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nanotimes EU-Projects
European Partnership for Next Generation of Stacked Solar Cells
Thin-film solar modules are an inexpensive and versatile alternative to traditional solar cells made of crystalline silicon. Eighteen leading industrial and research partners have joined forces in an EU Fast Track project aiming to further refine this technolo- gy. In the next three years, it is planned to produce a marketable prototype with an efficiency of twelve percent. The project is coordinated by Forschungs- zentrum Jülich and funded to the tune of EUR9.3 million by the EU.
In recent years, various companies have increased the efficiency of marketable thin-film solar modules to the present level of ten percent. Although these modules are still not as efficient as conventional solar cells, they can be produced much more economic- ally. In the case of thin-film modules, the silicon is applied to the substrate in a layer about one micro- metre thick and does not need to be carefully cut out from expensive wafers. Thin-film silicon solar mo- dules designed as tandem solar cells are particularly efficient. They consist of two layers one on top of the other, which absorb different fractions of sunlight.
Each of these two cell layers is divided into several sublayers which all influence each other in a com- plex manner. Since these interactions are difficult to predict, existing industrial thin-film solar cells make use of proven combinations of components and substrates. In the Fast Track project, leading repre- sentatives from research and industry who previously pursued different technologies are now pooling their expertise in order to combine the best components. By harmonizing and optimizing different approaches,
12-03 :: March/April 2012
a new generation of thin-film silicon solar modules will be created with an efficiency of twelve percent. This corresponds to an increase of twenty percent and under test conditions the costs should amount to less than EUR0.5 per watt nominal power.
In order to achieve this goal, the researchers will experiment with various nanomaterials and optical functional layers and refine the entire process chain. “The basic difficulty consists in adjusting the diffe- rent components to each other. A slight modification that improves the conductivity of one of the upper layers may, for example, have a negative impact on the current densities generated in the lower layers,” explains project coordinator, Dr. Aad Gordijn from Forschungszentrum Julich. The scientists in the Fast Track project aim to influence the optical and electronic properties even more effectively by ma- king use of nanocrystalline silicon dioxide – a novel “multiphase” material, whose solid structure displays greater degrees of freedom than pure silicon.
The project was launched on March 01, 2012 and will run until end of February 2015. Then, at the la- test, a new prototype should be available as a model for industrial production.
Lead-free Soldering for Electronics and Electricals
As of July 2006, EU guidelines have banned the use of lead solders, enforcing development of new joi- ning techniques in the area of electronic and micro-