Dependence of the optical properties of NiO thin films on film thickness and nano-structure

NiO films of different thickness ranging from 285 to 645 nm were deposited, using the electron beam physical vapor method at room temperature on glass substrates. Nano-structures of the films were obtained using X-ray diffraction (XRD) and atomic force microscopy (AFM). It was observed that NiO thin films grow with (200) preferred orientation that increases with film thickness. In addition crystallite size obtained from XRD results and grain size obtained from AFM analysis increased with film thickness. Transmittance spectra of NiO films were collected between 340 and 850 nm wavelength. Refractive indices and the thickness of these films obtained using Swanepoel method. Optical functions of these films showed that films were of homogenous structure and the results agree with reported data obtained using different methods of film deposition.