As part of the joint development program between CEA and 3SUN on tandem perovskite-on-silicon solar cell technology, a new milestone has been achieved, setting a new efficiency record of 30.8% (*1).
This cell was developed in the CEA laboratories on the campus of the National Institute for Solar Energy (INES).
*1 This record was certified by an independent organization after shading correction.
The tandem architecture used by CEA and 3SUN for this record surpasses the theoretical efficiency limit of around 29% for conventional silicon technologies currently produced in photovoltaic gigafactories. Furthermore, while most international records are achieved on surfaces of 1 cm², CEA and 3SUN achieved this performance on a 9 cm² cell, which should facilitate scaling to industrial production.
This success highlights the strong potential of tandem perovskite-on-silicon photovoltaic cells, positioning them as a credible successor to current conventional silicon-based technologies. The perovskite layer in the tandem cell enhances light absorption by capturing higher-energy photons (in the ultraviolet and part of the visible spectrum), thereby improving the technology's efficiency potential.
In just one year of development, the teams at CEA and 3SUN achieved a 2.4 percentage point efficiency increase for this type of cell, rising from 28.4% in January 2024 to 30.8% in January 2025. Building on this impressive momentum, the research program between CEA and 3SUN will continue in 2025 and beyond, aiming to address the remaining challenges to enable mass production. Key areas of focus include scaling up to larger cell surfaces and improving their lifespan.
Improving the efficiency of photovoltaic cells—maximizing their ability to convert solar energy into electricity—is a critical goal for the industry. To illustrate the potential of this tandem technology, we can estimate the benefits of replacing current conventional technologies (cells with around 25–26% efficiency) in solar fields with tandem cells reaching 30–31% efficiency:
"We are very proud of this new record," says François Legalland, Director of the Laboratory for Innovation in New Energy Technologies and Nanomaterials (LITEN) at CEA. "Our partnership with 3SUN, a major European industrial player in the sector, is now over 10 years old and continues to thrive. We are consistently improving this record, proving that the dominance of photovoltaic module production by Asia is not inevitable. Research institutions and industrial players can still be competitive in Europe. This is excellent news for our industrial and energy sovereignty."
This breakthrough represents a significant step towards the large-scale production of Tandem solar cells. Due to their high performance, these cells are set to replace conventional silicon solar cells. In the coming years, this technology is expected to become the standard in the photovoltaic industry, overcoming the limitations of silicon-based cells." Stefano Lorenzi, Head of 3SUN, emphasizes that "this technological advancement is crucial for maintaining European competitiveness and promoting a more sustainable future."
About the CEA
The CEA is a major player in research, serving the State, the economy, and citizens. It provides concrete solutions to their needs in four main areas: energy transition, digital transition, technologies for the medicine of the future, and defense and security. With 20,000 employees and located at the heart of territories across 9 centers equipped with large-scale research infrastructures, the CEA benefits from a wide range of academic and industrial partners in France, Europe, and internationally. It ranks first among French research organizations for patent filings in France and Europe, according to the Clarivate ranking.
To learn more: www.cea.fr
About 3SUN
3SUN (Enel Group), located in Sicily, is the first European gigafactory with new production lines for high-efficiency heterojunction silicon photovoltaic panels. Its capacity will reach 3 GW and will include both cell production and panel assembly.
To learn more: www.3sun.com/en