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Graphene

C

Also called monolayer graphene, single-layer graphene

van der Waals crystal semimetal

The material that started the field: a single sheet of carbon atoms that conducts electricity and heat exceptionally well, is nearly transparent, and is the strongest material ever measured. It cannot switch fully off the way a silicon transistor must, so its realistic future is in sensors, photonics, heat spreading and composites rather than in logic chips.

Crystal structure

  • C
Cell
Hexagonal, a = 2.46 Å
Atoms per cell
2
C–C bond
1.42 Å
Height
Flat: one atomic plane
Each carbon atom bonds to three neighbours, and the bonds close into hexagons. The dashed outline is one unit cell. It holds two atoms, one on each of the two triangular sublattices, A and B. Lattice constant 2.46 Å, the in-plane value of graphite.

What it looks like

A pale violet flake with several stepped regions of different shade, on a tan background, with a scale bar of 10 micrometres.
A flake peeled from graphite and pressed onto an oxidised silicon wafer, in an optical microscope. The shade changes in steps with the thickness, which is how the thinnest regions are found. Scale bar: 10 µm. Image: Harlequin Mantis, CC BY-SA 4.0; resized.
An orange image covered in a fine, regular pattern of rows, with a bright irregular patch at its centre.
Graphene grown on silicon carbide, imaged with a scanning tunnelling microscope. The fine regular pattern follows the carbon lattice; the bright patch is a single point defect. Image: Nathan Guisinger, Argonne National Laboratory, public domain; resized.

Key properties

  • Room-temperature mobility above 100,000 cm2/(V·s) in hBN-encapsulated devices; typically 2,000–15,000 cm2/(V·s) on SiO2
  • Fermi velocity ≈ 1 × 106 m/s, about 1/300 of the speed of light
  • Intrinsic strength ~130 GPa and Young’s modulus ~1 TPa (AFM nanoindentation of suspended flakes)
  • Thermal conductivity ~2,000–5,000 W/(m·K) for suspended monolayers at room temperature; the spread reflects measurement method
  • Absorbs 2.3% of white light per layer (πα)
  • Theoretical specific surface area 2,630 m2/g

How it is made

  • Mechanical exfoliation of graphite – highest quality, micrometre-scale flakes; the reference material for physics
  • CVD on copper foil at ~1,000 °C – continuous polycrystalline films, roll-to-roll capable, but must be transferred
  • Silicon sublimation from SiC above ~1,300 °C – transfer-free wafer-scale films; the basis of graphene quantum resistance standards
  • Liquid-phase or electrochemical exfoliation – tonnes of few-layer flakes for inks, coatings and composites
  • Epitaxy on single-crystal Cu(111) or Cu–Ni foils – single-orientation wafer-scale films, research to pilot stage

Uses, and how close they are

  • Composites, coatings and conductive inks (as few-layer flakes)deployed
  • Hall-effect magnetic field sensorsdeployed
  • Quantum Hall resistance standards (epitaxial graphene on SiC)deployed
  • Modulators and photodetectors on silicon photonicsprototype
  • Field-effect biosensors and neural interfacesprototype

Readiness runs lab → prototype → pilot → deployed.

Open problems

  1. Can single-crystal graphene be transferred at 300 mm scale without cracks, wrinkles and polymer residue – or grown directly on the target substrate at CMOS-compatible temperatures?
  2. Once grain boundaries are eliminated, what limits room-temperature mobility in large-area films: wrinkles, strain fluctuations or residual charged impurities?
  3. Is there a way to open a technologically useful band gap without sacrificing the carrier mobility that made graphene attractive?

Going deeper

Short notes for specialists. Choose a lens in the header and yours comes first.

For theoreticians · your lens

The textbook Dirac system: nearest-neighbour tight binding with t ≈ 2.7–3.0 eV reproduces the low-energy bands, and DFT places the Dirac cone correctly, but electron–electron interactions renormalise the Fermi velocity logarithmically towards charge neutrality – GW captures this, semilocal DFT does not. Flexural (ZA) phonons with quadratic dispersion dominate heat transport and make computed thermal conductivity strongly size- and strain-dependent. Most of the open physics has moved into stacks: see twisted and rhombohedral graphene.

For experimentalists · your lens

Find monolayers by optical contrast on 90 nm or 285–300 nm SiO2 and confirm with Raman: a single Lorentzian 2D band near 2,680 cm−1 (532 nm excitation) with a FWHM of ~25–30 cm−1, and I(2D)/I(G) above 2 in undoped samples; the D band near 1,350 cm−1 reports defects. Both G and 2D shift with strain and with doping, so separate the two with a G–2D correlation plot. For device quality, clean dry transfer and hBN encapsulation matter more than where the graphite came from.

For engineers · your lens

The missing band gap limits graphene FETs to on/off ratios of about ten at room temperature, which rules out digital logic. Graphene wins where fast carriers, an all-surface channel or transfer-free growth on SiC matter: RF, photonics, sensing and metrology. The practical bottlenecks are transfer yield, contact resistance (typically a few hundred Ω·µm, best reports near 100 Ω·µm) and doping variation from process residues.

In the research tracks

Theory frontiers

Growth methods

Readiness assessments

Recent news

The newest items tagged Graphene, from the news feed updated 5 Oct 2026.

Preprintnot yet peer reviewed arXiv

Fluctuation-induced magnetoresistance in graphene Hall bars at charge neutrality

In the temperature interval T∼50 - 100 K, the rate of electron-electron collisions in graphene devices may exceed the momentum relaxation rate due to disorder and electron-phonon scattering. In this regime, the motion of the electron liquid may be described by the hydrodynamic equations. In the hydrodynamic…

TheoryGraphene
Preprintnot yet peer reviewed arXiv

Quantum materials QED with van der Waals crystals

A central goal of the emerging field of materials QED is to harness subwavelength electromagnetic confinement in engineered cavities to tailor light-matter interactions. Here, we demonstrate that van der Waals multilayer cavities composed of stacked graphene and hexagonal boron nitride (hBN) provide unprecedented…

TheoryGraphenehBN
Preprintnot yet peer reviewed arXiv

Electrostatic Doping of Moiré Superlattices Controls the Optical Fingerprint of a WSe_2 /Twisted Bilayer Graphene heterostructure

We theoretically investigate the optical response of the WSe2 monolayer vertically stacked on twisted bilayer graphene (tBG) under electrostatic doping. In this heterostructure, the doped moiré superlattice of tBG generates a spatially modulated electrostatic potential that couples to the electron and hole constituents…

TheoryTwisted grapheneGrapheneWSe₂

All 450 items tagged Graphene in the news feed  ·  RSS feed for Graphene

Key references

  1. Electric field effect in atomically thin carbon filmsNovoselov et al. · Science 306, 666 (2004)cited by 67,052doi:10.1126/science.1102896
  2. The electronic properties of grapheneCastro Neto et al. · Reviews of Modern Physics 81, 109 (2009)cited by 24,886doi:10.1103/RevModPhys.81.109
  3. Measurement of the elastic properties and intrinsic strength of monolayer grapheneLee et al. · Science 321, 385 (2008)cited by 20,948doi:10.1126/science.1157996
Carbon Twisted graphene Twisted and rhombohedral multilayer graphene van der Waals crystal
type
depends on form
thickness
~0.7 nm
most mature
lab
Platform for correlated and topological electron states Carbon GO / rGO Graphene oxide and reduced graphene oxide nanosheet
type
depends on form
thickness
~0.8–1.2 nm per GO sheet
most mature
deployed
Conductive additives, coatings and composites (as rGO) Nitrides hBN Hexagonal boron nitride van der Waals crystal
type
insulator
thickness
~0.33 nm
band gap
5.95–6 eV
most mature
deployed
Lubricants, cosmetics and high-temperature ceramics (bulk hBN) Carbon Graphyne Graphyne and graphdiyne nanosheet
type
semiconductor
thickness
~0.35 nm interlayer spacing in layered graphdiyne
most mature
lab
Battery anodes and electrocatalyst supports