Investigation on Nanostructure and Morphologies of ZnO Nanowires Prepared by Hydrothermal Method

Abstract

In this study, we controlled nanostructure and morphologies of the vertically aligned zinc oxide nanowires (ZnO NWs) on 200 nm-thick zinc oxide seed layer. The ZnO nanowires were synthesized by the hydrothermal method at 90°C for 6 hours in the precursor solutions. The solutions with four different precursor concentrations of zinc nitrate and hexamethylenetetramine (HTMA) in distilled water were prepared at 5 to 20 mM. The effect of the precursor concentrations were systematically investigated based on the structural and morphologies of ZnO NWs. Most physical investigations were performed with grazing-incidence X-ray diffraction (GIXRD) and field-emission scanning electron microscopy (FE-SEM). From GIXRD, the peak intensity and full width at half maximum (FWHM) of the ZnO (002) were both increased as the precursor concentration was increased. It was also found that the diameter and length of the ZnO nanowires were increased with the increased precursor solution concentration. The average diameter and length of the ZnO NWs could be controlled from 60 to 135 nm and 0.39 to 1.73 μm, respectively.