Dye-Sensitized SolarCells Based on Ionic Polymer Electrolytes Prepared by in-suit Curing

초록

We prepared an ionic gel polymer electrolyte for dye sensitized solar cells without leakage problem. Triiodide compound (BTDI) was synthesized by the reaction of benzene tricarbonyl trichloride with diethylene glycol monotosylate and subsequent substitution of tosylate by iodide using NaI. Bisimidazole was prepared by the reaction of imidazole with the triethylene glycol ditosylate under a strong base NaH. BTDI and bisimidazole dissolved in an ionic liquid were injected into the cells and were permeated into the nanopores of TiO2. Then in situ crosslinking was carried out by heating to form a network structure of poly(imidazolium iodide), leading the ionic liquid electrolytes to a gel or a quasi-solid state. As low as 30 wt.% concentration of the monomers (BTDI and bisimidazole) in the electrolytes was found to be enough to form a stable gel type electrolyte. The DSSCs based on the gel polymer electrolytes showed as high as 1.15 % of power conversion efficiency with a short circuit current density of 5.69 mAcm-2, an open circuit voltage of 0.525V, and a fill factor of 0.43.