Four-junction solar cell
© Fraunhofer ISE
Four-junction solar cell by Fraunhofer ISE

The world’s most efficient solar cell

Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg have successfully increased the efficiency of the best four-junction solar cell to date from 46.1 to 47.6 percent at a concentration of 665 suns. This is a global milestone, as there is currently no solar cell with a higher efficiency worldwide.

It is thanks to improved antireflection layers that the efficiency of the best four-junction solar cell to date improved from 46.1 to 47.6 percent.

How did the ISE researchers manage to achieve this result?

„Each individual layer of the complex multi-junction solar cell undergoes further optimization. Improvements in the process technology are incorporated for metal contacts and antireflection layers“, it says in a press release by ISE, published on 30 May 2022.

To get to know ISE and the „50 Percent“ project, which aims at developing a solar cell with 50 percent efficiency for the first time, go here.


The Fraunhofer-Gesellschaft is the leading organization for applied research in Europe. Its research activities are conducted by 76 institutes and research institutions at locations throughout Germany, among them over 17 are located in Baden-Württemberg.

The Fraunhofer Institute for Solar Energy Systems in Freiburg, Baden-Württemberg, with a staff of around 1400, is the largest solar research institute in Europe. The Institute creates the technological foundations for supplying energy efficiently and on an environmentally sound basis in industrialized, threshold and developing countries.

Click here to get an overview of all research institutions in the German Southwest.

Additional tip for students:

Check out the Master Program of Solar Energy Engineering at the University of Freiburg.

Additional information for researchers:

To find open research positions in the field of environmental technologies in the German Southwest, use our job search.

Author: Leonie Rörich