Effect of TiO2 seed layer on structural and optical properties of ZnO nanostructures

TiO₂:ZnO nanostructures thin films have been fabricated on glass substrates via sol-gel spin-coating technique for deposition of TiO₂ seed layer and solution-immersion method for growth of ZnO nanostructures. The layer of TiO₂ were annealed at various temperatures ranging from 350 to 500°C for 2 hours to examine the effect of annealing TiO₂ seed on the growth of ZnO nanostructures. The surface topography of TiO₂ seed layer were investigated by Atomic Force Microscope (AFM) and surface morphology of TiO₂: ZnO nanostructures thin films were observed by Field Emission Scanning Electron Microscope (FESEM). The optical properties of TiO₂ seed layer and TiO₂: ZnO nanostructures thin films as a function of seed annealing were determined by Ultraviolet-Visible (UV-Vis) spectrophotometer. As the annealing temperature of the seed layer increase to 450°C, the surface of the seed layer improved which causes the diameter size reduction of ZnO nanostructures and enhance the UV absorption properties and optical transmittance.