Deposition of the nickel oxide films with different methods and investigation of some of its physical properties

In this study, nickel oxide films have been produced by chemical bath deposition (CBD), successive ionic layer adsorption and reaction (SILAR), sol- gel spin coating and ultrasonic spray pyrolysis methods using glass and florine-doped tin oxide (FTO) coated glass substrates. Some physical poperties of the films have been examined. X-ray diffraction spectra showed that NiO films are polycrystalline having face centered cubic in structure. Crystallite sizes of the samples varied in the range from10 to 33 nm depending on the deposition method and experimental parameters. FT-IR and Raman studies have been carried out to characterize the structural properties of the films. The morphological properties of the films have been investigated by field emission scanning electron microscope (FESEM). FESEM results revealed that morphological properties of the samples depend on the depeosition method and experimental paramaters. While the films deposited by CBD have morphology with nanoflake and nanosheets structures, the others fine grains covered on the surface. The materials have exhibited direct band gap characteristics and the band gap values of the samples are in the range of 3.37–3.93 eV. The electrochemical behaviour of the NiO films was studied by means of cyclic voltammetry in 0.3 M KOH solution. The reversibility and stability of samples were investigated for electrochromic applications.