Enhancement of photovoltage of dye-sensitized solid-state solar cells by introducing high-band-gap oxide layers

Electrodes constructed using nanocrystalline TiO2 particulates for dye-sensitized solid-state solar cells (SS-DSSCs) showed open-circuit voltage (Voc) in the 500–600 mV range, which is less than the theoretical expected value. Incorporation of high-band-gap semiconducting oxides with a flatband potential higher than TiO2, such as SrTiO3 or ZnO, results in a dramatic increase in Voc of SS-DSSC as compared to porous TiO2 nanocrystalline films. The observed photovoltage difference could be correlated to the difference in the flatband potential values of the respective oxides and shift of the flatband potentials of the oxide films. Hence, this method could be used to enhance the Voc and overall cell performance of SS-DSSC.