Poly(ionic liquid)/ionic liquid/graphene oxide composite quasi solid-state electrolytes for dye sensitized solar cells

Poly(ionic liquid)/ionic liquid/graphene oxide (poly(IL)/IL/GO) composite gel electrolytes containing poly(1-butyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide), 1-propyl-3-methylimidazolium iodide and graphene oxide are prepared for dye-sensitized solar cells (DSSCs), without any volatile organic solvent. The conductivity of the composite electrolyte is significantly increased by adding an appropriate amount of GO, and the DSSCs based on composite electrolytes containing GO show higher power conversion efficiency performance and better long-term stability compared to those without GO. The DSSC based on the composite electrolytes which contain 2 wt% of GO show an overall power conversion efficiency of 4.83% under simulated AM 1.5 solar spectrum irradiation. The superior long-term stability of the DSSCs indicates that this type of composite electrolyte could overcome the drawbacks of volatile liquid electrolytes, and offer a feasible method to fabricate DSSCs in future practical applications.