An efficient exciton harvest route for high-performance OLEDs based on aggregation-induced delayed fluorescence

Abstract

We managed to integrate the features of aggregation-induced emission (AIE) and thermally activated delayed fluorescence (TADF), by introducing a fluorine atom into the quinoxaline system for highly efficient fluorescent OLEDs. With a purposive design and well-controlled synthesis, two novel AIE-TADF compounds were demonstrated and characterized. Monofluoro-substituted SFDBQPXZ exhibited high efficiencies in a doped OLED with a maximum EQE of 23.5%, a maximum current efficiency (CE) of 78.3 cd A⁻¹ and a maximum power efficiency (PE) of 91.1 lm W⁻¹. Noteworthily, by employing SFDBQPXZ as an orange emitter in a non-doped device, we have realized a considerably high EQE over 10%. The high efficiency and low roll-off in the doped or non-doped devices make our strategy promising and meaningful for OLED applications.