Atomically-precise synthesis and simultaneous integration of 2D transition metal dichalcogenides enabled by nano-confinement

TL;DR

This paper presents a nano-confinement method using graphene or hBN layers to precisely synthesize and integrate 2D transition metal dichalcogenides with atomic accuracy, enabling high-quality, air-sensitive heterostructures.

Contribution

It introduces a nano-confined growth technique that achieves atomic-precision synthesis and clean integration of 2D TMDs with tailored morphologies and interfaces.

Findings

Successful synthesis of monolayer TMDs with controlled morphology

Creation of intrinsically-patterned TMD rings

Enhanced superconductivity in nano-confined NbSe2 monolayers

Abstract

Two-dimensional (2D) materials, such as graphene, transition metal dichalcogenides (TMDs), and hBN, exhibit intriguing properties that are sensitive to their atomic-scale structures and can be further enriched through van der Waals (vdW) integration. However, the precise synthesis and clean integration of 2D materials remain challenging. Here, using graphene or hBN as a vdW capping layer, we create a nano-confined environment that directs the growth kinetics of 2D TMDs (e.g., NbSe2 and MoS2), enabling precise formation of TMD monolayers with tailored morphologies, from isolated monolayer domains to large-scale continuous films and intrinsically-patterned rings. Moreover, Janus S-Mo-Se monolayers are synthesized with atomic precision via vdW-protected bottom-plane chalcogen substitution. Importantly, our approach simultaneously produces ultraclean vdW interfaces. This in situ encapsulation reliably preserves air-sensitive materials, as evidenced by the enhanced superconductivity of nano-confined NbSe2 monolayers. Altogether, our study establishes a versatile platform for the controlled synthesis and integration of 2D TMDs for advanced applications.