Group claims CPV efficiency record

The Fraunhofer Institute for Solar Energy (ISE), Soitec, CEA-Leti and the Helmholtz Center Berlin have developed a solar cell based on space technology with 44.7% efficiency, which they claim to be a new world record.

The cell is designed for use in concentrating PV (CPV), a technology that achieves more than twice the efficiency of conventional PV power plants in sun-rich locations, Fraunhofer says.

“This four-junction solar cell contains our collected expertise in this area over many years. Besides improved materials and optimisation of the structure, a new procedure called wafer bonding plays a central role,” says Frank Dimroth, project leader at Fraunhofer ISE in charge of the development.

“With this technology, we are able to connect two semiconductor crystals, which otherwise cannot be grown on top of each other with high crystal quality.”

The scientists use a so-called III-V multi-junction solar cell in the development, originally developed out of space-industry technology.

The CPV modules are produced by Soitec, a manufacturing spin-off of Fraunhofer ISE.

Soitec has CPV installations in 18 countries around the world.

Leti is an institute of CEA, a French research and technology organization. The Heimholtz Zentrum Berlin is  part of the Technical University of Ilmenau.