Decatungstate acid improves the photo-induced electron lifetime and retards the recombination in dye sensitized solar cells

Decatungstate acid (DA) was utilized to modify TiO2 in the photoanode of dye sensitized solar cells. The photo-induced electron lifetime was evidently improved and the recombination was greatly inhibited. DA can introduce levels of impurities and lower the Fermi level through a doping effect and thus increase the photocurrent. Moreover, the improved charge carrier density can be found through external electric field surface photovoltage and Mott–Schottky plots. A 22.94% enhancement in photocurrent was achieved with little degradation in photovoltage, leading to a 10.28% increase in optic-to-electric power conversion efficiency.