EFFECT OF Mg CONCENTRATION ON THE STRUCTURAL AND OPTICAL PROPERTIES OF ZnMgO THIN FILMS

ZnMgO thin films were synthesized and systematically investigated for their structural and optical properties. X-ray diffraction (XRD) revealed a strong c-axis preferred orientation with dominant (002) reflections, confirming the wurtzite phase of the alloy without detectable secondary MgO phases. The incorporation of Mg into ZnO induced a peak shift toward higher diffraction angles, consistent with lattice contraction due to the smaller ionic radius of Mg²⁺. Optical studies based on UV–Vis absorption spectra demonstrated a systematic blue shift in the absorption edge with increasing Mg concentration, widening the optical band gap from ~3.26 eV (ZnO) to ~3.44 eV (20% Mg). These findings highlight the tunability of ZnMgO films for potential applications in ultraviolet (UV) photodetectors, transparent conducting oxides, and band-aligned optoelectronic devices.