A <i>C</i> ₂ ‐Symmetric Chiral Emitter for Deep‐Blue Circularly Polarized Electroluminescence With High Dissymmetry Factors

Abstract

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.