Investigation of physical properties of CdO thin films prepared by SILAR method

In this study, cadmium oxide (CdO) thin films were obtained on glass substrates by using the Successive Ionic Layer Adsorption and Reaction (SILAR) method. The effects of different cycle numbers (50, 70, 90, 110) on the structural, morphological, optical and electrical properties of CdO thin films were investigated. Film thicknesses were determined by weighing method and calculated in the range of 46-245 nm. The crystal symmetry of CdO thin films were analysed by the X-Ray Diffraction (XRD) method and were found as the cubic structure. It was determined from Scanning Electron Microscopy (SEM) analyses that the particles were formed in a close packed structure. Fundamental optical constants were investigated using optical transmittance (%T) and optical absorption (A) measurements. UV-Vis spectrophotometer was used for these measurements. The %T values of CdO thin films varied in the range of 60-92% in the visible region (400-700 nm). In addition, the refractive index (n) values in the visible region were calculated as 1.35-2.09. The forbidden energy gaps (Eg) of CdO thin films were found in the range of 2.84-3.06 eV. It was determined by Hall measurements that CdO thin films are n-type semiconductors. As a result, it was found that each investigated parameter depends on the number of cycles. In addition, it can be said that the obtained CdO thin films are among the candidate materials that can be used in technological applications in the form of solar cells and transparent conductive oxide layer material.