Researchers from Los Alamos National Laboratory have tapped the efficiencies of nanotechnology to increase solar cells’ potential energy production by as much as 37 percent.
Solar cells generate electricity by absorbing photons and directing the resulting energy to move an electron from the low-energy valence band in a material to a higher-energy conduction band where it is free to flow.
Researchers working to squeeze more energy from sunlight are generally aiming for solar cells that can absorb and use a higher percentage of the wavelengths of light in the sun’s spectrum. Today’s commercial solar cells can use anywhere from 10 percent to 35 percent.
The Los Alamos researchers have found that it is possible to increase a cell’s energy production by making each photon move two electrons. “Carrier-multiplication-enhanced solar cells can, in principle, produce twice as large a current as conventional solar cells,” said Victor Klimov, a team leader at Los Alamos National Laboratory.
The method could increase what has been thought of as the maximum power conversion of solar cells by as much as 37 percent, depending on the materials used, resulting in a solar cell with a potential efficiency of over 60 percent. The method could also be used to increase the efficiency of other optical components, including amplifiers, lasers, switches and light absorbers, according to Klimov.
Solar crystals get 2-for-1
May 19/26, 2004
By Kimberly Patch, Technology Research News