Highly ordered semiconductor films morphologies such as nanowires, nanotubes and other examples grown from ZnO, TiO2, and other metal oxides has attracted much attention for the development of solar cells, optoelectronic devices, and sensors. The control and characterization of the binding mode, dye orientation, distance, aggregation phenomena, and in general of all aspects of the contact between a bound molecule and the semiconductor, are critically important to the understanding of electronic processes and for any kind of application. We will describe the synthesis and study of porphyrin model compounds and other organic dyes to study binding and electronic processes on ZnO, TiO2 and ZrO2 nanoparticles films as well as more ordered morphologies.