Fabricating CuS counter electrode for quantum dots-sensitized solar cells via electro-deposition and sulfurization of Cu₂O

Abstract CuS/FTO counter electrode (CE) with flower-like nonosheets structure was fabricated through electro-deposition of Cu₂O followed by sulfurization. This electrochemical method has better control over the morphology of CuS/FTO CE. And the application of FTO can avoid the continuous corrosion of Cu substrate in polysulfide electrolyte. Besides, through the optimization of electro-deposition, the CuS/FTO CE obtains excellent photoelectrochemical performance (photoelectric conversion efficiency (PCE) = 4.07%, fill factor (ff) = 0.50) which is much higher than Pt CE (PCE = 1.90%) and Cu₂S/Cu CE (PCE = 3.76%) prepared by directly immersing copper into polysulfide electrolyte. Therefore, the CuS/FTO CE prepared by electro-deposition of Cu₂O followed by sulfurization has shown much promise.