A comprehensive DFT study on the structural, electronic, elastic, and optical behaviour of CsPbF3 under the effect of stress

Abstract

Fluoro-perovskite compounds are important and auspicious materials according to their properties in photovoltaic anti-reflective coating and optoelectronics. In this study, the structural, mechanical, and optoelectronic properties of Cesium Lead Fluoride CsPbF₃ were investigated using first principle calculations with generalized gradient approximations. The effect of stress on the crystal structure of CsPbF₃ was examined at 0, 20, 40, and 59 GPa. It was found that the lattice constant is decreased with increasing stress, and the elastic, electronic, and optical properties of the material were significantly affected. The density of states and band gap of CsPbF₃ were also calculated, and the band gap was found to be zero at 59 GPa. The cubical structure of CsPbF₃ is distorted at 58 GPa. The various mechanical characteristics such as the bulk modulus, shear modulus, Young’s modulus, and Poisson ratio were derived and discussed. The results indicate that CsPbF₃ exhibits ductile behaviour and anisotropic nature under stress, and the increase in refractive index, absorption, reflectivity, and conductivity at high stress make it a promising material for optoelectronic devices.