Ab-initio study of the structural, electronic, optical, and thermoelectric properties of chalcogenide-doped Sr2UZnO6

The first principal calculation based on the Density Functional Theory (DFT) is utilized in order to investigate the structural, electrical, optical, and thermoelectric properties of pure as well as chalcogenes doped at oxygen position of Sr₂UZnO₆. Using the PBE-GGA + mBJ approximation, we found that the band gap values for pure Sr₂UZnO₆ are 2.081 eV. Additionally, the compounds under study, Sr₂UZnO${}_{6-x}$Y${}_x$ (where Y = Te, Se, S, and x = 0.083), are p-type semiconductors with a direct band gap. Furthermore, the band gap decreased from 2.081 eV for pure Sr₂UZnO₆ to 1.263 eV, 1.618 eV, and 1.486 eV for Sr₂UZnO_5.917Y_0.083 where Y = Te, Se, and S, respectively, following the substitution of chalcogen impurities on the oxygen site. In the visible range, the absorption can surpass $2.10^5{\mathrm{cm}}^{-1}$ due to the lowering of the band gap, particularly for Te-doped Sr₂UZnO₆. Furthermore, every structure studied is thermodynamically stable based on the enthalpy of formation. Additionally, all of the investigated compounds’ electrical and thermal conductivities rose with temperature, and type P behavior is suggested by the positive Seebeck coefficient values. In light of all these findings, we anticipate that Sr₂UZnO_5.917Y_0.083 (Y = Te, Se, S) doped compounds will be used as semiconductors in photovoltaic and thermoelectric devices.