Fig. 5: New opportunities in vdW-integrated heterostructures and superlattices beyond 2D materials.

a, A MESFET structure using one-step vdW integration of pre-fabricated metal electrodes with distinct work functions, resulting in a low Schottky barrier (SB) (source, S, and drain, D) and a large Schottky barrier (gate, G) through a single integration step. b, c, Schematic illustration of a vdW-integrated ferromagnetic (FM)/semiconductor junction (b) and a superconductor/insulator/superconductor junction (c) for coherent charge injection in quantum electronic devices. The defect- and pinning-free interface could considerably reduce interface disorder and the associated scattering that plague such devices. d, Heterostructure integration of n-GaN/p-WSe₂/n-GaN vdW structure (B, base; C, collector; E, emitter) for high performance heterojunction bipolar transistor by replacing p-GaN with p-type WSe₂. e, Schematic illustration of a vdW heterostructure (vdW metal, blue; stretchable semiconductor, red) with distinct stiffness under mechanical compression (bottom) and tension (top). The bonding-free vdW interaction allows two contacting materials to slide against each other and effectively release the local strain at the interface. f, g, Plug-and-probe vdW integration, where a complex structure (for example, source drain contacts and a gate stack) is pre-fabricated on wafer scales. Every time used, one piece of the structure is cut from the mother wafer and laminated on the target material within a few seconds for directly probing its intrinsic properties.