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.