Good solvent effects of C70 cluster formations and their electron-transporting and photoelectrochemical properties.
ABSTRACT Good solvent effects of C(70) cluster formations and their electron-transporting and photoelectrochemical properties have been systematically examined for the first time. Nano-to-micrometer scale assemblies of C(70) with different morphologies were prepared by rapidly injecting poor solvent (i.e., acetonitrile) into a solution of C(70) dissolved in various good solvents (i.e., benzene, toluene, chlorobenzene, etc). The cluster morphology engineering was successfully achieved by changing the good solvent, yielding the spherical, rodlike, or platelike clusters in the mixed solvents. The clusters of C(70) were electrophoretically deposited onto a nanostructured SnO(2) electrode to examine the photoelectrochemical properties under the white light or monochromatic light illumination. The maximum incident photon-to-current efficiency (IPCE) varied from 0.8 to 10% depending on the combinations of the poor-good solvents. The differences in the IPCE values are discussed in terms of the surface area, thickness, and electron mobility of the deposited cluster films. The electron mobility is found to be the most predominant factor for the IPCE, indicating the importance of the electron-transporting process in the overall photocurrent generation. In addition, the electron mobility is closely correlated with the underlying molecular alignment and the resultant cluster structure. Thus, these results will provide basic clue for the design of C(70)-based molecular devices including the organic photovoltaics.
- SourceAvailable from: Shigeru Deguchi[show abstract] [hide abstract]
ABSTRACT: Nanoparticles of C60, prepared by hand-grinding bulk solids in an agate mortar, were found to disperse stably in various organic solvents, in which molecular solubility of C60 is negligibly small. The resulting dispersions contained the C60 nanoparticles, whose average size varies between 200 and 300 nm depending on the solvent. The C60 concentrations in the dispersions were an order of magnitude higher than those prepared by the conventional methods.Chemistry Letters 03/2006; 35(4):396-397. · 1.59 Impact Factor