Fabrication and characterization of CdS doped ZnO nano thick films

In the present work, microstructural and optical properties of Cadmium Sulfide (CdS) doped Zinc Oxide (ZnO) thick film is investigated. Two samples undoped ZnO and 2 wt % CdS-doped ZnO thick film have been fabricated on the glass substrate. The fabricated film is characterized by X-Ray Diffraction (XRD) and Atomic Force Microscopy (AFM). X-ray diffraction patterns showed that crystallite size decreasing with CdS doping and it is 45 nm and 38 nm for ZnO and CdS-doped ZnO thick film. The variation on the surface morphology was observed using AFM measurement. The AFM results indicate that grain size and roughness parameter decreases, but microstrain increases with CdS content. The UV-Vis absorption spectra of the ZnO and ZnO-CdS showed that the optical band-gap decreased from 3.18eV to 2.10eV with 2 wt% CdS doping concentration. The present study demonstrates that fabricated films have polycrystalline structures and peaks matching the hexagonal ZnO structure.