General synthesis of two-dimensional van der Waals heterostructure arrays

Two-dimensional van der Waals heterostructures (vdWHs) have attracted considerable interest 1 , 2 , 3 , 4 . However, most vdWHs reported so far  are created by an arduous micromechanical exfoliation and manual restacking process 5 , which—although versatile for proof-of-concept demonstrations 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 and fundamental studies 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 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 VSe 2 /WSe 2 , NiTe 2 /WSe 2 , CoTe 2 /WSe 2 , NbTe 2 /WSe 2 , VS 2 /WSe 2 , VSe 2 /MoS 2 and VSe 2 /WS 2 . Systematic scanning transmission electron microscopy studies reveal nearly ideal vdW interfaces with widely tunable moiré superlattices. With the atomically clean vdW interface, we further show that the m-TMDs function as highly reliable synthetic vdW contacts for the underlying WSe 2 with excellent device performance and yield, delivering a high ON-current density of up to 900 microamperes per micrometre in bilayer WSe 2 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.