Solvent-free ionic liquid/poly(ionic liquid) electrolytes for quasi-solid-state dye-sensitized solar cells

Photochemically stable poly(ionic liquids) (poly(ILs)) including poly(1-butyl-3-vinylimidazolium bromide) ([PBVIm][Br]) and poly(1-butyl-3- vinylimidazolium bis(trifluoromethanesulfonyl)imide) ([PBVIm][TFSI]) were synthesized and dissolved in the room temperature ionic liquids (ILs) to form quasi-solid-state electrolytes for dye-sensitized solar cells (DSSCs), without using any volatile organic solvent. DSSCs based on IL/[PBVIm][TFSI] gel electrolyte yielded a power conversion efficiency of 4.4% under a simulated air mass 1.5 solar spectrum illumination at 100 mW cm^-2. The superior long-term stability of fabricated DSSCs indicated that the DSSCs based on solvent-free IL/poly(ILs) gel electrolytes could overcome the drawbacks of cells containing volatile solvents. © 2011 The Royal Society of Chemistry.