Vygintas Jankus
The role of exciplex states in phosphorescent OLEDs with poly(vinylcarbazole) (PVK) host
Jankus, Vygintas; Abdullah, Khalid; Griffiths, Gareth C.; Al-Attar, Hameed; Zheng, Yonghao; Bryce, Martin R.; Monkman, Andrew P.
Authors
Khalid Abdullah
Gareth C. Griffiths
Hameed Al-Attar
Yonghao Zheng
Professor Martin Bryce m.r.bryce@durham.ac.uk
Professor
Andrew P. Monkman
Abstract
Polymer light emitting diodes (PLEDs) may revolutionize lighting and display industries. PLEDs would enable printing of display or lighting panels on large area substrates that could substantially reduce fabrication costs by avoiding expensive vacuum processes presently used in OLED technologies. PVK is one of the most popular hosts for blue PLEDs. However, PVK has very poor electron transport properties and oxadiazole based electron dopants, e.g. PBD or OXD-7, are used to improve charge transport. This is generally ascribed to capture and transport of electrons on the PBD or OXD-7. Here we show that this is not necessarily the only reason for improved efficiency upon PVK doping. We demonstrate that devices with PVK doped with PBD or OXD-7 have emission lasting up to 1 ms which in some cases may be greater than prompt emission from excitons formed initially on the dopant. This long-lived emission is arising mainly due to formation of an exciplex between the PVK and PBD/OXD-7. This exciplex state then repopulates dopant iridium complexes over a long period of time giving very long-lived emission. We also note that this exciplex-fed long-lived emission from heavy metal complexes is observed in several PLEDs with PBD and PVK (and also OXD-7) doped with blue or green iridium phosphors indicating this to be a general phenomenon.
Citation
Jankus, V., Abdullah, K., Griffiths, G. C., Al-Attar, H., Zheng, Y., Bryce, M. R., & Monkman, A. P. (2015). The role of exciplex states in phosphorescent OLEDs with poly(vinylcarbazole) (PVK) host. Organic Electronics, 20, 97-102. https://doi.org/10.1016/j.orgel.2015.02.002
Journal Article Type | Article |
---|---|
Acceptance Date | Mar 26, 2015 |
Publication Date | May 1, 2015 |
Deposit Date | Mar 26, 2015 |
Publicly Available Date | Mar 31, 2015 |
Journal | Organic Electronics |
Print ISSN | 1566-1199 |
Publisher | Elsevier |
Peer Reviewed | Peer Reviewed |
Volume | 20 |
Pages | 97-102 |
DOI | https://doi.org/10.1016/j.orgel.2015.02.002 |
Keywords | Exciplex, PhOLED, PLED, PVK, PBD, Long-lived emission. |
Public URL | https://durham-repository.worktribe.com/output/1410817 |
Files
Accepted Journal Article
(357 Kb)
PDF
Copyright Statement
NOTICE: this is the author’s version of a work that was accepted for publication in Psychology of Organic Electronics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Organic Electronics, 20, May 2015, 10.1016/j.orgel.2015.02.002.
You might also like
Oligo(fluorenyl)pyridine ligands and their iridium complexes: Synthesis, photophysical properties and electrophosphorescent devices
(2005)
Presentation / Conference Contribution
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search