Interface Engineered Binary Platinum Free Alloy-based Counter Electrodes with Improved Performance in Dye-Sensitized Solar Cells

The high cost and platinum dissolution issues of counter electrodes (CEs) are two core problems for the development of dye-sensitized solar cells (DSSCs). In this work, different CEs based on binary alloy Ru(81.09)Co(18.91), Ru(80.55)Se(19.45) and Co(20.85)Se(79.15) nanostructures for DSSCs were successfully synthesized and investigated by a facile and environmentally friendly approach. Here, we found that the Co(20.85)Se(79.15) alloy CE-based device yields the higher photoelectric conversion efficiency of 7.08% compared with that (5.80%) of the DSSC using a pure Pt CE because of the larger number of active sites with improved charge transferability and reduced interface resistance by matching work function with the I(3)(‒)/I(‒) redox electrolyte. The inexpensive synthesis method, cost-effectiveness and superior catalytic activity of the Co(20.85)Se(79.15) alloy may open up a new avenue for the development of CEs for DSSCs in the near future.