Chiral Amine CsPbBr ₃ Nanocrystals: Ligand Exchange Strategy‐Induced Circularly Polarized Luminescence and Chirality Modulation

ABSTRACT Chiral lead halide perovskite nanocrystals (NCs) coherently integrate promising optical property with chirality, exhibiting great potential for next generation technologies across optoelectronics, asymmetric catalysis, chiral recognition, and 3D display technologies. However, the persistent challenges of weak optical activity and limited modulation methods in this material system severely hinder its practical implementation. Herein, a simple post‐treatment strategy is proposed for synthesizing chiral lead halide perovskite NCs with chiral amine ligands R/S‐3MPEA to modulate their optical properties and chiral characteristics. Experimental results demonstrate that the CsPbBr ₃ NCs treated with chiral amine ligands R/S‐3MPEA display mirror‐symmetric circular dichroism (CD) signals at 495 nm for R/S‐3MPEA‐modified NCs, with luminescence asymmetry factor g _lum reaching 0.64 × 10 ⁻³ , unambiguously confirming their chiral nature. Furthermore, these NCs achieve exceptional optical performance in the visible spectrum, characterized by extended fluorescence lifetimes as a result of passivation. Additionally, the fabrication of light‐emitting diodes (LEDs) based on the chiral CsPbBr ₃ NCs with a chromaticity coordinate of (0.1097, 0.7430) at 80 mA validates the practical application. This research provides additional experimental evidence for the synthesis of chiral perovskite NCs and establishes a foundation for their applications in optoelectronics, spintronics, and related fields.