Effect of sodium on photovoltaic properties of dye-sensitized solar cells assembled with anatase TiO2 nanosheets with exposed {001} facets

Anatase TiO2 nanosheets with exposed reactive {0 0 1} facets were prepared in the presence of HF. The photovoltaic properties of NaOH-washed anatase TiO2 nanosheets with exposed {0 0 1} facets were investigated by assembling the TiO2 as photoanodes in dye-sensitized solar cells (DSSCs). A decreased overall efficiency and increased recombination rate was observed in comparison with the H2O-washed counterpart by both dark current scan and open-circuit voltage decay scan, and XPS confirmed that the deleterious effect of sodium ions is responsible for this reduced efficiency in DSSCs. (C) 2012 Published by Elsevier Inc.