Solar power could get boost from new light absorption design

November 2, 2011

Solar power may be on the rise, but solar cells are only as efficient as the amount of sunlight they collect. Under the direction of a new professor at Northwestern University's McCormick School of Engineering and Applied Science, researchers have developed a new material that absorbs a wide range of wavelengths and could lead to more efficient and less expensive solar technology.

A paper describing the findings, "Broadband polarization-independent resonant using ultrathin plasmonic super absorbers," was published Tuesday in the journal Nature Communications.

"The is not like a laser – it's very broadband, starting with UV and going up to near-infrared," said Koray Aydin, assistant professor of electrical engineering and computer science and the paper's lead author. "To capture this light most efficiently, a solar cell needs to have a broadband response. This design allows us to achieve that."

The researchers used two unconventional materials – metal and silicon oxide – to create thin but complex, trapezoid-shaped metal gratings on the nanoscale that can trap a wider range of visible light. The use of these materials is unusual because on their own, they do not absorb light; however, they worked together on the nanoscale to achieve very high absorption rates, Aydin said.

The uniquely shaped grating captured a wide range of wavelengths due to the local optical resonances, causing light to spend more time inside the material until it gets absorbed. This composite metamaterial was also able to collect light from many different angles – a useful quality when dealing with sunlight, which hits at different angles as sun moves from east to west throughout the day.

This research is not directly applicable to solar cell technology because metal and silicon oxide cannot convert light to electricity; in fact, the photons are converted to heat and might allow novel ways to control the heat flow at the nanoscale. However, the innovative trapezoid shape could be replicated in semiconducting materials that could be used in solar cells, Aydin said.

If applied to semiconducting materials, the technology could lead to thinner, lower-cost, and more efficient solar cells, he said.

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5 / 5 (1) Nov 02, 2011
Better sensors, upgrade complete, new objective: Global catharsis regarding technological advancement.

Anyone else see where this is going? My hope is that Humans will discover QUICKLY that the Universe is not for the taking. If we venture off into space we should probably not play guessing games with whats good or bad but take a minimalist observer stance to ensure we don't create unforeseeable and regrettable circumstances.

What we do in one moment effects things in a complex way for possibly trillions of years to come.
Nov 02, 2011
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2 / 5 (4) Nov 03, 2011
A prominent result of plagiaristic cooperation between the Italian Institute of Technology (IIT) and Northwestern University at
3 / 5 (2) Nov 03, 2011
Their is a new story like this every week. This has gone on for years and years and years latter.. Nothing new on the market.
not rated yet Nov 05, 2011
is 3rd gen PV on the market yet?
5 / 5 (1) Nov 05, 2011

Think about where the human race was less than 100 years ago, now think about where it will be in 100 years.

We need to start thinking on much broader perspectives.

Just watch a little Star Trek, it's a moral compass not a nerd fest.

But sensors, shields and weapons are the fundamental trifecta of the blowhard space asstronauts.

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