Electrochemical properties of dye-sensitized solar cells fabricated with PVDF-type polymeric solid electrolytes

We report on PVDF-based polymeric solid electrolytes (PSE) for dye-sensitized solar cells (DSCs). The dependence of the short-circuit current density (J_sc) on the diffusion coefficient was discussed on the basis of the equivalent circuit analysis of photocurrent in DSC. When the back electron transfer from TiO₂ to an oxidized dye was taken into account, the diffusion coefficient dependence of J_sc was well explained. We confirmed that the J_sc of a PSE-based DSC with a 20 μm cell gap amounts to about 97% of that of a liquid-based DSC. We then focused on the cross-linking reaction of PVDF-HFP with amines. This cross-linking reaction allows us to carry out the otherwise inhibited in-situ reaction of the precursor inside a cell. We also studied DSCs fabricated with the cross-linked PVDF-HFP-based PSE. The energy conversion efficiency of the DSC was 4.8% with AM-1.5 illumination.