Dye-sensitized TiO2 solar cells using polymer gel electrolytes based on PVdF-HFP

The open-circuit voltage increases substantially and stability of dye-sensitized TiO2 solar cells is improved when polymer gel containing poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) in N-methyl-2-pyrrolidone replaces commonly used solvents such as acetonitrile (ACN) and 3-methoxypropionitrile (MPN). The energy conversion efficiency of the cell with 6 wt % PVdF-HFP is comparable to that obtainable in ACN and in MPN. The promising effect of PVdF-HFP as a gelator is attributed to its interaction with Li+ ions.