The sandwich structure electrodes based on wire-like TiO2–β-cyclodextrin–SWCNT composite for dye-sensitized solar cells

Wire-like TiO2–β-cyclodextrin (CD)–SWCNT composites have been successfully fabricated through solar-induced self-assembly. The wires with the mean diameter of 1 μm were uniform and stable. β-CD molecules acted as linkers between SWCNT and monodisperse TiO2 nanoparticles because β-CD can interact with both SWCNT and TiO2 nanoparticles. The sandwich structure electrode based on the wires in the middle was fabricated. And the dye-sensitized solar cells with this sandwich structure electrode, which exhibited enhanced power conversion efficiency, were systematically studied. The improved photoelectrical performance was attributed to the effective separation of photoinduced electrons and holes and the rapid transportation of photogenerated electrons of SWCNT, which was demonstrated by surface photovoltage spectroscopy (SPS) and electrochemical impedance spectroscopy (EIS).