Influence of deposition parameters on the structural and optical properties of CdS thin films obtained by micro-controlled SILAR deposition

Polycrystalline CdS films were obtained by a micro-controlled SILAR deposition technique, using aqueous solutions of cadmium acetate and thiourea as precursors. The structural and optical properties of the films were found to be influenced by various deposition parameters such as number of immersion cycles, concentration of the precursors and temperature of the solutions. Contrary to the observations made by some researchers, we found that the thickness of the films increased continuously with number of immersion cycles and also with concentration of the precursor solutions. We also found that the films covered the substrates uniformly, without any voids, unlike the films obtained by others. Effect of deposition parameters on thickness, substrate coverage, grain size, chemical composition, optical band gap and other properties of the films is discussed in detail.