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 scale1-4. 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).