We present a simple method for preparing heterostructures based on cadmium sulfide thin films modified by the addition of carbon nanostructures. For this particular system, we have examined the effect on the photocurrent produced by the addition of multiwall carbon nanotubes or multiwall carbon nanocones between the transparent metallic electrode and CdS, a II-VI semiconductor. Our preliminary results indicate the photocurrent through the semiconductor is strongly modified by the presence of carbon nanotubes or carbon cones.