Fig. 4: Schematics of state-of-the-art vdW-integrated electronic and optoelectronic devices.

a, 2D/2D planar transistor with a 2D semiconductor as the channel (MoS₂, yellow and black), a 2D dielectric (BN, blue) as the encapsulation layer and a 2D metallic material (graphene, red) as the contact electrodes. b, 2D/2D vdW magnetic vertical tunnelling junctions, with atomically thin CrI₃ (blue) as a spin-filter tunnel barrier and graphene (red colour) as the contact electrodes. GMR, giant magnetoresistance. c, 0D/2D photodiode created by vdW integration of quantum dots or plasmonic nanoparticles (blue) on top of graphene (red) without damaging the pristine graphene lattice, thus providing greatly enhanced photocurrent. d, 1.5D/2D top-gate FET based on the vdW integration of a 1.5D Al₂O₃ nanoribbon (as the dielectric; blue) on top of graphene (red) without damage in its pristine lattice. e, 1D/2D high-speed transistor obtained by vdW-integrating a 1D core–shell nanowire (as a self-aligned mask, blue) to enable the construction of 2D transistors (graphene, red) with high cut-off frequency. f, 2D/0D high-order superlattice obtained by intercalating 0D molecules (blue) into a 2D material (phosphorene, red), resulting in a stable superlattice with radically different constituents and tunable interlayer distances or band offset. g, 2D/3D tunnelling transistor constructed using 2D MoS₂ (blue and black) and 3D Ge (red). The vdW integration of MoS₂ enables the creation of an electronically abrupt junction for high-efficiency electron tunnelling, and 3D germanium provides well controlled doping density and the desired electron affinity for ultra-small subthreshold swing. h, 3D/3D vdW integration enables the creation of damage-free metal contacts (blue) on delicate perovskite (red), with much more efficient charge transport than that achieved with deposited contacts.