Preparation and Study of Cadmium Oxide Doped Gallium Oxide Thin Films and application of Gas Sensor

In this paper, the structure and optical properties of pure cadmium oxide films, and doped with gallium oxide have been achieved, the films were deposited on glass and silicon substrates, with different ratios (1,3,5,7)% via spry pyrolysis method, at the substrate temperature of ̊ C300. XRD results showed that all prepared films had a cubic polycrystalline structure, with preferred orientation of (111) for cadmium oxide. Surface morphology was studied using atomic force microscope (AFM), the grain size of the thin films was about 105.42-69.07 nm, with surface roughness is about (3.32-0.901) nm and root mean square (RMS) (3.97-1.05) nm for cadmium oxide films. The optical properties were studied using UV-VIS spectroscopy at wavelength (300-1100 nm), It was observed that the value of transmittance increases when the gallium doping are increasing and the films have a direct energy gap about (2.3-4) eV that increases with the increase in gallium concentration. Sensitivity properties of pure cadmium oxide films, and doped with gallium oxide was deposed on silicon substrates of NO2 gas at different operation temperatures was found that the films of CdO doped with Gallium oxide on silicon substrate has greater sensitivity than the films than the undoped and that the doping has improved the sensitivity of the membranes CdO.