Matthew W. Cooper, Xiaoqing Zhang, Yadong Zhang
Nov 6, 2018
Citations
0
Influential Citations
4
Citations
Journal
ACS Omega
Abstract
2-(4-(9,9-Dimethylacridin-10(9H)-yl)phenyl)-5-phenyl-1,3,4-oxadiazole has an energy difference between the lowest excited singlet and triplet states (ΔEST) of ca. 0.24 eV. Introduction of two electronegative fluorine atoms onto the acceptor portion of the molecule to give 2-(4-(9,9-dimethylacridin-10(9H)-yl)-3,5-difluorophenyl)-5-phenyl-1,3,4-oxadiazole lowers the energy of the singlet emission with a negligible effect on the corresponding triplet energy, leading to a donor–acceptor compound with decreased ΔEST of ca. 0.13 eV that displays thermally activated delayed fluorescence. Organic light-emitting diodes fabricated using the latter compound display high EQEmax of 21.9% at a luminance of 10 cd/m2 and sky-blue emission, however, they suffer from a large efficiency roll-off at increased luminance.