Effect of SiO2 and TiO2 Nanoparticles on the Performance of Dye-Sensitized Solar Cells using PVDF-HFP/PVA Gel Electrolytes

In this work, we aimed to study the effect of nanoparticles on the efficiency of dye-sensitiezed solar cells (DSSC) using polymer gel electrolytes (PGE) of PVDF-HFP/PVA blends. The concentration of polymer blend was fixed at 10 wt% with ratios of 8:2. The TiO2 and SiO2 nanoparticles was varied at 0.25 - 2.0 wt%. It was found that the efficiencies (eta) of the cells using liquid electrolyte and PGE were 3.49 +/- 0.05% and 3.26 +/- 0.09%, respectively. While the efficiencies of DSSCs using nanocomposite electrolytes was considerably decreased. The best effeciency of DSSCs using PGE containing 0.25 wt% TiO2 and 0.5 wt% SiO2 were found to be 2.71 +/- 0.10% and 3.03 +/- 0.09%, respectively. This may be due to the higher viscosity of the nanocomposite gels and phase separations between nanoparticles and polymer matrices. Furthermore, the electrical resistances of electrolytes were investigated by Electrochemical Impedance Spectroscopy (EIS). The EIS showed that DSSC using ionic liquid electrolyte (ILE) shows the lowest Rct2 and Rdiff, and the interfacial resistances. While the DSSC containing nanoparticles exhibits the higher Rct2 and Rdiff, corresponding to their DSSC efficiency. This result corresponding with their DSSCs effeciences. The functional groups of polymer gel electrolytes were investigated by Fourier transform infrared spectroscopy (FT-IR) and the thermal properties of polymer gel electrolytes were analysis by differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) for applications in dye-sensitized solar cells (DSSCs). (C) 2014 Elsevier Ltd.