Heliatek's organic tandem solar cell verified at 10.7% record conversion effciency

April 27, 2011 - Mark Osborne - pv-tech.org

Dresden, Germany-based OPV thin-film developer Heliatek has achieved a new organic tandem solar cell world record with 10.7% cell efficiency on a 1.1cm2 substrate. SGS undertook the testing and validated the figures. SGS also confirmed the OPV cell's merits in low light and high temperature operation.

“Heliatek is the only solar company in the world that uses the deposition of small organic molecules in a low temperature, roll-to-roll vacuum process,” noted Dr. Martin Pfeiffer, co-founder and CTO of Heliatek. “Our solar tandem cells are made of nanometers of thin layers of high purity and uniformity. This enables us to literally engineer the cell architecture to systematically improve efficiency and lifetime.”

Standard testing conditions (STC) were undertaken by SGS, which also established that under low light conditions and an irradiation of 100W/m², the efficiency is 15% higher compared to the standard efficiency measured at 1,000W/m². High temperature operation also demonstrated constant efficiency, claimed to be a unique characteristic for OPV technology in contrast to traditional solar technology where efficiency drops from 15% to 20% at elevated temperatures.

Heliatek is also claiming that real world outdoor conditions testing has shown its OPV technology has a 15% to 25% greater power output harvest, compared to that of crystalline and thin-film solar technologies.

Heliatek is currently seeking to raise €60 million from investors to equip and install a new 75MW roll-to-roll production line in Dresden, Germany. Initial volume production of its OPV technology is set for the third quarter of 2012.