A new material for solar cells consisting of copper-zinc-germanium-selenide can make solar panels generate even more energy. That is the conclusion of the European research project SWInG from IMO-IMOMEC, the integrated research institute of UHasselt and imec. “We could integrate this new material for solar cells as a second layer on top of the existing silicon layer of the solar panels. This means that the solar panels generate even more energy," says Prof. Bart Vermang. This research project was carried out within EnergyVille.


"The current generation of silicon solar panels achieve a maximum energy efficiency of around 25 percent," says Prof. Bart Vermang. “And that is very close to the theoretical limit of a solar panel. If we want to extract even more energy from a panel, then we have to look for new techniques and materials."

In the European SWInG project, which ran within EnergyVille, they searched for a material that could be placed as a second solar cell on top of the existing silicon solar panels. By placing this "tandem" of solar cells on top of each other, panels can generate even more energy. "We have been looking for the best material for such a second solar cell for some time, but the current materials all have flaws," explains Bart Vermang. “They are either not efficient enough, unstable, too scarce, or too expensive. That is why we have developed a new material ourselves consisting of copper, zinc, germanium and selenide. The germanium can also be replaced by silicon."

World record efficiency

The results of this new material for solar cells are excellent, says Bart Vermang: “Not only is this a very stable material that is sufficiently available and not too expensive, but after three years of research we have also achieved a world record efficiency of 8.4% with our prototype. That is unseen and, if adjustments are made to the solar cell structure, this material placed as a second layer above the silicon solar panels could increase the efficiency of solar panels beyond that theoretical limit of 30 percent.”

The results of this research are now published in the scientific journal Sustainable Energy & Fuels. “We are very proud of this research that we worked on together with a whole team of institutions, including UGent. Companies will also be able to work with these results. During our research we also worked closely with the Swedish solar energy company Midsummer. Hopefully companies will be able to apply this technology in the production process of solar panels, "says Bart Vermang. This research project received European funding of 3,250,000 euros.

New research: solar panels as windows

“Thanks to these great results, we have now been able to start a new European research project: Tech4Win. "In this project we want to develop transparent solar panels," says Bart Vermang. “This involves solar panels that are as transparent as a glass window, so they could be perfectly integrated into buildings. These panels will capture the ultraviolet and infrared solar rays - invisible to the human eye - and convert them into green electricity. ”In three years we hope to have the first prototypes ready. This is a European project of 3 million euros as well.

You can read the full article on the tandem cells here.

More info:

Bart Vermang (IMO-IMOMEC/EnergyVille): 0474 24 27 35



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These projects have received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 640868 (SWInG) and No 826002 (Tech4Win).

bart vermang


Bart Vermang

Professor UHasselt, visiting professor imec