Organic photovoltaics represent the third generation in the field of PV technology, similar to the organic display and lighting revolutions, and will enable flexible, beautiful, cheap, ubiquitous applications of the cells in the medium- to long-term. The technology marked another important milestone in January 2013 when a new world record of 12.0% cell efficiency was announced by Heliatek GmbH, the leader in organic solar films.
This world record, established in cooperation with the University of Ulm and Technical University Dresden, was measured and confirmed by the accredited testing facility SGS. Another advantage of the third generation PV tech, the superior low light and high temperature performance of organic photovoltaics (OPV) compared to traditional solar technologies, was also validated during the measurement campaign at SGS.
The 12.0% record cell on a standard size of 1.1 cm² combines two patented absorber materials, which convert light of different wavelengths. Using two different absorber materials creates a stronger absorption of photons and improves energetic utilization through a higher photovoltage. Thanks to OPV’s unique behavior at high temperatures and low light conditions, this 12% efficiency is comparable to about 14% to 15% efficiency for traditional solar technologies like crystalline silicon and thin film PV. Whereas those technologies significantly lose cell efficiency with rising temperatures and decreasing solar irradiation, organic cells increase their efficiency in these conditions leading to a much higher energy harvesting in real life environments.
“We are pleased to continue to lead the OPV industry with this landmark achievement. Our continuous progress comforts us in our ability to reach 15% efficiency by 2015 and gradually transfer our record efficiencies into Heliatek’s roll-to-roll production line. We manufacture solar films and not solar panels. Our customers in the building and construction material industry, in automotive and in light structures, such as shading and street furniture, are integrating these solar films as energy harvesting components to increase the functionality of their products,” commented Thibaud Le Séguillon, CEO of Heliatek.
Dr. Martin Pfeiffer, co-founder and CTO of Heliatek, added: “Achieving an unprecedented 12% OPV efficiency is a clear validation of Heliatek’s choice not to focus on printed polymers but to go with vacuum deposited oligomers. This technology has been used successfully for OLED displays over the last decade. Vacuum deposition allows for extremely thin yet homogeneous layers down to 5 nm. With this well-controlled, ultra-thin film process we can deposit a large number of layers on top of each other creating tandem, or even triple junction cells, to absorb a broader spectrum of light.”
The new world record efficiency for OPV shows the rapid advancements in this technology, since it topples a prior record of 10.7%, set just nine months earlier by the same company. This latest leap in cell efficiency was enabled by the cooperation of leading universities in the field of OPV, a company that is aiming to launch commercial application of the technology as early as this year, and research funding by the EU, the German government and the German Research Foundation (DFG). One of the two absorbers was developed and synthesized by Ulm University’s Institute of Organic Chemistry II and Advanced Materials, headed by Prof. Peter Bäuerle, co-founder of Heliatek. The cooperation also encompassed Prof. Karl Leo (co-founder of Heliatek) and Dr. Moritz Riede of the ‘Institut für Angewandte Photophysik’ (IAPP) of ‘TU Dresden’.
Heliatek’s OPV technology based on small molecules (oligomers) is currently being transferred to commercial production. A first small-scale production line was launched in spring 2012 and Heliatek Solar Films are currently being delivered to industry partners for product development. The commercialization of first partner applications with integrated Heliatek Solar Films as energy harvesting components is expected in late 2013. In parallel, Heliatek has launched a financing round to raise €60 million from current and new investors for a new roll-to-roll volume production line to draw on economies of scale.