Monolithic Perovskite-Perovskite-Silicon Triple-Junction Tandem Solar Cell with an Efficiency of over 20%

Here we report a monolithic perovskite-perovskite-silicon triple-junction tandem solar cel l with an efficiency of over 20%, an open-circuit voltage of 2.74 V, and a fill factor of 86%, which are the highest values for double-or triple-junction perovskite-based tandems reported to date. The concept and design presented here are an important milestone toward low-cost triple-junction tandem photovoltaics.