The effects of precursor concentration and thermal annealing on the growth of zinc oxide nanostructures grown on silicon substrate

摘要

This study focuses on the growth of Zinc Oxide (ZnO) nanostructures on SiO2/Si(100) substrate via chemical bath deposition (CBD) with varying NH4OH concentration and annealing temperature. The grown ZnO nanostructures were characterized via SEM-EDS for the surface morphology and elemental composition and UV-Vis spectroscopy for the reflectance measurement. Increasing the concentration of NH4OH produced denser ZnO nanostructures composed of rods having smaller diameter. It is believed that at higher concentration of NH4OH, more Zn(OH)2 seed will act as nucleation site for ZnO formation which suggests higher probability of ZnO growth. Thermal annealing increased the average diameter of ZnO nanorods. Annealing provided enough energy for unstable atoms to rearrange into a more suitable position. This would result to larger rods that have been formed in expense of the smaller rods. Furthermore, it is confirmed in the UV-Vis spectroscopy results that ZnO nanostructures were successfully grown on SiO2/Si(100) substrate. This successful growth of ZnO nanostructures is a promising material for solar cell technology.