Addition of 1 Methyl-3 Propyl Imidazolium Iodide Into Polymer Electrolyte System for Enhancement in Dye Sensitized Solar Cell Efficiency

Polymer electrolytes of methyl methacrylate–ethyl methacrylate–sodium iodide, incorporated with 1-methyl 3-propyl imidazolium iodide ionic liquid were prepared using solution casting technique. The interaction occurred between the ionic liquid with polymer electrolytes, and was confirmed using Fourier transform infrared spectroscopy. Impedance measurement revealed that the ionic conductivity increased with concentration of ionic liquid up to 6 wt% but decreased with further increase of ionic liquid. The increase in conductivity was due to the increase in the number of mobile ions while the decrease in conductivity was ascribed to the formation of ion pairs resulting from the presence of the excess ions. The total ionic transference number determined by dc-polarization technique showed that ions are the majority charge carriers in this system. The dye-sensitized solar cell, fabricated using the ionic liquid added electrolyte, gave a photovoltaic conversion efficiency of 1.05%.