Efficient Inorganic Vapor‐Assisted Defects Passivation for Perovskite Solar Module

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 CS 2 vapor‐assisted passivation strategy is proposed for perovskite solar module, aiming to passivate the iodine vacancy and uncoordinated Pb 2+ 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 CS 2 vapor passivated perovskite device presents a higher defect formation energy (0.54 eV) of iodine vacancy than the pristine (0.37 eV), while uncoordinated Pb 2+ is bonded with CS 2 . The shallow level defect passivation of iodine vacancy and uncoordinated Pb 2+ has obviously enhanced the device efficiencies (25.20% for 0.08 cm 2 and 20.66% for 40.6 cm 2 ) and the stability, exhibiting an average T 80 ‐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.