Synthesis and optical study of highly stable double perovskite Cs2CuBiCl6 for optoelectronic applications

Abstract

Lead-devoid halide-based double perovskite (DP) compounds are emerging as a potential candidate to replace the highly toxic and unstable lead-based perovskite materials. Here in this work we have synthesized and characterized a novel double perovskite material Cs2CuBiCl6 for the first time through an easy and commercial chemical route at ambient temperature. Further, we have investigated the morphological and optical behavior of synthesized double perovskite material. To check the crystallinity, phase formation, and purity of the DP, X-Ray diffraction (XRD) spectroscopy has been done at room temperature. A good crystalline and rhombohedral phase has been observed from the XRD plot, which is in good agreement with the reference data (ISCD#239874). Moreover, photoluminescence (PL) spectroscopy at room temperature (300K) of synthesized DP material has been done to observe its optical properties. A broad peak around 500 nm has been observed from the PL spectra corresponding to the energy of 2.5 eV, which further suggests the usefulness of the DP for visible range applications. The observed peak in the PL spectra is due to band-to-band transition and phonon-assisted carrier recombination of the excitons trapping. This novel study on the double perovskite material Cs2CuBiCl6 has opened a new path to develop optoelectronic devices based on non-toxic double perovskite material having better efficiency than the toxic counterpart.