The role of triplet states in the emission mechanism of polymer light-emitting diodes

被引：6

作者：

Arif, M. ^{[1
]}

Mukhopadhyay, S. ^{[2
]}

Ramasesha, S. ^{[2
]}

Guha, S. ^{[1
]}

机构：

[1] Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA

[2] Indian Inst Sci, Solid State & Struct Chem Unit, Bangalore 560012, Karnataka, India

来源：

EPL | 2009年 / 87卷 / 05期

基金：

美国国家科学基金会;

关键词：

SPECTRA; ELECTROLUMINESCENCE; POLYFLUORENE; FILMS; BAND;

D O I：

10.1209/0295-5075/87/57008

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The blue emission of polyfluorene (PF)-based light-emitting diodes (LEDs) is known to degrade due to a low-energy green emission, which hitherto has been attributed to oxidative defects. By studying the electroluminescence (EL) from ethyl-hexyl substituted PF LEDs in the presence of oxygen and in an inert atmosphere, and by using trace quantities of paramagnetic impurities (PM) in the polymer, we show that the triplet states play a major role in the low-energy emission mechanism. Our time-dependent many-body studies show a large cross-section for the triplet formation in the EL process in the presence of PM, primarily due to electron-hole recombination processes. Copyright (C) EPLA, 2009

引用

页数：5

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