The effect mechanism of 4-ethoxy-2-methylpyridine as an electrolyte additive on the performance of dye-sensitized solar cell

4-Ethoxy-2-methylpyridine (EOP), as an electrolyte additive, was added into electrolyte of dye-sensitized solar cell, and its effect on the performance of solar cells and mechanism were studied by electrochemical and spectral measurements. With increasing in EOP concentrations, the flatband potential of TiO2 electrode shifted negatively and the rate of interfacial recombination at the TiO2 electrode/dye/electrolyte interfaces was improved. The net effect of EOP was to improve the open-circuit photovoltage, indicating that the negative shift of conduction band of TiO2 was the predominated factor on determining the open-circuit photovoltage. The decline of short-circuit current of solar cell was ascribed to the slow dye regeneration and the low catalytic activity of counter electrode on triiodide reduction due to addition of EOP.