‘Magic’ Alloy Could Dramatically Boost Solar Panel Efficiency

Researchers at the University of Michigan have made what they claim is a major breakthrough in solar energy technology: a new alloy that captures near-infrared light.

The findings, published in the journal Applied Physics Letters, piggyback on another University of Michigan advancement announced in the same journal late last year that could improve the chemistry of photovoltaic panels, including allowing manufacturers to eliminate toxic beryllium from the devices.

Together, the discoveries would make so-called “concentrator photovoltaics” that could be more than twice as efficient and 30 percent cheaper than traditional solar panels, the researchers said. Store-bought panels only convert around 15 percent of the sun’s energy, they said. Concentrator photovoltaics, on the other hand, have conversion rates of 50 percent.

“The implications are that you could have a boost in the efficiency and a reduction in the cost through these two innovations for wide scale deployment of concentrator photovoltaics on Earth,” said Rachel Goldman, a professor of materials science at Michigan and a co-author on the studies.

Currently, solar panels don’t capture infrared light that’s invisible to the naked eye.

But Goldman and her colleagues mixed a cocktail of arsenic, gallium arsenide, nitrogen, bismuth, and a material now used in solar panels, silicon, to create a layer of chemicals a few microns thick that they could spray onto photovoltaic cells to harness infrared energy. A micron is around .00004 inches.

"'Magic' is not a word we use often as materials scientists," Goldman said in a statement. "But that's what it felt like when we finally got it right."