ABSTRACT Deep blue circularly polarized organic light‐emitting diodes (CP‐OLEDs) remain scarce due to the stringent requirement of simultaneously achieving a wide bandgap and strong chiroptical activity. Herein, we report DC‐TRZ , a C 2 ‐symmetric chiral emitter comprising a dimeric carbazole donor and a triphenyltriazine acceptor, which exhibits deep‐blue emission at 433 nm with the high emission efficiency of up to 79%. Its enantiopure ( R )‐ and ( S )‐isomers display pronounced Cotton effects and distinct circularly polarized luminescence (CPL). Notably, CP‐OLEDs based on ( R )‐ and ( S )‐ DC‐TRZ deliver deep‐blue electroluminescence with Commission Internationale de L'Eclairage (CIE) coordinates of (0.14, 0.07), achieving a maximum external quantum efficiency of 4.58% and record‐high luminescence dissymmetry factors of +2.7 × 10 −2 and −2.2 × 10 −2 , respectively, representing the highest values reported to date for blue CP‐OLEDs employing small organic molecules. These results demonstrate that DC‐TRZ functions as an efficient deep‐blue chiral emitter and highlights C 2 ‐symmetric axial chirality as a promising molecular design strategy for high‐performance CP‐OLED materials.
Ye et al. (Wed,) studied this question.