Kinetics of thermal-assisted delayed fluorescence in blue organic emitters with large singlet–triplet energy gap

Dias, Fernando B.

Abstract

The kinetics of thermally activated delayed fluorescence (TADF) is investigated in dilute solutions of organic materials with application in blue light-emitting diodes (OLEDs). A method to accurately determine the energy barrier (ΔEa) and the rate of reverse intersystem crossing (kRisc) in TADF emitters is developed, and applied to investigate the triplet-harvesting mechanism in blue-emitting materials with large singlet–triplet energy gap (ΔEST). In these materials, triplet–triplet annihilation (TTA) is the dominant mechanism for triplet harvesting; however, above a threshold temperature TADF is able to compete with TTA and give enhanced delayed fluorescence. Evidence is obtained for the interplay between the TTA and the TADF mechanisms in these materials.

Citation

Dias, F. B. (2015). Kinetics of thermal-assisted delayed fluorescence in blue organic emitters with large singlet–triplet energy gap. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 373(2044), Article 20140447. https://doi.org/10.1098/rsta.2014.0447

• Journal Article Type: Article
• Acceptance Date: Mar 9, 2015
• Publication Date: Jun 1, 2015
• Deposit Date: Jan 12, 2016
• Publicly Available Date: May 18, 2016
• Journal: Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences.
• Print ISSN: 1364-503X
• Electronic ISSN: 1471-2962
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 373
• Issue: 2044
• Article Number: 20140447
• DOI: https://doi.org/10.1098/rsta.2014.0447
• Keywords: Thermally activated delayed fluorescence, Delayed fluorescence, Organic light-emitting diodes, Reverse intersystem crossing, Triplet–triplet annihilation.
• Public URL: https://durham-repository.worktribe.com/output/1394868