Photoinduced electron transfer from synthetic chlorophyll analogue to fullerene C-60 on carbon paste electrode - Preparation of a novel solar cell

Upon a carbon paste electrode, fullerene C-60 and successively methyl pyrop heophorbide-a (chlorin) were casted to prepare a chlorin-fullerene modified carbon paste electrode (CFE). Photocurrents on the CFE were produced by ir radiating of visible lights (> 510 nm) in an aqueous solution of 0.05 M eth ylenediaminetetraacetic acid and 0.1 M Na2SO4 at pH 6.7. Larger anodic phot ocurrent was induced by the CEE than by the carbon paste electrodes modifie d with either the fullerene or the chlorin. In addition, the photocurrent o f the CFE was dependent upon the amount of fullerene casted. The photocurre nt action spectra of the CFE (at 300 mV vs. Ag/Ag+) showed that photoinduce d electron transfer occurred from the excited state of the chlorin to the f ullerene and/or from the chlorin to the photoexcited fullerene, and the ele ctron of the fullerene anion radical produced was then shifted to the carbo n paste. Upon irradiation of > 375 nm lights, the anodic photocurrent of th e CFE was enhanced by increase in the illuminated light power and reached 0 .03 mA cm(-2) in the present system. (C) 1999 Elsevier Science S.A. All rig hts reserved.