There’s a cottage industry in solar research involving the manipulation of quantum dots. Solar cells using these tiny particles of semiconductors are much less expensive to produce than traditional ones, because they can be made using simple chemical reactions. And scientists for a number of years now have been drawn to their ability to harvest invisible, infrared light in addition to visible light.
Alas, for the most part nobody’s been able to fully exploit the possibilities these nanomaterials offer—until, perhaps, now. The potential breakthrough comes from a team made up of scientists from the University at Buffalo, the Air Force Office of Scientific Research and the U.S. Army Research Laboratory. The university reports the researchers found that by “employing selective doping so that quantum dots within the solar cell have a significant built-in charge,” they could increase the efficiency of solar cells up to 45 percent.
Howzit work? Like this: Quantum dots have a tendency to create what the researchers call “a channel of recombination for electrons.” That is, they grab moving electrons and keep them from contributing to electric current. But by building in a charge, the quantum dots repel electrons, basically giving them no choice but to join in the electricity-generating fun.
This effect sounds vaguely similar to earlier work we reported on at Stanford, where a team of researchers coated a titanium dioxide semiconductor in their quantum dot solar cell with a very thin single layer of organic molecules. They found that just that single layer, less than a nanometer thick, was enough to triple the efficiency of the solar cells.
The Buffalo researchers have invested significant amounts of time in developing the quantum dots with a built-in-charge, dubbed “Q-BICs,” the school said. And they filed provisional patent applications through the school’s Office of Science, Technology Transfer and Economic Outreach to protect their technology. To further enhance the technology and bring it to the market, they have also founded a company, OPtoElectronic Nanodevices LLC. (OPEN LLC.), which is seeking funding from private investors and federal programs.
“Clean technology will really benefit the region, the state, the country,” electrical engineer and team member Vladimir Mitin (pictured above) said in a statement. “With high-efficiency solar cells, consumers can save money and providers can have a smaller solar field that produces more energy.”
In addition to Mitin, the team members included Andrei Sergeev and Nizami Vagidov from the University at Buffalo; Kitt Reinhardt of the Air Force Office of Scientific Research; and John Little and advanced nanofabrication expert Kimberly Sablon of the U.S. Army Research Laboratory.