Dye-sensitized solar cell with single-walled carbon nanotube thin film prepared by an electrolytic micelle disruption method as the counterelectrode

Several thin films of single-walled carbon nanotube (SWCNT) were prepared on ITO glasses by electrolytic micelle disruption methods using surfactants bearing a ferrocenyl moiety (1a and 1b). Surfactant 1a has a polyethylene glycol unit as the hydrophilic moiety, while surfactant 1b has an ammonium salt unit. The surfaces of the resulting films formed by the electrolysis methods were confirmed by SEM and AFM measurements, and then these images clearly exhibited that the entire surface of the ITO glass was uniformly covered with SWCNT. The thicknesses of the resulting films were estimated by the SEM images of cross-sections of the film. For example, the thickness of the film formed by the electrolysis for 12 hours was ca. 4500 angstrom. Besides the SEM images of the cross-sections of the resulting films, the UV-Vis spectroscopy showed clearly that the film thickness increased with electrolysis time. The photovoltaic performance of dye-sensitized solar cells (DSCs) using the resulting thin films as a counterelectrode material instead of a common platinized counterelectrode was investigated. As a result, the highest solar-to-electric energy conversion efficiency among the present investigations was found to be obtained in the case with the thin film formed by the electrolysis with surfactant 1a for 36 hours.