Effect of annealing temperature on structural, morphological and optical properties of Cu/NiO thin films

In this study, Cu/NiO thin films were first deposited on glass and silicon substrates by the RF reactive magnetron sputtering and then the samples thermally annealed at 473, 673 and 873 K. For investigation of structural, morphological and optical properties of the films different analysis were employed. X-ray diffraction results indicate that all samples are amorphous. FTIR analysis shows a peak in the wavelength range 596.52 cm-1, which is related to Ni-O bonding. EDS map analysis also confirms the presence of nickel, oxygen and copper in the prepared layers. The results of AFM and FESEM analysis show that the morphology of the films is strongly influenced by the annealing temperature. The average roughness of films was varied between 0.19-0.50 nm and root mean square roughness was changed between 0.25-0.63 nm. Also, by variation of annealing temperature the optical band gap of the samples effectively influenced and optical band gap of the samples has changed between 3.14-3.50 eV.