An Autocatalytic Factor in the Loss of Efficiency in Dye-Sensitized Solar Cells
We propose a passive factor, autocatalytic activity of some semiconductors (SnO2, WO3), for the loss of efficiency in dye-sensitized solar cells. On one hand, in the photoanode, SnO2 (or WO3) functions as a semiconductor to collect the photoelectrons that are generated by the sensitizer. On the other hand, SnO2 (or WO3) can also work as a catalyst to catalyze the recombination between the photoelectrons and the I3- ions, which results in a large current leakage, a low open-circuit voltage value, and a low efficiency. Some oxides, including, but not limited to, SnO2 and WO3, which have catalytic activity for I3- redn. or other oxidized species of the electrolyte are not suitable for use as semiconductor for the photoanode. In addn. to the semiconductors, phthalocyanine dyes also have catalytic activity for the recombination.
Record created on 2015-07-06, modified on 2016-09-29