The photovoltaics industry is booming – more and more solar modules are appearing on rooftops, and even large-scale solar power plants are increasingly feeding power into the grid. Multi-junction solar cells are particularly efficient in this regard: they can achieve efficiencies of up to 43 percent - twice the level of conventional solar cells made of crystalline silicon.
The trick: they consist of several semi-conductor layers that combine to transform the entire spectrum of sunlight into electrical energy. This technology is used in concentrator photovoltaics. There, lenses focus the light of the sun 500 times onto tiny solar cells. These concentrator systems produce solar electricity on a large scale, particularly in solar power plants located in areas rich in sunlight. Among the producers of these plants is SOITEC Solar GmbH, in Freiburg, Germany, a former spinoff of the Fraunhofer Institute or Solar Energy Systems ISE.
The multi-junction solar cells themselves consist of some 30 semi-conductor layers built up, layer for layer, on ultra-pure crystals of germanium or gallium arsenide. These materials are very costly, however. In a joint Franco-German project, researchers at ISE in Freiburg and their colleagues from the Carnot-Institut Laboratoire d‘électronique des technologies de l‘information CEA-LETI in Grenoble, France, are working to develop new substrates for multi-junction solar cells. The new technology replaces the expensive materials with reusable substrates. Whereas up until now the solar cells had to remain in place atop the germanium or gallium arsenide crystals, the solar cells are now removable from the new substrate which is recycled several times. This way, the cost of producing solar cells can be reduced by up to 20 percent.
„In the Solar-Bond project, two high-tech institutes have combined their skills,“ according to Dr. Frank Dimroth, Head of Department III-V - Epitaxy and Solar Cells at Fraunhofer ISE. „CEA-LETI is a leader in the microelectronics field and Fraunhofer ISE in photovoltaics.“ The French colleagues develop the substrate and adapt its properties to the requirements involved in growing multi-junction solar cells; the German scientists then apply the solar cells to these substrates and process them to create ready-to-use devices. The researchers are also working closely with SOITEC, a French company: in the future, the new solar cells will be used in their concentrator modules.
The scientists were honored for their international research on December 5, 2011, in Paris with the Franco-German Business Award 2011, presented by the Franco-German Chamber of Commerce and Industry AHK. The business award is presented in recognition of best practices over the past two years. Patrons of the award are the French Minister of Economy, Finance and Industry, François Baroin; and the German Federal Minister for Economics and Technology, Dr. Philipp Rösler.
SOLARBOND is one of 26 projects sponsored under the Inter Carnot Fraunhofer program (http://www.programme.inter.carnot.fraunhofer.org). The purpose of this program jointly run by the German Federal Ministry for Education and Research, Fraunhofer and The French National Research Agency is to establish strategic partnerships between French and German research and industrial organizations.
Karin Schneider | Fraunhofer-Institut
Reconstructing the richness of pristine oceans funded by the ERC
28.10.2019 | Johannes Gutenberg-Universität Mainz
AI for Understanding and Modelling the Earth System – International Research Team wins ERC Synergy Grant
14.10.2019 | Max-Planck-Institut für Biogeochemie
The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.
Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...
Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.
Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...
Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices
The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...
Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.
Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.
After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.
"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.
12.02.2020 | Event News
16.01.2020 | Event News
15.01.2020 | Event News
19.02.2020 | Life Sciences
19.02.2020 | Information Technology
19.02.2020 | Power and Electrical Engineering