The initial state of dark spots in degradation of polymer lighting-emitting diodes

被引:20
作者
Do, LM [1 ]
Hwang, DH [1 ]
Chu, HY [1 ]
Kim, SH [1 ]
Lee, JI [1 ]
Park, H [1 ]
Zyung, T [1 ]
机构
[1] Elect & Telecommun Res Inst, Yusong Gu, Taejon 305600, South Korea
关键词
degradation; electroluminescence; surface defects; interfaces; pin hole;
D O I
10.1016/S0379-6779(99)00374-4
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The initial state of dark spots in polymer light-emitting diodes (PLEDs) with poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) layer as an emissive layer has been investigated by in situ measurement with the interferometer, fluorescence microscope, and other various analytical instruments. Degradation of the device initiates with the dark spot that is the non-emissive portion of the polymer layer. The cross-sectional profile of interferometer image of Al electrode changes with operating time from dip to con-shaped sharp peak. It is clear that the dark spot originates from the pinhole leading to the severe damages on the microstructure of the polymer layer, polymer/metal interface, and metal electrode. Interferometer is a powerful tool for the investigation of the short-term degradation behavior of the polymeric EL devices. (C) 2000 Published by Elsevier Science S.A. All rights reserved.
引用
收藏
页码:249 / 251
页数:3
相关论文
共 11 条
[1]   Humidity-induced crystallization of tris (8-hydroxyquinoline) aluminum layers in organic light-emitting devices [J].
Aziz, H ;
Popovic, Z ;
Xie, S ;
Hor, AM ;
Hu, NX ;
Tripp, C ;
Xu, G .
APPLIED PHYSICS LETTERS, 1998, 72 (07) :756-758
[2]   Stability of polymer light-emitting diodes [J].
Berntsen, AJM ;
Van de Weijer, P ;
Croonen, Y ;
Liedenbaum, CTHF ;
Vleggaar, JJM .
PHILIPS JOURNAL OF RESEARCH, 1998, 51 (04) :511-525
[3]   LIGHT-EMITTING-DIODES BASED ON CONJUGATED POLYMERS [J].
BURROUGHES, JH ;
BRADLEY, DDC ;
BROWN, AR ;
MARKS, RN ;
MACKAY, K ;
FRIEND, RH ;
BURN, PL ;
HOLMES, AB .
NATURE, 1990, 347 (6293) :539-541
[4]   Electromigration of aluminum cathodes in polymer-based electroluminescent devices [J].
Cumpston, BH ;
Jensen, KF .
APPLIED PHYSICS LETTERS, 1996, 69 (25) :3941-3943
[5]   In situ investigation of degradation in polymeric electroluminescent devices using time-resolved confocal laser scanning microscope [J].
Do, LM ;
Kim, KJ ;
Zyung, T ;
Shim, HK ;
Kim, JJ .
APPLIED PHYSICS LETTERS, 1997, 70 (25) :3470-3472
[6]   OBSERVATION OF DEGRADATION PROCESSES OF AL ELECTRODES IN ORGANIC ELECTROLUMINESCENCE DEVICES BY ELECTROLUMINESCENCE MICROSCOPY, ATOMIC FARCE MICROSCOPY, SCANNING ELECTRON-MICROSCOPY, AND ANGER ELECTRON-SPECTROSCOPY [J].
DO, LM ;
HAN, EM ;
NIIDOME, Y ;
FUJIHIRA, M ;
KANNO, T ;
YOSHIDA, S ;
MAEDA, A ;
IKUSHIMA, AJ .
JOURNAL OF APPLIED PHYSICS, 1994, 76 (09) :5118-5121
[7]   Lifetime and degradation effects in polymer light-emitting diodes [J].
Parker, ID ;
Cao, Y ;
Yang, CY .
JOURNAL OF APPLIED PHYSICS, 1999, 85 (04) :2441-2447
[8]   Degradation of nonencapsulated polymer-based light-emitting diodes: Noise and morphology [J].
Savvateev, VN ;
Yakimov, AV ;
Davidov, D ;
Pogreb, RM ;
Neumann, R ;
Avny, Y .
APPLIED PHYSICS LETTERS, 1997, 71 (23) :3344-3346
[9]   Degradation and failure of MEH-PPV light-emitting diodes [J].
Scott, JC ;
Kaufman, JH ;
Brock, PJ ;
DiPietro, R ;
Salem, J ;
Goitia, JA .
JOURNAL OF APPLIED PHYSICS, 1996, 79 (05) :2745-2751
[10]   ORGANIC ELECTROLUMINESCENT DIODES [J].
TANG, CW ;
VANSLYKE, SA .
APPLIED PHYSICS LETTERS, 1987, 51 (12) :913-915