Solar cells break a new record

Green dye-sensitized solar cells © 2011 EPFL

Dye-sensitized Grätzel solar cells have just set a new efficiency benchmark. By changing the composition and color of the cells, an EPFL team has increased their efficiency to more than 12%. 

A group of EPFL scientists has improved the efficiency of the famous Grätzel solar cells to 12.3%. This performance is now comparable to silicon-based solar panels that are on the market today. And the costs of using this technology have come down slightly. 

The challenge was to increase the efficiency of the dye-sensitized cells, in order to produce more electricity. To do this, the chemists replaced the standard dye components – ruthenium and iodine – with porphyrin and cobalt. This combination allows them to increase the absorption of sunlight and results in a more efficient electron exchange. It’s this exchange of electrons from the dye to the substrate that produces electricity.