Effect of Al/LiF cathodes on emission efficiency of organic EL devices

被引:71
作者
Matsumura, M
Furukawa, K
Jinde, Y
机构
[1] Osaka Univ, Res Ctr Photoenerget Organ Mat, Osaka 5608531, Japan
[2] Minolta Co Ltd, Takatsuki Res Lab, Osaka 5690807, Japan
关键词
organic EL; electroluminescence; cathode; LiF;
D O I
10.1016/S0040-6090(98)00904-3
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
It has been reported that operational voltages of organic electroluminescent devices are much lowered by interposing a very thin LiF layer between an Al cathode and an Al-hydroxyquinoline (light emitting material) layer. At the same time, emission efficiency is increased. From the analyses of emission and currents of the devices, we attributed the lowering of the operational voltage to the enhanced electron injection due to a lowered work function of the cathode. The increased electron injection rate leads to a shift of the light emitting zone to a region close to the organic/organic interface. This shift was concluded to be the reason for the improvement of emission efficiency owing to die favorable interference effect of light in the device. (C) 1998 Elsevier Science S.A. All rights reserved.
引用
收藏
页码:96 / 100
页数:5
相关论文
共 9 条
[1]   Lithium-aluminum contacts for organic light-emitting devices [J].
Haskal, EI ;
Curioni, A ;
Seidler, PF ;
Andreoni, W .
APPLIED PHYSICS LETTERS, 1997, 71 (09) :1151-1153
[2]   Enhanced electron injection in organic electroluminescence devices using an Al/LiF electrode [J].
Hung, LS ;
Tang, CW ;
Mason, MG .
APPLIED PHYSICS LETTERS, 1997, 70 (02) :152-154
[3]   ELECTRON AND HOLE MOBILITY IN TRIS(8-HYDROXYQUINALINOLATO-N1,O8) ALUMINUM [J].
KEPLER, RG ;
BEESON, PM ;
JACOBS, SJ ;
ANDERSON, RA ;
SINCLAIR, MB ;
VALENCIA, VS ;
CAHILL, PA .
APPLIED PHYSICS LETTERS, 1995, 66 (26) :3618-3620
[4]   Analysis of current-voltage characteristics of organic electroluminescent devices on the basis of schottky emission mechanism [J].
Matsumura, M ;
Jinde, Y ;
Akai, T ;
Kimura, T .
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 1996, 35 (11) :5735-5739
[5]   Voltage dependence of light-emitting zone in aluminum-hydroxyquinoline layers of organic heterojunction EL devices [J].
Matsumura, M ;
Jinde, Y .
IEEE TRANSACTIONS ON ELECTRON DEVICES, 1997, 44 (08) :1229-1233
[6]   Height of the energy barrier existing between cathodes and hydroxyquinoline-aluminum complex of organic electroluminescence devices [J].
Matsumura, M ;
Akai, T ;
Saito, M ;
Kimura, T .
JOURNAL OF APPLIED PHYSICS, 1996, 79 (01) :264-268
[7]   CARRIER TUNNELING AND DEVICE CHARACTERISTICS IN POLYMER LIGHT-EMITTING-DIODES [J].
PARKER, ID .
JOURNAL OF APPLIED PHYSICS, 1994, 75 (03) :1656-1666
[8]  
Sato Y., 1996, Inorganic and Organic Electroluminescence, P255
[9]  
WAKIMOTO T, 1994, INT S IN ORG EL HAM, P77