A Comparable Study on the Arrays of Aligned ZnO Nanowires and TiO2 Nanotubes for Applications of Dye-sensitized Solar Cells

Vertically aligned ZnO nanowire array (NWA) was synthesized on the transparent conductive substrates by a facile hydrothermal method. Then, TiO2 nanotube array (NTA) was obtained by a successive treatment of the ZnO NWA. Moreover, two dye-sensitized solar cells (DSSCs) were fabricated using these samples as the photoanodes in order to investigate their photoelectrochemical performance. It is found that TiO2 NTA demonstrates a power conversion efficiency of ∼0.81%, which is three times higher than ZnO NWA. The DSSC devices were used with a simple diode model to evaluate the current-voltage (J-V) curves. Finally, it was revealed that the cell performance improvement is attributed to an increased shuttle resistance and a suppressed leakage current.