Synergistic Redox Modulation for High‐Performance Nickel Oxide‐Based Inverted Perovskite Solar Modules
Yan Liu, Bin Ding, Gao Zhang, Xintong Ma, Yao Wang, Xin Zhang, Lirong Zeng, Mohammad Khaja Nazeeruddin, Guan‐Jun Yang, Bo Chen
Abstract
Abstract Nickel oxide (NiO x )‐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 Ni 4+ and perovskite, alongside the facile conversion of iodide in perovskite into I 2 , significantly deteriorates the performance and reproducibility of NiO x ‐based perovskite photovoltaics. Here, potassium borohydride (KBH 4 ) is introduced as a dual‐action reductant, which effectively avoids the Ni 4+ /perovskite interface reaction and mitigates the iodide‐to‐I 2 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 NiO x ‐based perovskite solar cells is achieved, and a record efficiency of 20.2% for NiO x ‐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.