Tunable optoelectronic properties of selenium-doped zinc oxide nanostructures fabricated via sol–gel method

This study demonstrates the precise tuning of optoelectronic properties in selenium-doped zinc oxide (ZnO:Se) nanostructured films synthesized via a sol–gel spin-coating technique. We systematically investigate the impact of Se doping (1–5[Formula: see text]at.%) on the structural, optical, and electrical properties. X-ray diffraction (XRD) confirms the hexagonal wurtzite structure, with a dominant (002) orientation and lattice expansion evidenced by a peak shift from 34.45 ∘ to 34.12 ∘ . Field-emission scanning electron microscopy (FESEM) shows homogeneous nanoparticles with sizes of 18–24[Formula: see text]nm. Optically, the films exhibit high transparency [Formula: see text] and a controlled blue shift in the optical bandgap from 3.156[Formula: see text]eV to 3.184[Formula: see text]eV. This shift is correlated with a systematic decrease in electrical resistivity from 1463[Formula: see text] [Formula: see text] to 1091 [Formula: see text], supporting a Burstein–Moss effect driven by increased charge carriers. Photoluminescence (PL) spectra show that the defect-mediated luminescence can be modulated by doping concentration. The direct correlation established between Se-induced structural modifications and functional optoelectronic properties represents a significant advancement over prior studies. These results, achieved with a low-cost, scalable technique, highlight the strong potential of ZnO:Se nanostructures for application-specific devices such as transparent conducting oxides and ultraviolet (UV) photodetectors.