DFT Studies on Electronic and Optical Properties of Inorganic CsPbI3 Perovskite Absorber for Solar Cell Application

Abstract

We computed electronic and optical properties of inorganic cubic perovskite CsPbI3 absorber using Perdew--Burke--Ernzerhof (PBE) with Generalized Gradient Approximation (GGA) and modified Becke--Johnson (mBJ) exchange-correlation potential. The optimized lattice parameter is 6.3772 Åand the computed direct bandgap values at high symmetry point-R are 1.42 and 1.72 eV for GGA-PBE and mBJ exchange-correlation potential, respectively. Electronic as well as optical properties are investigated by computing projected density of states (PDOS), dielectric function, refractive index, extinction coefficients, reflectivity, and absorption as the function of energy. The large absorption coefficient of CsPbI3 is making it a promising absorber for photovoltaic applications.