Exploring the physical properties of novel double perovskites A2InAsO6 (A=Sr, Ba) for renewable energy applications: Ab-initio calculations

Nowadays, double perovskites for renewable energy are emerging materials because of their interesting properties such as simple and stable crystal structure. In our study, we theoretically explored the optoelectronic along with mechanical and thermoelectric characteristics of A2InAsO6 (A = Sr, Ba) using density functional theory and semi-classical Boltzmann theory followed by WIEN2k code. The thermodynamic and structural stabilities are determined based on the cohesive energy, enthalpy of formation and tolerance factor. The ductile and brittle behaviour has been checked by Pugh's ratios. The measured values of narrow direct energy band gaps are 0.70 eV for Sr2InAsO6, and 0.18 eV for Ba2InAsO6 with TB-mBJ approximation. These compositions are potentially used in optoelectronic applications because their electronic characteristics are tuneable. In the energy range 0-12 eV, the compositions under consideration exhibit a single-peaked response while the replacement of cation Sr with Ba caused a shift in optical structures towards lower energies. These compositions are also suitable for thermoelectric systems as they possess high values of the figure of merits at room temperature and the measured values 0.049 eV for Sr2InAsO6, and 0.10 eV for Ba2InSbO6 are recorded.