Effect of doping with cobalt on the structure and optical properties of zinc oxide thin films prepared by sol-gel method

Abstract

In this study, pure zinc oxide films doped with a cobalt percentage of 3% were prepared using Sol-Gel spin coating technique on a glass substrate at a temperature of 100 degrees Celsius. The structural and optical properties of these films have been studied. Structure properties are obtained by using x-ray diffraction (XRD) technique, they were carried out using a device of type (Panalytical X ‘Pert pro) with a target of type (Cu Kα) and a wavelength of (λ = 1.541 Ao). The diagnostic results showed that these films are polycrystalline and have a hexagonal structure with preferential orientation at (101). The Optical properties are concluded from absorption and transmission measurements, which are obtained by using the double beam UV-Visible1800 spectrophotometer in the wavelength (300–800) nm. It was found that the absorbance increases with increasing the doping percentage (1, 2, 3, and 4)mol%, while the transmittance is decreased. The optical properties also included the energy gap, the absorption coefficient, the reflectivity, the refractive index, the extinction coefficient, and the dielectric constant in its real and imaginary parts. It was found that the energy gap values decreased in the range 3.32–3.03 eV and the transmittance rate was 90% within the visible spectrum region.