Efficient Inorganic Vapor‐Assisted Defects Passivation for Perovskite Solar Module

Abstract Surface trap as intrinsic defects‐mediated non‐radiative charge recombination is a major obstacle to achieving the reliable fabrication of high‐efficiency and large‐area perovskite photovoltaics. Here a CS₂ vapor‐assisted passivation strategy is proposed for perovskite solar module, aiming to passivate the iodine vacancy and uncoordinated Pb²⁺ caused by ion migration. Significantly, this method can avoid the disadvantages of inhomogeneity film caused by spin‐coating‐assisted passivation and reconstruction of perovskite surface from solvent. The CS₂ vapor passivated perovskite device presents a higher defect formation energy (0.54 eV) of iodine vacancy than the pristine (0.37 eV), while uncoordinated Pb²⁺ is bonded with CS₂. The shallow level defect passivation of iodine vacancy and uncoordinated Pb²⁺ has obviously enhanced the device efficiencies (25.20% for 0.08 cm² and 20.66% for 40.6 cm²) and the stability, exhibiting an average T₈₀‐lifetime of 1040 h working at the maximum power point, and maintaining over 90% of initial efficiency after 2000 h at RH = 30% and 30 °C.