The Roth & Rau produced wafers use heterojunction technology and were presented at the 26th EU PVSEC conference, currently underway in Hamburg. The German equipment producer has developed the technology in partnership with the Universite de Neuchatel. The two have been working together since May 2008.
The pilot line where the 20 percent efficiency has been recorded is in Hohenstein-Ernstthal, where Roth & Rau is based, and the company claims the processes are being scaled up for mass production.
"The high level of output efficiency offered by heterojunction technology, combined with its excellent temperature coefficients (>five percent additional energy yield per module), address the key cost factors in the photovoltaics market," said Dietmar Roth, the companys CEO, in a statement announcing the efficiency rating.
Roth & Rau claims that heterojunction technology allows manufacturers to achieve cost savings, through low-temperature production and high output efficiency rates.