Strong Circularly Polarized Luminescence Promoted by AIE‐active Chiral Co‐assemblies in Liquid Crystal Polymer Films

Abstract Recently, extensive works have focused on increasing the dissymmetry factors ( g lum ) of various circularly polarized luminescence (CPL) materials, which is one of the most important factors for future applications of CPL. Herein, we designed a chiral co‐assembled liquid crystal polymer (LCP) PTZ@ R/S ‐PB2 , which was prepared by chiral binary co‐polymer ( R/S ‐PB2 ) doped with achiral phenothiazine derivation dye ( PTZ ). For comparison, ternary co‐polymerized LCP ( R/S ‐PT ) was synthesized by co‐polymerizing with mesogenic monomer, chiral monomer and emissive monomer. Both PTZ@ R/S ‐PB2 and R/S ‐PT showed aggregation‐induced emission (AIE) properties. Interestingly, the CPL signals of both PTZ@ R/S ‐PB2 and R/S ‐PT were reversed and amplified after thermal annealing treatment. The | g lum | values of the co‐assembled PTZ@ R/S ‐PB2 were up to 0.13 at a 32 nm thickness, which was 5.4 times that of R/S ‐PT (| g lum |=0.024). This is due to PTZ@ R/S ‐PB2 could form more orderly chiral co‐assembly structures. Noticeably, increasing the LCP film thickness could further improve the g lum value, and the maximum g lum of PTZ@ R/S ‐PB2 could be enhanced to +0.91/−0.82 at a 220 nm thickness.