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

Arif, M and Mukhopadhyay, S and Ramasesha, S and Guha, S (2009) The role of triplet states in the emission mechanism of polymer light-emitting diodes. In: EPL, 87 (5). 57008-p1.

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Abstract

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.

Item Type:	Journal Article
Publication:	EPL
Publisher:	Institute of Physics and IOP Publishing Limited 2009
Additional Information:	Copyright of this article belongs to Institute of Physics and IOP Publishing Limited 2009.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	17 Dec 2009 11:45
Last Modified:	19 Sep 2010 05:49
URI:	http://eprints.iisc.ac.in/id/eprint/24226

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