Spin-coated cobalt telluride counter electrodes for highly efficient dye-sensitized solar cells

In this report, cobalt telluride (CoTe) is synthesized in a water-oil heterogeneous system, and CoTe film fabricated by spin-coating method is applied as platinum (Pt) -free counter electrode for dye-sensitized solar cells. Field emission scanning electron microscopy finds that CoTe counter electrode exhibits porous structure. Cyclic voltammogram and electrochemical impedance spectroscopy demonstrate that CoTe has admirable electro catalytic activity toward the reduction of triiodide. The dye-sensitized solar cell based on CoTe counter electrode obtains a power conversion efficiency of 8.59%, which is higher than that with conventional platinum (Pt) counter electrode (8.19%). The impressive efficiency along with simple preparation of CoTe highlights the potential substitute for conventional noble metal Pt.