مشخصات پژوهش

ZnO micro and nanostructures were synthesized on a quartz substrate by the carbothermal evaporation method. The thin layers of gold were used as catalyst and synthesis were carried out at different persistence time. Characterization of the layer was conducted in order to study the effect of persistence time on morphology and crystal structure and optical properties of the fabricated ZnO nanostructures. The samples were characterized by scanning electron microscopy, x-ray diffraction (XRD) and UV-visible spectrophotometry which were performed to investigate the optical properties of fabricated ZnO layer. The XRD spectrum clearly shows that the structure is in a hexagonal wurtzite phase. Optical properties of ZnO micro and nanostructures were evaluated from transmittance data using the method proposed by Swanepoel (In the regions ?=200-900 nm). Our results 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. To the best of our knowledge, this is the first report on the study of the correlation of optical properties obtained by Swanepoel method and morphology of ZnO nanostructures.