Effect of Washing Treatment on the Morphology of Vertically Aligned ZnO Nanorods

Abstract

Vertically oriented ZnO nanorods were synthesized in a two steps technique involving the preparation of ZnO seed layer and the growth of ZnO nanorod on the glass substrate. ZnO seed layer was firstly deposited on the glass substrate by dip coating method, while well aligned ZnO nanorod were grown on seed layer coated substrate by hydrothermal method at 110 ^oC for 20 min. Crystalline structure, morphologies and band gap energy of the as-prepared ZnO nanorod were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and specular reflectance UV-Visible spectrophotometer, respectively. The XRD results showed that ZnO nanorods were wurtzite-structured with preferential orientation along (002) plane. It is shown that washing treatment on the as-prepared ZnO films provides a facile way to eliminate randomly oriented ZnO nanorods and results in vertically oriented nanorods on the glass substrate. Its textural coefficient is almost two times higher than ZnO nanorods previously reported.