Shape- and functionality-controlled organization of TiO₂- porphyrin-C₆₀ assemblies for improved performance of photochemical solar cells

Shape- and functionality-controlled organization of porphyrin derivatives-C₆₀ supramolecular assemblies using TiO₂ nanotubes and nanoparticles has been achieved for the development of photochemical solar cells. The differences in the efficiency of light-energy conversion of these solar cells are explained on the basis of the geometrical orientation of the porphyrins with respect to the TiO₂ surface and the supramolecular complex formed with C₆₀. The maximum photon-conversion efficiency (IPCE) of 60% obtained with TiO₂ nanotube architecture is higher than the value obtained with nanoparticle architecture. The results presented in this study show the importance of substrate morphology in promoting electron transport within the mesoscopic semiconductor film.