Optical and morphological properties of the CdO thin films as a function of film thickness

Abstract

It has been investigated the effect of film thickness on the optical and morphological properties of cadmium oxide (CdO) thin film. For this reason, transparent and conducting CdO thin films were deposited on glass substrates at 200 °C temperature using DC magnetron sputtering method. The power of the sputter in the experiment was set up to 100 W. In order to determine the morphological properties of the films, X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) was used. Also optical band gap of the films was determined by using UV–VIS spectroscopy. The XRD results showed that the films were in polycrystalline cubic structure. It was concluding that the surface roughness values decrease with the increasing film thickness. The changes of optical band gap of the CdO thin films was stable for the thickness of 100 nm and 150 nm but the band gap value increase about 0.3 eV with the film thickness of 200 nm.