摘要
Environment-friendly protic amine carboxylic acid ionic liquids(ILs)as solvents is a significant breakthrough with respect to traditional highly coordinating and toxic solvents in achieving efficient and stable perovskite solar cells(PSCs)with a simple one-step air processing and without an antisolvent treatment approach.However,it remains mysterious for the improved efficiency and stability of PSCs without any passivation strategy.Here,we unambiguously demonstrate that the three functions of solvents,additive,and passivation are present for protic amine carboxylic acid ILs.We found that the ILs have the capability to dissolve a series of perovskite precursors,induce oriented crystallization,and chemically passivate the grain boundaries.This is attributed to the unique molecular structure of ILs with carbonyl and amine groups,allowing for strong interaction with perovskite precursors by forming C=O…Pb chelate bonds and N-H…I hydrogen bonds in both solution and film.This finding is generic in nature with extension to a wide range of IL-based perovskite optoelectronics.
基金
This work was financially supported by the Natural Science Foundation of China(Grants 51972172,61705102,and 91833304)
the Natural Science Basic Research Plan in Shaanxi Province of China(2019JM-326)
the Young 1000 Talents Global Recruitment Program of China
the Fundamental Research Funds for the Central Universities
This work also was financially supported by the National Key Research and Development Program of China(grant no.2017YFA0403400).
