Effect of Ionic Liquids with Different Cations in I-/I3- Redox Electrolyte on the Performance of Dye-sensitized Solar Cells

The effect of the addition of ionic liquids with four different cations (imidazolium, pyrrolidinium, piperidinium and pyridinium) on the performance of dye-sensitized TiO2 solar cells based on electrolytes containing a t-butylpyridine (TBP) in 3-methoxypropionitrile (MPN) was studied. A total of 18 ionic liquids with mono-, di- and tri-alkyl derivatives were used in the present study, and among them a pyridinium cation with a mono-alkyl group showed better cell efficiency than the others. The best photoelectric conversion efficiency, 7.213%, was obtained using 1-hexylpyridinium iodide with an open-circuit photovoltage (V-oc) = 0.731 V, a short-circuit photocurrent density (J(sc)) = 16.175 mA/cm(2), and a fill factor (ff) = 0.610 under AM1.5 and 100 mW/cm(2) illumination.