Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Avoiding efficiency losses in silicon solar cells already in the production process

28.10.2015

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.


Researchers at the Photovoltaics Division of the University of Konstanz: Professor Giso Hahn, Svenja Wilking und Axel Herguth (from left).

TLB GmbH

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: siller@tlb.de

Weitere Informationen:

http://www.tlb.en
http://cms.uni-konstanz.de/en/physik/hahn/

Annette Siller | idw - Informationsdienst Wissenschaft

More articles from Power and Electrical Engineering:

nachricht Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University

nachricht TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>