Xanthan-Based Hydrogel for Stable and Efficient Quasi-Solid Truly Aqueous Dye-Sensitized Solar Cell with Cobalt Mediator

Aqueous dye-sensitized solar cells (DSSCs) are emerging as a promising alternative to enhance both the lifetime and environmental friendliness of traditional DSSCs. Herein, a cobalt-based, jellified (with xanthan gum) aqueous electrolyte, leading to a valuable efficiency exceeding 4% (VOC = 847 mV, JSC = 6.73 mA cm−2, fill factor =  74%), is reported. Design of experiment is used to precisely and significantly study, at a multivariate level, the effects produced by the Co2+ concentration, Co2+/Co3+ ratio, and xanthan gum amount modifications on the overall photovoltaic parameters of lab-scale solar cells.