Atomic Resolution Imaging of Halide Perovskites

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Halide perovskites are promising materials for various applications but are highly sensitive to electron radiation.
• This radiation sensitivity has historically prevented detailed atomic-scale structural investigations using electron microscopy.

Purpose of the Study:

• To overcome the limitations of radiation damage in studying halide perovskites at the atomic level.
• To achieve quantitative, atom-column-resolved structural determination of ultrathin two-dimensional (2D) CsPbBr₃ perovskites.

Main Methods:

• Application of low dose-rate in-line holography, combining aberration-corrected high-resolution transmission electron microscopy (HRTEM).
• Utilized exit-wave reconstruction to retrieve phase information from the electron wave function.
• Quantitative structure determination performed atom column by atom column.

Main Results:

• Successfully obtained the genuine atomic structure of ultrathin 2D CsPbBr₃ halide perovskites.
• Achieved quantitative structural determination without inducing electron beam-induced sample alterations.
• Enabled unambiguous analysis of coexisting high-temperature and low-temperature phases within single CsPbBr₃ particles due to high image quality.

Conclusions:

• The developed low-dose holographic technique effectively overcomes radiation sensitivity issues in halide perovskites.
• This approach provides unprecedented opportunities for atomic-level understanding of halide perovskites and other radiation-sensitive materials.
• Enables detailed structural analysis critical for optimizing material properties and applications.