Nobel laureate Alan Heeger, professor of physics at UC Santa Barbara, worked with Kwanghee Lee of Korea and a team of other scientists to create a tandem organic solar cell with increased efficiency. The discovery, explained in the July 13 issue of the journal Science, marks a step forward in materials science. The work described in the Science article was performed at UC Santa Barbara's Center for Polymers and Organic Solids.
Tandem cells are comprised of two multilayered parts that work together to gather a wider range of the spectrum of solar radiation at both shorter and longer wavelengths. "The result is six and a half percent efficiency," said Heeger. "This is the highest level achieved for solar cells made from organic materials. I am confident that we can make additional improvements that will yield efficiencies sufficiently high for commercial products." He expects this technology to be on the market in about three years.