Effects of supersaturation on CdS film growth from dilute solutions on glass substrate in chemical bath deposition process

CdS films were prepared on a glass substrate and their growth was analyzed as a function of the supersaturation ratio in dilute solutions. Nanocrystalline CdS with a hexagonal (wurtzite) structure is present in the CdS films and aggregated into colloidal particles. The particle size increases from 117 nm to 357 nm when the relative supersaturation ratio (Sr) increases from 0.4 to 1.0, but particle size decreases to 149 nm and the absorption edge blue shifts from 488 nm to 456 nm when Sr increases further to 4.0. The evolution of the CdS film is explained on the basis of the proposed growth kinetic model.