Morphological and Optical Study of Gamma Irradiated Zinc Oxide (ZNO) Nano Wires Grown via low Temperature Aqueous Chemical Growth (ACG) Method

Abstract

Zinc oxide (ZnO) nanowires have attracted considerable interest because of their wide direct band gap, high exciton binding energy, optical transparency, and potential applications in optoelectronic and sensing devices. In the present study, ZnO nanowires were synthesized using a low-temperature aqueous chemical growth (ACG) method and subsequently exposed to gamma radiation to investigate radiation-induced modifications in their morphology and optical properties. The synthesized nanowires were characterized before and after gamma irradiation using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Visible spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). The structural analysis confirmed the formation of crystalline ZnO with a hexagonal wurtzite structure. SEM observations revealed well-defined nanowire-like structures, while gamma irradiation produced noticeable changes in surface morphology, nanowire diameter, alignment, and surface roughness depending on the irradiation dose. UV–Visible analysis demonstrated strong absorption in the ultraviolet region, with irradiation-induced changes in the absorption edge and optical band gap. These changes were attributed to radiation-induced defects, oxygen vacancies, interstitial zinc, and modifications in the electronic structure of ZnO. FTIR analysis further confirmed the presence of Zn–O vibrational modes and changes in surface-related functional groups after irradiation. The results indicate that gamma irradiation provides an effective approach for tailoring the morphological and optical characteristics of ZnO nanowires and may enhance their suitability for radiation sensors, UV photodetectors, optoelectronic devices, and other advanced technological applications.