Spectroscopic Study and Probing the Chiroptical Activity in Inorganic Cesium Lead Halide Perovskite Nanocrystals

Development of inorganic semiconductor chiral materials with tunable chiroptical properties is of great practical importance for several biomedical and nanophotonics applications. Inducing a chiral response to colloidal semiconducting nanocrystals either by capping or by functionalizing the surface via phase transfer with stereospecific ligands could generate an active chiral response in presence of circularly polarized light. The primary goal of this work is to understand various mechanistic pathways of induced chirality in cesium lead halide based perovskite nanocrystals. We have performed a systematic investigation on chiroptical activity of these materials by monitoring their signal response using circular dichroism and time-resolved photoluminescence spectroscopy when different combinations of (S,±)- and (R, ±)- enantiomeric capping ligands are being incorporated in the synthesis of these nanocrystals. By exploiting these initial data, we will further expand our work into how different symmetry organic cations induce these perovskite nanocrystals to orient in a specific fashion so as to form various chiral space group configuration.