Efficiency boost

Solar cells just got a significant boost in efficiency thanks to a new device made at the University of California, Santa Barbara.

Solar cells just got a significant boost in efficiency thanks to a new type of device made at the Center for Polymers and Organic Solids at the University of California, Santa Barbara.

Nobel laureate Alan Heeger, Professor of physics at UC Santa Barbara, worked with Kwanghee Lee of Korea and a team of other scientists to create a new 'tandem' organic solar cell that led to the increase.

Tandem cells are comprised of two multilayered parts that work together to gather a wider range of the spectrum of solar radiation - at both short and long wavelengths.

'The result is six and a half percent efficiency,' said Prof Heeger. 'This is the highest level achieved for solar cells made from organic materials. I am confident that we can make additional improvements that will yield efficiencies sufficiently high for commercial products.'

The new solar cells can be fabricated over large areas by means of low-cost printing and coating technologies that can simultaneously pattern the active materials on lightweight flexible substrates.

The deposition of each layer of the multilayer structure by processing the materials from solution promises to make the solar cells inexpensive to produce.

In 2000, Heeger founded Konarka Technologies to develop and market solar cells. Heeger expects the new technology to be on the market in about three years.