Transmaterial

Transparent Solar Cells

Imagine a smart credit card that not only stores electronic money and records your transactions but also has its own energy source. Or a sun roof that delivers electricity to your car battery. Imagine each powered by flexible, ultra-thin, see-through solar panels.

These scenarios may not be far off, thanks to a photovoltaic cell production process unveiled by Toshiba scientists in May at the 16th European Photovoltaic Solar Energy Conference and Exhibition in Glasgow, Scotland. The Toshiba design is an improvement to the Graetzel cell, a new type of solar panel that relies on titanium dioxide nanocrystals coated with a dye. When struck by light, the dye "injects" energized electrons into the semiconducting titanium, which generates electrical power. Graetzel cells' advantages over conventional silicon solar panels include transparency, low materials costs and the ability to operate efficiently under cloudy skies.

Earlier Graetzel designs, however, mostly relied on a liquid electrolyte to replenish the dye with electrons; this proved impractical because of the risk of leakage. Toshiba is the first to succeed in encapsulating liquid electrolyte in a durable solid - a "cross-linked" gel that can withstand temperatures of up to 120 C.

Shuzi Hayase, a chief research scientist at Toshiba's Power Supply Materials & Devices Laboratory in Kawasaki, says the cells achieve a respectable 7.3 percent solar-energy conservation efficiency and should be easy to manufacture. "We do not need expensive production lines and sophisticated vacuum systems currently employed in the manufacture of silicon-based cells. The new cells could be manufactured by [silk-screen] printing technologies." [via Technology Review; suggested by Dorm Anderson, Seattle.]

posted by Blaine @ 7:45 AM