Organic Solar Cell Efficiency Tripled Thanks Nanostructure Sandwich

ORIGINAL: Clean technica

Nathan

December 10, 2012

Organic solar cells have received a big boost to their efficiency thanks to a new device designed by Princeton University. The newly designed, cheap, flexible plastic device more than triples the efficiency of organic solar cells.

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The new device is essentially a ‘sandwich’ of nanostructured metal and plastic that is able to trap light, increasing solar cell efficiency by 175 percent. According to the researchers, the device will also work to increase the efficiency of inorganic solar cells, but that side of things hasn’t been tested yet.

The device works by addressing two of the main causes of inefficiency in solar cells,

• light being reflected by the cell surface, and 
• the lack of an ability to fully capture the light that does enter the cell.

Princeton University writes: “With their new metallic sandwich, the researchers were able to address both problems. The sandwich — called a subwavelength plasmonic cavity — has an extraordinary ability to dampen reflection and trap light. The new technique allowed the research team to create a solar cell that only reflects about 4 percent of light and absorbs as much as 96 percent. It demonstrates 52 percent higher efficiency in converting light to electrical energy than a conventional solar cell.”

Those numbers are for direct sunlight — the device works even better for indirect light, as occurs on cloudy days. By “capturing these angled rays, the new structure boosts efficiency by an additional 81 percent, leading to the 175 percent total increase.”

The specifics of the device are rather complex, but it essentially works like a ‘black hole’ for light, completely trapping it.

While the system is essentially ready for commercial use, the researchers think that it may take some time before they are mass produced and used on a wide scale.

The research was just published online November 2, 2012, in the journal Optics Express.

Source: Princeton University Engineering School

Image Credits: Princeton University, Engineering School