Atomic-Scale Polarization and Strain at the Surface of Lead Halide Perovskite Nanocrystals

Shulin Chen, Jiayi Wang, Simil Thomas, Wasim J. Mir, Bingyao Shao, Jianxun Lu, Qingxiao Wang, Peng Gao, Omar F. Mohammed, Yu Han, Osman M. Bakr*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Inorganic halide perovskite nanocrystals (NCs) are being widely explored as next-generation optoelectronic materials. Critical to understanding the optoelectronic properties and stability behavior of perovskite NCs is the material’s surface structure, where the local atomic configuration deviates from that of the bulk. Through low-dose aberration-corrected scanning transmission electron microscopy and quantitative imaging analysis techniques, we directly observed the atomic structure at the surface of the CsPbBr3 NCs. CsPbBr3 NCs are terminated by a Cs−Br plane, and the surface Cs−Cs bond length decreases significantly (∼5.6%) relative to the bulk, imposing compressive strain and inducing polarization, which we also observed in CsPbI3 NCs. Density functional theory calculations suggest such a reconstructed surface contributes to the separation of holes and electrons. These findings enhance our fundamental understanding of the atomic-scale structure, strain, and polarity at the surface of inorganic halide perovskites and provide valuable insights into designing stable and efficient optoelectronic devices.

Original languageEnglish (US)
Pages (from-to)6002-6009
Number of pages8
JournalNano Letters
Volume23
Issue number13
DOIs
StatePublished - Jul 12 2023

Keywords

  • inorganic halide perovskites
  • low-dose TEM
  • polarization
  • surface strain
  • surface structure

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering

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