Chirality of CsPbBr₃ Nanocrystals with Varying Dimensions in the Presence of Chiral Molecules

Abstract

Chiral lead halide perovskite (LHP) nanocrystals (NCs) have been attracting considerable interest for circularly polarized luminescence (CPL)-based optoelectronic applications. This study combined experimental and computational analyses to investigate how the dimensionality of 3D (cubic) to 0D (quantum dots) influences the tunable chiral emission of CsPbBr 3 LHP NCs. The circular dichroism (CD) spectra have a significant blue shift from 508 to 406 nm. The dissymmetry factors for CD ( g CD ) change from ±2.5 × 10 –3 to ±7.5 × 10 –3 as dimensionality varies from 3D to 0D in the presence of the chiral molecule (cyclohexylethylamine, CHEA). A significant luminescence dissymmetry factor ( g lum ) of ±5.6 × 10 –4 is observed in the 0D CsPbBr 3 NCs. Theoretical calculations using structural distortion parameters, the extent of charge transfer, and electrostatic potential profiles have revealed that the most significant enhancement of the chirality transfer occurs from the CHEA molecules to 0D NCs, and the order of chirality transfer from CHEA to CsPbBr 3 NCs is 0D (quantum dots) > 2D (nanoplatelet) > 3D (cubic).