First stages of growth of CdS films on different substrates

Cadmium sulfide films were grown on glass, silicon, and ITO substrates by chemical-bath deposition (CBD) at 358 K, and studied by atomic force microscopy. Auger electron microscopy and X-ray diffraction. CdS film growth initiates immediately and thickness increases with deposition time. The ring roughness of CdS films grown for 1 to 10 min (thicknesses of 10 to 70 nm) was measured by atomic force microscopy. The roughness of films grown on ITO remains similar to that of the substrate regardless of deposition time. On the other hand, the roughness of CdS films grown on glass and silicon increases with deposition time, finally reaching a roughness similar to that of films grown on ITO. Auger profiles show that the CdS/substrate interface is not abrupt and depends on the substrate. Substrate roughness plays an important role during the initial CdS growth process. X-ray studies show that silicon substrates are not appropriate for CdS film growth by CBD. The most appropriate substrate is ITO.