Scientists at the U.S. Department of Energy’s Argonne National Laboratory and the University of Texas at Austin have together developed a new, inexpensive material that has the potential to capture and convert solar energy—particularly from the bluer part of the spectrum—much more efficiently than ever before.
Most simple solar cells handle these bluish hues of the electromagnetic spectrum inefficiently. Because of this limitation, scientists had originally believed that simple solar cells would never be able to convert more than about 34 percent of incoming solar radiation to electricity.
In their study, Korgel and his team used specialized spectroscopic equipment at Argonne’s Center for Nanoscale Materials to look at multiexciton generation in copper indium selenide, a material closely related to another more commonly produced thin film that holds the record for the most efficient thin-film semiconductor. “This is one of the first studies done of multiple exciton generation in such a familiar and inexpensive material,” said Argonne nanoscientist Richard Schaller.
The study mostly proves that the efficiency boost provided by multiple exciton extraction is possible in mass-producible materials.
“The holy grail of our research is not necessarily to boost efficiencies as high as they can theoretically go, but rather to combine increases in efficiency to the kind of large-scale roll-to-roll printing or processing technologies that will help us drive down costs,” Korgel said.