Composite Photoelectrode with TiO2 Nanofibers and Nanoparticles in Dye-Sensitized Solar Cells

We prepared a composite photoelectrode with TiO2 nanofibers and nanoparticles for use as the photoelectrode in dye-sensitized solar cells (DSCs). We fabricated TiO2 nanofibers by an electrospinning method. The porous structure of TiO2 nanofibers easily adsorbed the organic sensitizer. This also benefitted the electron transfer from the dye to the FTO electrode, because of the one-dimensional structure of the TiO2 nanofibers. The electrospinning process for fabricating the TiO2 nanofibers was optimized at an applied voltage of 20 kV. The average diameter of the TiO2 nanofibers was similar to 400 nm, while the thickness of the composite photoelectrode was 20 mu m. We observed by X-ray diffraction pattern the TiO2 nanofibers and TiO2 nanoparticles as an anatase phase. Compared with conventional TiO2 nanoparticle DSCs, TiO2-nanofiber-nanoparticle DSCs had a higher short circuit current density (J(sc)) of 12.92 mA/cm(2), and an enhanced power conversion efficiency of 4.79%. This value was 2.2 times higher than that of the conventional TiO2-nanoparticle DSCs.