Facile Fabrication and Photocurrent Generation Properties of Electrochemically Polymerized Fullerene–Poly(ethylene dioxythiophene) Composite Films

Fullerene–poly(ethylene dioxythiophene) (polyEDOT) composite films consisting of 3,4-ethyeledioxythiophene (EDOT) and a thiophene derivative of C 60 fullerene (ThC 60 ) or C 60 fullerene were fabricated on a transparent indium–tin-oxide (ITO) electrode by electrochemical polymerization of the electrolyte solution of ThC 60 (or C 60 ) and EDOT. Incorporation of the C 60 fullerene moiety in the polythiophene film was strongly suggested from absorption spectra of the composite film. We have found a higher degree of incorporation of the C 60 fullerene moiety into the ThC 60 –polyEDOT film, as compared with the C 60 –polyEDOT film. In the presence of methylviologen as an electron acceptor, the as-prepared C 60 –polyEDOT and ThC 60 –polyEDOT composite films generated stable cathodic photocurrents in the 400–700 nm region with broad peaks. The photocurrent intensity and the internal photon-to-current quantum efficiency of the ThC 60 –polyEDOT composite film were considerably larger than those of C 60 –polyEDOT and polyEDOT films. The thiophene unit of ThC 60 was confirmed to be quite effective for a stable incorporation of the C 60 fullerene moiety in the film and a higher photocurrent generation.