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  • Technical Review
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Probing charge density in materials with atomic resolution in real space

Nature Reviews Physics volume 5, pages 117–132 (2023)Cite this article

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Abstract

The charge distribution in materials at the nanoscale can often explain the origin of macroscopic properties such as localized conductivity or the plasmonic response and illuminate more fundamental changes in the microscopic structure such as changes in chemical bonding characteristics. Previously, direct visualization of the charge density with high spatial resolution was often a missing link in the formation of structure–property relationships, especially in heterogeneous materials systems. However, recent advancements in microscopy technology have enabled researchers to visualize the charge distribution in materials down to subatomic length scales. In this Technical Review, we discuss the developments in high-resolution real-space charge distribution imaging using diffraction techniques and electron microscopy, with a focus on the recent advancement of four-dimensional scanning transmission electron microscopy, electron holography, and applications to materials interfaces.

Key points

  • Real-space charge density imaging can provide key insights into the electronic properties of a material that are unavailable with other methods.

  • Transmission electron microscopy can provide high spatial resolution charge images through various methods.

  • Quantum crystallography and quantitative convergent beam electron diffraction can reveal the charge distribution in uniform structures with unparalleled accuracy and spatial resolution.

  • Phase-retrieval methods provide more direct ways to reveal the charge distribution in heterogeneous materials at atomic resolution in real space.

  • Continued development of both microscopy hardware and data analysis techniques will further enhance charge density imaging methods and expand our understanding of materials.

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Fig. 1 : X-ray and electron scattering.
Fig. 2: Quantitative convergent beam electron diffraction.
Fig. 3: 4D scanning transmission electron microscopy and holography.
Fig. 4: Applications to 2D materials.
Fig. 5: Applications to semiconductors.
Fig. 6: Applications to oxide interfaces.

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Acknowledgements

This work was supported primarily by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under grant number DE-SC0014430, and partially by the National Science Foundation under grant number DMR-2034738.

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Authors and Affiliations

  1. Department of Physics and Astronomy, University of California, Irvine, CA, USA

    Christopher Addiego & Xiaoqing Pan

  2. Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, USA

    Wenpei Gao

  3. Department of Materials Science and Engineering, University of California, Irvine, CA, USA

    Huaixun Huyan & Xiaoqing Pan

  4. Irvine Materials Research Institute, University of California, Irvine, CA, USA

    Xiaoqing Pan

  5. Center for Complex and Active Materials, University of California, Irvine, CA, USA

    Xiaoqing Pan

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  1. Christopher Addiego
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Addiego, C., Gao, W., Huyan, H. et al. Probing charge density in materials with atomic resolution in real space. Nat Rev Phys 5, 117–132 (2023). https://doi.org/10.1038/s42254-022-00541-4

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