Ab initio modeling of band gaps of cesium lead halide perovskites depending on the dopant amount

Abstract

Ab initio simulations of optical band gaps of cesium lead halide perovskites CsP b(I ₁– _xCl_x )₃ and CsP b(I ₁– _xBr_x )₃ are performed at the level of general gradient approximation of the density functional theory. We use supercell approach for computational modeling of disordered systems, which gives a description of the properties of the structure basing on the average over a set of multiple configurations, namely distributions of different species over a given set of atomic positions. The calculations were performed with the CRYSTAL 14 program package. The dependence of the band gap on the content x are investigated over the whole range 0 ≤ x ≤ 1.