Structural, mechanical, electronic, optical, and thermoelectric properties of Sr2XUO6 (X = Cr, Dy): A first principles investigation for photovoltaic applications

The physical characteristics of double perovskites (DPs) Sr₂XUO₆ (X = Cr, Dy) are investigated using a DFT-based analysis. According to the findings, both Sr₂CrUO₆ and Sr₂DyUO₆ retain the cubic structures. From the spin-resolved band structure (BS) and density of states (DOS) graphs, the semiconductor behavior was confirmed for Sr₂CrUO₆ and Sr₂DyUO₆.The calculated band gap (E_g) for the Sr₂CrUO₆ is 0.94 eV in spin-up region and 3.43 eV in spin-down region while for Sr₂DyUO₆, it is 0.31 eV in spin-up region and 0.46 eV for spin-down. Magnetic properties showed the magnetic moments (μ_B) for Sr₂CrUO₆ and Sr₂DyUO₆, as 4.00328 μ_B and 4.34692 μ_B, correspondingly. The magnetic moment's integral quantities reveal ferromagnetic (FM) character. Optical characteristics were also examined for Sr₂CrUO₆ and Sr₂DyUO₆, the measured values of ε₁(ω) at zero energy are approximately 5.05 and 9.94, correspondingly. The highest values of σ(ω) for Sr₂CrUO₆ and Sr₂DyUO₆ are calculated at 7.64 eV and 7.72 eV, correspondingly, indicating their appropriateness for the UV range. Thermoelectric (TE) features showed the high seebeck at lower temperature values suggesting their potential in TE uses. These findings show the potential of these DPs for applications in optoelectronic and TE devices.