Shelf-Life Studies on an Ionic-Liquid-Stabilized Dye-Sensitized Solar Cell

Dye-sensitized solar cells (DSSCs) with power conversion efficiencies up to 6% using two sets of electrolytes in a binary solvent of acetonitrile and ionic liquid were investigated for shelf-life stability over a period of 48 days. The ionic liquid, i.e., 1-butyl-3-methylimidazolium bromide (BMIBr), was synthesized using cheap and readily available raw materials. The proportions of ionic liquid to acetonitrile used in this study were 0%, 10%, 20%, 30%, 40%, and 50%. When the ionic liquid was increased beyond 30%, DSSCs showed substantially lower photoconversion efficiency. However, DSSCs fabricated with BMIBr showed better shelf-life stability as compared to the reference devices, as monitored for a period of 48 days. The study indicates no substantial chemical interaction of BMIBr with various components present in the electrolytes, showing only an inconsequential effect.