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Updated: Jul 10, 2025
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Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography
Published on: March 12, 2017
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Direct imaging of electron density with a scanning transmission electron microscope.
Ondrej Dyck1, Jawaher Almutlaq2, David Lingerfelt3
1Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA. dyckoe@ornl.gov.
Nature Communications
|November 20, 2023
Summary
Secondary electron e-beam-induced current (SEEBIC) imaging reveals electron density in WSe2 layers at the atomic scale. Observed contrasts challenge existing models, highlighting the need for advanced understanding of electron emission for future material analysis.
Area of Science:
- Materials Science
- Surface Science
- Condensed Matter Physics
Background:
- Secondary electron (SE) emission in scanning transmission electron microscopes can probe material properties at atomic resolution.
- Techniques like secondary electron e-beam-induced current (SEEBIC) offer potential for nanoscale characterization.
Purpose of the Study:
- To apply SEEBIC imaging to a stacked 2D heterostructure to map electron density.
- To investigate atomic-scale contrast in WSe2 using SEEBIC.
Main Methods:
- Application of the secondary electron e-beam-induced current (SEEBIC) imaging technique.
- Utilizing a stacked 2D heterostructure device with an encapsulated WSe2 layer.
Main Results:
- Spatially resolved electron density of the encapsulated WSe2 layer was revealed.
- The double Se lattice site exhibited higher emission than the W site.
- Observed contrast contradicted first-principles modeling of isolated WSe2 clusters.
Conclusions:
- Atomic-level SEEBIC contrast within a single material is achievable.
- Enhanced understanding of atomic-scale SE emission is necessary to explain observed contrasts.
- SEEBIC holds potential for revealing subtle information on interlayer bonding and electron orbitals.
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