the electrode. It relates to a manufacturing method.
【０００２】[0002]
【従来の技術】有機ＥＬ素子は、陽極から注入された正
孔と陰極から注入された電子が蛍光能を有する有機層
（以下発光層という）内で再結合し、励起状態からの失
括する際に光を放射する現象を利用するものである。こ
れらの研究は有機化合物の高い蛍光量子収率と、多種多
様に設計可能な分子構造に着目したところに端を発した
ものであったが、その発光輝度・発光効率は低く、実用
レベルとは言えなかった。しかし、その後、タング（Ｔ
ａｎｇ）とバンスリケ（Ｖａｎｓｌｙｋｅ）らは発光層
のみの構成から、正孔を輸送する能力に優れた材料（以
下正孔輸送層という）とを組み合わせた積層構造をとる
ことで、格段にその性能が向上することを報告した（ア
プライド・フィジックス・レター（Ａｐｐｌｉｅｄ Ｐ
ｈｙｓｉｃｓＬｅｔｔｅｒｓ），５１巻，９１３ペー
ジ，１９８７年）。これを機に研究は、正孔を注入する
為のみの役割を持った層（以下正孔注入層）、電子を輸
送する為のみの役割を持った層（電子輸送層）など完全
に機能分離がなされ、各有機材量の高性能化も相まって
表示装置としての実用化が近くなってきている。以下、
発光層、電子輸送層、正孔輸送層、正孔注入層を総じて
有機層という。2. Description of the Related Art In an organic EL device, holes injected from an anode and electrons injected from a cathode recombine in an organic layer having a fluorescent ability (hereinafter referred to as a light-emitting layer) and lose their excited state. In this case, a phenomenon of emitting light is used. These studies originated from focusing on the high fluorescence quantum yield of organic compounds and the molecular structures that can be designed in a wide variety of ways, but their luminous luminance and luminous efficiency were low, and they were not practical levels. I could not say it. However, after that, the tongue (T
Ang) and Vanslyke et al. have a layered structure combining a material having excellent hole transporting ability (hereinafter, referred to as a hole transporting layer) from a structure having only a light emitting layer, thereby significantly improving the performance. (Applied Physics Letter (Applied P)
Physics Letters), 51, 913, 1987). Taking advantage of this, research was conducted on a layer that only plays a role of injecting holes (hereafter, a hole injection layer) and a layer that plays a role only of transporting electrons (an electron transport layer). However, the practical use as a display device is approaching due to the high performance of each organic material. Less than,
The light emitting layer, the electron transport layer, the hole transport layer, and the hole injection layer are collectively referred to as an organic layer.
【０００３】最近では、緑色発光系としては正孔注入層
にスターバースト系アミンを用いることで輝度１０万ｃ
ｄ／ｍ2 以上、発光効率１０ｌｍ／Ｗ以上（月間ディス
プレイ、１９９５年９月号）、連続駆動時における輝度
の半減寿命５千時間以上が報告されている。また、青色
発光系としてはジスチリルアリーレン誘導体を発光材料
に用いて輝度２万ｃｄ／ｍ2 以上、発光効率５１ｍ／
Ｗ、半減寿命５千時間以上が報告されている（日本化学
会第７０春季年会特別講演）。Recently, as a green light-emitting system, a luminance of 100,000 c has been achieved by using a starburst amine in a hole injection layer.
d / m 2 or more, luminous efficiency of 10 lm / W or more (Monthly Display, September 1995), and a half-life of 5,000 hours or more of luminance during continuous driving are reported. In addition, as a blue light emitting system, a distyryl arylene derivative is used as a light emitting material, and a luminance of 20,000 cd / m 2 or more and a luminous efficiency of 51 m /
W, a half-life of 5,000 hours or more has been reported (special lecture of the 70th Annual Meeting of the Chemical Society of Japan).
【０００４】ここで、上記ＥＬ素子における陰極として
は、発光層への電子注入を容易にする為にできるだけ低
い仕事関数をもつ金属を使用することがよく、従来ＥＰ
０２７８７５７記載のようにアルカリ金属以外の仕事関
数が４ｅＶ以下の金属が用いられている。例えば、Ｍｇ
とＡｇ、Ｉｎ、Ｓｎ、Ｓｂ、Ｔｅ、Ｍｎのいずれかを蒸
着形成するものであり、均一かつ良好な面抵抗値を有す
る陰極が示されている。これを使用した具体例を図２を
用いて説明する。強い蛍光を放射する８−キノリノール
アルミ錯体（化１）を発光層１０５に、１，１−ビス
（４−ジ−ｐ−トリルアミノフェニル）シクロヘキサン
（化２）を正孔輸送層１０４に使用し、これらをガラス
などの支持基板１０１上に形成された陽極１０２とＭｇ
Ａｇ合金である陰極２０１との間に挿入することによ
り、５Ｖ印加時に約５０ｃｄ／ｍ2 、電力変換効率０．
４５％の緑色発光が得られている。Here, as the cathode of the EL element, a metal having a work function as low as possible to facilitate electron injection into the light emitting layer is often used.
As described in Japanese Patent No. 0278575, a metal having a work function of 4 eV or less other than an alkali metal is used. For example, Mg
And any one of Ag, In, Sn, Sb, Te, and Mn is formed by vapor deposition, and a cathode having a uniform and good sheet resistance is shown. A specific example using this will be described with reference to FIG. An 8-quinolinol aluminum complex (Chem. 1) emitting strong fluorescence is used for the light-emitting layer 105, and 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane (Chem. 2) is used for the hole transport layer 104. And an anode 102 formed on a supporting substrate 101 such as glass.
By being inserted between the cathode 201 made of an Ag alloy, when a voltage of 5 V is applied, about 50 cd / m 2 and a power conversion efficiency of 0.1 cd / m 2 .
45% green light emission is obtained.
【０００５】 [0005]
【０００６】しかし、この陰極の薄膜は断面ＳＥＭ観察
によると、１００〜１０００ｎｍ程度の空洞部が存在
し、酸素、水分等ＥＬ素子劣化の原因となる分子を容易
に透過させてしまう。また、場合によっては有機層との
密着性が不良となり、不均一な発光を与える場合が多々
あった。これらの課題を鑑みて報告されたアルミニウム
とリチウムを含有させた合金陰極は、前記ＭｇＡｇ系合
金よりもさらに電子注入特性に優れており（特開平５−
１２１１７２号公報）、薄膜の緻密性向上のみならず、
陰極をＡｌ：Ｌｉに変えるだけでＭｇＡｇ陰極を用いた
場合の素子よりも約１．５Ｖ低電圧で同一輝度が得られ
る。しかし、この方法では陰極と有機層との密着性が依
然悪いため、素子駆動時に発生する熱により陰極の膜は
がれによる発光効率低下や発光の不均一性が露呈してし
まっていた。However, according to cross-sectional SEM observation, the thin film of the cathode has a cavity of about 100 to 1000 nm, and easily transmits molecules such as oxygen and moisture which cause deterioration of the EL element. Further, in some cases, the adhesion to the organic layer becomes poor, and uneven light emission is often given. The alloy cathode containing aluminum and lithium, which has been reported in view of these problems, has more excellent electron injection characteristics than the MgAg-based alloy (Japanese Patent Application Laid-Open No. H05-205686).
No. 121172), not only the improvement of the denseness of the thin film,
By changing the cathode to Al: Li, the same luminance can be obtained at a voltage lower by about 1.5 V than the device using the MgAg cathode. However, in this method, the adhesion between the cathode and the organic layer is still poor, so that the heat generated at the time of driving the element exposes the luminous efficiency to decrease due to the peeling of the cathode film and the non-uniformity of the luminescence.
【０００７】そこで上記金属の特徴はそのままに、その
金属と付着・結合または錯体形成能を保有するアクセプ
ター性の有機物を混入する方法が開示されている（特開
平４−２３０９９７）。この方法では電子注入用金属と
して４．１ｅＶ以下の仕事関数を有する金属または電気
伝導性化合物（例えば、Ｂａ、Ｃａ、Ｅｕ、Ｓｃ、Ｍ
ｇ、Ｌｉ）と、この金属に対して付着または結合する性
質を保有する有機低分子および有機高分子化合物、例え
ば分子内に電子吸引基をもつキノイド構造をもつ化合物
などを用いている。さらに、これらの物質を共蒸着によ
って互いに混合しながら薄膜化し、これをＥＬ素子の陰
極として用いることによって薄膜の均一性・緻密性が高
まり、堆積抵抗率を大幅に低減することができる。その
結果、ＥＬ素子の発光効率と発光の均一性の向上に繋が
ることになる。Therefore, a method has been disclosed in which an acceptor organic substance having the ability to adhere to, bond to, or form a complex with the metal is mixed while retaining the characteristics of the metal (Japanese Patent Laid-Open No. 4-230997). In this method, a metal having a work function of 4.1 eV or less or an electrically conductive compound (for example, Ba, Ca, Eu, Sc, M
g, Li) and an organic low molecular weight or organic high molecular weight compound having the property of attaching or binding to the metal, for example, a compound having a quinoid structure having an electron withdrawing group in the molecule. Further, these materials are mixed with each other by co-evaporation to form a thin film, and the thin film is used as a cathode of an EL element, whereby the uniformity and denseness of the thin film are increased, and the deposition resistivity can be significantly reduced. As a result, the luminous efficiency and uniformity of luminescence of the EL element are improved.
【０００８】[0008]
【発明が解決しようとする課題】上記従来技術において
第一の問題点は、アクセプター性の強い有機物、例えば
テトラシアノキジメタン（ＴＣＮＱ）、アロキサジン、
５，１０，１５，２０−テトラフェニルポリフィリン
（ＴＰＰ）は、熱によって容易にその構造を変化させて
しまうことにある。つまり、素子駆動時および蒸着時等
の熱発生の過程で、陰極自体の膜構造を変化させてしま
う可能性が高い。その結果、堆積抵抗率を下げることは
可能でも、発光相当の有機層と陰極との接着性の低下を
招き、輝度劣化の直接的な原因となってしまう。The first problem in the above prior art is that an organic substance having a strong acceptor property, for example, tetracyano methane (TCNQ), alloxazine,
5,10,15,20-tetraphenylporphyrin (TPP) is characterized in that its structure is easily changed by heat. In other words, there is a high possibility that the film structure of the cathode itself will be changed during the process of generating heat during element driving and vapor deposition. As a result, although the deposition resistivity can be lowered, the adhesion between the organic layer corresponding to the light emission and the cathode is lowered, which directly causes the luminance degradation.
【０００９】第二の問題点は、有機物と陰極金属を同一
の真空チャンバー内で共蒸着すると、その壁面付着した
有機／無機の膜は容易に剥れることになり、真空系自体
の汚染が問題となってくることにある。このように、従
来技術では、陰極と有機層との密着性が低下して素子劣
化してしまうだけでなく、素子汚染の問題も同時に発生
してくる。The second problem is that when an organic substance and a cathode metal are co-deposited in the same vacuum chamber, the organic / inorganic film adhered to the wall surface is easily peeled off, which causes a problem of contamination of the vacuum system itself. It is to become. As described above, in the related art, not only the adhesion between the cathode and the organic layer is reduced to deteriorate the device, but also a problem of device contamination occurs at the same time.
【００１０】本発明は以上述べたような特開平４−２３
０９９７記載の内容に対する課題を克服して、上記有機
物を用いず、陰極を金属のみの構成で、さらに、均一・
緻密性を向上させると同時に有機層との密着性が良好な
材料およびその薄膜形成の方法を提供し、ＥＬ素子の高
輝度・高効率化ならびに長寿命化を実現することを目的
とする。[0010] The present invention relates to Japanese Patent Application Laid-Open No.
No. 9997, the cathode is composed of only metal without using the organic substance, and the uniformity and
It is an object of the present invention to provide a material which improves the compactness and has good adhesion to an organic layer and a method for forming a thin film thereof, and realizes high luminance, high efficiency and long life of an EL element.
【００１１】[0011]
【課題を解決するための手段】前述の課題解決のために
本発明が提供する手段は、電子注入用電極が少なくとも
サマリウムを含有することを特徴とする発光素子用電
極、若しくは電子注入用電極として、少なくとも１モル
％以上のサマリウムおよび０．０１〜５モル％のアルカ
リ金属を含有することを特徴とする発光素子用電極であ
る。また、その製造方法は、電子注入用電極を共蒸着に
よって形成することを特徴とするか、もしくは電子注入
電極を構成する電極材料が予めアーク溶融法により合金
化され、これを電子注入用電極としてただ１つの蒸発源
から蒸着法によって形成することを特徴とする。さらに
は、上記記載の材料を用いて形成される陰極を有するＥ
Ｌ素子ならびにその製造方法である。In order to solve the above-mentioned problems, the present invention provides a light emitting element electrode or an electron injection electrode characterized in that the electron injection electrode contains at least samarium. And at least 1 mol% or more of samarium and 0.01 to 5 mol% of an alkali metal. Further, the manufacturing method is characterized in that the electron injection electrode is formed by co-evaporation, or the electrode material constituting the electron injection electrode is alloyed in advance by an arc melting method, and this is used as the electron injection electrode. It is characterized by being formed by evaporation from only one evaporation source. Further, an E having a cathode formed by using the above-described material may be used.
An L element and a manufacturing method thereof.
【００１２】電子注入用電極としては、より電子を注入
しやすい金属、すなわち仕事関数をできるだけ小さくす
る必要がある。ランタノイド系サマリウムは仕事関数が
２．７ｅＶと低く、従来の電子注入電極、例えばＭｇＡ
ｇ（３．６ｅＶ）、ＡｌＬｉ（２．９ｅＶ）と比較して
も小さい。換言すれば、より電子を注入しやすい金属で
あり、ＥＬ素子の高輝度・高効率化の為には陰極として
好適である。さらに本発明の第２の作用として、サマリ
ウムはアルカリ金属、例えばリチウムやカリウム、ナト
リウムなどと合金化された場合、室温下で安定構造をと
ることが知られており、このために酸化に伴う著しい仕
事関数の低下、ひいてはＥＬ素子の劣化を大幅に改善で
きることが上げられる。また、サマリウムの融点は他の
金属と比較しても約１０００℃と低いため従来の蒸着
法、つまり抵抗加熱蒸着や電子ビーム蒸着が可能であ
り、蒸着前後の輻射熱は下地である有機層付近でおよそ
５℃の温度上昇のみで、損傷を与える心配もない。As the electron injection electrode, it is necessary to reduce the work function as much as possible of a metal into which electrons can be easily injected. The lanthanoid-based samarium has a low work function of 2.7 eV, and has a conventional electron injection electrode such as MgA.
g (3.6 eV) and smaller than AlLi (2.9 eV). In other words, it is a metal into which electrons can be more easily injected, and is suitable as a cathode for achieving high luminance and high efficiency of the EL element. Further, as a second function of the present invention, it is known that samarium has a stable structure at room temperature when alloyed with an alkali metal, for example, lithium, potassium, or sodium. It can be pointed out that the reduction of the work function and the deterioration of the EL element can be greatly improved. In addition, since the melting point of samarium is as low as about 1000 ° C. as compared with other metals, a conventional vapor deposition method, that is, resistance heating vapor deposition or electron beam vapor deposition can be performed, and radiant heat before and after vapor deposition is close to the underlying organic layer. With only a temperature rise of about 5 ° C., there is no risk of damage.
【００１３】もう一つの作用として、サマリウムと有機
層との密着性が良好であるということがあげられる。例
えば前述の８−キノリノールアルミ錯体との密着性は引
き倒し法で測定した結果、約３．５×１０10Ｎ／ｍ2 と
従来の電子注入用電極よりも１桁大きい。これはサマリ
ウムと有機層との分子間力が従来よりも１桁大きいこと
を示しており、ＥＬ素子の寿命を大幅に改善する大きな
要因となる。Another effect is that the adhesion between samarium and the organic layer is good. For example, the adhesion to the aforementioned 8-quinolinol aluminum complex is about 3.5 × 10 10 N / m 2, which is one order of magnitude larger than that of a conventional electron injection electrode, as measured by a pull-down method. This indicates that the intermolecular force between the samarium and the organic layer is one order of magnitude larger than the conventional one, which is a major factor in greatly improving the life of the EL element.
【００１４】[0014]
【発明の実施の形態】本発明の電子注入電極を陰極とし
て用いたＥＬ素子の構成は、各種の態様があるが、基本
的には一対の電極（陽極と陰極）間に、発光層を挾持し
た構成とし、これに必要に応じて正孔輸送層や電子注入
層を介在させればよい。具体的には、（１）陽極／発光
層／陰極，（２）陽極／正孔輸送層／発光層／陰極，
（３）陽極／正孔注入層／正孔輸送層／発光層／陰極，
（４）陽極／正孔輸送層／発光層／電子輸送層／陰極，
（５）陽極／正孔注入層／正孔輸送層／発光層／電子輸
送層／陰極，（６）陽極／正孔注入層／発光層／電子注
入層／陰極などの構成を挙げることができる。また、前
記構成の素子においては、いずれも基板に支持されてい
ることが好ましく、この基板については特に制限はな
く、従来ＥＬ素子に慣用されているもの、例えば、ガラ
ス、透明プラスチック、石英などからなるものを用いる
ことができる。DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of an EL device using the electron injection electrode of the present invention as a cathode has various aspects. Basically, a light emitting layer is sandwiched between a pair of electrodes (anode and cathode). In this case, a hole transport layer or an electron injection layer may be interposed as necessary. Specifically, (1) anode / light-emitting layer / cathode, (2) anode / hole transport layer / light-emitting layer / cathode,
(3) anode / hole injection layer / hole transport layer / emission layer / cathode,
(4) anode / hole transport layer / emission layer / electron transport layer / cathode,
(5) Anode / Hole Injection Layer / Hole Transport Layer / Emitting Layer / Electron Transport Layer / Cathode, (6) Anode / Hole Injection Layer / Emission Layer / Electron Injection Layer / Cathode . Further, in the device having the above-described structure, it is preferable that each of the devices is supported by a substrate, and the substrate is not particularly limited. For example, glass, transparent plastic, quartz, or the like, which is conventionally used for an EL device, may be used. Can be used.
【００１５】次に、本発明の実施の形態について（３）
の構成について図１を参照して詳細に説明する。まず支
持基板１０１上に形成される陽極１０２としては仕事関
数の大きな（４．１ｅＶ以上）金属、合金、電気伝導性
化合物およびこれらの混合物を電極材料とするものが好
ましく用いられる。このような電極材料としては、ＩＴ
Ｏ、ＳｎＯ2 、ＺｎＯなどの誘電性透明材料が挙げられ
る。陽極１０２は、これらの電極材料を蒸着やスパッタ
リングなどの方法により、薄膜を形成させることにより
作成することができる。この電極より発光をとりだす場
合、透過率を５０％よりも大きくすることが望ましく、
また、電極としてのシート抵抗は数百Ω／□以下が好ま
しい。さらにその膜厚は、通常１０ｎｍないし１μｍ、
好ましくは、１０〜２００ｎｍの範囲で選ばれる。な
お、このＥＬ素子においては、陽極１０２または陰極の
いずれか一方が透明あるいは半透明であることが、ＥＬ
からの発光取り出し効率を上げるために好都合である。Next, an embodiment of the present invention (3)
Will be described in detail with reference to FIG. First, as the anode 102 formed on the support substrate 101, a metal, an alloy, an electrically conductive compound, or a mixture thereof having a large work function (4.1 eV or more) as an electrode material is preferably used. Such electrode materials include IT
A dielectric transparent material such as O, SnO2, and ZnO can be used. The anode 102 can be formed by forming a thin film from these electrode materials by a method such as evaporation or sputtering. When light is emitted from this electrode, it is desirable that the transmittance be greater than 50%.
Further, the sheet resistance as an electrode is preferably several hundred Ω / □ or less. Further, the film thickness is usually 10 nm to 1 μm,
Preferably, it is selected in the range of 10 to 200 nm. In this EL device, it is required that either the anode 102 or the cathode be transparent or translucent.
This is convenient for increasing the efficiency of extracting light from the light source.
【００１６】つぎに形成される正孔注入層１０３として
は、電界を与えられた２個の電極間に配置されて陽極か
ら正孔を注入しうる化合物であり、かつ陽極との密着性
の良い化合物が選択される。具体的には、陽極１０２の
イオン化ポテンシャルと正孔輸送層１０４のイオン化ポ
テンシャルとの中間の値（約４．９ｅＶ〜６．０ｅＶ）
をとり、かつ陽極１０２との付着力が碁盤目テープ法
（ＪＩＳＺ１５２２）において、室温下条件でテープに
より剥がれない程度（１３００ｇｆ／２４ｍｍ）の値を
とる必要がある。材料の具体例としては、フタロシアニ
ン誘導体、トリアミン誘導体、パラ−（９−アントリ
ル）−Ｎ，Ｎ−ジ−パラ−トリルアニリン（特開平３−
１１１４８５号公報などに記載のもの）、テトラメチル
−ビス（４−ジ−ｐ−トリルアミノフェニル）−ｐ−キ
シレン（特開平３−２６９０８４号公報などに記載のも
の）などが挙げられる。The hole injection layer 103 to be formed next is a compound which is arranged between two electrodes to which an electric field is applied and which can inject holes from the anode and has good adhesion to the anode. A compound is selected. Specifically, an intermediate value (about 4.9 eV to 6.0 eV) between the ionization potential of the anode 102 and the ionization potential of the hole transport layer 104
In addition, it is necessary that the adhesive force with the anode 102 has a value (1300 gf / 24 mm) at which the tape is not peeled off at room temperature by the cross-cut tape method (JISZ1522). Specific examples of the material include phthalocyanine derivatives, triamine derivatives, para- (9-anthryl) -N, N-di-para-tolylaniline (Japanese Unexamined Patent Publication No.
And the like, and tetramethyl-bis (4-di-p-tolylaminophenyl) -p-xylene (as described in JP-A-3-269084).
【００１７】一方、正孔輸送層１０４に用いられる化合
物としては、正孔を適切に発光層１０５へ伝達しうる材
料であって、例えば１０4 〜１０6 Ｖ／ｃｍの電界印加
時に、少なくとも１０-6ｃｍ2 ／Ｖ・Ｓｅｃの正孔移動
度を持つものが好適である。このような材料について前
記性能を有するものであれば特に制限はなく、電子写真
用材料で従来正孔伝達材料として慣用的に使用されてい
るもの、もしくはＥＬ材料の正孔輸送材料として公知の
ものの中から選択される。具体的には、例えばトリアゾ
ール誘導体（米国特許第３，１１２，１９７号明細書記
載のもの）、オキサジアゾール誘導体（米国特許第３，
１８９，４４７号明細書などに記載）、イミダゾール誘
導体（特公昭３７−１６０９６号などに記載のもの）、
ポリアリールアルカン誘導体（米国特許３，６１５，４
０２号明細書，同３，８２０，９８９号明細書、同３，
５４２，５４４号明細書，特開昭４５−５５５号公報，
同５１−１０９８３号公報，特開昭５１−９３２２４号
公報，同５１−１７１０５号公報，同５６−４１４８号
公報，同５５−１０８６６７号公報，同５５−１５６９
５３号公報，同５６−３６６５６号公報などに記載のも
の）、ピラゾリン誘導体およびピラゾロン誘導体（米国
特許第３，１８０，７２９号明細書，同４，２７８，７
４６号明細書，特開昭５５−８８０６４号公報，同５５
−８８０６５号公報，同４９−１０５５３７号公報，同
５５−５１０８６号公報，同５６−８００５１号公報，
同５６−８８１４１号公報，同５７−４５５４５号公
報，同５４−１１２６３７号公報，同５５−７４５４６
号公報などに記載のもの）、フェニレンジアミン誘導体
（米国特許第３，６１５，４０４号明細書，特公昭５１
−１０１０５号公報，同４６−３７１２号公報，同４７
−２５３３６号公報，特開昭５４−５３４３５号公報，
同５４−１１０５３６号公報，同５４−１１９９２５号
公報などに記載のもの）、アリールアミン誘導体（米国
特許第３，５６７，４５０号明細書，同３，１８０，７
０３号明細書，同３，２４０，５９７号明細書，同３６
５８，５２０号明細書，同４，２３２，１０３号明細
書，同４，１７５，９６１号明細書，同４，０１２，３
７６号明細書，特公昭４９−３５７０２号公報，同３９
−２７５７７号公報，特開昭５５−１４４２５０号公
報，同５６−１１９１３２号公報，同５６−２２４３７
号公報，***特許第１，１１０，５１８号明細書などに
記載のもの）、アミノ置換カルコン誘導体（米国特許第
３，５２６，５０１号明細書などに記載のもの）、オキ
サゾール誘導体（米国特許第３，２５７，２０３号明細
書に記載のもの）、スチリルアントラセン誘導体（特開
昭５６−４６２３４号公報などに記載のもの）、フルオ
レノン誘導体（特開昭５４−１１０８３７号公報などに
記載のもの）、ヒドラゾン誘導体（米国特許３，７１
７，４６２号明細書，特開昭５４−５９１４３号公報，
同５５−５２０６３号公報，同５５−５２０６４号公
報，同５５−４６７６０号公報，同５７−１１３５０号
公報，同５７−１４８７４９号公報などに記載されてい
るもの）、スチルベン誘導体（特開昭６１−２１０３６
３号公報，同６１−２２８４５１号公報，同６１−１４
６４２号公報，同６１−７２２５５号公報，同６２−４
７６４６号公報，同６２−３６６７４号公報，同６２−
１０６５２号公報，同６２−３０２５５号公報，同６０
−９３４４５号公報，同６０−９４４６２号公報，同６
０−１７４７４９号公報，同６０−１７５０５２号公報
などに記載のもの）、ポリフィリン化合物（特開昭６３
−２９５６９５号公報などに記載のもの）、芳香族第三
級アミン化合物およびスチリルアミン化合物（米国特許
４，１２７，４１２号明細書，特開昭５３−２７０３３
号公報，同５４−５８４４５号公報，同５４−１４９６
３４号公報，同５４−６４２９９号公報，同５５−７９
４５０号公報，同５５−１４４２５０号公報，同５６−
１１９１３２号公報，同６１−２９５５５８号公報，同
６１−９８３５３号公報，同６３−２９５６９５号公報
などに記載のもの）などを挙げることができる。On the other hand, the compound used for the hole transport layer 104 is a material capable of appropriately transmitting holes to the light emitting layer 105. For example, when the electric field of 10 4 to 10 6 V / cm is applied, at least 10 Those having a hole mobility of −6 cm 2 / V · Sec are preferred. There is no particular limitation on such a material as long as it has the above-mentioned performance, and any of electrophotographic materials conventionally used as a hole transporting material or those known as a hole transporting material of an EL material can be used. Selected from among. Specifically, for example, a triazole derivative (described in US Pat. No. 3,112,197), an oxadiazole derivative (US Pat. No. 3,112,197)
189,447, etc.), imidazole derivatives (described in JP-B-37-16096, etc.),
Polyarylalkane derivatives (US Pat. No. 3,615,4)
No. 02, 3,820,989, No. 3,
542,544, JP-A-45-555,
JP-A-51-10983, JP-A-51-93224, JP-A-51-17105, JP-A-56-4148, JP-A-55-108667, and JP-A-55-1569.
53, 56-36656, etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. Nos. 3,180,729 and 4,278,7).
46, JP-A-55-88064, 55
JP-A-88065, JP-A-49-105537, JP-A-55-51086, and JP-A-56-80051,
JP-A-56-88141, JP-A-57-45545, JP-A-54-112637, and JP-A-55-74546.
And phenylenediamine derivatives (US Pat. No. 3,615,404, JP-B-51).
Nos. -10105 and 46-3712, 47
JP-A-25-336, JP-A-54-53435,
Nos. 54-110536 and 54-119925, and arylamine derivatives (U.S. Pat. Nos. 3,567,450 and 3,180,7).
No. 03, 3,240, 597, 36
58,520, 4,232,103, 4,175,961, 4,012,3
No. 76, JP-B-49-35702, 39
-27577, JP-A-55-144250, 56-119132 and 56-22437.
No. 1,110,518), amino-substituted chalcone derivatives (such as those described in US Pat. No. 3,526,501), and oxazole derivatives (such as those described in US Pat. No. 3,526,501). 3,257,203), styryl anthracene derivatives (described in JP-A-56-46234, etc.), and fluorenone derivatives (described in JP-A-54-110837, etc.) Hydrazone derivatives (US Pat. No. 3,71
7,462, JP-A-54-59143,
JP-A-55-52063, JP-A-55-52064, JP-A-55-46760, JP-A-57-11350, JP-A-57-148749, etc.), stilbene derivatives (Japanese Unexamined Patent Publication No. Sho 61) −21036
No. 3, No. 61-228451, No. 61-14
Nos. 642, 61-72255, 62-4
7646, 62-36674, 62-
Nos. 10652, 62-30255, 60
-93445, 60-94462, 6
And porphyrin compounds (as disclosed in JP-A Nos. 0-174747 and 60-175052).
No. 2,295,695), aromatic tertiary amine compounds and styrylamine compounds (U.S. Pat. No. 4,127,412, JP-A-53-27033).
Gazette, JP-A-54-58445, JP-A-54-1496
Nos. 34, 54-64299, 55-79
Nos. 450, 55-144250, 56-
No. 119132, No. 61-295558, No. 61-98353, No. 63-295695) and the like.
【００１８】上記ＥＬ素子における発光層１０５材料と
しては、正孔輸送層１０４から注入された正孔および陰
極１０６から注入された電子が再結合する場であるの
で、これらのキャリアが可能な限り再結合する為に、構
造上にキャリアトラップとなるような構造・不純物を含
有してはならない。つまり、材料自体の精製を再結晶や
トレインサブリメーション法を用いて材料純度を９９％
以上まで高める必要がある。さらに、薄膜形成時で発生
する周囲からの不純物混入を避けるために、真空中や不
活性ガス中での作業が好ましい。また、発光層１０５か
らの発光取り出しを効率よく行う為にも、蛍光の量子収
率が高い化合物であるほど好適である。具体的には、テ
トラフェニルブタジエンなどの芳香族化合物（特開昭５
７−５１７８１号公報などに記載のもの）、８−ヒドロ
キシキノリンなどの金属錯体（特開昭５９−１９４３９
３号公報，米国特許第５，１５１，６２９号明細書，米
国特許５，１４１，６７１号明細書などに記載のも
の）、シクロペンタジエン誘導体（特開平２−２８９６
７５号公報などに記載のもの）、ペリノン誘導体（特開
平２−２８９７６号公報などに記載のもの）、オキサジ
アゾール誘導体（特開平２−２１６７９１号公報などに
記載のもの）、ビススチリルベンゼン誘導体（特開平１
−２４５０８７号公報などに記載のもの）、ペリレン誘
導体（特開平２−２８９８９０号公報，同３−７９１号
公報などに記載のもの）、クマリン化合物（特開平２−
１９１６９４号公報，同３−７９２号公報などに記載の
もの）、希土類錯体（特開平１−２５６５８４号公報な
どに記載のもの）、ジスチリルピラジン誘導体（特開平
２−２５６５８４号公報などに記載のもの）、ｐ−フェ
ニレン化合物（特開平３−３３１８３号公報などに記載
のもの）、チアジアゾロピリジン誘導体（特開平３−３
７２９２号公報などに記載のもの）、ピロロピリジン誘
導体（特開平３−３７２９３号公報などに記載のも
の）、ナフチリジン誘導体（特開平３−２０３９８２号
公報などに記載のもの）などが挙げられる。The material of the light emitting layer 105 in the above EL device is a place where holes injected from the hole transport layer 104 and electrons injected from the cathode 106 are recombined. In order to combine them, the structure must not contain a structure or an impurity that may serve as a carrier trap. In other words, the purity of the material itself is reduced to 99% using recrystallization or train sublimation.
It is necessary to increase to the above. Furthermore, in order to avoid contamination from the surroundings that occurs during the formation of the thin film, it is preferable to work in a vacuum or in an inert gas. In order to efficiently extract light from the light-emitting layer 105, a compound having a higher fluorescence quantum yield is more suitable. Specifically, aromatic compounds such as tetraphenylbutadiene (Japanese Unexamined Patent Application Publication No.
And metal complexes such as 8-hydroxyquinoline (JP-A-59-19439).
No. 3, U.S. Pat. No. 5,151,629, U.S. Pat. No. 5,141,671), cyclopentadiene derivative (JP-A-2-2896).
No. 75), perinone derivatives (described in JP-A-2-28976), oxadiazole derivatives (described in JP-A-2-216791), bisstyrylbenzene derivatives (Japanese Unexamined Patent Publication No.
), Perylene derivatives (as described in JP-A-2-289890, JP-A-3-791 and the like), coumarin compounds (as described in JP-A-2-28990).
JP-A-191694, JP-A-3-792, etc.), rare earth complexes (described in JP-A-1-256584, etc.), distyrylpyrazine derivatives (described in JP-A-2-256584, etc.). ), A p-phenylene compound (described in JP-A-3-33183, etc.), a thiadiazolopyridine derivative (JP-A-3-3
No. 7292), pyrrolopyridine derivatives (described in JP-A-3-37293, etc.), and naphthyridine derivatives (described in JP-A-3-203982).
【００１９】次に上記の有機層を陽極１０２上に形成す
る方法について説明する。薄膜を形成する手段には様々
な方法を用いることが可能であるが、均一で緻密な薄膜
構造を得るため、気相からの沈着により薄膜を形成する
方法、すなわち蒸着法を用いることが好ましい。図３は
蒸着法を用いた有機層形成の成膜製造装置の一例であ
る。この成膜製造装置は基板３０２を保持する基板ホル
ダー３０１と、蒸着源３０４およびシャッター３０３
と、水晶振動子３０５とがベルジャー３０６内に設けて
ある。さらに、この蒸着源３０４は成膜コントローラ３
０７によって電流制御可能な電源３０８に連結してお
り、この機構によって所望の蒸着速度、蒸着膜厚を再現
よく得ることができる。Next, a method for forming the above organic layer on the anode 102 will be described. Various methods can be used for forming a thin film. However, in order to obtain a uniform and dense thin film structure, it is preferable to use a method of forming a thin film by deposition from a gas phase, that is, an evaporation method. FIG. 3 shows an example of a film forming apparatus for forming an organic layer using a vapor deposition method. This film forming apparatus includes a substrate holder 301 for holding a substrate 302, an evaporation source 304 and a shutter 303.
And a quartz oscillator 305 are provided in the bell jar 306. Further, the vapor deposition source 304 is
07, it is connected to a power source 308 capable of controlling the current, and this mechanism makes it possible to obtain a desired deposition rate and a deposited film thickness with good reproducibility.
【００２０】実際の蒸着にあたっては、ベルジャー３０
６内の圧力を１０-3Ｐａ以下になるまで減圧し、蒸着源
３０４を用いて化合物の蒸気圧が十分高まるまで加熱す
る。意図する蒸着速度に達したところで蒸着源３０４上
にあるシャッター３０３を開き、蒸着し、目的の膜厚に
達した時点で、シャッター３０３を閉じて作成を止め
る。ここで、蒸着速度は薄膜構造を緻密にする為に、
０．０５〜１．５ｎｍ／Ｓｅｃ程度、膜厚は１００ｎｍ
以下が最適である。基板温度については特に限定されな
いが、有機膜の薄膜性は、溶融、結晶化などにより失わ
れることがあるため、０℃〜１００℃が好ましく、室温
温度とすることが好ましい。また、上記有機層は真空を
破らずに連続蒸着することが望ましく、このため、蒸着
源３０４はＥＬ素子を構成する材料の数だけ設置されて
いることが好適である。In actual deposition, the bell jar 30
The pressure inside 6 is reduced to 10 −3 Pa or less, and heating is performed using the evaporation source 304 until the vapor pressure of the compound is sufficiently increased. When the intended deposition rate is reached, the shutter 303 on the deposition source 304 is opened to perform deposition, and when the target film thickness is reached, the shutter 303 is closed to stop production. Here, the deposition rate is to make the thin film structure dense,
About 0.05-1.5 nm / Sec, film thickness 100 nm
The following are optimal. The substrate temperature is not particularly limited, but the thin film property of the organic film may be lost due to melting, crystallization, or the like. Therefore, the temperature is preferably 0 ° C to 100 ° C, and more preferably the room temperature. In addition, it is desirable that the organic layer be continuously vapor-deposited without breaking the vacuum. Therefore, it is preferable that the vapor-deposition sources 304 are provided by the number of materials constituting the EL element.
【００２１】次に本発明の実施の形態について説明す
る。陰極すなわち電子注入用電極であるサマリウムはそ
れ自体仕事関数が低く、薄膜性に優れているので有機層
形成と同様の方法で成膜可能である。しかし、より安定
性を向上させるためにはアルカリ金属を微量混入する必
要がある。ここで選択されるアルカリ金属とは、リチウ
ム、ナトリウム、カリウム、ルビジウム、セシウムなど
を指し、混入量としては０．００５〜２０モル％、さら
には０．０１〜５モル％程度が最も好適である。これ
は、成膜されたサマリウム分子間隙にアルカリ金属のよ
うな小さな分子が分散され、サマリウムの熱分子運動を
抑制する効果と仕事関数を低下させないような成分比の
合金となる為の条件である。これらの材料についての成
膜法はサマリウム用の蒸着源およびアルカリ金属用の蒸
着源を別々に用意し、上記方法によって共蒸着すればよ
く、アルカリ金属の濃度を上記値になるよう設定するこ
とで達成される。Next, an embodiment of the present invention will be described. Since samarium, which is a cathode, ie, an electrode for electron injection, has a low work function and excellent thin film properties, it can be formed by the same method as that for forming an organic layer. However, in order to further improve the stability, it is necessary to mix a small amount of an alkali metal. The alkali metal selected here refers to lithium, sodium, potassium, rubidium, cesium and the like, and the mixing amount is most preferably about 0.005 to 20 mol%, and more preferably about 0.01 to 5 mol%. . This is a condition in which small molecules such as alkali metals are dispersed in the formed samarium intermolecular gaps, and an alloy having a component ratio that suppresses the thermal molecular motion of samarium and does not lower the work function. . The film formation method for these materials may be prepared by separately providing a deposition source for samarium and a deposition source for alkali metal, and performing co-deposition by the above method, and setting the concentration of the alkali metal to the above value. Achieved.
【００２２】さらに、本発明の第二の形態として、事前
にサマリウムとアルカリ金属をアーク溶解法によって所
望の成分比として作製しておく方法がある。これは、所
望とする金属の成分比を得るためのアルカリ金属の蒸着
速度は小さく（０．００１〜０．０１ｎｍ／ｓｅｃ程
度）、それを蒸着源３０４でコントロールすることは困
難である。そこでこの方法をとることによって簡便にか
つ正確に濃度比をコントロールできる。Further, as a second embodiment of the present invention, there is a method in which samarium and an alkali metal are prepared in advance at a desired component ratio by an arc melting method. This is because the deposition rate of an alkali metal for obtaining a desired metal component ratio is small (about 0.001 to 0.01 nm / sec), and it is difficult to control the deposition rate with the deposition source 304. Therefore, by using this method, the concentration ratio can be easily and accurately controlled.
【００２３】次に本発明を実施例および比較例に基づい
てさらに詳しく説明する。Next, the present invention will be described in more detail based on examples and comparative examples.
【００２４】実施例１ 無アルカリガラスを純水およびイソプロピルアルコール
を用いてそれぞれ３０分間超音波洗浄し、イソプロピル
アルコールに浸漬させた後取り出し、乾燥窒素ガスにて
ブロー乾燥した。さらに、ＵＶオゾン洗浄装置（サムコ
インターナショナル製）で２００℃３０分で洗浄を行っ
たのち、これを基板として、蒸着装置（ＡＮＥＬＶＡ社
製）の基板ホルダーに取り付けた。また、タングステン
製の抵抗加熱ボートにサマリウムを１ｇ入れ、この抵抗
加熱ボートを蒸着装置の端子に取り付けた。そして、真
空槽を４×１０-5Ｐａまで排気し、抵抗加熱ボートに通
電・加熱を行い、０．７ｎｍ／ｓｅｃの蒸着速度になる
よう設定した。この後、基板を覆っているシャッターを
開いて蒸着を開始し、補正した水晶振動子によって膜厚
が１５０ｎｍになるまで成膜した。真空槽を大気圧に戻
し、薄膜を取り出した後、膜表面を表面荒さ計で膜厚測
定すると１５０ｎｍ±７ｎｍのほぼ均一な鏡面であっ
た。さらに、この薄膜の反射率を測定した結果、波長５
００〜５５０ｎｍで７８％、波長４００〜４５０ｎｍで
８５％と良好な値を示した。また、４端子法による面抵
抗の測定により求めた値と膜厚から算出した抵抗率の温
度係数は１．８４×１０-3Ｋ-1と良好な値を示した。
「化学便覧」改訂４版：基礎編ＩＩ・丸善・平成５年に
よるとＡｌ単体の抵抗率の温度係数は４．２９×１０-3
Ｋ-1である。したがって、この実施例で得られた薄膜は
これに比べても良好な値を保有しており、薄膜構造の安
定性に優れていることがわかる。また、この薄膜を光電
子放出法によって仕事関数を測定すると２．７ｅＶとい
う値が得られ、電子注入用電極として優れていることが
分かった。Example 1 An alkali-free glass was subjected to ultrasonic cleaning using pure water and isopropyl alcohol for 30 minutes each, immersed in isopropyl alcohol, taken out, and blow-dried with dry nitrogen gas. Further, after cleaning was performed at 200 ° C. for 30 minutes by a UV ozone cleaning device (manufactured by Samco International), the substrate was mounted on a substrate holder of a vapor deposition device (manufactured by ANELVA) as a substrate. Further, 1 g of samarium was put into a tungsten resistance heating boat, and this resistance heating boat was attached to a terminal of a vapor deposition apparatus. Then, the vacuum chamber was evacuated to 4 × 10 −5 Pa, the resistance heating boat was energized and heated, and the deposition rate was set to 0.7 nm / sec. Thereafter, the shutter covering the substrate was opened to start vapor deposition, and a film was formed by the corrected quartz oscillator until the film thickness became 150 nm. After the vacuum chamber was returned to atmospheric pressure and the thin film was taken out, the film surface was measured for film thickness with a surface roughness meter. Further, as a result of measuring the reflectivity of this thin film, the wavelength
A good value of 78% at 00 to 550 nm and 85% at a wavelength of 400 to 450 nm was shown. Further, the temperature coefficient of resistivity calculated from the value obtained by measuring the sheet resistance by the four-terminal method and the film thickness showed a good value of 1.84 × 10 −3 K −1 .
According to "Chemical Handbook" 4th revised edition: Basics II, Maruzen, 1993, the temperature coefficient of resistivity of Al alone is 4.29 × 10 -3.
K- 1 . Therefore, the thin film obtained in this example has a better value than this, which indicates that the stability of the thin film structure is excellent. When the work function of this thin film was measured by a photoelectron emission method, a value of 2.7 eV was obtained, which proved to be excellent as an electrode for electron injection.
【００２５】実施例２〜６ 実施例１と同様の方法で基板およびサマリウムを蒸着装
置にセットすること以外に、第１表に示した材料をタン
グステン製ボートに１ｇ入れたものを別の蒸着装置内の
端子に取り付けた。真空槽を１×１０-4Ｐａになるまで
排気し、まず、第１表に示した材料が入ったボートに通
電し、これを加熱して第１表記載の蒸着速度になるよう
設定した。次に、サマリウムが入ったボートに通電し、
加熱を行うことで０．７ｎｍ／ｓｅｃに設定した。この
後、基板を覆っていたシャッターを開いて上記二つの材
料を同時に蒸着し、補正した水晶振動子により膜厚が１
７０ｎｍとなったところで再度シャッターを閉じて成膜
を完了した。真空槽を大気圧に戻し、薄膜を取り出し光
電子放出法で仕事関数を、表面荒さ計で膜厚分布を、さ
らに面抵抗の温度計数を測定した（第１表）。第１表に
示すように、各種のアルカリ金属を用いてサマリウム：
アルカリ金属合金からなる優れた電極用薄膜を得ること
ができた。Examples 2 to 6 In addition to setting the substrate and samarium in a vapor deposition apparatus in the same manner as in Example 1, a tungsten boat containing 1 g of the materials shown in Table 1 was used in another vapor deposition apparatus. Attached to the terminal inside. The vacuum chamber was evacuated to 1 × 10 −4 Pa. First, the boat containing the materials shown in Table 1 was energized and heated to set the vapor deposition rate as shown in Table 1. Next, energize the boat containing samarium,
It was set to 0.7 nm / sec by heating. Thereafter, the shutter covering the substrate is opened, and the above two materials are simultaneously vapor-deposited.
When the thickness reached 70 nm, the shutter was closed again to complete the film formation. The vacuum chamber was returned to atmospheric pressure, the thin film was taken out, the work function was measured by a photoelectron emission method, the film thickness distribution was measured by a surface roughness meter, and the temperature coefficient of sheet resistance was measured (Table 1). As shown in Table 1, samarium using various alkali metals:
An excellent thin film for an electrode made of an alkali metal alloy was obtained.
【００２６】[0026]
【表１】 [Table 1]
【００２７】実施例７ リチウムがサマリウムに対して０．０２モル％となるよ
うな組成比で、両者をアーク溶解炉中にセットし、これ
を１２００℃に加熱・溶融させた後、室温になるまで放
置するとサマリウム：リチウムからなる合金が得られ
る。次に実施例１と同様に基板をセットした後、この材
料をタングステン製のボートに１ｇ入れ装置内の端子に
取り付けた。そして、真空槽を２×１０-4Ｐａまで排気
し、ボートに通電・加熱を行った。蒸着速度が０．５ｎ
ｍ／ｓｅｃとなったところで基板を覆っているシャッタ
ーを開け、蒸着を開始し、水晶振動子により膜厚が１７
０ｎｍとなったところでシャッターを閉じて成膜を完了
した。真空槽を大気圧に戻し、サマリウム：リチウムか
らなる薄膜を取り出した後、これをＩＣＰにより組成分
析を行うとリチウムが０．０４モル％混入されているこ
とが確認できた。さらに、仕事関数を測定したところ
２．７ｅＶであり、電子注入電極として優れた性能を有
することが分かった。また、仕事関数の時間依存性を測
定すると、２７０時間経過後においても初期の値（２．
７ｅＶ）を維持しており、薄膜構造が安定であることが
分かった。Example 7 Both were set in an arc melting furnace at a composition ratio such that lithium was 0.02 mol% with respect to samarium, and heated and melted at 1200 ° C., and then cooled to room temperature. When left to stand, an alloy consisting of samarium: lithium is obtained. Next, after setting the substrate in the same manner as in Example 1, 1 g of this material was put in a tungsten boat and attached to the terminals in the apparatus. Then, the vacuum chamber was evacuated to 2 × 10 −4 Pa, and the boat was energized and heated. 0.5n deposition rate
At m / sec, the shutter covering the substrate was opened to start evaporation, and the film thickness was reduced to 17 by a quartz oscillator.
When the thickness reached 0 nm, the shutter was closed to complete the film formation. After the vacuum chamber was returned to atmospheric pressure and a thin film composed of samarium: lithium was taken out, and subjected to composition analysis by ICP, it was confirmed that lithium was incorporated at 0.04 mol%. Further, when the work function was measured, it was 2.7 eV, and it was found that the work function was excellent as an electron injection electrode. When the time dependence of the work function is measured, the initial value (2.
7 eV), and it was found that the thin film structure was stable.
【００２８】比較例１ アルカリ金属の代わりに特開平４−２３０９９７に記載
の５，１０，１５，２０−テトラフェニルポリフィリン
（ＴＰＰ）を用いたこと以外は実施例２〜６と同様な方
法でサマリウム：ＴＰＰからなる薄膜を作成した。この
薄膜の仕事関数を測定した結果、３．２ｅＶとサマリウ
ム単体よりも０．５ｅＶ高い値となった。さらに仕事関
数の時間依存性を測定すると約１００時間経過時に３．
８ｅＶと約０．６ｅＶの上昇がみられた。このことは換
言すると、電子の注入が経時で悪劣化することを意味し
ている。Comparative Example 1 Samarium was prepared in the same manner as in Examples 2 to 6, except that 5,10,15,20-tetraphenylporphyrin (TPP) described in JP-A-4-230997 was used in place of the alkali metal. : A thin film made of TPP was prepared. As a result of measuring the work function of this thin film, it was 3.2 eV, a value higher by 0.5 eV than that of samarium alone. Further, when the time dependency of the work function is measured, it is determined that the time is about 100 hours.
8 eV and an increase of about 0.6 eV were observed. In other words, this means that the electron injection deteriorates with time.
【００２９】実施例８ ＩＴＯ付き白板ガラス（ＨＯＹＡ社製）を純水とイソプ
ロピルアルコールにて、それぞれ超音波洗浄を４０分間
行ったあと、さらに沸騰させたイソプロピルアルコール
上で乾燥させた。さらにＵＶ，オゾン洗浄装置にてこの
基板を１０分間洗浄し、真空蒸着装置（ＡＮＥＬＶＡ社
製）の基板ホルダーに取り付けた。また、モリブデン製
抵抗加熱用ボートに正孔注入材料パラー（９−アントリ
ル）−Ｎ，Ｎ−ジ−パラ−トリヌアニリン（ＰＡＰＴ
Ａ）を１００ｍｇ入れ、これを通電用端子に取り付け
た。さらに、別のモリブデン製ボートに正孔輸送材料Ｔ
ＰＤを２００ｍｇ入れ、これを別の通電用端子に取り付
けた。最後に発光材料として８−キノリノールアルミ錯
体を２００ｍｇモリブデン製ボートに入れ、真空槽を２
×１０-4Ｐａまで排気した。そして、ＰＡＰＴＡの入っ
たボートに通電し、０．２〜０．３ｎｍ／ｓｅｃの蒸着
速度で４０ｎｍの膜厚になるまで蒸着した。次にＴＰＤ
の入ったボートに通電し、これを０．２〜０．３ｎｍ／
ｓｅｃの蒸着速度で２０ｎｍの膜厚となるよう蒸着し
た。最後に前記方法と同様に８−キノリノールアルミ錯
体を０．３〜０．５ｎｍ／ｓｅｃの速度で５０ｎｍ成膜
した。次に真空槽を大気圧に戻し、基盤／ＰＡＰＴＡ層
／ＴＰＤ層／８−キノリノールアルミ錯体層の上部にス
テンレス製蒸着マスクを取り付けた。Example 8 A white plate glass with ITO (manufactured by HOYA) was subjected to ultrasonic cleaning with pure water and isopropyl alcohol for 40 minutes, respectively, and then dried over boiling isopropyl alcohol. The substrate was further washed for 10 minutes with a UV / ozone cleaning device, and attached to a substrate holder of a vacuum evaporation device (manufactured by ANELVA). Further, a hole injection material para (9-anthryl) -N, N-di-para-trinuaniline (PAPT) was added to a molybdenum resistance heating boat.
A) was charged in an amount of 100 mg and attached to a current-carrying terminal. Further, another molybdenum boat was used to transport the hole transport material T
200 mg of PD was put, and this was attached to another energizing terminal. Finally, 200 mg of 8-quinolinol aluminum complex was put into a molybdenum boat as a luminescent material, and the vacuum chamber was
Evacuation was performed to × 10 −4 Pa. Then, electricity was supplied to the boat containing PAPTA, and vapor deposition was performed at a vapor deposition rate of 0.2 to 0.3 nm / sec until the film thickness reached 40 nm. Next, TPD
Is supplied to the boat containing 0.2 to 0.3 nm /
The deposition was performed at a deposition rate of sec to a thickness of 20 nm. Finally, an 8-quinolinol aluminum complex was formed into a 50 nm film at a rate of 0.3 to 0.5 nm / sec in the same manner as in the above method. Next, the vacuum chamber was returned to atmospheric pressure, and a stainless steel vapor deposition mask was mounted on the base / PAPTA layer / TPD layer / 8-quinolinol aluminum complex layer.
【００３０】また、タングステン製ボートにサマリウム
を１ｇ入れ、通電用端子に取り付けた。真空槽を１×１
０-4Ｐａまで排気した後、前記端子に通電を行い、サマ
リウムの蒸着速度が０．８〜１．２ｎｍ／ｓｅｃになる
よう調節した。蒸着速度が安定したところで基板を覆っ
ているシャッターを開け、膜厚１７０ｎｍになるまで蒸
着を行った。再び真空槽を大気下に戻し、ガラス／ＩＴ
Ｏ／ＰＡＰＴＡ層／ＴＰＤ層／８−キノリノールアルミ
錯体層／サマリウムよりなるＥＬ素子を作製した。この
素子のＩＴＯを正極、サマリウム電極を負極にし、５Ｖ
印加した結果、電流が１０ｍＡ／ｃｍ2 流れ、輝度２０
００ｃｄ／ｍ2 の緑色発光を得た。この時の発光効率は
１２．７ルーメン／ワット（Ｉｍ／Ｗ）であった。ま
た、この素子を大気中で５０００時間保存した後、ダー
クスポット面積の観察を行った結果、発光面積に対する
割合は約５％であった。さらに、サマリウムからなる陰
極部を碁盤目テープ法によって引き剥し、密着力を評価
すると、その負荷は１５００ｇｆ／２４ｍｍであった。Further, 1 g of samarium was put into a tungsten boat, and attached to a current-carrying terminal. 1 × 1 vacuum chamber
After evacuation to 0 -4 Pa, the terminals were energized to adjust the samarium deposition rate to 0.8 to 1.2 nm / sec. When the deposition rate was stabilized, the shutter covering the substrate was opened, and deposition was performed until the film thickness reached 170 nm. The vacuum chamber is returned to the atmosphere again, and the glass / IT
An EL device composed of O / PAPTA layer / TPD layer / 8-quinolinol aluminum complex layer / samarium was produced. The ITO of this element was used as a positive electrode and the samarium electrode was used as a negative electrode.
As a result, a current of 10 mA / cm 2 flows and a luminance of 20
Green light emission of 00 cd / m 2 was obtained. The luminous efficiency at this time was 12.7 lumen / watt (Im / W). After storing the device in the air for 5000 hours, the area of the dark spot was observed. As a result, the ratio to the light emitting area was about 5%. Further, when the cathode portion made of samarium was peeled off by a grid tape method and the adhesion was evaluated, the load was 1500 gf / 24 mm.
【００３１】実施例９ 実施例８と同様にして基板／ＩＴＯ／ＰＡＰＴＡ層／Ｔ
ＰＤ層／８−キノリノールアルミ錯体層を作製した後、
サマリウムのみからなる陰極にかえてサマリウム：リチ
ウムからなる陰極を作製した。蒸着速度はサマリウムが
０．７〜１．２ｎｍ／ｓｅｃ、リチウムが０．００８〜
０．０１ｎｍ／ｓｅｃであり膜厚は１７０ｎｍであっ
た。実施例８と同様に通電試験を行った結果、５Ｖ印加
した時に、１２ｍＡ／ｃｍ2 の電流が流れ、輝度２８０
０ｃｄ／ｍ2 を得た。この時の発光効率は１４．７１ｍ
／Ｗであった。また、この素子を大気中で５０００時間
保存した後、ダークスポット面積の観察を行った結果、
発光面積に対する割合は約１％であった。さらに、サマ
リウム：リチウムからなる陰極部を碁盤目テープ法によ
って引き剥がし、密着力を評価すると、その負荷は１８
００ｇｆ／２４ｍｍであった。Example 9 In the same manner as in Example 8, the substrate / ITO / PAPTA layer / T
After preparing a PD layer / 8-quinolinol aluminum complex layer,
A cathode composed of samarium: lithium was produced in place of the cathode composed of only samarium. The deposition rate is 0.7 to 1.2 nm / sec for samarium and 0.008 to lithium.
It was 0.01 nm / sec and the film thickness was 170 nm. As a result of conducting an energization test in the same manner as in Example 8, when a voltage of 5 V was applied, a current of 12 mA / cm 2 flowed and a luminance of 280
0 cd / m 2 was obtained. The luminous efficiency at this time is 14.71 m
/ W. After storing the device for 5000 hours in the air, the dark spot area was observed.
The ratio to the light emitting area was about 1%. Further, when the cathode portion made of samarium: lithium was peeled off by the grid tape method and the adhesion was evaluated, the load was 18%.
It was 00 gf / 24 mm.
【００３２】実施例１０ 実施例８と同様にして基板／ＩＴＯ／ＰＡＰＴＡ層／Ｔ
ＰＤ層／８−キノリノールアルミ錯体層を作製した後、
サマリウムのみからなる陰極に代えて、あらかじめ実施
例７の方法により合金化されたサマリウム：リチウムか
らなる陰極を作製した。蒸着速度はサマリウム：リチウ
ム合金が０．５ｎｍ／ｓｅｃであり、膜厚は１７ｎｍで
あった。実施例８と同様に通電試験を行った結果、５Ｖ
印加したときに１２．４ｍＡ／ｃｍ2 の電流が流れ、そ
のときの輝度は２８７０ｃｄ／ｍ2 であった。この時の
発光効率は１４．５１ｍ／Ｗであった。また、この素子
を大気中で５０００時間保存した後、ダークスポット面
積の観察を行った結果、発光面積に対する割合は約１．
１％であった。さらに、サマリウム：リチウムからなる
陰極部を碁盤目テープ法によって引き剥がし、密着力を
評価すると、その負荷は１８２０ｇｆ／２４ｍｍであっ
た。Example 10 In the same manner as in Example 8, the substrate / ITO / PAPTA layer / T
After preparing a PD layer / 8-quinolinol aluminum complex layer,
Instead of the cathode composed of samarium alone, a cathode composed of samarium: lithium alloyed in advance by the method of Example 7 was produced. The deposition rate was 0.5 nm / sec for samarium: lithium alloy, and the film thickness was 17 nm. As a result of conducting an energization test in the same manner as in Example 8, 5 V
When applied, a current of 12.4 mA / cm 2 flowed, and the luminance at that time was 2870 cd / m 2 . The luminous efficiency at this time was 14.51 m / W. After the device was stored in the air for 5000 hours, the area of the dark spot was observed.
1%. Further, when the cathode portion made of samarium: lithium was peeled off by a grid tape method and the adhesion was evaluated, the load was 1,820 gf / 24 mm.
【００３３】比較例２ 実施例８と同様にして基板／ＩＴＯ／ＰＡＰＴＡ層／Ｔ
ＰＤ層／８−キノリノールアルミ錯体層を作製した後、
リチウムの代わりに特開平４−２３０９９７に記載の
５，１０，１５，２０−テトラフェニルポリフィリン
（ＴＰＰ）を用いたこと以外は実施例８と同様な方法で
サマリウム：ＴＰＰからなる薄膜を作製した。この時の
蒸着速度はサマリウムが０．７〜１．２ｎｍ／ｓｅｃ、
ＴＰＰで０．０５〜０．０６ｎｍ／ｓｅｃで膜厚１７０
ｎｍとなるまで蒸着し、素子を作製した。このガラス／
ＩＴＯ／ＰＡＰＴＡ層／ＴＰＤ層／８−キノリノールア
ルミ錯体層／サマリウム：ＴＰＰを実施例８と同様に通
電試験を行った結果、６Ｖ印加時に１４ｍＡ／ｃｍ2 の
電流が流れ、輝度は２８０ｃｄ／ｍ2 であった。この時
の発光効率は１．０１ｍ／Ｗであった。Comparative Example 2 Substrate / ITO / PAPTA layer / T
After preparing a PD layer / 8-quinolinol aluminum complex layer,
A thin film composed of samarium: TPP was prepared in the same manner as in Example 8, except that 5,10,15,20-tetraphenylporphyrin (TPP) described in JP-A-4-230997 was used instead of lithium. The deposition rate at this time is 0.7 to 1.2 nm / sec for samarium,
Film thickness 170 at 0.05 to 0.06 nm / sec by TPP
The element was formed by vapor deposition until the thickness became nm. This glass /
An ITO / PAPTA layer / TPD layer / 8-quinolinol aluminum complex layer / samarium: As a result of conducting an electric current test in the same manner as in Example 8, a current of 14 mA / cm 2 flows when 6 V is applied, and the luminance is 280 cd / m 2. Met. At this time, the luminous efficiency was 1.01 m / W.
【００３４】また、この素子を大気中で１００時間保存
した後、ダークスポット面積の観察を行った結果、発光
面積に対する割合は約８０％であった。さらに、サマリ
ウム：ＴＰＰからなる陰極部を碁盤目テープ法によって
引き剥がし、密着力を評価すると、その負荷は５００ｇ
ｆ／２４ｍｍであった。After the device was stored in the air for 100 hours, the dark spot area was observed. As a result, the ratio to the light emitting area was about 80%. Further, the cathode portion made of samarium: TPP was peeled off by a grid tape method, and the adhesion was evaluated. The load was 500 g.
f / 24 mm.
【００３５】[0035]
【発明の効果】以上説明したように、本発明の薄膜電子
注入用電極を用いることによる第１の効果は、ＥＬ素子
用電極として使用することで長寿命化が図れることにあ
る。その理由は、サマリウムを用いると、薄膜の均一
製、緻密製が高まり、下地となる有機層への密着力が向
上するとともに、酸化などによる仕事関数の悪劣化のな
い安定構造をとるためである。As described above, the first effect of the use of the thin-film electron injection electrode of the present invention is that the life can be extended by using it as an EL element electrode. The reason for this is that when samarium is used, the uniformity and denseness of the thin film are increased, the adhesion to the underlying organic layer is improved, and a stable structure is obtained that does not deteriorate the work function due to oxidation or the like. .
【００３６】第２の効果はＥＬ素子の発光効率を高め、
発光の均一性を与えることができ、かつ低電圧で高輝度
のＥＬ発光が得られることにある。その理由はサマリウ
ム：アルカリ金属のもつ仕事関数の低さにより、電子の
注入が容易に起こり得ることによる。このような効果に
加えて、従来の蒸着法により容易に成膜できる為、有機
膜などに対して損傷を与えることもない。以上の理由か
ら、本発明の薄膜電極を用いたＥＬ素子は、各種表示装
置の発光材料として、有効な利用が期待される。The second effect is to increase the luminous efficiency of the EL element,
The object is to provide uniformity of light emission and to obtain high-luminance EL light emission at a low voltage. The reason is that electron injection can easily occur due to the low work function of samarium: alkali metal. In addition to such an effect, since a film can be easily formed by a conventional vapor deposition method, there is no damage to an organic film or the like. For the above reasons, the EL element using the thin film electrode of the present invention is expected to be effectively used as a light emitting material for various display devices.
【図１】本発明の実施の形態を示す斜視図である。FIG. 1 is a perspective view showing an embodiment of the present invention.
【図２】従来のＥＬ素子の構造を示した斜視図である。FIG. 2 is a perspective view showing a structure of a conventional EL element.
【図３】本発明の製造装置を示す構成図である。FIG. 3 is a configuration diagram showing a manufacturing apparatus of the present invention.
１０１ 支持基板 １０２ 陽極 １０３ 正孔注入層 １０４ 正孔輸送層 １０５ 発光層 １０６ 陰極 ２０１ ＭｇＡｇ陰極 ３０１ 基板ホルダー ３０２ 基板 ３０３ シャッター ３０４ 蒸着源 ３０５ 水晶振動子 ３０６ ベルジャー ３０７ 成膜コントローラ ３０８ 電源 ３０９ リーク弁 ３１０ 排気系 Reference Signs List 101 support substrate 102 anode 103 hole injection layer 104 hole transport layer 105 light emitting layer 106 cathode 201 MgAg cathode 301 substrate holder 302 substrate 303 shutter 304 evaporation source 305 crystal oscillator 306 bell jar 307 film formation controller 308 power supply 309 leak valve 310 exhaust system
Claims (7)
を含有することを特徴とする発光素子用電極。1. An electrode for a light emitting element, wherein the electrode for electron injection contains at least samarium.
ル％以上のサマリウムおよび０．０１〜５モル％のアル
カリ金属を含有することを特徴とする発光素子用電極。2. An electrode for a light emitting element, which comprises at least 1 mol% or more of samarium and 0.01 to 5 mol% of an alkali metal as an electron injection electrode.
成することを特徴とする発光素子用電極の製造方法。3. A method of manufacturing an electrode for a light emitting device, wherein the electrode for electron injection is formed by co-evaporation.
用電極材料が予めアーク溶融法により合金化され、これ
を前記電子注入用電極としてただ１つの蒸発源から蒸着
法によって形成することを特徴とする発光素子用電極の
製造方法。4. The method according to claim 1, wherein the electrode material for electron injection according to claim 1 or 2 is alloyed in advance by an arc melting method, and is formed as an electrode for electron injection from a single evaporation source by a vapor deposition method. A method for manufacturing an electrode for a light-emitting element, which is characterized by the following.
用電極を、陰極として用いることを特徴とするＥＬ素
子。5. An EL device, wherein the electrode for a light-emitting device according to claim 1 or 2 is used as a cathode.
機発光層を含む１層以上の有機薄膜層を順次積層して構
成されるＥＬ素子の製造方法において、請求項１または
請求項２記載の電子注入用電極を共蒸着して陰極を形成
することを特徴とするＥＬ素子の製造方法。6. The method according to claim 1, wherein at least one organic thin-film layer including at least an organic light-emitting layer is sequentially laminated between electrodes facing each other. A method for manufacturing an EL device, comprising forming a cathode by co-evaporating an injection electrode.
機発光層を含む１層以上の有機薄膜層を順次積層して構
成されるＥＬ素子の製造方法において、請求項４に記載
の方法により陰極形成することを特徴とするＥＬ素子の
製造方法。7. A method for manufacturing an EL device, comprising: sequentially laminating one or more organic thin-film layers including at least an organic light-emitting layer between electrodes facing each other, forming a cathode by the method according to claim 4. A method of manufacturing an EL element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8308077A JP2828076B2 (en) | 1996-11-19 | 1996-11-19 | Electrode for light emitting element, method of manufacturing the same, and EL element having the electrode and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8308077A JP2828076B2 (en) | 1996-11-19 | 1996-11-19 | Electrode for light emitting element, method of manufacturing the same, and EL element having the electrode and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10149884A true JPH10149884A (en) | 1998-06-02 |
| JP2828076B2 JP2828076B2 (en) | 1998-11-25 |
Family
ID=17976604
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8308077A Expired - Fee Related JP2828076B2 (en) | 1996-11-19 | 1996-11-19 | Electrode for light emitting element, method of manufacturing the same, and EL element having the electrode and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2828076B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9627644B2 (en) | 2013-02-08 | 2017-04-18 | Samsung Display Co., Ltd. | Organic light emitting diode device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04230997A (en) * | 1990-06-14 | 1992-08-19 | Idemitsu Kosan Co Ltd | Thin film electrode for element, electroluminescence element with it, and manufacture thereof |
| JPH05251185A (en) * | 1992-03-06 | 1993-09-28 | Idemitsu Kosan Co Ltd | Organic electroluminescence element |
-
1996
- 1996-11-19 JP JP8308077A patent/JP2828076B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04230997A (en) * | 1990-06-14 | 1992-08-19 | Idemitsu Kosan Co Ltd | Thin film electrode for element, electroluminescence element with it, and manufacture thereof |
| JPH05251185A (en) * | 1992-03-06 | 1993-09-28 | Idemitsu Kosan Co Ltd | Organic electroluminescence element |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9627644B2 (en) | 2013-02-08 | 2017-04-18 | Samsung Display Co., Ltd. | Organic light emitting diode device |
| TWI622197B (en) * | 2013-02-08 | 2018-04-21 | 三星顯示器有限公司 | Organic light emitting diode device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2828076B2 (en) | 1998-11-25 |
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