bottleneck due to the lack of efficient emitters with simultaneous high exciton utilization
efficiency (EUE) and short excited-state lifetime. Different from the fluorescence,
phosphorescence, thermally activated delayed fluorescence (TADF), and organic radical
materials traditionally used in OLEDs, we demonstrate herein a new type of emitter, cerium
(III) complex Ce-1 with spin-allowed and parity-allowed d–f transition of the centre Ce3+ ion …