TiO2-nanotube-based dye-sensitized solar cells fabricated by an efficient anodic oxidation for high surface area

Nanostructured semiconducting metal-oxides and particularly one-dimensional nanotube devices offer enhanced energy conversion efficiencies in dye-sensitized solar cells (DSSCs). To absorb a sufficient light, the thickness and surface area of TiO2 photoelectrode are important. We focus on the preparation of transparent TiO2 nanotube photoelectrode grown perpendicularly on a conductive glass substrate. For growing nanotube array using anodization method, deposition of high-quality titanium is needed. We could obtain relatively longer 680-nm-thick TiO2 nanotube arrays in glycerol-based electrolyte than those of others result (⩽360 nm). After crystallization, the nanotube arrays were treated with TiCl4 to enhance the photogenerated current and then integrated into the DSSC structure using a N3 ruthenium-based dye. The DSSC using TiCl4-treated TiO2 nanotube exhibited a conversion efficiency of 0.31% under 100 mV/cm2 (AM 1.5) illumination.