Lead carboxylates passivation for metre-scale perovskite solar modules

Environmentally sensitive ammonium halides have emerged as indispensable surface passivators for perovskite solar cells, demonstrating broadly effective performance at the laboratory scale^1-4. However, the sensitivity of ammonium halides to humidity typically necessitates operation under an inert atmosphere⁵. Coupled with the heterogeneous distribution of passivators during large-area slot-die coating, applying such surface treatment techniques to the fabrication of metre-scale perovskite solar modules (PSMs) under ambient conditions remains challenging. Here we instead use chemically stable lead carboxylates as passivators on perovskite films engineered to have a naturally formed formamidinium iodide (FAI)-enriched surface by means of a high-saturated vapour pressure (SVP) solvent system (2-methoxyethanol (2-Me), 1,3-dioxolane (DOL) and dimethyl sulfoxide (DMSO)). By treating the tailored surface with lead dioleate (Pb(OA)₂) to enhance carrier transport and surface passivation, we fabricated PSMs that achieved certified efficiencies of 24.0% (aperture area of 810 cm²) and 22.0% (total area 0.72 m²) and passed all International Electrotechnical Commission (IEC) 61215 reliability tests. These results represent the highest reported performance for scalable, industrially viable perovskite photovoltaics (PVs).