High‐Performance Solution Processable Single‐Emitting‐Layer White Circularly Polarized Electroluminescence

Abstract

Achieving efficient circularly polarized white organic light‐emitting diode (CP‐WOLED) remains a significant challenge. In this study, a proof‐of‐concept for realizing CP‐WOLED is proposed using an electroplex emission strategy between a chiral thermally activated delayed fluorescence (TADF) emitter and hole‐transporting material. A series of chiral polymers (R/S)‐E‐x (x = 0.02, 0.05, and 0.1) are designed and prepared via random copolymerization of a chiral chromophore and styrene moiety, which shows typical TADF character. The neat film of (R/S)‐E‐0.1 presents distinct chiroptical properties with a dissymmetry factor (|glum|) of 2.8 × 10−3. Notably, solution‐processable, single‐emitting‐layer CP‐WOLEDs are fabricated using these chiral polymers in combination with 1,1‐bis[(di‐4‐tolylamino)phenyl]cyclohexane (TAPC) as the emitter, achieving a record maximum external quantum efficiency of 15.1% and Commission Internationale de lʹeclairage coordinate of (0.36, 0.40). Importantly, these CP‐WOLEDs exhibit an impressive |gEL| value of 2.4 × 10−3. This research provides a straightforward and effective strategy for the realization of high‐performance CP‐WOLED.