Germany’s Institute for Solar Energy Research Hamelin (ISFH) has announced that its Calibration and Test Center (CalTeC) now offers calibration services for large-area perovskite-silicon tandem solar cells. The expanded capability supports devices up to the G12 wafer format (210 × 210 mm), addressing the growing need for reliable efficiency measurements as tandem technologies move from lab-scale research to commercial development.
According to ISFH, the new calibration approach addresses key challenges specific to tandem devices, including subcell-specific spectral adjustment, spectral mismatch correction, shading effects from contact grids, irradiance non-uniformity across large areas, and temperature control. The measurement protocols also take into account metastability effects.
“Tandem solar cells are much more complex than conventional silicon cells. Specialized calibration is needed to ensure that reported efficiencies are accurate, comparable, and trusted,” said Karsten Bothe, head of the ISFH CalTeC solar cell calibration laboratory.
ISFH notes that scaling tandem cells from small-area devices (around 1 cm²) to wafer-scale formats introduces significant metrology challenges, requiring dedicated calibration methodologies alongside advances in device fabrication.
ISFH CalTeC has been accredited for calibrating wafer-based silicon solar cells since 2016 and has provided services to over 70 companies in 20 countries. Since 2018, it has also been authorized to independently verify PV conversion efficiencies, including multiple world-record silicon solar cell results.
