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New Quantum Dots Make Cheaper Solar Panels

U.S. Scientists Say a New Method of Producing Molecular Specks of Semiconductors Called Quantum Dots May Result in Better, Cheaper Solar Energy

HOUSTON (UPI) May 3, 2007
-- The research by scientists at Rice University's Center for Biological and Environmental Nanotechnology involves a new chemical method of making four-legged cadmium selenide quantum dots, which are particularly effective at converting sunlight into electrical energy.

Four-legged quantum dots, called tetrapods, are much more efficient at converting sunlight into electricity than regular quantum dots.

But the new study's principal investigator, Assistant Professor Michael Wong, said there has been no efficient and consistent way of producing tetrapods, since current technology leads to uneven particles. Even in the best recipe, 30 percent of the prepared particles are not tetrapods.

The new technology -- developed by Wong, graduate students Subashini Asokan and Karl Krueger, and CBEN Director Vicki Colvin -- produces same-sized particles, in which more than 90 percent are tetrapods.

The new recipe uses cetyltrimethylammonium bromide instead of the standard alkylphosphonic acid compounds, Wong said, noting cetyltrimethylammonium bromide is safer and much cheaper than alkylphosphonic acids. That, he said, means cheaper raw materials and fewer purification steps.

The research is detailed in the journal Small.

Copyright 2007 by United Press International. All Rights Reserved

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