Atomic Layer Deposition of Transition Metal Dichalcogenides

Atomic layer deposition (ALD) of transition metal dichalcogenides (TMDCs) offers unprecedented control over film thickness, composition and uniformity at the atomic scale. By exploiting sequential, self-limiting surface reactions, ALD enables the conformal growth of ultrathin layers on wafer-scale and three-dimensional substrates. TMDCs such as molybdenum disulfide (MoS₂), tungsten diselenide (WSe₂) and related alloys display layer-dependent bandgaps, high carrier mobilities and strong light–matter interactions, making them prime candidates for next-generation electronics, optoelectronics, flexible devices and electrocatalysts. The low-temperature variants of ALD, including plasma-enhanced processes, broaden the range of compatible substrates and allow direct integration with temperature-sensitive materials. Recent advances have focused on refining precursor chemistry, tailoring plasma conditions and exploiting self-limiting growth modes to achieve precise stoichiometry, polycrystallinity or single-crystal domains as required by specific applications. The global significance of this work lies in its potential to unlock scalable fabrication routes for two-dimensional devices, bridging the gap between laboratory-scale demonstrations and industrial implementation.

Research from Nature Portfolio

An early demonstration of self-limiting layer synthesis (SLS) via ALD achieved atomic-scale control of MoS₂ thickness across wafer-scale substrates. In this process, the number of layers is determined by thermodynamic equilibrium rather than pulse count, yielding uniform monolayer and few-layer films with more than 90% coverage. The high crystalline quality films, characterised by spectroscopic and microscopic techniques, supported top-gated field-effect transistors exhibiting on/off current ratios exceeding 10⁸. The same SLS approach was extended to fabricate MoS₂/WSe₂ heterostructures, in which gate-tunable rectifying diodes demonstrated the versatility of ALD for creating atomically abrupt van der Waals interfaces.

Atomic Layer Deposition of Transition Metal Dichalcogenides publication trend

The graph below shows the total number of articles in atomic layer deposition of transition metal dichalcogenides across all publications each year (not limited to Nature Index journals).

Technical terms

Atomic layer deposition (ALD): A thin film technique based on sequential, self-limiting surface reactions to achieve atomic-scale thickness control and conformal coverage.

Transition metal dichalcogenide (TMDC): A layered material composed of a transition metal sandwiched between two chalcogen atoms, exhibiting tunable electronic and optical properties when thinned to a few layers or monolayer.

Plasma-enhanced atomic layer deposition (PEALD): A variant of ALD that uses plasma to activate or modify precursors, enabling lower deposition temperatures and improved film crystallinity or composition control.

Self-limiting layer synthesis: An ALD growth mode in which layer number is governed by thermodynamic equilibrium rather than precursor dose, allowing precise monolayer control independent of pulse cycles.

Stoichiometry: The ratio of elements in a compound, critical in TMDCs for defining electronic band structure and charge-transport properties.

References

1. Self-Limiting Layer Synthesis of Transition Metal Dichalcogenides. Scientific Reports (2016).
2. Large-area synthesis of high electrical performance MoS2 by a commercially scalable atomic layer deposition process. npj 2D Materials and Applications (2023).
3. Toolbox of Advanced Atomic Layer Deposition Processes for Tailoring Large-Area MoS2 Thin Films at 150 °C. ACS Applied Materials & Interfaces (2023).
4. Atomic Layer Deposition of Large-Area Polycrystalline Transition Metal Dichalcogenides from 100 °C through Control of Plasma Chemistry. Chemistry of Materials (2022).