STRUCTURAL AND OPTOELECTRONIC PROPERTIES OF CHALCOGENIDE PEROVSKITES; A DFT STUDY

Abstract

The structural, optical, electronic and mechanical properties of barium bases chalcogenide material BaZrS₃ have been investigated by utilizing the first principle simulation which is based on density functional theory (DFT) with framework of CASTEP code by using Perdew-Burke-Enernhoff generalized gradient approximation (PBE-GGA) functional. Lattice constant of the sample BaZrS₃ have been found a=b=c=5.066 A^o with the bond angle α=β=γ=90^o. It has been found our material is stable in cubic phase structure with energy of -2808.93eV with the unit cell volume of 129.72 (A^o)³. This material have direct band gap of energy 0.458eV. In the range of energy from 0—60eV, the Kramer Kroning relation is best way to calculate parameters such as dielectric function, refractive coefficient, absorption coefficient, reflectivity, optical conductivity and energy loss function in order to know their optical performance. The calculated mechanical properties indicate that the material BaZrS₃ is found mechanically stable and all the elastic constants have positive values and elastic anisotropic value is 0.158. The calculated poisson ratio represents the brittle nature of material BaZrS₃. The B_H/G_H shows the value of 1.9 which also indicates the ductile nature of BaZrS_3­. The stability and conductivity of this material is also confirmed by its total energy value. The partial density of states also describes that by doping the band gap energies are reduced. It can cause to increment in conductivity of compound BaZrS₃. By studying these characteristics, we found that our material is chemically stable and can be used in storage devices. The outcomes of results for our material BaZrS₃ shows that because of suitable band gap high absorption coefficient value making it a best option  for renewable energy harvesting devices such as photovoltaic devices. Its composition also makes it a candidate to be used in semiconductor devices.