Effect of zinc on structural and some optical properties of CdS thin films

Abstract

This research deals with the study of the structural and optical properties of pure and Zinc doped CdS films with different doping ratios (3,6 and 9) % volume percentage. Thin films of CdS were deposited on glass substrates at temperature 400^oC by using of chemical spray pyrolysis with spray rate 3ml/sec and  with different thickness. The structural properties for the prepared films were studied through test of X-Ray diffraction and it appeared that the films are polycrystalline having hexagonal structure. it is also showed the film prepared has a preferred orientation along (002).The grain size was found to be decreased with increasing (Zn) concentration, on the other hand the atomic force microcopy (AFM) showed an decrease in (RMS) values with increasing (Zn) concentration, also the optical properties of these films were studied by measuring transmission and absorption spectra as a function of wavelength, and it was found that the transmittance increases with increasing (Zn) concentration, as well as the optical energy gap increases with increasing (Zn) concentration.

Keywords: thin films, optical energy gap, structural properties.