High efficiency cells from lower grade silicon

The pioneering photovoltaic research group at the UNSW has developed a method to make hydrogen atoms within silicon more active and therefore capable of reducing impurities in lower-quality silicon. UNSW researcher Stuart Wenham says the technique has the potential to increase photovoltaic cell efficiency from 19% to between 21 and 23%.

"This process will allow lower-quality silicon to outperform solar cells made from better-quality materials," said Wenham, in a statement announcing the development of the new technique. The technique hinges on controlling the charge state of hydrogen atoms within the silicon. By doing so the mobility of the hydrogen can been improved up to 10,000 times, allowing it to chemically bond to defects and contaminates within the silicon.

"Our research team at UNSW has worked out how to control the charge state of hydrogen atoms in silicon – something that other people haven’t previously been able to do," summarizes Wenham.

The project has been supported by the newly formed Australian Renewable Energy Agency and is expected to run until 2016. UNSW is working with eight industry partners looking to commercialize the technology.

Martin Green elected to Royal Society

The news comes on top of the announcement last week that the UNSW’s Martin Green has been elected into the Fellowship of the Royal Society. The society is the U.K.’s most prestigious scientific body, which includes some of the world’s most distinguished scientists and engineers, including 80 Nobel Laureates.

Green has been labeled the "Father of Photovoltaics" for his pioneering research into c-Si PV technology. UNSW currently holds the world record for c-Si cell efficiency of 25%.

In an interview with pv magazine, Martin Green said that efficiency is a key driver for photovoltaics. "I’m expecting that the low costs being attained by the technology right now is exciting for everyone involved in the industry, so despite the present period of financial hardship, I think everyone has realized that the technology has got to the stage where it’s got a guaranteed future," said Green.

Green is currently working on "third generation" solar technology, which will employ multiple semiconductor technologies on top of c-Si. "Our UNSW research group would like to be the one to develop a practical cell that takes us from 25% to over 40% efficiency."

The Royal Society elects 44 fellows and eight Foreign Members each years. Green joins illustrious company including Richard Dawkins and Stephen Hawking. "It’s really quite an honor," said Green.