Semiconducting and Optomechanical Insights Into Rare‐Earth Copper Oxy‐Sulfates for Advanced Energy Technologies

In this study, DFT approach is used by applying Kohn–Sham/Hartree–Fock‐coupled perturbation method within generalized gradient approximation (GGA)–Perdew Burke Ernzerhof (PBE) and GGA + U functional to estimate structural, optical, electronic, mechanical, and thermodynamic properties of oxy‐sulfates family (XCuSO, X = La, Lu, Sc, and Y) compounds. Electronic properties reveal strong influence of metallic cations on the band gap values (1.17 to 1.63 eV), which have presented semiconductor natures. Optical properties such as dielectric function values (8–12) and strong optical absorption (> 10 5 cm −1 ) have been calculated along with strong refractive index, extinction coefficient, optical conductivity, which are appeared in the visible region of spectra, showing the potential of compounds for energy conversion applications. Mechanical properties have been explored to estimate the ductile‐brittle natures of the compounds, and have resulted with ductile natures for YCuSO and LuCuSO and brittle for LaCuSO and ScCuSO compounds. Moreover, thermodynamics characteristics have been examined up to 1000 K temperature range indicating potential of the compounds to be used for application up to 600 K (operating window). All such outcomes are presenting the potential of compounds for energy conversion applications such as photovoltaics (PVs).