Electron Microscopy Techniques in Two-Dimensional Materials

Two-dimensional materials present a platform where every atomic displacement and defect can profoundly influence electronic, optical and catalytic performance. Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM), especially when combined with aberration correction, now routinely achieve sub-Ångström resolution, permitting direct visualisation of individual atoms. In situ approaches—such as heating, gas or liquid cell environments—capture real-time structural evolution under stimuli, while spectroscopic modes like electron energy loss spectroscopy (EELS) provide chemical and bonding information at the atomic scale. These capabilities have unveiled cation diffusion pathways, edge reconstructions and phase transformations in van der Waals materials, as well as enabled the fabrication of size-quantised nanopores. Coupled with advanced image analysis and machine learning, modern electron microscopy not only characterises but also drives controlled modifications in two-dimensional systems, paving the way for atom-scale engineering of next-generation devices.

Research from Nature Portfolio

Recent studies have employed time-resolved STEM to capture atomistic cation diffusion and surface reconstruction in layered van der Waals compounds, revealing how in-plane migration of Ge and Bi leads to non-centrosymmetric triple-layer formations. In situ temperature-controlled STEM has directly imaged edge evolution and chemically driven phase transitions in transition-metal dichalcogenide monolayers, demonstrating programmable access to metastable edge configurations with distinct magnetic and catalytic properties. Separately, conventional TEM has been harnessed to fabricate individual triangular nanopores in hexagonal boron nitride with atomic precision, establishing controllable pore geometries suited to molecular sensing, filtration and water desalination applications.

Research from all publishers

Advances in beam-driven defect manipulation have shown atom-by-atom control of silicon dopants in graphene, enabling directed trajectories around hexagonal rings and real-time feedback detection of manipulation events. Deep-learning frameworks applied to dynamic STEM data have automated the rapid classification of defect types and mapped phase evolution in WS₂, yielding quantitative insights into sulfur vacancy diffusion and dopant–vacancy interactions. Comprehensive reviews of defect engineering strategies tie electron-beam irradiation protocols to tailored electronic and optoelectronic functionalities in two-dimensional materials, underscoring the critical role of controlled defect populations for device performance.

Electron Microscopy Techniques in Two-Dimensional Materials publication trend

The graph below shows the total number of articles in electron microscopy techniques in two-dimensional materials across all publications each year (not limited to Nature Index journals).

Technical terms

Scanning transmission electron microscopy (STEM): A mode of TEM in which a focused electron probe is scanned across the sample to form high-resolution images and spectra.

Aberration correction: Optical adjustments in electron lenses that compensate for distortions, enabling sub-Ångström spatial resolution.

In situ imaging: Observation of structural or chemical changes within the microscope under controlled environments (temperature, gas, liquid).

Electron energy loss spectroscopy (EELS): Spectroscopic technique measuring energy losses of transmitted electrons to reveal elemental composition and bonding.

Van der Waals gap: The weakly bonded interlayer space in layered materials, critical for diffusion and reconstruction studies.

Point defect: A localized disruption in a crystal lattice, such as a vacancy or single-atom substitution, that can alter material properties.

References

1. Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps. Nature Communications (2023).
2. In situ edge engineering in two-dimensional transition metal dichalcogenides. Nature Communications (2018).
3. Fabrication of Subnanometer-Precision Nanopores in Hexagonal Boron Nitride. Scientific Reports (2017).
4. Electron-Beam Manipulation of Silicon Dopants in Graphene. Nano Letters (2018).
5. Deep learning analysis of defect and phase evolution during electron beam-induced transformations in WS2. npj Computational Materials (2019).
6. Defect Engineering in 2D Materials: Precise Manipulation and Improved Functionalities. Research (2019).