Researchers from King Abdullah University of Science and Technology (KAUST) recently achieved a landmark breakthrough in renewable energy technology. The Saudi Arabian team collaborated with Delft University of Technology and LMU Munich to enhance perovskite-silicon tandem solar cells. Consequently, they demonstrated that controlling nanoscale surface roughness at the recombination layer can boost energy performance to 33.2%.
This milestone significantly exceeds the 29.5% certified efficiency record that Oxford PV researchers established only one year ago in 2024. Tandem cells differ from traditional single-mineral photovoltaic cells because they combine two distinct materials to capture more sunlight effectively. While traditional silicon panels usually reach 23% efficiency, perovskite materials offer exceptional light absorption and much higher charge-carrier mobility.
Furthermore, perovskite films utilize low-cost solution-based methods like inkjet printing rather than the energy-intensive purification required for standard silicon. The research team focused specifically on the silicon bottom cell, which researchers often overlook despite its critical role in performance.
Engineering the Nanoscale Surface
The study found that “nanoroughness” on the bottom cell directly influences perovskite crystallization and the overall quality of the interface. By applying plasma treatments to nanocrystalline silicon layers, the engineers successfully improved electrical contact and reduced significant energy recombination losses.
Erkan Aydin, the co-corresponding author, explained the technical impact of this discovery to industry reporters during a recent interview. “The key novelty lies in demonstrating that we can deliberately engineer nanoroughness to improve the performance of tandem solar cells,” Aydin said. He noted that this strategy requires no new materials, making it highly compatible with existing silicon manufacturing routes.
The International Energy Agency reports that solar electricity costs fell by 82% over the last decade due to manufacturing improvements. Therefore, the introduction of perovskite technology could accelerate this downward price trend while making solar installations more affordable globally.
Stefaan De Wolf, another lead author, emphasized that the KPV-lab now aims to bring these emerging technologies to the market. “We work on single, dual, and triple-junction configurations to tailor PV cell technologies for deployment in hot, sunny climates,” De Wolf added. This innovation provides a vital design parameter for the next generation of high-efficiency, commercial-grade solar power modules.
