A thin film is a layer of material ranging from fractions of a nanometer to several micrometers in thickness. The controlled production of materials as thin films is a crucial step in many applications. CdS thin films were prepared by spray pyrolysis procedure at temperature 450 oC. The XRD, AFM and UV-Visible analysis were utilized to investigate the CdS films. The XRD investigation showed that prepared thin films have hexagonal structure with a particular direction along (101) plane. The crystallite size was measured from X-ray diffraction utilizing Scherrer’s equation. Atomic force microscopy (AFM) confirmed that the grain was consistently disseminated over the outside of the substrate for the CdS films. The grain size of the nanoparticles were calculated 66.26, 57.11 and 56.52 nm for the CdS, CdS :2% Cu, CdS :4% Cu respectively. The optical properties were done utilizing the UV-Visible analysis. It is found that Cu content affect the optical properties and via increasing the Cu amount, the band gap was decreased.
