Enhanced Bandgap Flexibility in Perovskite-Silicon Tandem Solar Cells via Three-Terminal Architecture.

Monolithic perovskite/silicon tandem photovoltaics are among the most promising high-efficiency technologies for next-generation photovoltaics. However, the commercial development of two-terminal (2T) tandem configurations is limited by their operational instability of wide-bandgap perovskite materials, which leads to current mismatch and increased sensitivity to solar spectral variations. Three-terminal (3T) tandem architectures offer a viable route to address these limitations. Here, we demonstrate the real-world advantages of 3T perovskite/silicon tandem solar cells in mitigating current mismatch limitations and losses arising from solar spectral variations. Our 3T tandem solar cells achieve a power conversion efficiency of 30.1%, integrating a front-side textured interdigitated back contact (IBC) and poly-Si on oxide contact (POLO) silicon bottom cell. This is one of the highest efficiencies reported for 3T tandem solar cells so far. Through a direct comparison of 2T and 3T tandem configurations enabled by a novel measurement framework, we reveal that 3T architectures decouple performance from perovskite bandgap constraints, alleviating the need for the current matching. Additionally, 3T tandem solar cells exhibit enhanced spectral resilience under varying solar spectra when the top cell limits the short-circuit current. These findings underscore the potential of 3T architectures for stable and efficient tandem photovoltaics under real-world operating conditions.