Preparation of highly efficient gel-state dye-sensitized solar cells using polymer gel electrolytes based on poly(acrylonitrile-co-vinyl acetate)

A highly efficient gel-state electrolyte was fabricated by using poly(acrylonitrile -co-vinyl acetate) (PAN-VA) as the gelator of an 3-methoxypropionitrile (MPN)-based liquid electrolyte and was applied in dye-sensitized solar cells (DSSCs). The VA segaments act to dissolve the copolymer into the electrolyte, forming a gel-state structure. The electric conductivity of the gel-state electrolyte is comparable to that of the liquid electrolyte, attributed to the enhancement effect of the AN segments to the dissociation of LiI and 1-propyl-2,3-dimethylimidazolium iodide (DMPII). This effect also leads to a slightly downward shift of the TiO₂ conduction band edge toward positive potentials. The energy conversion efficiency of the DSSC achieved by using this gel-electrolyte is 8.34%, which is 97% the value of the liquid-state cell (8.63%).