Scalable two-terminal all-perovskite tandem solar modules with a 19.1% efficiency

Monolithic all-perovskite tandem photovoltaics promise low-cost, high-efficiency solar energy harvesting with thin-film advantages. This work reports laser-scribed all-perovskite tandem modules processed exclusively with scalable fabrication methods (blade coating and vacuum deposition), achieving power conversion efficiencies up to 19.1% on a 12.25 cm² aperture area with a 94.7% geometric fill factor and stable power output. Compared with spin-coated reference tandem cells (23.5% efficiency, 0.1 cm²), these prototypes demonstrate substantial advances in technological readiness. Electroluminescence imaging and laser-beam-induced current mapping show homogeneous current collection in both subcells over the entire module area, explaining the low losses (<5%) in open-circuit voltage and fill factor for the scalable modules.