Efficient Near-Infrared-Transparent Perovskite Solar Cells Enabling Direct Comparison of 4‑Terminal and Monolithic Perovskite/Silicon Tandem Cells

Combining market-proven silicon solar cell technology with an efficient wide band gap top cell into a tandem device is an attractive approach to reduce the cost of photovoltaic systems. For this, perovskite solar cells are promising high-efficiency top cell candidates, but their typical device size (<0.2 cm²), is still far from standard industrial sizes. We present a 1 cm² near-infrared transparent perovskite solar cell with 14.5% steady-state efficiency, as compared to 16.4% on 0.25 cm². By mechanically stacking these cells with silicon heterojunction cells, we experimentally demonstrate a 4-terminal tandem measurement with a steady-state efficiency of 25.2%, with a 0.25 cm² top cell. The developed top cell processing methods enable the fabrication of a 20.5% efficient and 1.43 cm² large monolithic perovskite/silicon heterojunction tandem solar cell, featuring a rear-side textured bottom cell to increase its near-infrared spectral response. Finally, we compare both tandem configurations to identify efficiency-limiting factors and discuss the potential for further performance improvement