The role of controlled nucleation in the growth of CdS thin films on ITO/glass for solar cells

The MOCVD growth of cadmium sulphide from dimethyl cadmium and ditertiarybutyl sulphide on indium tin oxide (ITO) coated glass is optimized in this work. Optimum transmission characteristics and grain size are observed for films grown at 290 degrees C at VI/II ratios of 1-1.5. This was related to the identification of a nucleation delay during in situ growth monitoring via laser interferometry. The nucleation delay is noted to vary with temperature and also VI/II ratio, allowing the rationalization of the resulting film quality in terms of this observation. Structural analysis indicates polycrystalline CdS of hexagonal phase of (1 0 0) preferred orientation. (C) 1998 Kluwer Academic Publishers.