Studies on the effects of Cd ion sources and chelating reagents on atomic layer CdS deposition by successive ionic layer adsorption and reaction (SILAR) method

Abstract

CdS thin films were fabricated on an ITO-covered glass substrate by the successive ionic layer adsorption and reaction (SILAR) method under various conditions. By changing Cd ion sources, chelating reagents, and pH the obtained films were evaluated by their thickness, crystallinity, crystallite size, surface roughness and elemental composition. CdCl₂ and triethanolamine were found to provide the most well crystallized thick films among six Cd salts and six chelating reagents. In the present study, no marked effect of pH on the film quality was observed compared to the effect of the difference in the counter ions. The effects of counter ions, chelating reagents, and pH could be explained in terms of the stability constant of Cd²⁺ for these chemical species and SH⁻.