General synthesis of two-dimensional van der Waals heterostructure arrays.

Two-dimensional van der Waals heterostructures (vdWHs) have attracted considerable interest1–4. However, most vdWHs reported so far  are created by an arduous micromechanical exfoliation and manual restacking process5, which—although versatile for proof-of-concept demonstrations6–16 and fundamental studies17–30—is clearly not scalable for practical technologies. Here we report a general synthetic strategy for two-dimensional vdWH arrays between metallic transition-metal dichalcogenides (m-TMDs) and semiconducting TMDs (s-TMDs). By selectively patterning nucleation sites on monolayer or bilayer s-TMDs, we precisely control the nucleation and growth of diverse m-TMDs with designable periodic arrangements and tunable lateral dimensions at the predesignated spatial locations, producing a series of vdWH arrays, including VSe2/WSe2, NiTe2/WSe2, CoTe2/WSe2, NbTe2/WSe2, VS2/WSe2, VSe2/MoS2 and VSe2/WS2. Systematic scanning transmission electron microscopy studies reveal nearly ideal vdW interfaces with widely tunable moire superlattices. With the atomically clean vdW interface, we further show that the m-TMDs function as highly reliable synthetic vdW contacts for the underlying WSe2 with excellent device performance and yield, delivering a high ON-current density of up to 900 microamperes per micrometre in bilayer WSe2 transistors. This general synthesis of diverse two-dimensional vdWH arrays provides a versatile material platform for exploring exotic physics and promises a scalable pathway to high-performance devices. A general strategy for the synthesis of two-dimensional van der Waals heterostructure arrays is used to produce high-performance electronic devices, showing the potential of this scalable approach for practical technologies.