Degradation mechanism of phosphorescent-dye-doped polymer light-emitting diodes

被引：110

作者：

Chang, SC ^{[1
]}

He, G ^{[1
]}

Chen, FC ^{[1
]}

Guo, TF ^{[1
]}

Yang, Y ^{[1
]}

机构：

[1] Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA

来源：

APPLIED PHYSICS LETTERS | 2001年 / 79卷 / 13期

关键词：

D O I：

10.1063/1.1404995

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The degradation mechanism of phosphorescent-dye-doped polymer light-emitting diodes (PLEDs) is investigated. The active medium of our PLED is a polymer blend comprising poly(vinylcarbazole) (PVK), [2-(4-biphenylyl)-5-(4-tert-butyl-phenyl)-1,3,4-oxadiazole] (t-PBD), and platinum(II)-2,8,12,17-tetraethyl-3,7,13,18-tetramethylporphyrin (PtOX). The cyclic voltammetry result shows that the reductive reversibility of PtOX is poor. This result suggests that PLED doped with PtOX is not stable if PtOXs trap electrons and turn into anionic PtOX species. This was indeed verified by fabricating single-layer PLEDs with various amounts of electron-transporting material, t-PBD. A slower degradation rate was observed from the devices with higher concentration of t-PBD, because of the reduction of the electron accumulation at the PtOX sites. The half decay lifetime of our phosphorescent polymer LED has been improved by a factor of similar to 40, from 1.2 to 45 h. (C) 2001 American Institute of Physics.

引用

页码：2088 / 2090

页数：3

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