The Structural Origin of Chiroptical Properties in Perovskite Nanocrystals with Chiral Organic Ligands

The authors investigate how chiral ligands attached to perovskite nanocrystal (PNC) surfaces structurally distort the perovskite lattice. Chiral electro-optical properties of the resulting PNCs are demonstrated through the fabrication of a circularly polarized light (CPL) detector with a discrimination of up to 14% between left- and right-handed CPL. Both experimental and electronic-structure-based simulations are combined to provide insights into the interactions (both structural and electronic) between chiral organic ligands and PNCs. The major finding is a centro-asymmetric distortion of the surface lattice that penetrates up to five atomic unit cells deep into the PNCs, which is the likely cause of the chiral-optical properties. Spin-polarized transport through chiral-PNCs results from the chiral-induced spin selectivity effect and amplifies the discrimination between left and right-handed CPL as is experimentally demonstrated in the detectors.