(409e) Chiral Low-Dimensional Hybrid Perovskites for Circularly Polarized Light Detecting

As ionic semiconductors, the flexible crystal structures and tunable compositions make it possible to rationally design hybrid perovskites with desired properties. Chiral perovskites demonstrate such possibility and the breakthrough with respect to the development of a new class of chiral semiconductors, which opens up new applications of hybrid perovskites to chiroptoelectronics, ferroelectrics, and spintronics. We demonstrate that the chirality of 2D halide perovskites can be widely tuned via incorporation of mixed chiral and achiral organic ligands in the organic layer. A broad range of alkyl and aryl chiral and achiral cations are used in forming 2D chiral halide perovskites. Additionally, we synthesize semiconducting organic cations and integrate them into 2D chiral halide perovskites to tune the band structure and charge transport. To reveal the origin of the chirality, we conduct density functional theory calculations to gain the insights of hydrogen bonding and octahedral structure as well as their relationship to the electronic band structure and spin spilt. We perform temperature dependent powder X-ray diffraction and pair distribution function measurements to investigate structural variations with temperature to help understanding the observation of the unique behavior exhibited in the temperature dependent circularly polarized photoluminescent measurements. We construct photodiode-typed CPL photodetectors and demonstrate a record high distinguishability of right-handed and left-handed circularly polarized light. While many phenomena are unknown and needed further investigations, our work provides a new way to manipulate chirality of 2D perovskites, which could lead to broader applications.