Counter electrodes from Mo–Se nanosheet alloys for bifacial dye-sensitized solar cells.

Pursuit of cost-effective counter electrodes (CEs) with no sacrifice of photovoltaic performances is a persistent objective for dye-sensitized solar cells (DSSCs). We launch here the experimental realization of molybdenum selenide (Mo–Se) binary nanosheet CEs by a mild solution method. Due to high optical transparency, the bifacial DSSCs from cost-effective Mo–Se alloy CEs can realize electricity generation from either front or rear side. Particularly, the resultant Mo–Se alloy CEs show superior catalytic activity and charge-transfer ability toward I − / I 3 − redox electrolyte. The maximum front and rear efficiencies of 8.05% and 5.92% are recorded under simulated air mass 1.5 global irradiation, respectively. The impressive efficiency along with fast start-up, multiple start capability, and simple preparation highlights the potential application of the cost-effective and transparent Mo–Se alloy CE in robust bifacial DSSCs. [ABSTRACT FROM AUTHOR]