Electronic Structure and Optical Spectra of Halide Perovskites A2BCl6[(A = Cs; B = Se, Sn, Te, Ti, Zr) and (A = K; B = Pd, Pt, Sn)] for Photovoltaic and Optoelectronic Applications

Abstract

A precise and systematic analysis for A2BCl6[(A = Cs; B = Se, Sn, Te, Ti, Zr) and (A = K; B = Pd, Pt, Sn)] is performed to investigate structural stability as well as optical and electrical properties using pseudopotential plane wave method. The calculated lattice constants show consistency with the experimental results that ensure their structural stability. From the electronic band structure results, Cs2BCl6(B = Se, Sn, Te, Ti, Zr) and K2BCl6(B = Pd, Pt, Sn) are established to be within an energy bandgap that varies between 1.131 and 3.731 eV. The metallic behavior of the materials for Cs2BCl6(B = Ta, W) and K2BCl6(B = Ta, W, Mn, Mo, Os, Re, Ru, Ta, Tc) is confirmed showing the presence of conducting characteristics. The dielectric function is large in the near‐ultraviolet region (3.10–4.13 eV). The extinction coefficient of A2BCl6has the ability to work for implementations like Bragg's reflectors, optical and optoelectronic devices. The optical parameters of A2BCl6disclose that the working constructions have an elevated dielectric constant. Analysis of the electronic and optical properties demonstrates that these double‐perovskite materials are suitable for photovoltaic and optoelectronic applications.