Chemical and conformational control of the energy gaps involved in the thermally activated delayed fluorescence mechanism

dos Santos, Paloma L.; Etherington, Marc K.; Monkman, Andrew P.

Abstract

This review summarises the significant developments in our understanding and control of thermally-activated delayed fluorescence (TADF) molecules and the spin–vibronic coupling mechanism, from which we have designed new generations of emitters. It covers both the theoretical and experimental characterization of the physical and chemical aspects of model TADF emitters. We focus on how to correctly obtain the singlet–triplet energy gaps (ΔEST) that must be overcome by the triplet excited states in the reverse intersystem crossing (rISC) process, highlighting the differences between: the ΔEST estimated from the energy difference between the fluorescence and phosphorescence (1CT–3LE gap); and the activation energy (Ea) estimated from the Arrhenius plot (1CT–3CT gap). The discussion considers the different external factors and design principles that can influence these energy gaps and ultimately the device performance.

Citation

dos Santos, P. L., Etherington, M. K., & Monkman, A. P. (2018). Chemical and conformational control of the energy gaps involved in the thermally activated delayed fluorescence mechanism. Journal of Materials Chemistry C Materials for optical and electronic devices, 6(18), 4842-4853. https://doi.org/10.1039/c8tc00991k

• Journal Article Type: Article
• Acceptance Date: Apr 18, 2018
• Online Publication Date: Apr 18, 2018
• Publication Date: 2018-05
• Deposit Date: Apr 27, 2018
• Publicly Available Date: Apr 9, 2021
• Journal: Journal of Materials Chemistry C Materials for optical and electronic devices
• Print ISSN: 2050-7526
• Electronic ISSN: 2050-7534
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Issue: 18
• Pages: 4842-4853
• DOI: https://doi.org/10.1039/c8tc00991k
• Public URL: https://durham-repository.worktribe.com/output/1360075