Hope for the German solar industry: Researchers are finally competing with China

(Fraunhofer ISE)Researchers managed to produce a solar cell with 31.6 percent efficiency.

The next generation of photovoltaic technology is poised for a significant breakthrough: a new design for solar cells offers the potential for more efficient and sustainable use of solar energy.

As part of the “MaNiTU” lead project, six Fraunhofer Institutes conducted research over five years to make the technology of perovskite-silicon tandem solar cells marketable. The results show that high levels of efficiency can be achieved using industry-related processes and that sustainable solutions for the circular economy are possible.

Perovskite-silicon tandem solar cells are set to revolutionize the solar industry

Perovskite-silicon tandem solar cells combine two layers with different material properties to better exploit the solar spectrum. With an efficiency of over 30 percent for lead-containing perovskites, they significantly outperform conventional silicon solar cells. The aim of the project was to develop sustainable and scalable production processes that can bring this technology to market maturity.

A central focus of the project was on the development of industry-related processes. The researchers combined vapor deposition and wet chemical deposition to realize high-quality perovskite thin films on silicon cells. Efficiencies of 31.6 percent were achieved on a square centimeter of cell area. In parallel, the team researched alternative lead-free perovskite materials, but was unable to achieve sufficient efficiency.

The temperature sensitivity of the perovskite cells posed a further challenge. The front contact systems had to be manufactured at temperatures below 100 degrees Celsius, which the researchers solved using a novel combination of deposition and sputtering processes. These procedures are now to be put into practice with industrial partners.

“MaNiTU” project is a milestone for the European PV industry

An important aspect of the project is sustainability. Despite the use of lead-containing perovskites, the Fraunhofer Institutes developed recycling concepts to close the material cycle. This makes it possible to minimize the environmental impact and extend the life of the module. The results of the life cycle analysis show that tandem solar cells with comparable degradation rates and suitable recycling processes are a sustainable product.

The results of the “MaNiTU” project mark a milestone for the European photovoltaics industry. The combination of high efficiency, sustainable production processes and recyclability positions tandem solar cells as a key technology for the energy transition.

With a long-term efficiency target of 39.5 percent and the possibility of large-scale production of perovskite-silicon tandem solar cells, the Fraunhofer Society shows that Europe can continue to play a leading role in solar technology.