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 l aser pulse induced photocurrent transients. The experimental curves were co mpared to simulations using a diffusion model with an initial electron dist ribution of an exponential decay. The simulations were optimized with respe ct to the experimental curves giving an apparent diffusion coefficient of 6 x 10(-6) cm(2)/S for the electrons with an electrolyte of 0.1 M KI in prop ylene carbonate, the potential being +300 mV vs Ag/AgCl in ethanol. The cha rge transport was highly dependent on electrolyte composition and light int ensity.