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Proceedings Paper

Degradation of wide band-gap electrolumienscent materials by exciton-polaron interactions (Presentation Recording)
Author(s): Hany Aziz; Qi Wang

Paper Abstract

The limited performance stability and gradual loss in the electroluminescence efficiency of OLEDs utilizing wide band-gap materials, such as blue-emitting phosphorescent and fluorescent devices, continues to be a challenge for wider technology adoption. We recently found that interactions between excitons and polarons play an important role in the aging behavior of electroluminescent materials, and that a correlation exists between the susceptibility of these materials to this aging mode and their band-gap. This degradation mode is also found to be often associated with the emergence of new bands - at longer wavelength - in the electroluminescence spectra of the materials, that can often be detected after prolonged electrical driving. Such bands contribute to the increased spectral broadening and color purity loss often observed in these devices over time. Exciton-polaron interactions, and the associated degradation, are also found to occur most significantly in the vicinity of device inter-layer interfaces such as at the interface between the emitter layer and the electron or hole transport layers. New results obtained from investigations of these phenomena in a wide range of commonly used host and guest OLED materials will be presented.

Paper Details

Date Published: 5 October 2015
PDF: 1 pages
Proc. SPIE 9566, Organic Light Emitting Materials and Devices XIX, 95660V (5 October 2015); doi: 10.1117/12.2187247
Show Author Affiliations
Hany Aziz, Univ. of Waterloo (Canada)
Qi Wang, Univ. of Waterloo (Canada)


Published in SPIE Proceedings Vol. 9566:
Organic Light Emitting Materials and Devices XIX
Franky So; Chihaya Adachi; Jang-Joo Kim, Editor(s)

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