Four-Terminal Perovskite/Perovskite/Silicon Triple-Junction Tandem Solar Cells with over 30% Power Conversion Efficiency

The first four-terminal perovskite/perovskite/silicon triple-junction tandem solar cells are reported, with the device structure comprising a perovskite single-junction top cell and monolithic perovskite/silicon tandem bottom cell, yielding a 31.5% power conversion efficiency. Key to this result was the hole-transporting-layer engineering of the top cell, which led to enhanced performance and reproducibility of the 1 cm(2) semitransparent inverted perovskite solar cells.