Formation of CdxPb1−xS/Cd1-δS thin-film two-phase compositions by chemical bath deposition: composition, structure, and optical properties

Abstract

The possibility of forming thin-film two-phase compositions CdxPb1-xS/Cd1-S by using the chemical bath deposition from aqueous media with adding various cadmium salts has been demonstrated. The crystal structure, chemical composition, morphology, and the band gap were studied by the X-ray diffraction, scanning electron microscopy, elemental analysis, Auger and Raman spectroscopy, and diffuse reflectance measurements. The formation of a CdxPb1-xS/Cd1-S substitutional solid solution phase in well-faceted crystallites on the substrate of an X-ray amorphous CdS phase has been experimentally proved. The found differences in their composition are the result of the effect of the nucleophilicity of the anionic component of the cadmium salt on the kinetics of thiourea decomposition. The results demonstrate the possibility of forming thin-film two-phase compositions or heterostructures on the base of cadmium and lead sulfides in one technological stage by using chemical bath deposition, which can be important for the creation of solar cells.