Ab initio study of optical and bulk properties of cesium lead halide perovskite solid solutions

Abstract: The first principles calculations of band gaps and bulk moduli of cesium lead halide perovskite solid solutions, $CsPb(I_{1-x}Cl_x)3$ and $CsPb(I{1-x}Br_x)_3$, 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 onfigurations, namely distributions of different species over a given set of atomic positions. The calculations were performed with the CRYSTAL14 program package. The dependence of the band gap and bulk modulus on the content $x$ are investigated over the whole range $0\le x\le 1$.