Eco-Friendly Aqueous Dye-Sensitized Solar Cell with a Copper(I/II) Electrolyte System: Efficient Performance under Ambient Light Conditions

Organic solvents used in electrolytes of dye-sensitized solar cells (DSCs) are generally toxic and not environmentally safe, which renders their use, especially in indoor solar modules, difficult. In this paper, an eco-friendly DSC is presented based on an aqueous electrolyte system where the redox couple is composed of a water-soluble polypyridyl copper complex, [Cu(I)(dc-dmbpy)2Cl/Cu(II)(dc-dmbpy)2Cl2, dc-dmbpy = 6,6′-dimethyl-2,2′-bipyridine-4,4′-dicarboxylate]. Good photo-conversion efficiencies (PCE % ∼ 7%) have been attained with this water-soluble redox couple under ambient light conditions when coupled with a ruthenium-based dye, C106. This is the first time such a copper complex is in an aqueous DSC and eventually lays a foundation for the further development of eco-friendly water-based DSCs.