Abstract
Metal-halide perovskites have found applications in solar cells due to their low cost compared to silicon solar cells and high photon conversion efficiency. If chiral organics are incorporated into their structure, metal-halide perovskites are also a promising alternative to standard methods for the detection of Circularly Polarized Light (CPL). Lead-halide perovskites are highly efficient as light absorbers, but suffer from poor stability and are environmentally toxic, so a lead-free alternative with similar photophysical characteristics is highly sought-after. We present a novel chiral and lead-free layered double perovskite, (S)-(−)-b-methylphenethyl-ammonium]4 CuBiI8. We simulated its structure using DFT as implemented in Quantum ESPRESSO (QE) and compared its Raman spectra to experiment. A compositionally identical compound, differing only in that Ag's are present in the Cu sites, was already known in the literature [D. Li, et al. Angew. Chem., Int. Ed. 60, 8415–8418 (2021).]. We obtained theoretical relaxed structures of both the Ag-based and Cu-based compounds and characterized their Raman peaks and electronic structure, and quantified their degree of structural distortion by calculating their octahedral distortion parameters.
*R. J. L. and D. A. S. were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award Number DE-SC0025805. This research used resources of the National Energy Research Scientific Computing Center; a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 using NERSC award FES-ERCAP0028527. Computational resources were also provided by the Pinnacles cluster at the Cyberinfrastructure and Research Technologies (CIRT) of the University of California, Merced, supported by the National Science Foundation under MRI Award #2019144.
