Triple RISC-Assisted Exciton-Harvesting System for Efficient White Organic Light-Emitting Diodes.

Developing white organic light-emitting diodes (WOLEDs) with high exciton utilization, balanced charge transport, and stable complementary emission remains a challenge for solid-state lighting and display applications. Herein, a triplet reverse intersystem crossing (RISC)-assisted strategy is proposed to enhance triplet exciton harvesting to construct efficient hybrid WOLEDs. The increased RISC channels promote the up-conversion of triplet excitons into radiative singlet excitons, thereby improving the overall exciton utilization efficiency. By further introducing an ultrathin PO-01 layer as an orange orange-emitting component, a hybrid WOLED with a current efficiency of 49.1 cd/A and 34.8 lm/W is realized. Moreover, suppressed efficiency roll-offs and stable spectra are achieved due to balanced charge transport. This work provides a practical route toward high-performance WOLEDs.