Swedish researchers double efficiency of dye-sensitized solar cells

Swedish researchers double efficiency of dye-sensitized solar cells

IPCE of modified DSSCs reaches 44 percent
By Paul Buckley

Power Management DesignLine Europe
(05/01/2009 1:42 PM EDT)

Winchester, UK - The efficiency of a dye-based solar energy device is claimed to have been more than doubled by researchers from the Royal Institute of Technology in Stockholm, Sweden.

Licheng Sun and Anders Hagfeldt at the Royal Institute of Technology believe their device could be combined with more traditional Graetzel-type dye-sensitized cells to build doubly-active solar cells.

Dye-sensitized solar cells (DSSCs) feature a photo-active anode to harvest light energy with a dye which passes electrons to an n-type semiconductor that coats the anode. A reverse type of solar cell has also been developed which sees dyes interact with p-type semiconductors positioned at a light-harvesting cathode

Sun and Hagfeldt claim to have improved the performance of the p-type DSSC by altering the structure of the polyaromatic dye to improve the charge separation which ensured the light-excited electron and the hole it leaves behind both travel around the electric circuit instead of directly recombining. The thickness of the p-type semiconductor (NiO) layer and the electrolyte composition were also refined.

The researchers claim that the incident photon to current conversion efficiency (IPCE) of the modified devices has reached above 44 per cent, more than double the efficiency of previous p-type photocathodes.