Novel cyclic sulfonium iodide containing siloxane high performance electrolyte for dye-sensitized solar cell

A new type of solid and gel state electrolytes based on siloxane cyclic sulfonium iodides was synthesized and used in dye-sensitized solar cells. The resulting electrolytes were characterized by 1H NMR, TGA, diffusion coefficient, and ion conductivity. The thermo-oxidative stabilities of the prepared ionic species are lower than that of DMII because the bond strength of S+–C in thiophenium is lower than that of N+–C in imidazolium. Among the three SiCSIs based electrolytes, SiCSI3 showed a maximum photo-conversion efficiency of 7.3%. In addition, the performance of the DSSCs showed relatively reasonable compared with the imidazolium type DMII electrolyte.