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

The research examines the exceptional physical characteristics of MgAB (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, MgBiI demonstrates high ductility, while MgNF and MgBiBr 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, MgNF can be considered as a wide-bandgap insulator with the bandgap of 6.789 eV, whereas MgBiBr and MgBiI 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, MgBiBr and MgBiI 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 MgNF is a good heat sink material, MgBiBr and MgBiI are favorable for thermal barrier coating materials. Due to their high absorption coefficients, low reflectance and suitable conductivity, both MgBiBr and MgBiI could be regarded as the most appropriate materials for the creation of the next generation of photovoltaic converters.