Preparation of PVDF-HFP/Mesoporous Silica Composite Polymer Electrolytes for Dye-Sensitized Solar Cell

In this study, a series of composite gel electrolytes for dye-sensitized solar cells were prepared by introducing the mesoporous SiO2 powders (MSP) synthesized into the quasi-solid state electrolyte based on poly(vinylidenefluoride-co-hexafluoropropylene)(P(VDFHFP)) as matrix and propylene carbonate (PC) diethyl carbonate (DEC) as plasticizers. The effect of addition of MSP on the properties of the composite gel electrolytes was investigated by SEM, AC impedance, linear sweep voltammetry and photocurrent-voltage measurements. It was found that the MSP were well distributed in the gel electrolyte matrix and the charge transport of the I /I3 redox couple in the composite gel electrolyte was significantly improved due to the presence of MSP, consequently, the apparent diffusion coefficient of the triiodide was able to increase for about 40%. Besides, the addition of MSP also resulted in enhancing the conductivity. The impedance spectroscopy result showed that the room temperature conductivity was increased to about 2.24 times. The best overall light-to-electricalenergy conversion efficiency obtained for the DSSC fabricated with the composite gel electrolyte was 4.08%, which is about 37 % higher than that with the electrolyte without MSP additive under the same condition.