S. Korean scientists develop highly efficient plastic-based solar cell

Thai News Agency MCOT, April 27, 2009

SEOUL, April 27 (Yonhap) -- South Korean scientists said Monday that they have created a highly efficient plastic-based power cell that can speed up commercial use of solar energy.

The team led by Lee Kwang-hee at the Gwangju Institute of Science and Technology (GIST), said the solar cells are designed to mimic the photovoltaic activities of plants, and reached an unprecedented energy efficiency rate of 6.2 percent.

"This is the highest number reached by any single-layer plastic, organic photovoltaic solar cell created in the world to date and should greatly help commercial use of power generation using sunlight," the material science professor at the state-run laboratory said.

If fully developed the solar cells, which can easily bend, could be attached to coats, bags, various electronic appliances and building windows.

The breakthrough has been confirmed by the U.S. National Renewable Energy Laboratory and published in the latest on-line international journal of Nature Photonics.

Energy efficiency indicates the percentage of sunshine that solar cells turn into electricity.

Lee's team's said they used a new material that have "open circuit voltage" properties and titanium oxide to bring about high efficiency.

He added that under so-called green light conditions, the energy efficiency of the new plastic power cells reached 17 percent, which is more than enough to start commercial power generation. Experts said an efficiency rate of 7 percent must be reached for plastic solar cells to become commercially viable.

Conventional inorganic silicon-based solar cells used in homes have an efficiency rate of 7 to 8 percent, while very expensive panels placed on satellites have numbers reaching 15 percent.

The technology, developed jointly with U.S. researchers led by Alan Heeger of the University of California, Santa Barbara, is an extension of cutting edge research carried out in the past.

The Lee-Heeger team announced in 2007 that they had built a stacked or double-layered organic photovoltaic that had a power efficiency of 6.5 percent.

The result was published in the journal Nature. (Yonhap)