Raman Spectroscopy of Two-Dimensional Materials

Raman spectroscopy has emerged as an indispensable tool for characterising two-dimensional materials—atomically thin crystals such as graphene and transition-metal dichalcogenides—through the inelastic scattering of monochromatic light by vibrational modes. This non-destructive technique provides detailed information on lattice symmetry, chemical composition, strain, doping level and temperature, all of which influence the position, intensity and width of Raman peaks. High-frequency intralayer modes probe covalent bonding and electronic band structure, while low-frequency interlayer shear and breathing modes sensitively report on van der Waals coupling, stacking order and layer number. Resonant and double-resonant Raman processes further illuminate phonon–electron interactions and intervalley scattering pathways, offering insights into exciton–phonon coupling and bandgap transitions. The versatility of Raman spectroscopy extends from fundamental studies of moiré superlattices and twistronics to rapid, large-area quality control during growth and device fabrication. Its global impact is evident in advancing electronics, photonics and energy applications by guiding material synthesis, heterostructure assembly and scalable production of two-dimensional devices.

Research from Nature Portfolio

Recent studies have demonstrated precise control of twist angles in bilayer MoS2 grown by chemical vapour deposition, enabling systematic observation of moiré periodicity effects on interlayer coupling and associated shifts in low-frequency Raman modes. Investigations of double-resonance Raman scattering in monolayer and bulk MoS2 have elucidated how excitation-energy-dependent phonon signatures arise from specific acoustic phonons and intervalley electronic transitions, clarifying the mechanisms of valley depolarisation. Furthermore, the development of a comprehensive first-principles library of resonant Raman spectra covering hundreds of two-dimensional monolayers now allows rapid, automated identification of material composition and structural phase from experimental spectra, bridging theory and experiment for high-throughput analysis.

Raman Spectroscopy of Two-Dimensional Materials publication trend

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

Technical terms

Raman spectroscopy: Optical technique measuring inelastic scattering of monochromatic light to characterise vibrational and low-frequency modes in materials.

Two-dimensional materials (2DMs): Atomically thin crystals, such as graphene, MoS2 and WS2, exhibiting pronounced anisotropy and tunable electronic, optical and mechanical properties.

Double-resonance Raman scattering: A higher-order Raman process involving two phonons or an intervalley electronic transition, sensitive to excitation wavelength and crystal symmetry.

Moiré superlattice: A periodic interference pattern formed when two similar lattices are overlaid with a twist angle, altering electronic band structures and phonon modes.

Interlayer shear and breathing modes: Low-frequency phonon modes corresponding to relative lateral sliding and perpendicular motion of adjacent layers in van der Waals materials.

References

1. Precise control of the interlayer twist angle in large scale MoS2 homostructures. Nature Communications (2020).
2. Intervalley scattering by acoustic phonons in two-dimensional MoS2 revealed by double-resonance Raman spectroscopy. Nature Communications (2017).
3. A library of ab initio Raman spectra for automated identification of 2D materials. Nature Communications (2020).
4. Application of Raman spectroscopy to probe fundamental properties of two-dimensional materials. npj 2D Materials and Applications (2020).
5. Large‐Scale Mapping of Moiré Superlattices by Hyperspectral Raman Imaging. Advanced Materials (2021).
6. Mapping of Low-Frequency Raman Modes in CVD-Grown Transition Metal Dichalcogenides: Layer Number, Stacking Orientation and Resonant Effects. Scientific Reports (2016).