Influence of Heat Treatments on the Properties of ZnO Nanorods Prepared by Hydrothermal Synthesis

Abstract

ZnO nanorods were grown on bare or SiO2-coated Si wafers by the hydrothermal method. The ZnO nanorods were annealed at 200, 400, and 600°C, respectively. The structural, optical, and electrical property variation of the ZnO nanorods with the annealing temperature was investigated by X-ray diffraction, field-emission scanning electron microscopy, photoluminescence, and current–voltage measurements. For the ZnO nanorods, compressive strain was detected, which decreased with annealing. Moreover, annealing at 600°C led to nanorod agglomeration. The ZnO nanorods annealed at 400°C exhibited the highest crystallinity.