Two-Dimensional Materials and Van der Waals Heterostructures

Two-dimensional (2D) materials are crystalline sheets one or a few atoms thick, characterised by strong in-plane covalent bonds and weak out-of-plane van der Waals forces. Beginning with graphene, the family of 2D materials has rapidly grown to include transition metal dichalcogenides (TMDs), hexagonal boron nitride, black phosphorus, 2D magnets and topological insulators. These atomically thin crystals exhibit distinctive mechanical flexibility, high carrier mobility, tunable bandgaps and strong light–matter interactions. By stacking individual 2D layers in a chosen order, researchers create van der Waals heterostructures in which each sheet retains its intrinsic properties while interlayer coupling gives rise to emergent phenomena such as moiré superlattices, interfacial superconductivity and engineered exciton dynamics. The modularity of van der Waals assembly enables bespoke design of electronic, photonic and energy‐conversion devices. Key challenges include scalable synthesis, precise control over layer orientation and twist angle, defect management and integration into complex architectures for real‐world applications.

Research from Nature Portfolio

Recent studies have advanced both synthesis methods and fundamental understanding of 2D materials. One investigation developed a microwave‐assisted strategy to transform bulk MoS₂ into free‐standing molybdenene whiskers. These metallic 2D sheets, millimetres in length, exhibited electrical conductivities of about 940 S m⁻¹ and, when hybridised with h-BN or MoS₂ layers, showed tunable optical and electronic properties. Practical demonstrations included surface-enhanced Raman sensing platforms and scanning probe cantilevers. Another report introduced a gold-assisted exfoliation technique that exploits strong adhesion between Au and layered crystals to isolate high-quality monolayers from over 40 material systems, including elemental sheets, TMDs, magnets and superconductors. The method yielded millimetre-scale, contamination-free monolayers and vertical heterojunctions, enabling large-area studies of fundamental properties and device prototypes.

Two-Dimensional Materials and Van der Waals Heterostructures publication trend

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

Technical terms

Two-dimensional materials: Crystals one or a few atomic layers thick, held together by in-plane covalent bonds and weak interlayer van der Waals forces.

Van der Waals heterostructure: A stack of distinct 2D layers assembled by van der Waals interactions, enabling new interfacial electronic and optical phenomena.

Mechanical exfoliation: A top-down method for isolating monolayers or few-layer flakes from bulk crystals, often using adhesive tapes or metal films.

Transition metal dichalcogenides (TMDs): Layered compounds (e.g. MoS₂, WS₂) with semiconducting bandgaps, strong spin–orbit coupling and valley-selective physics.

Dirac materials: Systems in which charge carriers mimic massless Dirac fermions, characterised by linear energy–momentum dispersion and high mobility.

References

1. Microwave synthesis of molybdenene from MoS2. Nature Nanotechnology (2023).
2. Mechanism of Gold-Assisted Exfoliation of Centimeter-Sized Transition-Metal Dichalcogenide Monolayers. ACS Nano (2018).
3. Recent progress in the synthesis of novel two-dimensional van der Waals materials. National Science Review (2021).
4. 2D materials: increscent quantum flatland with immense potential for applications. Nano Convergence (2022).