Researchers: Quantum Dots Boost Solar Cell Efficiency by 45%

The U. of Buffalo (NY) says adding quantum dots into solar cells could increase their efficiency by a whopping 45%.

Their research, published in last May in the journal Nano Letters (here’s a PDF of the paper), says that embedding quantum dots allows the cells to harvest infrared light, and also increase the lifetime of photoelectrons.

Using quantum dots to boost solar cell efficiency isn’t exactly new; it’s been investigated for at least the past decade (here’s one example). For the Buffalo team, the key appears to be that not only can they embed quantum dots, but they can be selectively doped to contain “a significant built-in charge” (dubbed “Q-BICs”), which forces electrons to keep bouncing around and thus minimizes recombination losses. They also claim the technology can be applied to many different solar PV structures — their research relied on a InAs/GaAs test device.

Adding two quantum dots increases conversion efficiency by just 4.5%; adding four or six QDs improves efficiency by 30% and 50% respectively — in the latter, the device went from 9.3% to 14% efficiency.

A spinoff company, OPtoElectronic Nanodevices LLC, has been formed to commercialize the technology, and is currently seeking funding from private investors and federal programs (hence the delayed timing of the PR vs. the published paper). The research was done in conjunction with researchers from both the Air Force Office of Scientific Research and US Army Research Labs.

Growth diagram of a delta-doped QD structure. (Source: Vladimir Mitin/U. Buffalo)

(Source: Vladimir Mitin/U. Buffalo)

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Jim is Contributing Editor for RenewableEnergyWorld.com, covering the solar and wind beats. He previously was associate editor for Solid State Technology and Photovoltaics World, and has covered semiconductor manufacturing and related industries, renewable energy and industrial lasers since 2003. His work has earned both internal awards and an Azbee Award from the American Society of Business Press Editors. Jim has 17 years of experience in producing websites and e-Newsletters in various technology markets.

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