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 (0.54eV) of iodine vacancy than the pristine (0.37eV), 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 0.08cm2 and 20.66% for 40.6cm2 ) and the stability, exhibiting an average T80 -lifetime of 1040h working at the maximum power point, and maintaining over 90% of initial efficiency after 2000h at RH=30% and 30°C.