From Lab to Fab: World Record Solar Cell Goes from Lab to Industry
In the HySPRINT lab at HZB, the team of Steve Albrecht developed a perovskite technology which can now be combined with mass produced silicon solar cells by QCELLS to make highly efficient tandem cells. © Amran Al-Ashouri/HZB
Q CELLS and Helmholtz-Zentrum Berlin achieve a new world record efficiency for a 2-terminal tandem solar cell combining a mass-production ready silicon bottom cell based on Q.ANTUM technology and a top-cell based on perovskite technology. The efficiency is 28.7%.
Q CELLS, a renowned total energy solutions provider in solar, energy storage, downstream project business and energy retail, has set a new world-record tandem cell efficiency of 28.7% in collaboration with researchers at Helmholtz-Zentrum Berlin using a Q.ANTUM-based silicon bottom cell in combination with a perovskite-based top cell.
Q CELLS’ R&D team in Thalheim, Germany, has worked jointly with Helmholtz-Zentrum Berlin over the past three years to create a tandem solar cell comprising a silicon-based Q.ANTUMbottom cell and a perovskite-based top cell. This latest record efficiency result of 28.7% is an improvement of almost one percent point compared with the 2020 record value of 27.8 % (which was independently verified by the Fraunhofer ISE Callab). This boost in tandem efficiency has been enabled by improvement of both the perovskite and the silicon sub cells. The research and development was partly funded by the German Federal Ministry for Economic Affairs and Climate Action (BMWK) and the state of Saxony-Anhalt.
While the solar research community has witnessed even higher perovskite-tandem cell efficiencies, these records have been achieved using lab technology that is not directly transferrable into mass production. The achievement of Q CELLS and Helmholtz-Zentrum Berlin is noteworthy principally because the 28.7% efficiency was reached using an industry feasible and cost-efficient bottom cell structure based on the Q.ANTUM technology.
In the past year, Q CELLS announced that it is to boost its R&D investment in Germany to €125 million over the next three years. A sizeable portion of that figure is earmarked for the continuous support of Q CELLS’ R&D department on the commercialization of perovskite-silicon tandem technology.
“Our experts have achieved several world records for tandem cells combining perovskite top cells with other bottom cells on a laboratory scale. We promote knowledge and technology transfer and welcome the fruitful collaboration with Q CELLS. It is remarkable how close the jointly achieved efficiency with a mass production ready bottom cell already comes to what we can reach at a lab scale”, Prof. Dr. Bernd Rech, scientific director of HZB said.
Prof. Dr. Steve Albrecht, group leader at HZB and Juniorprofessor at Technische Universität Berlin added: “It is highly exciting that we enable this high tandem efficiency utilizing industry relevant bottom cells with a high market share, so there might be fast impact of the tandem technology to revolutionize the PV market.”
Dr. Daniel Jeong, CTO of Q CELLS, said: “Q CELLS is excited to announce this joint new world-record in tandem cell efficiency together with Helmholtz-Zentrum Berlin. Both teams of researchers have collaborated closely to develop a tandem cell technology, which would be able to accelerate the commercialization process and, ultimately, deliver to the industry a genuine leap forward in photovoltaic performance. Q CELLS is confident that it can once again shape the next-generation of solar cells, and will continue to invest heavily in supporting research and development in this field.”
About Q CELLS
Q CELLS is one of the world’s largest and most recognized photovoltaic manufacturers for its high-performance, high-quality solar cells and modules. It is headquartered in Seoul, South Korea (Global Executive HQ) and Thalheim, Germany (Technology & Innovation HQ) with its diverse international manufacturing facilities in the U.S., Malaysia, China, and South Korea. Q CELLS offers the full spectrum of photovoltaic products, applications and solutions, from cells and modules to kits to systems to large-scale solar power plants. Through its growing global business network spanning Europe, North America, Asia, South America, Africa and the Middle East, Q CELLS provides excellent services and long-term partnerships to its customers in the utility, commercial, governmental and residential markets. For more information, visit: www.q-cells.com.
- Imaging Ellipsometry for Process Control of Thin-Film DevicesA German–Israeli research team led by Dr. Andreas Furchner has demonstrated how imaging ellipsometry enables non-destructive characterisation and quality control of microstructured MXene thin films during device fabrication. The authors used two complementary ellipsometry approaches for precise, multi-scale access to key material properties. The work positions imaging ellipsometry as a powerful platform for monitoring thin-film uniformity, device integrity, and functionality throughout processing, including critical lithographic steps. The study was published in Applied Physics Letters and selected as an Editor’s Pick.
- Cool vaccines in rural Kenya: solar solution has been awarded by UNIn May 2026, Tabitha Awuor Amollo is spending some weeks as a guest scientist at HZB, analysing perovskite thin films at BESSY II. The Kenyan physicist from Egerton University, Nairobi, was recently recognised for her achievements in research and teaching. For the development of a solar-powered refrigeration system for use in rural health centres, she has been awarded the 2026 Organization for Women in Science for the Developing World (OWSD)-Elsevier Foundation Award. An interview on exceptional projects and daily struggles of a scientist. Questions were asked by Antonia Rötger.
- BESSY II: How intrinsic oxygen shortens the lifespan of solid-state batteriesAlthough solid-state batteries (SSBs) demonstrate high performance and are intrinsically safe, their capacity currently declines rapidly. A team from the TU Wien, Humboldt-University Berlin and HZB has now analysed a TiS₂|Li₃YCl₆ solid-state half-cell in operando at BESSY II using a special sample environment that allows for non-destructive investigation under real operating conditions. Data obtained by combination of soft and hard X-ray photoelectron spectroscopy (XPS and HAXPES) revealed a new degradation mechanism that had not previously been identified in solid-state batteries. They have gained some surprising insights, particularly regarding the harmful role played by intrinsic oxygen. This study provides valuable information for improving design and handling of such batteries.