Charge transport properties in dye-sensitized nanostructured TiO2 thin film electrodes studied by photoinduced current transients

The charge transport in dye-sensitized nanostructured TiO2 was studied by laser pulse induced photocurrent transients. The exptl. curves were compared to simulations using a diffusion model with an initial electron distribution of an exponential decay. The simulations were optimized with respect to the exptl. curves giving an apparent diffusion coeff. of 6 × 10-6 cm2/s for the electrons with an electrolyte of 0.1M KI in propylene carbonate, the potential being +300 mV vs. Ag/AgCl in EtOH. The charge transport was highly dependent on electrolyte compn. and light intensity.