TiO2 nanotube array films were synthesized by the anodic oxidation of a Ti plate in an NH4F electrolyte. The thickness of the films was dependent upon the oxidation time. Nanotube clusters were produced when the films were subjected to sonication. Pastes were subsequently prepared by mixing the nanotube clusters with TiO2 nanoparticles. The pastes were used to fabricate photoelectrodes of dye-sensitized solar cells. The generation efficiencies of cells with TiO2 nanotube clusters were lower than those of cells without these clusters. TiO2 nanotube clusters were very large, and therefore, they might have intercepted the ionic transport.