The role of ammonia reagent in the surface texture and photoreactivity of thin cadmium sulfide films

A smooth method of improving the surface texture of thin CdS films is presented in this work. The use of ammonia solution in this matter has been found to be safe, since no deleterious compound is released. The low rate of the process involved allows for an easy follow up of the photoreactive behavior of each of the samples treated for different immersion times. Monitoring of the change that occurred revealed that optimal conditions can be attained from either a single wet treatment of the sample or a repetitive wet treatment of the same sample in the same medium. Microstructure modification is likely to be the main factor responsible for the improvement in photoreactivity. A shiny electrochemical deposit engendered by the second method does not modify this behavior. That compound probably leads to a progressive change of the semiconductor‐electrolyte junction in semiconductor insulator‐electrolyte type.