Evaluating the influence of polyethylene glycol as a surfactant on CdO films grown by SILAR method

Nanocrystalline cadmium oxide (CdO) films have been prepared on glass substrates by the Successive Ionic Layer Adsorption and Reaction (SILAR) technique in the presence of polyethylene glycol (PEG) at different levels. The influence of PEG concentrations on structural, morphological and optical characteristics of the CdO films was elucidated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis spectroscopy. XRD analysis indicated that all the films had a polycrystalline structure with (111) preferential orientation. The SEM analysis showed that the CdO films prepared with different levels of surfactants presented different morphologies. From the UV-Vis analysis of the CdO films, the direct band gap energy of the CdO films was dramatically affected by the amount of PEG content. The variation of the band gap energy can be ascribed to the improvement in the crystalline quality of the films. The investigations revealed that the amount of PEG doping during the growth process of CdO nanostructures has a significant impact on the physical and optical characteristics of CdO films.