Telecommunication satellites are demanding ever-increasing power for new technologies. This makes ever-more efficient and lightweight solar generators a must for full electric propulsion satellite platforms.
AZUR SPACE, German-based company and European leader for multi-junction solar cells, rose to the challenge of developing and qualifying a new cell to meet this rapidly evolving brief. With the support of the ARTES C&G programme, the ‘4G32C’ solar cell has trumped AZUR’s own best-selling product as the first upright metamorphic 4J (4 junction) cell on the market for high end-of-life efficiency in geostationary orbit applications.
Satellite on-board systems require a continuous power supply for the whole lifetime of the satellite. But space is an extreme environment and satellites are exposed to strong, high-energy electron and proton beams, X-ray radiation and cosmic rays for more than 15 years.
Electric orbit raising also involves encountering intense particle irradiation (involving several trips through the Van Allen belt) – creating a demand for solar cells with even higher radiation hardness or ‘resilience’.
High performance, lightweight and cost-effective solar generators are therefore necessary to keep overheads low. For the solar cell, this translates into high end-of-life (EOL) efficiency, low weight and low production costs.
AZUR’s space-qualified 3G30C-Advanced cell is currently a best-in-class product already providing the world’s highest EOL efficiencies. But with the support of the ARTES C&G programme AZUR have now improved on this state-of-the-art technology; as Evelyne Simon, Technical Officer at ESA explains:
“The 4G32C is AZUR’s next generation product, based upon a four-junction upright metamorphic solar cell structure and implements AZUR’s proprietary radiation-hard cell design, achieving extraordinary EOL efficiencies.”
She continues: “The new product provides a similar interface to the current product while exceeding the power output of all previous products, not only at ‘beginning-of-life’ but especially also at ‘end-of-life’. This product secures AZUR SPACE’s leadership position on the space solar cells market.”
The project was not without challenges, however, involving the handling and processing of fragile and curved cells. The implementation of AZUR’s proprietary radiation-hardening design was also a major task during the project. But as Wolfgang Guter, Director of Technology, AZUR SPACE points out: “The most demanding task facing the team was the transfer of all the processes into a production environment with high throughput and high yield. We are very happy with the help of ARTES to have succeeded.”
He adds: “At high fluences (energy radiation levels) and even at beginning-of-life this novel cell clearly exceeds the already excellent performance of the 3G30C-Advanced product. It especially outshines all past solar cell designs on the market for satellite EOL.”
About AZUR SPACE
Based on more than 55 years of experience in space solar cells and more than 25 years in
III-V epitaxial technology, including development and high volume production, AZUR SPACE is the global leader in the development and production of multi-junction solar cells for space and terrestrial concentrated photovoltaic applications.