Tuesday, April 26, 2011

#ENERGY: "Nanotube-based solar cells harness viruses"

The M13 virus consists of a strand of DNA (coil at right) attached to a bundle of proteins called peptides (purple) which attach to the carbon nanotubes (gray) and hold them in place. A coating of titanium dioxide (yellow) attaches to dye molecules (red) which surrounds the bundle. Credit: Matt Klug, Biomolecular Materials Group, MIT.

Living viruses can be harnessed to install highly conductive carbon nanotubes into the anode structures of dye sensitized solar cells, boosting their efficiency by almost one third, according to researchers at the Massachusetts Institute of Technology (MIT). Dye sensitized solar cells are a photo-electro-chemical system that positions a semiconductor between a photo-sensitized anode and an electrolyte. Titanium dioxide nanoparticles covered with a dye absorb sunlight, releasing electrons into the anode. These electrons are then collected to power a load, then returned by the cathode to the electrolyte—and the cycle continues. By harnessing a virus to lace the anode with nanotubes, efficiency was boosted from under eight- to over 10.6-percent, according to the MIT researchers.
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