Quantum Dots May Boost Solar-cell Efficiency (moved from ATSNN), page 1

The path to a more efficient solar-cell may be coming soon, thanks to research being performed at the U.S. Department of Energy's National Renewable Energy Laboratory. Investigators there have demonstrated quantum dots that produce an average of three electrons per photon absorbed, as opposed to traditional photovoltaic cells which produce only a single electron per photon. The work helps confirm previous theoretical work by Arthur Nozik that predicted that quantum dots could be up to 65% efficient at converting solar energy into electricity. The most efficient cells today are only 33% efficient.

lfw.pennnet.com
May 24, 2005, Golden, CO--Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have shown that the use of quantum dots may greatly increase the amount of electricity produced by solar cells.

In a paper published in a May issue of the American Chemical Society's Nano Letters journal, an NREL team found that quantum dots produce as many as three electrons from one high-energy photon of sunlight. When existing photovoltaic solar cells absorb a photon of sunlight, the energy gets converted to at most one electron, and the rest is lost as heat.

The research demonstrates the potential for photovoltaic cells that reduce wasteful heat and maximize the amount of the sun's energy that is converted to electricity--a key step toward making solar energy more cost-competitive with conventional power sources.

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This is very exciting and welcome news. Of course, the concept has not been demonstrated outside of the laboratory, and only at the microscopic level. Further work will be required to mass produce the quantum dots, engineer them into a solar cell configuration, and incorporate them into large scale arrays.

Once again, basic research related to nano-technology and fundamental quantum mechanics has led to a breakthrough that could revolutionize the future of energy production and utilization.

The link below is to the abstract in Nano Letters. You'll either need a subscription to the journal or will have to visit a university library to read the full text.

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