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Durham University

Department of Physics

Staff profile

Publication details for Associate Professor Fernando Dias

Dias, Fernando 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): 20140447.

Author(s) from Durham

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.