A C(2)-Symmetric Chiral Emitter for Deep-Blue Circularly Polarized Electroluminescence With High Dissymmetry Factors.

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-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 and -2.2 × 10, 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-symmetric axial chirality as a promising molecular design strategy for high-performance CP-OLED materials.