The authors are grateful to Cambridge Display Technology Ltd. for provision of the devices used in this work, and to Drs. Clare Foden, Jeremy Burroughes, and Jonathan Halls for useful discussions.
Internal Field Screening in Polymer Light-Emitting Diodes†
Article first published online: 17 JUN 2004
Copyright © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Functional Materials
Volume 14, Issue 6, pages 562–570, June, 2004
How to Cite
Brewer, P. J., Lane, P. A., deMello, A. J., Bradley, D. D. C. and deMello, J. C. (2004), Internal Field Screening in Polymer Light-Emitting Diodes. Adv. Funct. Mater., 14: 562–570. doi: 10.1002/adfm.200305126
- Issue published online: 17 JUN 2004
- Article first published online: 17 JUN 2004
- Manuscript Accepted: 14 FEB 2004
- Manuscript Received: 6 NOV 2003
- Electromodulation spectroscopy;
- Light-emitting diodes, organic;
- Poly(3,4-ethylenedioxythiophene) (PEDOT);
We use electromodulation spectroscopy and modeling studies to probe the electric-field distribution in polyfluorene-based polymer light-emitting diodes containing poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate). The bulk internal field is shown to be zero under ordinary operating conditions, with trapped electrons close to the anode fully screening the bulk semiconductor from the external field. The effect has far-reaching implications for the understanding and optimization of organic devices.