Dr Fernando Dias f.m.b.dias@durham.ac.uk
Associate Professor
Triplet Harvesting with 100% Efficiency by Way of Thermally Activated Delayed Fluorescence in Charge Transfer OLED Emitters.
Dias, F.B.; Bourdakos, K.N.; Jankus, V.; Moss, K.C.; Kamtekar, K.T.; Bhalla, V.; Santos, J.; Bryce, M.R.; Monkman, A.P.
Authors
K.N. Bourdakos
V. Jankus
K.C. Moss
K.T. Kamtekar
V. Bhalla
J. Santos
Professor Martin Bryce m.r.bryce@durham.ac.uk
Professor
Professor Andrew Monkman a.p.monkman@durham.ac.uk
Professor
Abstract
Organic light-emitting diodes (OLEDs) have their performance limited by the number of emissive singlet states created upon charge recombination (25%). Recently, a novel strategy has been proposed, based on thermally activated up-conversion of triplet to singlet states, yielding delayed fluorescence (TADF), which greatly enhances electroluminescence. The energy barrier for this reverse intersystem crossing mechanism is proportional to the exchange energy (ΔEST) between the singlet and triplet states; therefore, materials with intramolecular charge transfer (ICT) states, where it is known that the exchange energy is small, are perfect candidates. However, here it is shown that triplet states can be harvested with 100% efficiency via TADF, even in materials with ΔEST of more than 20 kT (where k is the Boltzmann constant and T is the temperature) at room temperature. The key role played by lone pair electrons in achieving this high efficiency in a series of ICT molecules is elucidated. The results show the complex photophysics of efficient TADF materials and give clear guidelines for designing new emitters.
Journal Article Type | Article |
---|---|
Publication Date | 2013-07 |
Deposit Date | Sep 17, 2013 |
Journal | Advanced Materials |
Print ISSN | 0935-9648 |
Electronic ISSN | 1521-4095 |
Publisher | Wiley |
Peer Reviewed | Peer Reviewed |
Volume | 25 |
Issue | 27 |
Pages | 3707-3714 |
DOI | https://doi.org/10.1002/adma.201300753 |
Keywords | Organic semiconductors, Conjugated materials, Organic light-emitting diodes, Delayed fluorescence. |
Public URL | https://durham-repository.worktribe.com/output/1477823 |
You might also like
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