Sunday, April 12, 2009

Diatom nanostructure improves solar cell efficiency

Salt water centric diatom frustule (skeleton). Diatoms are microscopic, unicellular algae that produce intricate silica (glass) cell walls that overlap like the top and bottom of a box. When diatoms die, their soft, internal parts deteriorate, leaving their hard, porous, glass skeletons behind. Diatoms are found in aquatic environments, and saltwater diatom skeletons appear in the fossil record as early as the Jurassic period (180 million years ago). In the United States, numerous deposits of diatom skeletons are found on the floors of former aquatic inland and coastal habitats. Important commercially, diatomite is used in a variety of ways: as fine abrasive (in silver polish and toothpaste), as filters, as mineral fillers, as insulating materials, and as anti-caking agents. Image and text copyright © Dennis Kunkel. All rights reserved.

CORVALLIS, Ore. – Engineers at Oregon State University have discovered a way to use an ancient life form to create one of the newest technologies for solar energy, in systems that may be surprisingly simple to build compared to existing silicon-based solar cells.

The secret: diatoms.

These tiny, single-celled marine life forms have existed for at least 100 million years and are the basis for much of the life in the oceans, but they also have rigid shells that can be used to create order in a natural way at the extraordinarily small level of nanotechnology.

By using biology instead of conventional semiconductor manufacturing approaches, researchers at OSU and Portland State University have created a new way to make “dye-sensitized” solar cells, in which photons bounce around like they were in a pinball machine, striking these dyes and producing electricity. This technology may be slightly more expensive than some existing approaches to make dye-sensitized solar cells, but can potentially triple the electrical output.

“Most existing solar cell technology is based on silicon and is nearing the limits of what we may be able to accomplish with that,” said Greg Rorrer, an OSU professor of chemical engineering. “There’s an enormous opportunity to develop different types of solar energy technology, and it’s likely that several forms will ultimately all find uses, depending on the situation.”

Dye-sensitized technology, for instance, uses environmentally benign materials and works well in lower light conditions. And the new findings offer advances in manufacturing simplicity and efficiency.

“Dye-sensitized solar cells already exist,” Rorrer said. “What’s different in our approach are the steps we take to make these devices, and the potential improvements they offer.” …

Ancient Diatoms Lead to New Technology for Solar Energy

Technorati Tags: ,

1 comment:

Nimvoker said...

That is very interesting!!