Anchoring CoS on three-dimensional porous rGO thin films as efficient counter electrodes for dye-sensitized solar cells

Rational design of advanced cost-effective counter electrode (CE) is vital for the development of dye-sensitized solar cells (DSSCs). Herein, we report a novel CoS/reduced graphene oxide (CoS/rGO) composite counter electrode via a facile and rapid microwave irradiation plus ion exchange method. CoS nanoparticles are strongly anchored on three-dimensional (3D) porous rGO thin films. Due to positive advantages including high catalytic properties, enhanced active area, and electrical conductivity, the DSSC based on CoS/rGO counter electrode is endowed with a power conversion efficiency (PCE) of 6.86%, superior to that based on sputtered Pt counter electrode (6.50%). Our results indicate that CoS/rGO composite thin film is a low-cost and highly efficient CE for DSSCs.