Low-temperature growth and optical properties of ZnO nanorods

Zinc oxide (ZnO) nanorods were grown on ITO conducting glass by the chemical solution deposition method (CBD) in an aqueous solution that contained zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and methenamine (C6H12N4). The size of ZnO nanorods increased with molar concentration of zinc nitrate, and the nanorods with different aspect ratios also formed through tuning the reaction time when the molar concentration was 0.1 M. The length of nanorods increased significantly with the reaction time, but the thickness of the film deposited on the substrate only slightly increased. From the X-ray measurement results, it can be seen that the growth orientation of the as-prepared ZnO nanorods was [0 0 2]. Photoluminescence measurements were also carried out, the result showed a blue shift in violet emission with the reduction in crystal size.