Highly efficient polymer gel electrolytes for dye-sensitized solar cells

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) based polymer gel electrolytes were prepared to replace liquid electrolytes of dye-sensitized TiO/sub 2/ cells. The fill factors and the energy conversion efficiencies of the PVDF based cells are improved about 17% by adding PVDF to N-methyl-2-pyrrolidone (NMP) liquid I/sup -//I/sub 3//sup -/ redox electrolytes. The open-circuit voltage and stability of dye-sensitized TiO/sub 2/ solar cells are improved while the short-circuit photocurrent density decreases when gel electrolyte containing PVdF-HFP in NMP replaces typical solvents such as acetonitrile (AN) and 3-methoxypropionitrile (3-Me). The energy conversion efficiency of the cell with 6 wt% of the polymer is comparable to that obtainable in AN and 3-Me.