Solid state dye sensitized photoelectrochemical cell

A quasi-solid-state photoelectrochemical cell employing a dye-sensitized, nanocrystalline TiO₂ electrode and a polymer gel electrolyte has been fabricated. The cells show open-circuit voltages close to 0.6 V and short-circuit currents larger than 3 mA cm^-2 under 30 mW cm^-2 white light illumination. Fill factors and open circuit voltages of the cell are comparable to those of similar cells with liquid electrolytes. Overall energy conversion efficiencies of 3-5% have been achieved. Photocurrent transients have relatively long rise time constants, indicating that electron transport in the TiO₂ electrodes is controlled by a trapping process. At high light intensity the photocurrent rise is followed by a decay process due to the limitation of ion transport in the electrolyte.