Study of the Some Optical and Structural Properties of Cadmium-Oxide Thin Films Prepared Using Spin-Coating Technique

In this research, cadmium-oxide thin films are prepared using spin-coating technique. The study is focused on clarifying the effect of changing temperature on the optical properties of cadmium-oxide films deposited on glass substrates with an area of 1.5×2 cm² at different temperatures. The behaviour of the visible absorption spectra of cadmium-oxide films is also studied as a function of wavelength. These results show that the absorption intensity decreases with increasing temperature, which indicates an increase in the concentration of the film material. Some optical constants are also studied, such as the refractive index, the real and imaginary parts of dielectric constant, the extinction coefficient, and the electrical-conductivity coefficient. As found, all values of these constants change with increasing temperature. Through the absorption spectrum, the optical energy gap is calculated and it is found that there is a slight change with increasing temperature, as its value decreases from 2.27 to 2.24 eV, when the temperature increases from 400°C to 500°C. The results obtained contribute to understanding the suitability of the material for optical and electronic applications.