Find in Library

Abstract Nickel oxide (NiOx)‐based inverted perovskite solar cells stand as promising candidates for advancing perovskite photovoltaics towards commercialization, leveraging their remarkable stability, scalability, and cost‐effectiveness. However, the interfacial redox reaction between high‐valence Ni4+ and perovskite, alongside the facile conversion of iodide in perovskite into I2, significantly deteriorates the performance and reproducibility of NiOx‐based perovskite photovoltaics. Here, potassium borohydride (KBH4) is introduced as a dual‐action reductant, which effectively avoids the Ni4+/perovskite interface reaction and mitigates the iodide‐to‐I2 oxidation within perovskite film. This synergistic redox modulation significantly suppresses nonradiative recombination and increases the carrier lifetime. As a result, an impressive power conversion efficiency of 24.17% for NiOx‐based perovskite solar cells is achieved, and a record efficiency of 20.2% for NiOx‐based perovskite solar modules fabricated under ambient conditions. Notably, when evaluated using the ISOS‐L‐2 standard protocol, the module retains 94% of its initial efficiency after 2000 h of continuous illumination under maximum power point at 65 °C in ambient air.