A record breaking development for organic solar cells has been achieved by Heliatek. The company commissioned accredited and independent testing 
facility, SGS to tests its latest organic photovoltaic (OPV) cells and the results revealed the OPV to achieve 10.7 percent cell efficiency on 1.1 cm2.
It also demonstrated a high level of low-light and high-temperature performances for the OPV compared to traditional solar technologies.
The key to the company’s achievements with this technology are small organic molecules – oligomers – developed and synthesised at its own lab in Ulm, Germany.
Dr. Martin Pfeiffer, co-founder and CTO of Heliatek, explains: ‘Heliatek uses the deposition of small organic molecules in a low temperature, roll-to-roll vacuum process. Our solar tandem cells are made of nanometers thin layers of high purity and uniformity. This enables us to literally engineer the cell architecture to systematically improve efficiency and lifetime.’
The measurement tests included efficiency measurements under standard testing conditions (STC) of the solar industry as well as performance measurements at low light and high temperatures of up to 80 °C. The test results not only set a new world record for OPV with 10.7 percent cell efficiency, but the additional measurements highlight the superior performance of Heliatek’s OPV cells under real life conditions.
The measurement results for low light established that the efficiency not only remains constant, but even increases gradually. At an irradiation of 100 W/m² the efficiency is 15 percent higher compared to the standard efficiency measured at 1,000 W/m².
Additionally, the 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.
These technology advantages translate into a higher harvesting factor under real life conditions. First outdoor tests have shown that the harvesting factor of the organic solar cells is 15 percent to 25 percent higher than crystalline and thin film solar.
Heliatek
