Effect of annealing temperature on structural and optical properties of nickel oxide thin films by dip coating method

Sol-gel dip coating technique has been successfully employed for deposition of nanocrystalline nickel oxide thin films from hydrated nickel chloride solution on glass substrate at temperatures 300°C and 400°C. Structural and optical properties of nickel oxide films were studied by X-ray diffraction (XRD), Fourier transformed infrared (FTIR) and UV-Visible spectroscopic techniques. XRD analysis shows that the film is polycrystalline nature with hexagonal structure of Ni₂O₃ along (002) orientation centered at 31.93°. The crystallite size was evaluated to be 72.5 nm by using Scherrer's equation. The composition of nanostructured film was confirmed by FTIR spectra and the optical transmittance of prepared thin films decreases with annealing temperature. Hence, it confirms the suitability of these films for various optoelectronic applications.