Chiral TADF Polymers Realizing Highly‐Efficient Deep‐Red Circularly Polarized Electroluminescence Over 660 nm

Abstract Circularly polarized electroluminescence (CPEL) from thermally activated delayed fluorescence (TADF) emitters have been widely reported in recent years. However, a universal strategy for designing deep‐red chiral TADF emitters is still unexplored. Herein, to address the problem, a pair of chiral donor intermediates are designed and synthesized for preparing deep‐red chiral TADF emitters, and two novel chiral TADF polymers R‐P and S‐P are developed through this strategy. The polymers exhibit intense mirror‐image circularly polarized luminescence (CPL) signals in toluene dilute solution. Besides, a series of solution‐processed circularly polarized polymer light‐emitting diode (CP‐PLED) devices are fabricated with R‐P and S‐P . The corresponding devices achieve persuasive performance with external quantum efficiencies (EQEs) of 6.2% and 5.8% at the wavelength of 662 nm, respectively. Besides, mirror‐image CPEL signals are detected with electroluminescence dissymmetry factors (gEL) of +1.6 × 10 −3 and −1.7 × 10 −3 from the corresponding CP‐PLED devices, respectively.