An accurate prediction of electronic structure, mechanical stability and optical response of BaCuF3 fluoroperovskite for solar cell application

Abstract

This study utilizes the first-principles modelling approach based on the density functional theory (DFT) framework to investigate the structural, mechanical, and optoelectronic properties of the BaCuF3 fluoroperovskite. Initially, the three distinct cubic structures of BaCuF3 were simulated based on the positioning of F atoms. This investigation aimed to determine the most stable configuration for BaCuF3. The structural stability of all compounds has been evaluated through the formation enthalpy calculations. In addition, the mechanical stability is assessed by the investigation of elastic stiffness constants. The mechanical stability of the α-BaCuF3 and β-BaCuF3 compounds has been observed. However, the γ-BaCuF3 compound is deemed unstable due to its failure to meet the Born-stability criterion (C44 < 0). The ductility of α-BaCuF3 and the brittleness of β-BaCuF3 have been determined by exploring Pugh's and passion ratios and the Cauchy pressure. The electronic characteristics have been evaluated by examining electronic band structure, density of states and partial density of states. The compounds α-BaCuF3 and β-BaCuF3 have been seen to have indirect and direct band gaps of 0.14 eV (M–Γ) and 1.22 eV (Γ–Γ), respectively. Several optical parameters have been calculated and compared. The materials that have been chosen exhibit significant optical conductivity and absorption coefficients when exposed to high-energy photons while also demonstrating transparency at lower incident photon energy ranges. Our investigations into the optical properties have determined that α-BaCuF3 and β-BaCuF3 exhibit favourable characteristics for solar cell implementation, high-frequency UV, and optoelectronic devices.