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Updated: Aug 5, 2026

Facile Synthesis of Colloidal Lead Halide Perovskite Nanoplatelets via Ligand-Assisted Reprecipitation
Published on: October 1, 2019
Ligand-Enabled Chemical-Potential Modulation of A-Site Cation Reactivity Stabilizes Tin Halide Perovskite
1School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
None:
Tin halide perovskite nanocrystals offer a lead‑free platform for optoelectronics, but their practical use is severely hampered by rapid oxidation degradation. However, conventional strategies that strength Sn2+ participation and stability inevitably face a trade-off between lattice Sn vacancies (VSn) formation and surface Sn2+ exposure. Here, we move beyond Sn2+-centric strategies to an A-site reactivity regulation strategy. By selectively suppressing A-site cation reactivity, Sn2+ efficiently incorporates during their crystallization, thereby simultaneously suppressing VSn formation and lowering surface Sn2+ exposure. Using CsSnBr3 nanocrystal as model system, this strategy enables precise control over product composition and crystallization kinetics, yielding nanocrystal films can preserve > 92% of the perovskite phase and 81% of initial emission after 60 h of air exposure. Ligand exchange experiment decouples the surface and lattice effect, confirming the dominant role of lattice VSn in determining air stability. Extending this strategy to CsSnCl3, FASnBr3 and CsSnI3 nanocrystals demonstrated its generality across A/X‑site chemistries. This work establishes a new strategy to control vacancy formation and surface redox processes. The ligand-enabled chemical-potential modulation provides a general and predictive means to access this control.
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