Effect of heat treatments on the morphological properties of ZnO thin films onto ITO substrate deposited by sol-gel spin coating method
S. Ilican, Y. Caglar, M. Caglar, F. Yakuphanoglu
Anadolu University, TR
Keywords: ZnO, sol-gel spin coating, grain size, morphological properties.
Abstract:ZnO thin films have been deposited onto ITO glass substrates by the sol-gel spin coating method. Zinc acetate dehydrate, 2-methoxyethanol and monoethanolamine were used as a starting material, solvent and stabilizer, respectively. The coating solution was dropped into ITO substrate, which was rotated at 3000 rpm for 30 s using a spin coater. After the spin coating process the film was dried at 300 oC for 10 min in a furnace to evaporate the solvent and to remove organic residuals. This coating/drying procedure was repeated for twelve times, before the films were inserted into a tube furnace and annealed at 500 oC and 600 oC in air for 1 h. The effects of heat treatment on the crystalline structure and orientation of the ZnO films have been investigated using X-ray diffraction (XRD) study. The grain size of the films was calculated using the Debye-Scherrer formula. Surface morphology of the films has been also analyzed by a scanning electron microscope (SEM) and atomic force microscope (AFM). The important changes in crystalline structure of the ZnO thin films were observed due to the heat treatment.