EPFL and CSEM have achieved 30.02% efficiency for a triple-junction solar cell using silicon and perovskite layers
This is an improvement over the previous certified efficiency of 27.1% achieved by the NUS
The team was able to achieve efficiency gains by improving voltage in the top perovskite cell, boosting current in the middle cell, and adding nanoparticles to enhance light absorption
Researchers from Switzerland’s École polytechnique fédérale de Lausanne (EPFL) along with the Swiss Center for Electronics and Microtechnology (CSEM), have announced achieving 30.02% solar cell power conversion efficiency for a triple-junction tandem solar cell.
This configuration comprises a silicon bottom cell with perovskite thin-films deposited on the middle and top layers. The team shows this is an improvement over the 13% efficiency it initially achieved in 2018, and exceeds the previously certified record of 27.1% achieved by the National University of Singapore (NUS).
The researchers were able to increase the efficiency level by focusing on 2 limitations of triple-junction solar cells: low voltage in the top perovskite cell and low current generation in the middle cell.
To address these challenges, they added a molecule to guide perovskite crystal formation, which helped eliminate defects. As a result, the top cell was able to create a higher voltage of 1.4 V under sunlight. They also developed a 3-step method to fabricate a middle cell that improved light absorption in the near-infrared part of the solar spectrum.
The addition of nanoparticles between the bottom silicon cell and the middle perovskite cell further boosted the current by reflecting additional sunlight into the middle cell.
“We show that with clever design and processing, we can approach performance levels traditionally reserved for the most expensive III–V multi-junction solar cells used in space, which are composed of multiple semiconductor layers,” said Kerem Artuk, the First Author of the research and an EPFL PhD Graduate now working with CSEM.
“These can reach up to 37% efficiency, and cost around 1,000 times more than terrestrial cells per watt. Our approach opens the door to a new generation of industrially viable, high-efficiency multi-junction photovoltaics,” added Artuk.
“By demonstrating that low-cost perovskite materials can approach the performance of the most advanced space-grade photovoltaics, this research sets a new benchmark for multi-junction photovoltaics,” stated EPFL Team Leader Christian Wolff.
Funded by the likes of Fraunhofer ISE, University of Freiburg, Empa, and University of Queensland, among others, the research is now published in the Nature journal under the title Triple-junction solar cells with cyanate in ultrawide-bandgap perovskites.
On April 22, 2026, TaiyangNews will host the maiden edition of its Virtual Conference on Next-Generation PV Technology 2026. The event will bring together key stakeholders working on silicon-perovskite tandem technologies. Registrations for the event are free and open here.