Structural, morphological, dielectric and semiconducting properties of ZnO nanoparticles calcined at 500 °C

Metal oxide semiconductors (MOS) occupy a prominent position in both academic research and industrial applications owing to their diverse and distinctive properties, including electrical, optical, mechanical, magnetic, and electrochromic characteristics. In this study, we focused on zinc oxide nanoparticles (ZnO NPs) synthesized via a cost-effective co-precipitation method. Characterization techniques such as FT-IR, powder XRD, XPS, and UV-vis spectroscopy confirmed the successful synthesis of ZnO NPs, which exhibited an optical band gap of approximately 3.16 eV. Dielectric studies showed a dielectric constant value of ∼98 at 10³ Hz, remaining stable at higher frequencies due to reduced charge accumulation at grain boundaries. Impedance spectroscopy indicated that increasing temperature decreased the semicircle radius in Cole-Cole plots, reflecting enhanced charge carrier mobility and confirming semiconducting behavior. The AC conductivity ranged from 10^-8 to 10^-5 S cm^-1, slightly increasing with frequency, suggesting improved charge carrier mobility. These findings underline the promising potential of ZnO NPs for advanced technological applications, particularly in spintronic devices and UV photodetectors.