STRUCTURAL AND OPTICAL PROPERTY MODULATION OF ZINC OXIDE NANOPARTICLES BY CALCIUM AND DYSPROSIUM IONS DOPING: AN EXPERIMENTAL STUDY

Zinc oxide nanoparticles (ZnO NPs) have attracted considerable interest owing to their versatile optical, luminescent, magnetic, and electrical properties. A range of synthesis methods have been reported for ZnO NPs, including co-precipitation, hydrothermal, solid-state reaction, and sol–gel processing. In this study, pure ZnO, [Formula: see text] -doped ZnO, and [Formula: see text] doped ZnO nanoparticles were synthesized via the sol–gel route. The resulting powders were characterized by powder X-ray diffraction (XRD), UV–Visible spectroscopy, and Fourier-transform infrared (FT-IR) spectroscopy to assess phase formation, optical behavior, and bonding environments. XRD and FT-IR analyses confirmed the formation of doped and undoped ZnO nanoparticles, with crystallite sizes estimated from the Debye–Scherrer formula in the range of approximately 31–40[Formula: see text]nm. The direct optical band gap ([Formula: see text]) and the Urbach energy ([Formula: see text]) were extracted from UV–Vis transmittance data, with the undoped ZnO exhibiting an [Formula: see text] of 3.377[Formula: see text]eV. The measured [Formula: see text] values span from 0.175 to 1.441[Formula: see text]eV, reflecting dopant- and defect-related tail states that influence optical absorption. Across the series, the dopants modulate structural and optical properties, revealing clear dopant structure property relationships pertinent to ZnO-based functional materials.