Study on spray deposited Ni-doped CuO nanostructured thin films: microstructural and optical behavior

In this study, CuO and Ni-doped CuO thin films are deposited on glass substrates at 400 °C by the spray pyrolysis as easy, available, and low-cost deposition technique. The surface roughness and shape parameters of the deposited films were investigated by the high-resolution atomic force microscopy. X-ray diffraction (XRD) characteristic technique was used to identify the crystal structure and determine the average grain size, and structural defects of the investigated films. The XRD pattern revealed that the CuO and Ni-doped CuO films exhibit nanocrystalline structure with the monoclinic phase. The average grain size slightly changed with the doping level of Ni while it increased with the electron beam-irradiation doses. The optical properties like transmission, absorbance, and reflectance were recorded in a wide range of wavelengths. The optical band gap values changed with Ni doping level according to the slight changes in the crystal structure of the studied films. Also, the optical band gap decreased with the electron beam-irradiation doses due to the crystal structure improvement with irradiation doses. J–V characteristics of the Ag/p-CuO/n-ZnO/FTO/Ag device also have been studied and the ideality factor and potential barrier height have been determined in the dark and illumination.