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

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%).