The graphene family of 2D materials

Graphene is one of many crystals a few atoms thick. Hexagonal boron nitride is a flat insulator, monolayer MoS₂ a direct-gap semiconductor, phosphorene a p-type semiconductor with a puckered, anisotropic lattice, borophene a 2D metal and CrI₃ a magnet, and all of them can be stacked layer by layer into van der Waals heterostructures.

1. Graphene: A two-dimensional semimetal with a tiny overlap between valence and conduction bands and a strong ambipolar field effect (Novoselov et al. 2004). 2. hBN: Atomically smooth and relatively free of dangling bonds and charge traps, with a lattice constant similar to graphite’s and a large band gap; graphene on hBN is almost an order of magnitude better in mobility and carrier uniformity than on SiO₂ (Dean et al. 2010). 3. MoS₂: Thinned to one layer, the indirect gap rises by more than 0.6 eV and MoS₂ becomes a direct-gap semiconductor that emits light strongly (Mak et al. 2010); single-layer transistors with its 1.8 eV gap reached at least 200 cm²/V·s and on/off ratios of 10⁸ (Radisavljevic et al. 2011). 4. Phosphorene: A p-type semiconductor with a direct gap larger than bulk black phosphorus’s 0.31–0.36 eV; few-layer transistors showed hole mobilities of 286 cm²/V·s and on/off ratios up to 10⁴ (Liu et al. 2014). 5. Silicene and borophene: Both grown on silver: silicene, a buckled honeycomb predicted to carry Dirac-like electrons, on Ag(111) (Vogt et al. 2012); borophene, a highly anisotropic 2D metal, on silver under ultrahigh vacuum (Mannix et al. 2015). 6. CrI₃: A monolayer Ising ferromagnet with spins out of the plane and a Curie temperature of 45 K, against 61 K in the bulk crystal (Huang et al. 2017). 7. Stacks: Isolated atomic planes can be reassembled layer by layer in a chosen sequence into van der Waals heterostructures (Geim & Grigorieva 2013).

Geim & Grigorieva, “Van der Waals heterostructures”, Nature 2013 (doi:10.1038/nature12385); Dean et al., “Boron nitride substrates for high-quality graphene electronics”, Nat. Nanotechnol. 2010 (doi:10.1038/nnano.2010.172); Mak et al., “Atomically thin MoS2: a new direct-gap semiconductor”, Phys. Rev. Lett. 2010 (doi:10.1103/PhysRevLett.105.136805); Radisavljevic et al., “Single-layer MoS2 transistors”, Nat. Nanotechnol. 2011 (doi:10.1038/nnano.2010.279); Liu et al., “Phosphorene: an unexplored 2D semiconductor with a high hole mobility”, ACS Nano 2014 (doi:10.1021/nn501226z); Huang et al., “Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit”, Nature 2017 (doi:10.1038/nature22391); Novoselov et al., “Electric field effect in atomically thin carbon films”, Science 2004 (doi:10.1126/science.1102896); Vogt et al., “Silicene: compelling experimental evidence for graphenelike two-dimensional silicon”, Phys. Rev. Lett. 2012 (doi:10.1103/PhysRevLett.108.155501); Mannix et al., “Synthesis of borophenes: anisotropic, two-dimensional boron polymorphs”, Science 2015 (doi:10.1126/science.aad1080); Cahangirov et al., “Two- and one-dimensional honeycomb structures of silicon and germanium”, Phys. Rev. Lett. 2009 (doi:10.1103/PhysRevLett.102.236804).

Yes. Open it in the LabCanvas editor: all 37 layers are editable, including 6 generated objects (structures, plots, equipment) with their own settings. Change the text, colours and layout, then export PNG, TIFF, SVG or PDF.

Not to view it here. To open and edit it, sign in to LabCanvas or create a free account (the free plan keeps up to 3 designs). Downloading the figure is part of LabCanvas Pro (US$19 a month or US$199 a year).