Highly efficient telluride electrocatalysts for use as Pt-free counter electrodes in dye-sensitized solar cells.

Two transition metal tellurides, CoTe and NiTe2, were synthesized and for the first time employed as the counter electrodes (CEs) with high catalytic activity for reduction of I3(-) in dye-sensitized solar cells (DSCs). Using CoTe and NiTe2-based CEs, photoelectric conversion efficiencies (PCEs) of 6.92% and 7.21% were achieved for DSCs, respectively, comparable to that of 7.04% achieved when using a Pt-based CE. The results indicated that, serving as a CE in DSCs, telluride could be a cost-effective and efficient alternative to the noble metal Pt.