Influence of Substrate Material on Structure Formation and Optical Properties of CdS Thin Films by Chemical Spray Pyrolysis

Abstract

Cadmium sulfide (CdS) thin films have been deposited on a variety of substrates by using homemade chemical spray technique (CSP). A study of the effect of substrate material on the structure and optical properties of the fabricated films is reported. X-ray diffraction studies confirm the polycrystalline nature of the films with hexagonal structure and a preferential orientation along the (002) plane. The surface morphological studies revealed the nanocrystalline grains, and all the deposited films have uniform well covered grain size on the surface of the substrates. The compositional analyses showed highly stoichiometric, and the S/Cd atomic ratio is close to one. The optical studies showed the average transmittance of the films deposited on different substrates in the visible and near infrared regions is about (65 to 80) %, and band gap varied from (2.432 to 2.444) eV. The obtained results indicated that the substrate nature has a strong factor influencing on the formation and optical properties of CdS films.