D‐A* Co‐polymerization Realizing Chiral Thermally Activated Delayed Fluorescent Polymers for Highly Efficient Circularly Polarized Polymer Light‐emitting Diodes

Abstract Circularly polarized electroluminescence (CPEL) from polymers with thermally activated delayed fluorescence (TADF) properties has been rapidly developed in recent years. So far, the designing strategies of such chiral TADF‐active polymers are still limited. In this work, a new strategy of D−A* co‐polymerization was proposed and two chiral polymers R‐pSACODP and S‐pSACODP were synthesized. The circularly polarized polymer light‐emitting diode (CP‐PLED) devices fabricated with R‐pSACODP and S‐pSACODP achieved comparable performances with maximum external quantum efficiencies (EQEs) of 12.0 % and 11.7 % at the wavelength of 581 nm, respectively. Moreover, mirror‐imaged CPEL signals were also detected with electroluminescence dissymmetry factors ( g EL ) of −1.1×10 −3 and +1.3×10 −3 from the corresponding CP‐PLED devices, respectively. The results in this work effectively extend the designing strategies for the achievement of CPEL from chiral TADF‐active polymers.