In this study, we used secondary anodization to prepare open-end TiO2 nanotube arrays and then transferred them to fluorine-doped tin oxide (FTO) glass attached to front-illuminated dye-sensitized solar cells (DSSCs). X-ray diffraction (XRD) patterns found that TiO2 nanotubes form the anatase phase when the annealing temperature is greater than 280 ℃. The best annealing temperature for TiO2 nanotubes is 450 ℃. From field-emission scanning electron microscopy (FE-SEM) analysis, the lengths of TiO2 nanotubes were 15, 21, and 28 µm when anodized for 2, 3, and 4 h, respectively. The conversion efficiency for different lengths of TiO2 nanotube photoelectrodes was 4.82, 5.08, and 4.85% for lengths of 15, 21, and 28 µm, respectively. From the results of electrochemistry impedance spectroscopy (EIS), the value of Rk was 5.4, 5.5, and 5.4 Ω for lengths of TiO2 nanotubes of 15, 21, and 28 µm, respectively. These results indicate that the electron recombination rates for different lengths of TiO2 nanotubes are nearly identical. In addition, the value of Rd ware 8.6, 7.2, and 8.5 Ω for lengths of TiO2 nanotubes of 15, 21, and 28 µm, respectively. This result reveals that overlong TiO2 nanotubes make it difficult for the I3− anion to diffuse to the counter electrode, resulting in an increase in diffusion transfer resistance Rd and a decrease in conversion efficiency of the DSSCs. In general, the open-end TiO2 nanotubes attached to front-illuminated DSSCs have a better conversion efficiency for DSSCs than those with back-side illumination, and the best conversion efficiency for DSSCs is 5.08% when the length of the TiO2 nanotubes is 21 µm.