Study of double perovskites X2InSbO6 (X = Sr, Ba) for renewable energy; alternative of organic-inorganic perovskites

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 X2InSbO6 (X = Sr, Ba) using density functional theory followed by Wein2k code. The thermodynamic and structural stabilities are determined based on the enthalpy of formation and tolerance factor. The ductile and brittle behavior has been checked by Passion and Pugh's ratios. The measured values of energy band gaps are 2.55 eV for Sr2InSbO6, and 1.75 eV for Ba2InSbO6. These compositions are potentially used in optoelectronic applications because their electronic characteristics are controllable. 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 are 0.77 for Sr2InSbO6 and 0.75 for Ba2InSbO6 are recorded.