Boosting optoelectronic and thermoelectric performance of double perovskite oxide Ba2MgWO6 with Ni substitution: A first-principles study

Abstract

Double perovskite oxides are promising materials for green energy production, particularly in solar cells and thermoelectric generators. However, their typically large band gap energy limits their effectiveness. Here, we study the electronic, optical, and thermoelectric performance of double perovskite oxide Ba₂MgWO₆ with Ni substitution using density functional theory (DFT). Our results show that the band gap energy reduces from 3.17 eV to 1.87 eV by increasing Ni content from 0 to 100%. This tuning of the band gap energy within the visible region remarkably enhances the absorption coefficient (∼10⁴ cm⁻¹) and the optical conductivity (∼10¹⁵ sec^-1). Meanwhile, the thermoelectric performance improves, indicated by an increase in the figure of merit from 0.84 to 0.96 at room temperature. These findings suggest new opportunities for optimizing the electronic, optical, and thermoelectric properties of double perovskite oxides for energy-related applications.