Fabrication and performance of the Pt-Ru/Ni-P/FTO counter electrode for dye-sensitized solar cells

•Pt-Ru alloy acts as the catalyst of counter electrodes in dye-sensitized solar cell.•Ni-P/FTO (fluorine-doped SnO2) substrate is prepared by electroless plating method.•Pt-Ru/Ni-P/FTO counter electrode is fabricated by electrodeposition method.•The Ni-P sublayer improves the conductivity and light reflectance of FTO substrate.•The cell with Pt-Ru/Ni-P/FTO counter electrode exhibits an improved efficiency.

In this paper, Pt-Ru/Ni-P/FTO has been designed and fabricated as the counter electrode for dye-sensitized solar cells. The Pt-Ru catalytic layer and Ni-P alloy sublayer are prepared by traditional electrodeposition method and a simple electroless plating method, respectively, and the preparation conditions have been optimized. The scanning electron microscopy (SEM) images show that the Pt-Ru particles are evenly distributed on FTO and Ni-P/FTO substrate. By X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), it is confirmed that the Ni-P amorphous alloy has been formed, and no other compounds involved Ni and P have been formed. The electrochemical measurement results reveal that the Pt-Ru electrode has higher catalytic activity and stability towards tri-iodine reduction reaction than Pt electrode in the organic medium. The Ni-P sublayer deposited on FTO glasses increases the conductivity and light-reflection ability of the counter electrode, and this contributes to lowering the inner resistance of the cell and improving the light utilization efficiency. Through the photovoltaic test, it is confirmed that the energy conversion efficiency of a single DSSC with the optimized Pt-Ru/Ni-P/FTO counter electrode is increased by 29% compared with that of the cell based on the Pt/FTO counter electrode under the same conditions.