Abstract
Oxide films of nickel were prepared at different concentrations, flow gas of oxygen by sputtering the nickel target at room temperature. X-ray diffraction measurements detect NiO0.96 phase forming the non-stoichiometries nickel oxide crystals. Thin film thickness decreases exponentially from 141 nm to 50 nm when the oxygen rate increases from 10 to 50 SCCM. Moreover, the crystallite size of nickel oxide decreases as the oxygen gas concentration increases from 198.88 angstrom to 82.05 angstrom for the plane (101) and 149.31 angstrom to 46.26 angstrom for the plane (012), respectively. Raman spectroscopy used to detect the structural change in the nickel oxide lattice as the oxygen flow rate changes. Films morphology has a spherical shape aggregated to form bigger particles for films prepared at 40 SCCM and the particle size is around 50 nm. The optical spectra transmittance and reflectance were measured to determine the optical transition and the role of the oxygen gas content on the optical band gap were studied. The optical band gap values changed from 3.74 eV for an oxygen rate of 10 SCCM to 3.8 eV at 50 SCCM. Photoluminescence behavior of the films was studied and confirms the presence of vacancies or defects in the nickel oxide lattice.