Activating the Chiroptical Properties of High-Fold Axial Chiral Perovskite by a Chiral Induction Strategy.

Chiral perovskites typically exhibit efficient circular dichroism and circularly polarized luminescence, demonstrating promising applications in chiroptical and spintronic devices. However, the relationship between the chiroptical properties and structurally symmetric elements of chiral perovskites has not been established. The unique structure of the high-fold axis may impart distinctive chiral optoelectronic properties, yet it remains unexplored. Here, we have successfully constructed a pair of chiral perovskite enantiomers with both 6-fold screw and 3-fold rotation axes. Enantiomeric enrichment was achieved by employing a chiral induction strategy. Their chiroptical properties were systematically investigated by circular dichroism. Furthermore, systematic theoretical calculations were conducted to reveal the mechanism of chirality transfer and the Rashba splitting, which compensate for the adverse influence of chiral distortion on carrier transport. Our work offers a novel strategy to construct high-fold axial chiral perovskites and bridges the knowledge gap between their crystal structures and their chiroptical properties.