Low-temperature Fabrication of Nano-porous TiO2 Layers for Dye-sensitized Solar Cells. Fabrication of Ion-diffusion Paths

In dye-sensitized solar cells, it is required to build up both of ion paths and electron paths in TiO2 layers for low-temperature fabrication process. In this report, ion paths are focused on. Semiconductive layers are composed of TiO2 nanocrystals (P25) and needle-shape TiO2 crystals (FTL 100). By adding 20% of the needles into P25, photocurrent increased from 5.3 to 7.7 mA/cm2. Pore distributions, surface areas, Cole–Cole plot and currents passing through TiO2 layers were measured. These results suggest that the increase in the photocurrent is associated with the formation of ion paths in TiO2 layers.