Newly predicted halide perovskites Mg3AB3 (A = N, Bi; B = F, Br, I) for next-generation photovoltaic applications: a first-principles study

Abstract

The research examines the exceptional physical characteristics of Mg₃AB₃ (A = N, Bi; B = F, Br, I) perovskite compounds through density functional theory to assess their feasibility for photovoltaic applications. Mechanical characterization further supports their stability where out of all the compounds, Mg₃BiI₃ demonstrates high ductility, while Mg₃NF₃ and Mg₃BiBr₃ possess a brittle nature. The calculated elastic constants and anisotropy factors also substantiate their mechanical stability, while there is an observed declining trend in Debye temperature with increase in atomic number. From the electronic point of view, Mg₃NF₃ can be considered as a wide-bandgap insulator with the bandgap of 6.789 eV, whereas Mg₃BiBr₃ and Mg₃BiI₃ can be classified as semiconductors suitable for photovoltaic applications bandgaps of 1.626 eV and 0.867 eV, respectively. The optical characteristics of such materials are excellent and pronounced by high absorption coefficients, low reflectivity, and good dielectrics, which are very important in the collection of solar energy. Among them, Mg₃BiBr₃ and Mg₃BiI₃ possess high light absorption coefficient, moderate reflectivity, and good electrical conductivity, indicating that they are quite suitable for applying the photoelectric conversion materials for solar cells. In addition, thermal analysis shows that Mg₃NF₃ is a good heat sink material, Mg₃BiBr₃ and Mg₃BiI₃ are favorable for thermal barrier coating materials. Due to their high absorption coefficients, low reflectance and suitable conductivity, both Mg₃BiBr₃ and Mg₃BiI₃ could be regarded as the most appropriate materials for the creation of the next generation of photovoltaic converters.