Epitaxial Growth of Two-Dimensional Transition Metal Dichalcogenides

The epitaxial growth of two-dimensional transition metal dichalcogenides (TMDs) has emerged as a pivotal strategy for producing atomically thin semiconductors with controlled orientation, uniform thickness and large domain sizes. By depositing TMD layers directly onto crystalline substrates under well-controlled conditions, researchers can exploit the registry between the lattice of the substrate and the emerging TMD film. This registry promotes unidirectional alignment of islands, seamless stitching of domains and reduction of grain boundaries, which in turn enhance electronic mobility, optical uniformity and device reproducibility. Techniques such as chemical vapour deposition, metal–organic chemical vapour deposition and atomic layer epitaxy have been adapted to balance lateral and vertical growth, tailor precursor fluxes and engineer interfacial layers. Central to this endeavour is an understanding of substrate symmetry, lattice mismatch and van der Waals interactions, which collectively determine the nucleation density, edge propagation and eventual film quality. Progress in this field promises wafer-scale fabrication of monolayer and multilayer TMDs for next-generation electronics, optoelectronics and flexible devices.

Research from Nature Portfolio

Recent studies have demonstrated wafer-scale epitaxy of monolayer MoS₂ through interfacial buffer-layer engineering on c-plane sapphire, achieving unidirectional domain alignment and seamless stitching across a two-inch wafer. The resulting films exhibit high phonon circular dichroism, strong exciton valley polarisation and room-temperature mobilities exceeding 140 cm² V⁻¹ s⁻¹, with on/off ratios above 10⁹. A complementary approach has revealed a universal methodology for non-centrosymmetric TMD epitaxy by synchronising grain nucleation with atomic-step formation on various oxide substrates; this method achieves unidirectional alignment of MoS₂, WS₂, MoSe₂, WSe₂ and related alloys on sapphire, MgO and TiO₂ planes, pointing towards a general mechanism for large-area single crystals. Another advancement exploits templated growth of monolayer TMD ribbons on high-Miller-index Au facets, where step edges guide the formation of aligned MoS₂, WS₂ and quaternary alloys; these ribbons merge into inch-scale single-crystal films via one-dimensional edge epitaxy, underscoring an alternative pathway to uniform large-area TMD films.

Epitaxial Growth of Two-Dimensional Transition Metal Dichalcogenides publication trend

The graph below shows the total number of articles in epitaxial growth of two-dimensional transition metal dichalcogenides across all publications each year (not limited to Nature Index journals).

Technical terms

Epitaxy: Oriented growth of a crystalline film on a crystalline substrate, guided by lattice alignment.

Two-dimensional materials: Atomically thin layers with strong in-plane bonds and weak interlayer interactions.

Transition metal dichalcogenides: Layered compounds of the form MX₂, where M is a transition metal and X is a chalcogen, exhibiting semiconductor behaviour in monolayer form.

Chemical vapour deposition (CVD): A process that delivers gaseous precursors to a heated substrate to grow thin films.

Van der Waals epitaxy: Growth of layered materials on substrates with weak interfacial forces, allowing lattice mismatch tolerance.

Substrate symmetry: Crystallographic orientation of the substrate surface that influences the nucleation and orientation of the overlying film.

References

1. The epitaxy of 2D materials growth. Nature Communications (2020).
2. Epitaxy of wafer-scale single-crystal MoS2 monolayer via buffer layer control. Nature Communications (2024).
3. Universal epitaxy of non-centrosymmetric two-dimensional single-crystal metal dichalcogenides. Nature Communications (2023).
4. Epitaxial growth of inch-scale single-crystal transition metal dichalcogenides through the patching of unidirectionally orientated ribbons. Nature Communications (2022).
5. Layer-by-layer epitaxy of multi-layer MoS2 wafers. National Science Review (2022).
6. Ultrafast growth of large single crystals of monolayer WS2 and WSe2. National Science Review (2020).
7. Growth-Etch Metal–Organic Chemical Vapor Deposition Approach of WS2 Atomic Layers. ACS Nano (2020).