Structural, Morphological, Vibrational, and Optical Properties of Mg-Doped ZnO Nanoparticles Synthesized via Sol–Gel Method

Abstract

Zn_1–xMg_xO (x = 0, 0.05, 0.1, and 0.15) nanoparticles (NPs) were prepared via the sol–gel method. A comprehensive investigation of the structural, morphological, vibrational, and optical characteristics of the prepared NPs was carried out by using the X-ray diffraction method (XRD), scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), and Ultraviolet-visible (UV–Vis) spectroscopy. XRD analysis confirmed the hexagonal wurtzite structure of ZnO. The average crystallite size decreased with increasing Mg concentration. Surface morphology was revealed by the SEM. FTIR spectra exhibited peaks below 700 cm^–1 corresponding to the zinc oxide (ZnO) and doped ZnO NPs. The UV–Vis result shows a blue shift in the optical bandgap for all samples when the Mg concentration increases in the ZnO lattice. The Tauc equation and Urbach tail analysis were employed to determine the optical bandgap, assess interband transitions, and evaluate defect-related states. The increased bandgap and improved optical characteristics make Mg-doped ZnO NPs promising candidates for optoelectronic devices, particularly in UV detectors and photovoltaic applications.