Roth & Rau reaches 21 percent wafer efficiency


In September, Roth & Rau presented its new heterojunction solar cells at the EU PVSEC, with an efficiency of 20 percent, as verified by the Fraunhofer Institute for Solar Energy Systems. Now, just three months later, the German photovoltaic company says it has hit 21 percent at its research line in Neuchâtel, Germany.

The key, says the company, lies in its HELiA coating system. It explains that the modularly designed system, which has been developed for deposition of TCO and metal layers by sputter deposition, "is capable of depositing uniform, well controlled, thin layers of intrinsic and doped a-Si:H layers onto a textured silicon wafer surface."

In a statement released, the company wrote, "At an output efficiency rate of 20 percent, this technology … already reduces solar electricity generation costs by around 15 percent compared with the latest technology available for traditional crystalline solar cells."

Egbert Vetter, Vice President for R&D added that the next stage is to transferring the new results onto mass production systems; a goal that Roth & Rau is confident will be achieved in the near future.