Facile synthesis of Bi2S3–C composite microspheres as low-cost counter electrodes for dye-sensitized solar cells

Abstract

Porous bismuth sulfide–carbon (Bi₂S₃–C) composite microspheres were synthesized via a facile solvothermal route and served as a low-cost counter electrode material for Pt-free dye-sensitized solar cells (DSSCs). The electrochemical performance analysis indicates that the Bi₂S₃–C electrode has lower charge transfer resistance at the electrolyte/electrode interface, smaller Nernst diffusion impedance of iodide in electrolyte and higher catalytic ability than the bare Bi₂S₃ electrode. After optimization of the content of carbon, the DSSC with the Bi₂S₃–C counter electrode exhibited an excellent power conversion efficiency of 6.72%, which is comparable to that of the Pt-based DSSC (6.74%).