Growth and Characterization of CdS Thin Films by Chemical Bath Deposition

Thin films of cadmium sulfide (CdS) were grown by Chemical Bath Deposition (CBD) technique. Cadmium sulfide, and thiourea were used as the source materials for the preparation of the films. The films were deposited onto the good quality glass plates (75 mm X 25mm) as substrates. To carry out the growth, 1 M Cadmium sulfide solution was prepared and required amount of triethanolamine was added to form a bound stable complex. The substrates (glass plates) were stirred in the solution at the temperature 55oC with a constant rate of rotation 60 rpm using a DC motor. The pH of the reaction mixture was maintained using appropriate quantities of Sodium hydroxide and aqueous ammonia were added for the film adherence to the substrate support. Thickness of the film gets nearly saturated when the deposition time is above 90 min. Electrical resistivity of the grown CdS film was found to be of the order of 10 Ω-cm as measured by using Four-Probe method.