Investigated the structural, optoelectronic, mechanical, and thermoelectric properties of Sr ₂ BTaO ₆ (B = Sb, Bi) for solar cell applications

Density functional theory was used to investigate the unit structure of Sr2BTaO6 (B = Sb, Bi) double perovskite oxides. The full-potential linearized augmented plane wave technique is used to calculate structural, electronic, electron localization function (ELF), mechanical, optical, and thermoelectric, properties. We optimized the compounds at ground level by using the Murnaghan equation of state. Additionally, the formation, cohesive energy, and Goldschmidt tolerance factor were calculated to assure the structure's stability. With the aid of symmetric lines, we examined the Sr2BTaO6 (B = Sb, Bi) were found to be semiconductors with indirect band gaps of 2.066 and 0.972 eV, correspondingly. To analyze the bonding in the material and also the magnitude of charge transformation from inter-band and intra-band, we considered the electron localization function (ELF). The independent elastic coefficient (Cij), and other parameters were calculated for the material's mechanical stability. To achieve the maximum absorption coefficient, the optical properties with all parameters were computed in given double perovskites materials. Lastly, The BoltzTrap code is also used to compute transport characteristics like as the Seebeck coefficient (S), a figure of merit (ZT), electrical conductivity (σ/τ), power factor (PF), and thermal conductivity (κ/τ). Sr2BiTaO6 appears to be a more promising material as compared to Sr2SbTaO6 for thermal devices based on ZT estimates against chemical potential and carriers' concentrations. All computed properties outcomes advocated that these materials are an attractive source for thermal devices as well as solar applications.