Electronic Structure and Optical Spectra of Halide Perovskites A<sub>2</sub>BCl<sub>6</sub> [(A = Cs; B = Se, Sn, Te, Ti, Zr) and (A = K; B = Pd, Pt, Sn)] for Photovoltaic and Optoelectronic Applications
Saadi Berri, N. Bouarissa
Abstract
A precise and systematic analysis for A 2 BCl 6 [(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, Cs 2 BCl 6 (B = Se, Sn, Te, Ti, Zr) and K 2 BCl 6 (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 Cs 2 BCl 6 (B = Ta, W) and K 2 BCl 6 (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 A 2 BCl 6 has the ability to work for implementations like Bragg's reflectors, optical and optoelectronic devices. The optical parameters of A 2 BCl 6 disclose 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.