From basic idea to implementation: University of Konstanz, Germany, invested 10 years of research and development work: Under operating conditions, however, Cz-silicon solar cells suffer from so-called light-induced degradation (LID), due to which the efficiency of a Cz-silicon solar cell is considerably reduced after only a few hours of exposure to solar radiation. Depending on the material and production process, the loss in efficiency can be more than one percent absolute.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Konstanz in patenting and marketing its innovation.
One of the biggest challenges in the context of ‘renewable energies` is the even more efficient use of the raw materials available to us. Particularly when it comes to generating electricity from sunlight, a lot of research is carried out on how to further increase conversion efficiency of solar cells.
In the past decade, the efficiency of solar cells in industrial mass production has been continuously improved. About 15 years ago, solar cells were able to convert only approx. 15 percent of solar radiation into electricity. In the meantime, efficiency could be increased to approx. 20 percent.
This excellent efficiency is only reached on industrial scale with monocrystalline solar cells using silicon wafers grown by the Czochralski (Cz) technique. Under operating conditions, however, Cz-silicon solar cells suffer from so-called light-induced degradation (LID), due to which the efficiency of a Cz-silicon solar cell is considerably reduced after only a few hours of exposure to solar radiation. Depending on the material and production process, the loss in efficiency can be more than one percent absolute.
Researchers at the Photovoltaics Division of the University of Konstanz introduced a method to neutralize this type of degradation as early as in 2006. The process developed and optimized over the years by Axel Herguth, Svenja Wilking and Professor Giso Hahn can easily be integrated into the production process. The scientists made use of the fact that the degraded solar cells can be regenerated by exposing them to light energy at temperatures above 100 degrees Celsius. Alternatively, regeneration can also be achieved using voltage instead of light.
The regeneration process can be integrated at different stages into the production sequence, for solar cells, e.g., directly after the co-firing process or separately at the end of production. Another option is to apply the regeneration process to finished modules.
The economic potential of the regeneration effect is enormous: If the degradation-caused loss in efficiency of one percent absolute is nearly completely offset, this results in an additional power output of approx. five percent. With a 100 MWp line, this corresponds to more than one million euros per year.
"This means the return on invest is secured after only a few months, which significantly increases economic attractiveness and the opportunities for use of this groundbreaking technology," explains Professor Hahn, Head of Photovoltaic Division at the University of Konstanz.
Patents for the process and the regeneration furnace have already been granted in the most important industrial nations and regions such as in the United States, in Europe and China. In the meantime, first installations based on the patented method have been integrated into production processes. However, it is also likely that a number of imitation products have appeared on the market. "Our key challenge for the coming years will be to enforce the patents held by the University of Konstanz," says Dr.-Ing. Hubert Siller, Innovation Manager at TLB, Karlsruhe.
In recent years, this well-known method has been further developed and modified by Axel Herguth and Svenja Wilking, who are engaged in research at the University of Konstanz. The enhanced process control allows the regeneration process to be carried out much faster during the co-firing step. According to the researchers, this is due to a larger amount of hydrogen released from the silicon nitride anti-reflective coating into the silicon during co-firing. The process can thus be sped up considerably, improving its efficiency and making it attractive for inline processes in industrial mass production, for example. Ideally, this process may follow or even be integrated into the co-firing step. Professor Hahn is optimistic about the future: "We are confident that the regeneration method discovered and developed by our team of researchers will become an integral part of a lot of new solar cell production lines because it helps to achieve the high level of stable efficiency that is required by the market. Moreover, current production lines can be retrofitted with minimal effort by using this unique regeneration technology.”
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Konstanz in patenting and marketing its innovation. Acting on behalf of the University, TLB is in charge of the commercial implementation of this future-orientated technology at a global level. For more detailed information, please contact Dr.-Ing. Hubert Siller, email: email@example.com
Annette Siller | idw - Informationsdienst Wissenschaft
Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences
Researchers develop environmentally friendly soy air filter
16.01.2017 | Washington State University
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Life Sciences
18.01.2017 | Health and Medicine
17.01.2017 | Earth Sciences