“It is a world record for organic photovoltaic, with 10.7% cell efficiency on 1.1cm2,” said the firm.
The firm uses vacuum-deposited small oligomer molecules, developed and synthesised at its own lab in Ulm, Germany.
The record cells are tandem, having two layers absorbing different wavelengths.
“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,” said CTO and co-founder Dr Martin Pfeiffer.
Additional tests, claimed the firm, show superior performance in low light.
“The measurement results for low light established that the efficiency not only remains constant, but even increases gradually,” said Heliatek. “At an irradiation of 100W/m² the efficiency is 15% higher compared to the standard efficiency measured at 1,000W/m².”
And that “measurements at high temperatures confirmed that the efficiency remains constant. This behaviour is unique for OPV technology in contrast to traditional solar technology which efficiency drops 15 to 20% at elevated temperatures”, said the firm. “First outdoor tests have shown that the harvesting factor of Heliatek’s organic solar cells is 15 to 25% higher than crystalline and thin film solar.”
Heliatek is currently working on its first roll-to-roll manufacturing line installed in Dresden, Germany, to go in production in the third quarter of 2012, and has kicked off a third financing round to raise €60m from current and new investors.