Investigation of structural and optical properties of copper doped NiO thin films deposited by RF magnetron reactive sputtering

Different percentages of copper doped NiO thin films were deposited on corning glass by RF magnetron sputtering process in fixed vacuum condition, 0–18% in five steps. The plasma were mixture of Ar + O2 with fixed ratio of 10% during the coating process. Characterization of these films were performed using X-ray diffraction, atomic force microscopy, UV–vis spectroscopy. EDS and ellipsometry have also been done to investigate elemental composition and film thickness. It is found that with increasing Cu dopant percentage, the crystalline quality decrease tending to amorphous structure. The X-ray diffraction pattern also shows that the films have cubic phase with preferred orientation (200). Measured optical transmittance declined with increasing copper dopant and the band gap (Eg) decrease −up to 12%- monotonically.