Effect of Anion on Optoelectronic and Thermoelectric Properties Cubic Double Perovskites A₂(Sr, Ba)WMgO₆ for Low-Cost Energy Technologies: A Computational Simulation Study

Oxide-based perovskites are promising for solar cell use due to their nontoxicity, inexpensive price, and outstanding optical characteristics. The first-principles research of new double perovskites (DPs) A₂WMgO₆ (A = Sr, Ba) was carried out using Density Functional Theory (DFT) principles. The generalized gradient approximation (GGA) within the Perdew-Burke-Ernzerhof (PBE) functional was used with TB-mBJ to determine the electronic structure. The structural, elastic, electrical, vibratory, and thermoelectric properties have all been studied. The calculated band structure demonstrates the semiconducting nature, which shows indirect bandgaps of 3.15 eV and 2.94 eV for Sr₂WMgO₆ and Ba₂WMgO₆, respectively. Measured mechanical properties, such as the bulk modulus, elastic constants, and Poisson ratio are used to predict elastic durability. The Brillouin zone (BZ) extreme symmetry planes analyze the phonon dispersion curves. Phonon vector visualizations illustrate the dynamic robustness of the materials. The optical properties of real and imaginary dielectric functions, refractive index, and absorption coefficient were computed, indicating that they might be employed in optoelectronic and photovoltaic applications. In addition to these characteristics, Boltzmann’s theory is used to analyze the thermal electricity of Sr₂WMgO₆ and Ba₂WMgO₆. The performance figure for each was computed over the 200–1200 K temperature range and chemical potentials to evaluate these materials’ potential for use in future energy systems. This article aims to inspire experimental investigators to synthesize Sr₂WMgO₆ and Ba₂WMgO₆ for use in modern technology by describing various essential properties of these compounds.