Effects of Persistence Time and Au- catalyst on the Growth and Optical Properties of ZnO Micro and Nanostructures

In this paper، we study the growth of ZnO micro and nanostructures on a quartz substrate by means of carbothermal evaporation. Effects of persistence time and Au thin film as a catalyst on growth process and optical properties such as refractive index (n) and optical gap energy (Εg) of the grown ZnO are investigated. The samples were characterized by scanning electron microscopy،x-ray diffraction (XRD) and UV-visible characterization. The XRD spectrum clearly shows that the structure is in hexagonal wurtzite phase. Our results also indicate that increasing the persistence time as well as decreasing the size of ZnO nanostructures enhances the optical band gap to about 3/46 eV.