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Intrinsic Degradation in Alq3-Based OLEDs Probed by Deep-Level Optical Spectroscopy

Published online by Cambridge University Press:  31 January 2011

Yoshitaka Nakano*
Affiliation:
[email protected], Chubu University, Institute of Science and Technology Research, Kasugai, Japan
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Abstract

We have successfully investigated degradation-induced variations in electronic band-gap states in the emissive region of the Alq3-based OLEDs by a deep-level optical spectroscopy technique. Through the intrinsic degradation, both deep-level traps and near-band-edge transitions in the Alq3 emissive zone are found to be red-shifted significantly towards their corresponding bulk levels of the Alq3 single layer. These variations in the interfacial electronic states are probably induced by the intrinsic degradation and indicate that initial molecular structures characteristic of the Alq3 emissive zone are transformed into the bulk-like relaxed ones through the degradation.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

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