| Abstract: | A new ionic liquid, 1‐vinyl‐3‐heptylimidazolium iodide (VHpII), was synthesized and applied as a redox electrolyte for dye‐sensitized solar cells. The chemical structure of the synthesized VHpII was confirmed using 1H NMR. Thermogravimetric analysis showed that the VHpII was stable for thermal stress of up to 250°C. The energy conversion efficiencies of the VHpII‐based dye‐sensitized solar cells were investigated in terms of the effect of a lithium iodide addition. A solar cell containing the redox couple of VHpII and iodine showed a conversion efficiency of 2.63% under 1 sun light intensity at AM 1.5. Adding 0.4 M LiI results in a conversion efficiency of 3.63%, which was an improvement of about 40%. The increased conversion efficiency was ascribed to an increase in external quantum efficiency. |
