TY - JOUR
T1 - Effects of Moisture-Based Grain Boundary Passivation on Cell Performance and Ionic Migration in Organic-Inorganic Halide Perovskite Solar Cells
AU - Hoque, Md Nadim Ferdous
AU - He, Rui
AU - Warzywoda, Juliusz
AU - Fan, Zhaoyang
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/9/12
Y1 - 2018/9/12
N2 - Because of the polycrystalline nature, grain boundaries (GBs) in hybrid perovskite thin films play critical roles in determining the charge collection efficiency of perovskite solar cells (PSCs), material stability, and in particular the ion migration, considering their relatively soft ionic bonds with low formation energy. Different GB passivation methods are being studied, and introducing PbI2-rich phase at GBs in methylammonium lead iodide (MAPbI3) has been found to be useful. In this study, combining macroscale measurements with tip-based microscopic probing that includes scanning Kelvin probe microscopy for surface potential mapping and conductive atomic force microscopy for charge transport mapping, we revealed the effects of PbI2-rich phase at GBs, which was introduced in moisture-assisted synthesis of MAPbI3 thin films. It was found that PbI2 passivation of GBs could change the surface potential and charge carrier screening and significantly retard current conduction at the GB while enhancing conduction through the grain interior. Inhibition of ion migration at GBs, as well as enhanced PSC device performance, is reported.
AB - Because of the polycrystalline nature, grain boundaries (GBs) in hybrid perovskite thin films play critical roles in determining the charge collection efficiency of perovskite solar cells (PSCs), material stability, and in particular the ion migration, considering their relatively soft ionic bonds with low formation energy. Different GB passivation methods are being studied, and introducing PbI2-rich phase at GBs in methylammonium lead iodide (MAPbI3) has been found to be useful. In this study, combining macroscale measurements with tip-based microscopic probing that includes scanning Kelvin probe microscopy for surface potential mapping and conductive atomic force microscopy for charge transport mapping, we revealed the effects of PbI2-rich phase at GBs, which was introduced in moisture-assisted synthesis of MAPbI3 thin films. It was found that PbI2 passivation of GBs could change the surface potential and charge carrier screening and significantly retard current conduction at the GB while enhancing conduction through the grain interior. Inhibition of ion migration at GBs, as well as enhanced PSC device performance, is reported.
KW - conductive atomic force microscopy
KW - contact potential difference
KW - grain boundaries
KW - ion migration
KW - passivation
KW - perovskite
KW - scanning Kelvin probe microscopy
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U2 - 10.1021/acsami.8b08981
DO - 10.1021/acsami.8b08981
M3 - Article
C2 - 30118195
AN - SCOPUS:85052857808
SN - 1944-8244
VL - 10
SP - 30322
EP - 30329
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 36
ER -