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

Shape- and functionality-con(t)rolled organization of porphyrin derivativeS-C-60 supramolecular assemblies using TiO2 nanotubes and nanoparticles has been achieved for the development of photochemical solar cells. The differences in the efficiency of lightenergy 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 C-60. 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.