The microstructure and surface morphology of chemical bath-deposited (CBD) nanocrystalline US 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 US films exhibit the coexistence of hexagonal and cubic phases. This is related to the polymorphic tendency of the US structure and indicates a strong influence of local parameters in the deposition conditions. Microscopic studies indicated that US films are formed from coalescence of individual crystallites with a high degree of crystallinity. The preferred orientation of US film is due to the controlled nucleation process associated with the low-formation rate of US. In CdS:Ag alloys, presence of A(g2)S 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 mu m corresponding to monocrystalline MnS species is indicated. (c) 2005 Elsevier B.V. All rights reserved.