Improvement of adhesion of Pt-free counter electrodes for low-cost dye-sensitized solar cells

We fabricated low-cost carbon and carbides counter electrodes (CEs) with excellent adhesion by adding an industrial conductive carbon paste (CC) as a binder for dye-sensitized solar cells (DSSCs). We compared the electrochemical catalytic activity of CC and carbon dye (Cd)/CC in the reduction of triiodide to iodide using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CC and Cd/CC electrodes both exhibit electrochemical catalytic activity for triiodide reduction. After investigating the influence of CC on the performance of DSSCs, we also chose several transition metal carbides, including molybdenum carbide (MoC), tungsten carbide (WC), ordered mesoporous carbon (OMC), MoC embedded in OMC (MoC-OMC), and WC embedded in OMC (WC-OMC) as catalytic materials of CEs. DSSCs based on the carbon and carbides CEs reached efficiencies of 4.50–6.81%. The results indicate that CC is a superior binder for Pt-free catalysts in DSSCs.