Perovskite–silicon tandem solar modules with optimised light harvesting

Perovskite–silicon tandem solar cells are potentially attractive, inexpensive solutions to surpass the power conversion efficiency limits of market-leading silicon solar cells. While such tandem solar cells have been demonstrated to reach high efficiencies, they require advanced light management to utilise the solar spectrum efficiently. Moreover, area upscaling with minimal optical losses is necessary to transfer the properties of lab scale devices to commercial scale products. Here, we demonstrate four-terminal perovskite–silicon tandem solar modules with efficient light management. With rigorous optical simulations of the complete tandem stack, we design light management concepts that minimise overall reflection and enhance complementary absorption of the subcells. The optical optimisation results in four-terminal tandem power conversion efficiencies of 25.3% on 0.13 cm2 and 23.9% on 4 cm2, both exceeding the stand-alone silicon solar cell power conversion efficiency of 23.0%.