Pbs-Cds bilayers prepared by the chemical bath deposition technique at different reaction temperatures

The chemical bath deposition (CBD) technique was used for PbS-CdS thin film s synthesis, on glass substrates, in an alkaline solution. This heterostruc ture of firmly adhered films is useful for solar absorbers, solar device co ntrol, and other important applications. The reactive substances used to ob tain the PbS layers were lead acetate and thiourea whereas the substances t o obtain the CdS layers were cadmium chloride and thiourea. The PbS layers of 40 nm in thickness were grown at room temperature during 75 min. Differe nt CdS layers were grown at constant temperatures in the range 30-80 degree s C, during 30, 60 and 90 min in each case. The two-layers system was chara cterized by X-ray diffraction, scanning electron microscopy, and optical ab sorption measurements. The formation of CdS clusters on the films' surface was studied as a function of the reaction temperature. (C) 1999 Elsevier Sc ience S.A. All rights reserved.