First-principle calculation of the physical properties of tri-halide perovskite FrSrX3 (X = F, Cl, Br, and I): A DFT study

Inorganic metal halide perovskites, valued for their non-toxic environment and optoelectronic application, have come under increasing investigation through DFT-based ab initio simulations in order to understand their intrinsic physical characteristics. The observed lattice constants of the FrSrX3 (X = F, Cl, Br, and I) compounds are found to be 4.849, 5.733, 6.033, and 6.479 Å, respectively, and the structural stability was confirmed by negative formation enthalpy. Among the compounds, FrSrI3 has the lowest bandgap, which may be of interest in optoelectronic applications. Moreover, the semiconducting characteristics of these materials are also exhibited through the computation of the density of states and projection of the electronic states from atomic orbitals. The dual chemical bonding features appear in the provided bond lengths and charge density distributions, resulting in the compound’s stability. Electrical conductivity and photoemission rely on the halide’s behavior, which exhibits varying behavior in the low and high energy ranges. The analysis of the mechanical features of the resulting compounds shows varying sizes of the perovskite structure of FrSrX3 (where X = F, Cl, Br, and I). Anisotropic behavior, however, is slightly more acutely stated in compounds containing the halogen iodine. The anisotropy of these materials is depicted in three-dimensional elastic moduli diagrams featuring preload direction and angle using the ELATE tool. Therefore, this work provides important insights into the design and construction of lead-free inorganic perovskites, which is crucial for extending the role of these materials in the development of future-generation optoelectronic devices.