First-principles study on the electronic and optical properties of cubic ABX3 halide perovskites

The electronic properties of ABX₃ type compounds in the cubic phase are systematically studied using the first-principles calculations. The chemical trend of their properties as A or B or X varies is fully investigated. The optical properties of the ABX₃ compounds are also investigated. Our calculations show that taking into account the spin–orbit coupling effect is crucial for predicting the accurate band gap of these halide perovskites. We predict that CH₃NH₃SnBr₃ is a promising material for solar cells absorber with a perfect band gap and good optical absorption.