Organic photovoltaic (OPV) cells convert electromagnetic energy (sunlight) into electricity by the photovoltaic effect. Assemblies of cells are used to make solar modules or photovoltaic arrays. Solar power is gradually becoming cost-competitive with traditional mainstream energy sources, but to achieve this still requires significant further reductions in the costs of materials, manufacturing and installation. Organic solar cells hold the promise of addressing these issues due to their potential to be manufactured on large areas at high speeds on lightweight substrates like plastic, but still require further increases in efficiency and operational lifetime to be truly cost-competitive with traditional energy sources. However, in the short term, other properties unique to organic solar cells - such as the ability to be light, flexible and optically semi-transparent - make them perfectly suited for use in architectural or other design areas, such as windows that can be used as solar panels, for use in office buildings or cars, where other energy technologies are infeasible. The key challenge, then, is enabling efficient enough organic solar technology that can also be cost-effectively and reliably manufactured at industrial scale. Earlier in the year, Polyera has achieved a certified world-record 9.1% efficient polymer/fullerene organic solar cell in an inverted bulk heterojunction architecture using its newest proprietary ActivInk® PV2000 semiconductor material. The results represent a significant step in that direction, demonstrating 9.1% power-conversion efficiency (i.e. how much energy from the sun is converted into usable electricity) combined with other very important - but often overlooked - factors that affect a technology’s true commercial viability. An inverted cell architecture, for example, provides a number of commercially-relevant benefits, such as making solar panels easier to manufacture and improving their useful life. The active layer materials can also be deposited using a significantly broader range of film thicknesses without lowering cell efficiency; this broader process window improves yields and further simplifies manufacturing. Polyera’s materials can also be processed at low enough temperatures to be compatible with a wide range of simple printing processes and common, inexpensive plastic substrates like PET or PEN

A German company has commissioned SGS, an accredited and independent testing facility, with a measurement campaign of its latest organic photovoltaic (OPV) cells. The result of this campaign is a new world record for OPV with 10.7 % cell efficiency on 1.1 cm². It also confirms the superior low light and high temperature performances of OPV compared to traditional solar technologies. The company- Heliatek GmbH, continues to set new world records for organic solar cells. The key to this success is the family of small organic molecules - oligomers - developed and synthesized at its own lab in Ulm, Germany. Dr. Martin Pfeiffer, co-founder and CTO of Heliatek, explains: “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. 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 campaign of SGS 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 % 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% 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 behavior 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 these organic solar cells is 15% to 25% higher than crystalline and thin film solar. The company 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. It has also kicked off a third financing round to raise €60 million from current and new investors for a new roll-to-roll 75 MWp production line