Surface Passivation Suppresses Local Ion Motion in Halide Perovskites.
J Phys Chem Lett
; 14(26): 6092-6098, 2023 Jul 06.
Article
em En
| MEDLINE
| ID: mdl-37364056
ABSTRACT
We use scanning probe microscopy to study ion migration in formamidinium (FA)-containing halide perovskite semiconductor Cs0.22FA0.78Pb(I0.85Br0.15)3 in the presence and absence of chemical surface passivation. We measure the evolving contact potential difference (CPD) using scanning Kelvin probe microscopy (SKPM) following voltage poling. We find that ion migration leads to a â¼100 mV shift in the CPD of control films after poling with 3 V for only a few seconds. Moreover, we find that ion migration is heterogeneous, with domain interfaces leading to a larger CPD shift than domain interiors. Application of (3-aminopropyl)trimethoxysilane (APTMS) as a surface passivator further leads to 5-fold reduction in the CPD shift from â¼100 to â¼20 mV. We use hyperspectral microscopy to confirm that APTMS-treated perovskite films undergo less photoinduced halide migration than control films. We interpret these results as due to a reduction in the halide vacancy concentration after APTMS passivation.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
J Phys Chem Lett
Ano de publicação:
2023
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Article