High‐Performance Solution Processable Single‐Emitting‐Layer White Circularly Polarized Electroluminescence
Peng Fan, Lei Hua, Xiaoyi Lai, Hua‐Xiu Ni, Weiguo Zhu, You‐Xuan Zheng, Yafei Wang
Abstract
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 (| g lum |) 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 | g EL | value of 2.4 × 10 −3 . This research provides a straightforward and effective strategy for the realization of high‐performance CP‐WOLED.