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In CH 3 NH 3 PbI 3 Perovskite Film, the Surface Termination Layer Dominates the Moisture Degradation Pathway
Author(s) -
Lu Yue,
Si Zhixiang,
Liu Hongpeng,
Ge Yang,
Hu Jingcong,
Zhang Zeyu,
Mu Xulin,
Selvakumar Karuppaiah,
Sui Manling
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202003121
Subject(s) - perovskite (structure) , degradation (telecommunications) , chemical engineering , materials science , moisture , dissociation (chemistry) , crystallite , molecule , layer (electronics) , decomposition , humidity , inorganic chemistry , chemistry , nanotechnology , organic chemistry , composite material , metallurgy , telecommunications , physics , computer science , engineering , thermodynamics
Theoretical studies have shown that surface terminations, such as MAI or PbI layers, greatly affect the environmental stability of organic–inorganic perovskite. However, until now, there has been little effort to experimentally detect the existence of MAI or PbI terminations on MAPbI 3 grains, let alone disclose their effects on the humidity degradation pathway of perovskite solar cell. Here, we successfully modified and detected the surface terminations of MAI and PbI species on polycrystalline MAPbI 3 films. MAI‐terminated perovskite film followed the moisture degradation process from MAPbI 3 to hydrate MAPbI 3 ⋅H 2 O and then into PbI 2 , with penetration of water molecules being the main driving force leading to the degradation of MAPbI 3 layer by layer. In contrast, for the PbI‐terminated perovskite film in a humid atmosphere, a deprotonation degradation pathway was confirmed, in which the film preferentially degraded directly from MAPbI 3 into PbI 2 , here the iodine defects played a key role in promoting the dissociation of water molecules into OH − and further catalyzing the decomposition of perovskite.