Colloidal synthesis of nanostructured pure ZnO and Cd doped ZnO thin films and their characterization

Thin films of intrinsic and Cd-doped ZnO with different cadmium concentrations were prepared by colloidal route technique associated with dip-coating onto glass substrates. Zinc acetate dehydrate, Cadmium acetate, methanol and ethanolamine were used as a starting materials, solvent and stabilizer, respectively. Nanostructured ZnO thin films with different concentrations of Cd doping (0, 2 and 10 wt%) are annealed at 500 degrees C for 2 h. The films were characterized by different methods to understand their structural, optical and electrical properties such as the film surface is with a ganglia-like structure as observed by Environmental Scanning Electron Microscopy (ESEM). The films were characterized by grazing incidence X-ray diffraction, its comprise of ZnO nanocrystallites with hexagonal crystal structure with a presence of CdO nanocrystallites with cubic crystal structure in 10% Cd-doped ZnO film (ZnO/CdO nanocomposite), as revealed by means of X-ray diffraction (XRD), the Raman and the Rutherford backscattering spectrometry (RBS) confirmed that. All films exhibit a transmittance above 75-90% along the visible range up to 800 nm and a sharp absorption onset about 375 nm corresponding to the fundamental absorption edge 3.2 eV (UV-vis). Photoluminescence of the films showed an ultraviolet UV and visible emissions like violet, blue and green related to defects. (C) 2016 Elsevier GmbH. All rights reserved.