Technologies for highest PV efficiencies

Visualization of the “Center for High Efficiency Solar Cells” on the campus of Fraunhofer ISE in Freiburg. The foundation stone of the new building was laid in October 2017.

Center for High Efficiency Solar Cells

In the “Center for High Efficiency Solar Cells”, we evaluate technologies with which highest PV efficiency values can be achieved, and implement them at the uppermost international level. Applications for high efficiency solar cells include not only conventional solar modules but also power supplies for satellites, electric vehicles, autonomous sensors and electronic devices. Fraunhofer ISE holds several world records in the high efficiency solar cell sector, such as the record efficiency value for multicrystalline silicon (22.3 %), but also the absolute efficiency record of 46.1 %, based on a III-V multi-junction cell architecture.

In order to advance this top position still further, we laid the foundation stone for a new laboratory building in 2017, which will contain clean-room laboratories with equipment suitable for meeting future technological challenges. In the new “Center for High Efficiency Solar Cells”, advanced PV technology can be tested and optimized in state-of-the-art laboratories with a floor area exceeding 1000 m2. Research will be conducted there on innovative processes and technology for future application in industry. In addition to further development of silicon and III-V technology, one focus of the new center is on the combination of these two materials: High efficiency silicon-based tandem cells represent one of the most promising photovoltaic technologies. With the new laboratory, Fraunhofer ISE intends to develop path-breaking new solar cell types and technology also in the future, and to contribute to making the German photovoltaic industry internationally competitive.

Technical Facilities

Flexibly usable clean-room laboratory in future with 740 m²

Further laboratory areas of 340 m²

High-temperature diffusion (BBr3, POCl3)

High-temperature oxidation (dry and moist)

Ion implantation (P, B, H, Ga, Si)

Wet-chemical processes for purification and structuring

Yellow-light zone for photolithography and laser lithography to create microstructures with bifacial alignment

Wafer-bonding technology

Plasma technology (PECVD and etching)

Atomic layer deposition (ALD)

Processing of wafer dimensions up to 157 x 157 mm2

Thermal and electron-beam evaporation of metals and dielectric layers

Galvanic metallization

Extensive instrumentation for characterizing materials and components