Novel organic solar cells have been prepared using molecular clusters of porphyrin dendrimer (donor) and
fullerene (acceptor) dye units assembled on SnO2 electrodes. The molecular clusters of porphyrin with dendritic
structure and fullerene exhibit controlled size and shape in contrast with the reference systems (a porphyrin
dimer and a porphyrin−fullerene dyad) without dendritic structure in TEM images, which show rather irregular
and smaller clusters. The composite molecular nanoclusters of dendritic porphyrin and fullerene prepared in
acetonitrile/toluene mixed solvent absorb light over entire spectrum of visible light. The comparison of
photoelectrochemical properties of composite molecular cluster of porphyrin and fullerene with that of molecular
cluster of porphyrin−C60 dyad with covalent linkage shows the importance of interpenetrating structure in
each network to transport hole and electron efficiently. Furthermore, organic photovoltaic cells using clusters
of supramolecular complexes of V-shaped porphyrin dimer and porphyrin dendrimers with fullerene exhibit
remarkable enhancement in the photoelectrochemical performance as well as broader photoresponse in the
visible and near-infrared regions as compared with the reference system. This clearly indicates that the π−π
interaction between porphyrins and fullerenes in the supramolecular clusters plays an important role in
improving the light energy conversion efficiency.
accelerating voltage. Samples for TEM were prepared by dispersing the powdered sample in ethanol by sonication and then drop-drying on a copper grid (400 mesh, electron microscopy sciences) coated with carbon film. High-resolution TEM images were obtained with a JEOL-2010 microscope. SAEDS measurements were performed using a 25 nm electron beam attached with a JEOL-2010 TEM instrument. The AFM images of the sample loaded on a Si substrate were obtained using a Digital Instruments 3100 dimension AFM operating in non-contact mode. The DC magnetic measurements in the temperature range 5±100 K were performed in a commercial (Quantum Design) super-conducting quantum-interference device (SQUID) magnetometer.
Multiple photosynthetic reaction centres have successfully been constructed using supramolecular complexes of zinc porphyrin dendrimers [D(ZnP)(n): n = 4, 8, 16] with fulleropyrrolidine bearing a pyridine ligand (C(60)py). Efficient energy migration occurs completely between the ZnP units of dendrimers prior to the electron transfer with increasing the generation of dendrimers to attain an extremely long charge-separation lifetime.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.