Local surface structure and interface properties of sprayed CdS films in a Schottky barrier cell

The surface microstructure of sprayed CdS films, studied by atomic force microscopy, has been correlated with their interface properties at the CdS/S-x(-2)/S-2) junction. It has been shown that the specificity of the film microstructure induced by the heating atmosphere remains valid even at the submicrometre level. From the grain density n, taken as the morphology parameter, and the surface roughness sigma, the topographic one, a quantitative quality factor q is defined here as the product q = n sigma. It is observed that the interface parameters, the width of the space charge region omega and the flat band potential E(fb), are both related to the q value. omega appears to increase with increasing q while E(fb) decreases. These behaviours seem to be limited to a certain range of q values.