One‐Step Synthesis of a MoS 2 −CuS Composite with High Electrochemical Activity as an Effective Counter Electrode for CdS/CdSe Sensitized Solar Cells

Inorganic nanostructured composite materials involving metal sulfides are increasingly important in electrochemical applications like solar cells. In this research, we have developed a one‐step in situ solvothermal method to synthesize a MoS 2 −CuS composite. MoS 2 sheets increase electron‐transfer ability, assisting the improvement in catalytic activity of the MoS 2 −CuS counter electrode. The charge‐transfer resistance derived from impedance spectroscopy for the MoS 2 −CuS composite counter electrode at the electrode/electrolyte interface is very low, as compared to MoS 2 , mostly owing to the increased number of active catalytic sites for the reduction of polysulfide electrolyte. The Tafel polarization plot shows excellent electrocatalytic activity of the MoS 2 −CuS composite towards polysulfide electrolyte. Finally, the CdS/CdSe sensitized solar cell achieves a power conversion efficiency of about 5 % upon optimization of the MoS 2 −CuS composition.