Effect of the TiO2Nanotubes in the Photoelectrode on Efficiency of Dye-sensitized Solar Cell

The effect of TiO 2 nanotube (TNT) and nanoparticle (TNP) composite photoelectrode and the role of TNT to enhance the photo conversion efficiency in dye-sensitized solar cell (DSSC) have investigated in this study.Results demonstrated that the increase of the TNT content (1-15 %) into the electron collecting TNP film increases the open-circuit potential (V oc ) and short circuit current density (J sc ).Based on the impedance analysis, the increased V oc was attributed to the suppressed recombination between electrode and electrolyte or dye.Photochemical analysis revealed that the increased J sc with the increased TNT content was due to the scattering effect and the reduced electron diffusion path of TNT.The highest J sc (12.6 mA/cm 2 ), V oc (711 mV) and conversion efficiency (5.9%) were obtained in the composite photoelectrode with 15% TNT.However, J sc and V oc was decreased for the case of 20% TNT, which results from the significant reduction of adsorbed dye amount and the poor attachment of the film on the fluorine-doped tin oxide (FTO).Therefore, application of this composite photoelectrode is expected to be a promising approach to improve the energy conversion efficiency of DSSC.