Self degradation of polymer electrolyte based dye-sensitized solar cells and their remedy

Self degradation of dye-sensitized solar cells (DSSC) has been observed due to shrinkage of the polymer electrolytes at room temperature with a relatively high humidity atmosphere. The cell efficiency has also shown to depend on the shrinkage of the polymer. The actual interface area between the polymer electrolyte and the dye soaked nanoporous TiO2 electrode has been observed to become reduced for alkali salt complexed poly(ethylene oxide) (PEO) polymer electrolyte. This problem can relatively easily be reduced by two step casting and by incorporating ionic liquids in the polymer electrolyte. A possible reason has been sought as the reduced crystallinity and growth of spherulites in the polymer matrix.