Structural and Optical Properties of Zinc Oxide (ZnO) based Thin Films Deposited by Sol-Gel Spin Coating Method

Abstract

The structural and optical properties of ZnO thin films deposited by sol-gel spin coating method have been investigated. The ZnO thin films were deposited on corning glass 7059 substrate from zinc acetate (ZnAc), ethanol, and stearic acid as starting material, solvent and stabilizer were used, respectively. The characteristics of the film were analysed from transmittance spectra obtained by UV-Vis spectroscopy measurement, while the atomic structure of the films analysed from XRD and AFM measurement. The results showed that the characteristics of ZnO thin films were strongly depend on annealing temperature. The XRD measurement indicated that deposited film shows a type of nanocrystalline peak broadening with hexagonal structure and preferential orientation along (002) crystal plane. The transmittance value of the ZnO films was relatively high (75 - 80 %). The optical band gap of ZnO films decreases with increasing in annealing temperature. AFM images showed the annealing temperature effects surface morphology of the films.