High Efficiency for Resource Efficiency in the Energy Transition
“Our vision is to build a more efficient and environmentally friendly photovoltaic industry in Europe. We also believe that the results of our work will significantly transform other sectors of the III-V semiconductor industry and contribute to greater sustainability, particularly if hundreds of tons of GaAs can be saved each year.”
Objectives
The goal of the project is to develop highly efficient photovoltaic modules based on ultra-thin III-V multi-junction solar cells that combine economic viability, environmental sustainability, and maximum efficiency.
As part of the project, researchers aim to create, for the first time, a III-V multi-junction solar cell detached from its substrate, with a thickness of just three micrometers (0.003 mm), that achieves an efficiency of over 35% without light concentration. For its fabrication, approximately 20 individual steps are being developed—ranging from the substrate through epitaxy and metallization to anti-reflective coatings—which must be optimally coordinated with one another.
The production technology is being further developed so that it is not only suitable for small areas but also enables scaling up to the gigawatt production level. To this end, equipment and processes are being developed for high-rate epitaxy as well as for the fabrication of contacts and anti-reflective coatings without the need for cleanroom processes.
Expensive single crystals (e.g., made of germanium), onto which the solar cell layers are deposited, are intended to be detached during the process and reused multiple times. This conserves valuable resources and makes the solar cells significantly more cost-effective.
If successfully implemented, the project will not only represent a significant advance in photovoltaic research, but will also open up the prospect of establishing a new, internationally competitive photovoltaic industry in Europe, characterized by significantly higher module efficiencies.
At the same time, the cell processes developed are to be used in the latest generation of concentrating solar modules (micro-CPV), in which sunlight is concentrated many times over. The aim is to demonstrate that this technology represents a particularly environmentally friendly option for solar power generation in sun-rich regions. The electricity generated can then be converted into hydrogen or other chemical energy carriers, for example through electrolysis.
To this end, the micro-CPV modules and their manufacturing processes are being adapted to the new thin-film solar cells. In addition, smaller, sun-tracking systems are being set up to gather comprehensive data on performance and reliability.
