Structural and morphological studies of chemical bath-deposited nanocrystalline CdS films and its alloys

The microstructure and surface morphology of chemical bath-deposited (CBD) nanocrystalline CdS films, its alloys (CdS:Ag and CdS:Mn) and the influence of growth conditions on their properties have been investigated by means of X-ray diffraction (XRD), scanning electron microscopic (SEM) and transmission electron microscopic (TEM) studies, respectively. CBD nanocrystalline CdS films exhibit the co-existence of hexagonal and cubic phases. This is related to the polymorphic tendency of the CdS structure and indicates a strong influence of local parameters in the deposition conditions. Microscopic studies indicated that CdS films are formed from coalescence of individual crystallites with a high degree of crystallinity. The preferred orientation of CdS film is due to the controlled nucleation process associated with the low-formation rate of CdS. In CdS:Ag alloys, presence of Ag2S monoclinic species is indicated and presence of uniform, monodispersive and spherical crystallites is evident. In CdS:Mn alloys, presence of well-defined hexagonal structures with size distribution of the order of 0.2–2.0 μm corresponding to monocrystalline MnS species is indicated.