المستخلص
This study investigates the effect of varying copper oxide (CuO) concentrations (20%,40%,60%, and 80%) mixed with cobaltoxied (Co3O4)thin films, produced on glass substrates using the chemical spray pyrolysis technique. The impact of these mixing ratios on the optical and structural properties of Co3O4 films was examined. The x-ray diffraction test examined Co3O4 thin films with varying molar ratios (0.1,0.2,0.25, and 0.3) M. The structure’s polycrystalline nature and the cubic crystal system of the film were revealed by X-ray diffraction research. For the pure Co3O4 with 0.1M sample, the high intensity appeared at (2θ =36.88˚) and the dominant trend of growth is (311). The crystallite size of the pure Co3O4 with 0.1M sample is 8.92 nm, and the size of the crystallites increases as the molar concentration increases from 0.2, 0.25, 0.3)M to 10.09, 9.64, and 7.17 nm. The Co3O4: CuO sample, it is polycrystalline, and the film’s crystal system is cubic. The high intensity appeared at (2θ =36.46˚) before annealing and (2θ 37.03˚) following annealing for (80%Co3O4:20%CuO), and the dominant trend of growth is (113). The crystallite size increases with increasing mixing ratio of (CuO). The surface morphology of pure and mixed thin films deposited on glass substrates by chemical spray pyrolysis technique was examined by Field Emission Scanning Electron Microscope (FE-SEM).
FE-SEM micrographs for pure cobalt oxide Co3O4 and mixed (Co3O4: CuO) films deposited on glass substrates at various ratios. It was noticed that the mixing ratio of CuO exhibits some changes in the Co3O4 surface morphology where the surface was found to be densely packed with crystallites.
It was found that the pure Co3O4 thin film was smooth, thick, and non-homogeneous with pinholes. Additionally, it was observed that the grains exhibit a variety of spherical-like shapes and sizes, as well as tiny cauliflower. FE-SEM micrographs of Co3O4 thin film deposited with 20% of CuO showed large clusters of spherical or semispherical shaped grains on some parts of the images, indicating an irregular growth rate of the grains. The images exhibited a dense compact of the grains covering the entire surface without any defects like cracks or pinholes. The mixing ratios (40, 60 and 80) increased the particle size.
The result of optical measurement by UV-Vis spectrophotometer where showed that the thin films of (Co3O4 and Co3O4:CuO) exhibit direct transition energy band gap. The absorbance of the films rises with the rising mixing ratio. As the mixing ratio is increased, the energy gap narrows.
Hall effect measurements confirmed that all films exhibit p-type conductivity. Higher CuO content led to increased electrical conductivity, carrier mobility, and charge carrier concentration, indicating enhanced electronic performance at higher CuO ratios. Also, the PL test of the films showed that the energy gaps are slightly more than the value calculated by the UV-ViS spectrophotometer when the energy gap.
