A Universal Interfacial Dipole Strategy for Defect Suppression in Inverted Perovskite Solar Cells With Tunable Bandgaps

ABSTRACT Perovskite solar cells (PSCs) experience significant photovoltage losses due to nonradiative recombination, especially in p–i–n devices with Fullerene C 60 as the electron transport layer (ETL), which limits device performance. To tackle this issue, we propose a strategy that synergistically suppresses nonradiative recombination at the perovskite/C 60 interface by employing a 2D heterointerface with a two‐site anchor bridge, which reduces the surface defect density. This process elevates the fermi level and enhances the electric field, facilitating electron extraction at the perovskite/C 60 heterointerface. As a result, nonradiative recombination at this electron‐selective perovskite contact is greatly suppressed. p–i–n PSCs fabricated using this interface engineering approach achieved a power conversion efficiency (PCE) of 26.32% and demonstrated excellent stability under continuous maximum power point tracking, along with an open‐circuit voltage (Voc) of 1.217 V. This broadly applicable and scalable approach further delivers an impressive V oc of up to 1.368 V in wide‐bandgap (1.8 eV) devices. Overall, the strategy offers a viable pathway toward efficient and stable inverted PSCs, demonstrating broad compatibility with diverse perovskite compositions.