Date: 16/01/2013

Low cost Organic Solar PV, the opposite of OLED reaches efficiency of 12%

The new trend in electronics now is use of organic material as semiconductor, conductor and insulator material. The advantage is they are environment friendly and can be made at room temperature, so that Billion $ costing fabs are not required. One such device is Organic Solar PV. The organic light emitting device (OLED) is already a success in the market with the recent launch of 55 Inch OLED TV by LG. The Solar PV does the exactly opposite job of OLED, i.e., instead of emitting light it converts light into electrical energy. One of the company leading in organic Solar PV is Germany based Heliatek GmbH.

Heliatek GmbH has announced it has achieved a record-breaking 12.0% cell efficiency for its organic solar cells. Heliatek developed this tech in cooperation with the University of Ulm and TU Dresden. The performance measurement done at SGS also validated the superior low light and high temperature performances of organic photovoltaics (OPV) compared to traditional solar technologies, says Heliatek.

Heliatek explains: 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.

The ultrathin Heliatek Solar Films will be produced in different transparency levels enabling building glass to harvest energy, says Heliatek.

"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 - that is only one ten thousandth of a human hair or twice the size of a strand of a human DNA. 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."

Tech explanation by Heliatek:
Heliatek's OPV technology based on small molecules (oligomers) is currently being transferred to commercial production. The first production line was launched in spring 2012 and Heliatek Solar Films are already 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.

About Heliatek's organic solar film technology: The key to Heliatek's success is the family of small organic molecules - oligomers - developed and synthesized at its own laboratory in Ulm, Germany. Heliatek is the only company in the world that uses the deposition of small organic molecules in a low temperature, roll-to-roll vacuum process. Its organic solar cells are made of nanometers-thin layers of high purity and uniformity. This enables the company to literally engineer the cell architecture to systematically improve efficiency and lifespan. This technology is very similar to the well-established OLED technology (organic LEDs) except that it operates in reverse, taking in light to create electricity. This gives Heliatek access to readily available manufacturing equipment, giving it a fast track to reliable volume production.
Author: Srinivasa Reddy N