Chiral CsPbBr ₃ Nanorods With Effective Circularly Polarized Luminescence via Vacancy‐Mediated Regrowth Directed by Chiral Ligands

ABSTRACT We report a vacancy‐mediated, chiral‐ligand‐assisted strategy for synthesizing chiral CsPbBr 3 perovskite nanorods with strong circularly polarized luminescence (CPL) and high photoluminescence quantum yield (PLQY). The method involves the formation of a bromide‐vacancy‐rich FAPbBr 3 shell on ultra‐small CsPbBr 3 nanocrystals, followed by the introduction of R/S ‐PEABr, where Br − ions mediate electrostatic assembly and promote anisotropic regrowth into nanorods. Chiral R/S ‐MBA + ligands simultaneously cap the nanorod surfaces, regulating growth and inducing chirality. The resulting nanorods exhibit a PLQY of 91%, and a maximum dissymmetry factor (| g lum |) of 2.2 × 10 −3 is obtained in the film state. When used as the emissive layer in circularly polarized light‐emitting diodes (CP‐LEDs), the devices demonstrate electroluminescence centered at 498 nm, a maximum luminance of 436.7 cd/m 2 , an external quantum efficiency of 2.7%, and a maximum circular polarization of | g CP‐EL | = 2.5 × 10 −4 . This work advances the controlled synthesis of chiral perovskite nanostructures and highlights their potential for high‐performance chiral optoelectronic applications.