Self-organization of porphyrins and fullerenes for molecular photoelectrochemical devices

We have constructed a variety of molecular assemblies of porphyrin as a donor and fullerene as an acceptor on electrodes for molecular photoelectrochemical devices. Highly efficient energy- and electron-transfer processes have been realized at gold electrodes modified with self-assembled monolayers of porphyrin- or fullerene linked systems mimicking light-harvesting and charge separation in bacterial photosynthesis. Highly ordered organization of porphyrins and fullerenes has also been achieved using step-by-step self-assembly of porphyrin and fullerene units by association with gold nanoparticles or dendrimers on tin oxide electrodes, which exhibit high power-conversion efficiency of up to 1.5%. These results will provide valuable information on the design of donor-acceptor type molecular assemblies that can be tailored to construct highly efficient organic solar cells.