October 20, 2008
Dye solar cell goes both ways
Add the right material to a dye-sensitized
solar cell and position it so that it captures light from the front
and back and you can boost the amount of electricity the cell generates.
The active layer in dye-sensitized solar cells is a dye-covered
semiconductor material. The dye absorbs photons and emits electrons.
The semiconductor transports the electrons to an electrode.
Solar cells can generally generate up to 50 percent more electricity
by capturing light from both the front and back, but the back sides
of standard dye-sensitized solar cells tend to be less efficient than
their front sides.
The two-way dye-sensitized solar cell has a layer of silicon
oxide insulating the semiconductor from the back electrode and a carefully
sized semiconductor layer. These boost the back side efficiency to
close to that of the front side.
Dye-sensitized solar cells are relatively inefficient but
Bifacial solar cells can be positioned facing east and west
to capture morning and afternoon light.
Bifacial Dye-Sensitized Solar Cells Based on an Ionic
Nature Photonics, published online October 19, 2008
Laboratory of Photonics
and Interfaces, Ecole Polytechnique de Lausanne
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