The compound ferrocene is proving a hit as an efficient electrolyte in dye-sensitized solar cells, reports a paper in Nature Chemistry this week. This iron ‘sandwich’ compound has the advantage over other electrolytes in that its structure has the potential to be tuned to improve its efficiency.
The technology behind these solar cells — in which sunlight is absorbed by a dye — is two decades old, and improvements in their performance by small adjustments in the types of chemicals used as the electrolyte are levelling off. Leone Spiccia, Udo Bach and colleagues replaced the traditional iodide electrolyte with a ferrocene-based one, and made solar cells that achieved efficiencies approaching those of iodide. One of the great advantages of ferrocene, however, is the ease with which its structure can be altered, and the researchers predict that this can be used to improve its efficiency.
Previous efforts to use metal compounds as the electrolyte have resulted in poor performance, and many proved corrosive to the solar cells. The ferrocene electrolyte does not corrode the cell and its behaviour is well understood.