A nonstoichiometric SnO(2-δ) nanocrystal-based counter electrode for remarkably improving the performance of dye-sensitized solar cells.

We report the fabrication of a highly active nonstoichiometric SnO2-δ based counter electrode for dye-sensitized solar cells (DSSCs). The introduction of oxygen vacancies into SnO2 results in a much lower charge transfer resistance and a higher polarization current density. The solar energy conversion efficiency of the SnO2-δ based DSSCs is increased by 67%.