DFT investigation on the electronic and optical properties of Br-doped CH3NH₃SnI3 perovskite

Abstract

The growing need for solar energy is driving research to develop new materials for photovoltaic cells. The material CH3NH3SnI3, commonly known as perovskite, exhibits intriguing properties that make it a promising candidate for various optoelectronic applications. Through the application of density functional theory (DFT), we have investigated the electronic and optical characteristics of pure and bromine-doped CH3NH3SnI3 perovskite in our research article. The evaluation of various physical properties, such as band structures, the total density of states (TDOS), absorption coefficient, extinction coefficient, and refractive index, was carried out utilizing the Cambridge Serial Total Energy Package CASTEP code, as a computational tool. The band gap analysis shows that both CH3NH3SnI3 pure and doped with bromine (Br) are semiconductors. The calculated absorption coefficient of CH3NH3SnI3 pure indicates its absorption peak at 340.53 nm. It can be concluded that the CH3NH3SnI3 system is useful for converting solar radiations into electricity and making it suitable for use as an absorber of visible light. The obtained results demonstrate a noteworthy congruence with previous experimental studies focused on the optoelectronic characteristics of the CH3NH3SnI3 material.