Effect of annealing temperature on structural and optical properties of cobalt oxide thin films prepared by electrostatic spray deposition technique

Abstract

In this work, cobalt oxide thin films were prepared by electrostatic spray deposition (ESD) technique on glass substrate. The influence of the annealing temperature on properties of cobalt oxide film was investigated. The structural, optical and morphology of cobalt oxide thin films were characterized by X-ray diffraction (XRD), Raman spectroscopy, UV-Visible spectrophotometer, scanning electron microscope, respectively. The crystalline parameters such as crystalline size of films can be obtained from XRD spectra. Phase transformation due to the different annealing temperature in cobalt oxide film has been observed. Moreover, at the higher annealing temperature, the optical band gap in cobalt oxide films were shifted to lower value due to the change in crystalline size and the defect sites in films.