Glycerin-based electrolyte for reduced drying of dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) are of high interest especially for applications on flexible or even stretchable substrates, such as architectural textiles. One of the main challenges for such use is the electrolyte which is usually fluid and thus leaks not only through porous textile structures, but also through the edges of common glass-based DSSCs. Possibilities to overcome this problem are complete sealing of glass-based cells, preparation of solid-state electrolytes or embedding a fluid electrolyte in a textile-based matrix. Here we report on a new route to avoid evaporation of the electrolyte. Using glycerin as the base for a iodine-triiodide electrolyte, glass-based DSSCs showed constant or even increasing efficiencies during more than four months, while the reference cells based on a commercially available water-based iodine-triiodide electrolyte showed decreasing efficiencies already after four weeks and were completely dried after two months. Our results suggest using glycerin-based fluid electrolyte, possibly in combination with a textile-based matrix, to create durable DSSCs without the necessity to perfectly seal them.