Efficient gel-state dye-sensitized solar cells adopting polymer gel electrolyte based on poly(methyl methacrylate)

Abstract

We report an effective method to fabricate gel-state dye-sensitized solar cells (DSSCs) based on the PMMA polymer gel electrolyte. In this approach, the liquid-state polymer electrolyte solution was prepared by simply mixing the traditional liquid-state electrolyte with the polymer gelator solution and was injected into the DSSC in its liquid state. The liquid-state polymer electrolyte was then converted to the gel state (i.e., in situ gelation) simply by evaporating a portion of solvents at elevated temperatures. With this approach, liquid electrolytes already well developed and optimized for DSSCs can be readily adopted. Filling in the liquid/solution state ensures effective penetration of the electrolyte into pores of TiO2 nanoparticle electrodes for attaining good contact and interface properties. The in situ gelation by heating (solvent evaporation) much simplifies the process. The polymer gel electrolyte thus prepared exhibited high ion conductivity and diffusivity comparable to those of traditional liquid electrolytes. The gel-state DSSCs thus fabricated exhibited a high power-conversion efficiency of 8.03% and much improved stability compared to the traditional liquid DSSC.