spore: profile
id: graphene
spore_version: 0.2
family: carbon-materials
name: Graphene
abbreviation: Graphene
role: 2D carbon sheet (single-layer and few-layer), also sold as graphene nanoplatelets
category: carbon
type: Graphene
summary: |
  Graphene is a single sheet of carbon atoms in a hexagonal lattice, one atom thick. Few-layer graphene and graphene nanoplatelets are stacks of a few to many such sheets. The ideal single-layer values quoted here (mobility, strength, stiffness, optical absorption) come from a manufacturer's properties page and an editorial review. Commercial nanoplatelet values were not read in this run and are not included.
best_for: Ideal single-layer mechanics and electronics, where a very high carrier mobility or stiffness per unit mass is the goal
weakest_at: Commercial material properties were not verified in this run, so real nanoplatelet performance is not established here
identity:
  formula: C (single sheet of sp2-bonded carbon atoms in a hexagonal lattice; nanoplatelets are stacked sheets)
  cas: ''
  crystal_system: hexagonal lattice (two-dimensional)
  space_group: ''
  source: graphenea
  where: Graphene Structure section (atomic thickness 0.345 nm); C-C bond length in Mechanical Strength section
tags:
  environments: []
  stresses: []
  applications:
    - thermal-control
    - electronics-and-chips
properties:
  - benchmark: thickness
    label: Atomic thickness of one graphene layer
    value: 0.345
    unit: nm
    scope: material
    conditions:
      basis: single atomic layer, as printed on the manufacturer's properties page
    method: Value printed on the Graphenea properties page
    status: ground
    source: graphenea
    where: Graphene Structure section
  - benchmark: electron_mobility
    label: Theoretical electron mobility limit, single-layer graphene
    value: 200000
    unit: cm2/(V.s)
    scope: material
    conditions:
      basis: theoretical limit for an ideal single layer, as printed; sample and temperature not given
      substrate: none stated
    method: Theoretical limit printed on the Graphenea properties page
    status: calculated
    source: graphenea
    where: Electronic Properties section, 'Theoretical mobility limit'
  - benchmark: electron_mobility
    label: Mobility limit with SiO2 substrate
    value: 40000
    unit: cm2/(V.s)
    scope: material
    conditions:
      basis: mobility limit for graphene on a SiO2 substrate, as printed
      substrate: SiO2
    method: Limit printed on the Graphenea properties page
    status: calculated
    source: graphenea
    where: Electronic Properties section
  - benchmark: electron_mobility
    label: Electron mobility previously reported
    value: 15000
    bound: lower
    unit: cm2/(V.s)
    scope: material
    conditions:
      basis: previously reported value, as printed (above 15,000); sample and temperature not stated
    method: Printed on the Graphenea properties page
    status: ground
    note: Experimental lower bound from the page; the page gives no sample or temperature, so it is not comparable with the theoretical limit.
    source: graphenea
    where: Electronic Properties section
  - benchmark: young_modulus
    label: Young's modulus, single-layer graphene (manufacturer page)
    value: 0.5
    unit: TPa
    scope: material
    conditions:
      basis: ideal single layer, as printed; test method not stated
    method: Printed on the Graphenea properties page
    status: ground
    note: Differs from the 1 TPa given in the editorial review below; the two sources do not agree.
    source: graphenea
    where: Mechanical Strength section
  - benchmark: young_modulus
    label: Young's modulus, graphene (editorial review)
    value: 1
    unit: TPa
    scope: material
    conditions:
      basis: no conditions stated; the review does not say single-layer explicitly
    method: Value stated in the opening paragraph of an open-access editorial
    status: ground
    note: Second source value; see the Graphenea entry for the 0.5 TPa figure.
    source: rhee2020
    where: Opening paragraph
  - benchmark: intrinsic_strength
    label: Intrinsic tensile strength, ideal graphene
    value: 130
    unit: GPa
    scope: material
    conditions:
      basis: intrinsic (ideal, defect-free) strength; test conditions not stated in the source
    method: Printed on the Graphenea properties page; the same 130 GPa figure appears in the editorial review
    status: ground
    source: graphenea
    where: Mechanical Strength section, 'Ultimate tensile strength'
  - benchmark: intrinsic_strength
    label: Intrinsic strength, graphene (editorial review)
    value: 130
    unit: GPa
    scope: material
    conditions:
      basis: no conditions stated
    method: Value stated in the opening paragraph of an open-access editorial
    status: ground
    source: rhee2020
    where: Opening paragraph
  - benchmark: optical_absorption
    label: White-light absorption by one layer
    value: 2.3
    unit: '%'
    scope: material
    conditions:
      basis: one layer of graphene, white light, as printed
    method: Printed on the Graphenea properties page
    status: ground
    source: graphenea
    where: Optical Properties section
  - benchmark: spring_constant
    label: Spring constant, graphene membrane (AFM)
    value: 1
    value_high: 5
    bound: range
    unit: N/m
    scope: material
    conditions:
      basis: range printed on the Graphenea page; test geometry not stated
    method: Printed on the Graphenea properties page
    status: ground
    source: graphenea
    where: Mechanical Strength section
  - benchmark: areal_density
    label: Areal density of a graphene sheet
    value: 0.77
    unit: mg/m2
    scope: material
    conditions:
      basis: single sheet, as printed
    method: Printed on the Graphenea properties page
    status: ground
    source: graphenea
    where: Mechanical Strength section
  - benchmark: bond_length
    label: Carbon-carbon bond length in graphene
    value: 0.142
    unit: nm
    scope: material
    conditions:
      basis: in-plane C-C bond, as printed
    method: Value printed on the Graphenea properties page
    status: ground
    source: graphenea
    where: Mechanical Strength section
  - benchmark: thermal_conductivity
    label: Thermal conductivity, suspended graphene flakes (optothermal)
    value: 2000
    value_high: 5000
    bound: range
    unit: W/mK
    scope: material
    conditions:
      basis: room temperature, suspended large-area graphene flakes; range as stated in the review; single-layer not separated
      substrate: none (suspended)
    method: Range given in the review, citing optothermal Raman measurements by Balandin and co-workers
    status: ground
    source: yan2015
    where: Introduction, paragraph on thermal properties of graphene
  - benchmark: thermal_conductivity
    label: Thermal conductivity, graphene on SiO2/Si
    value: 600
    unit: W/mK
    scope: material
    conditions:
      basis: near room temperature, in-plane, as cited in the review
      substrate: SiO2/Si
    method: Value cited in the review from Seol et al.
    status: ground
    note: Supported graphene conducts less heat than suspended graphene because of coupling to the substrate.
    source: yan2015
    where: Section on thermal conductivity of supported graphene
  - benchmark: thermal_conductivity
    label: Thermal conductivity, single-layer graphene encased in SiO2
    value: 160
    unit: W/mK
    scope: material
    conditions:
      basis: single-layer graphene encased in oxide, at 310 K
      temperature: 310 K
      substrate: SiO2 encased
    method: Value cited in the review for encased single-layer graphene
    status: ground
    source: nika2012
    where: Section on encased graphene (encased single-layer graphene paragraph)
corrosion:
  - environment: Supported on SiO2/Si substrate
    headline: Heat conduction falls when graphene sits on a substrate
    effect: Thermal conductivity of graphene on SiO2/Si is cited near 600 W/mK at room temperature, against 2000 to 5000 W/mK for suspended flakes. The review ascribes the drop to thermal coupling to the substrate and to scattering at substrate defects and impurities.
    source: yan2015
    where: Section on thermal conductivity of supported graphene
  - environment: Encased in SiO2 oxide
    headline: Encasing lowers heat conduction further
    effect: Single-layer graphene encased in oxide is cited at about 160 W/mK at 310 K, the lowest of the substrate and encasement values cited here.
    source: nika2012
    where: Section on encased graphene
risks:
  hazards:
    - text: No workplace exposure limit is set for graphene. The HSE guidance says the ACGIH threshold for graphite respirable dust is not an appropriate limit for graphene. Nanomaterials are treated as substances of high concern, so a precautionary approach applies until inhalation hazards are clear.
      ghs: []
      source: hsg272
      where: Workplace exposure limits section and Control of risk section
    - text: Exposure can occur by inhalation, through the skin and by ingestion. Few investigations into skin effects have been reported for nanomaterials other than cosmetics.
      ghs: []
      source: hsg272
      where: Hazard section, paragraph on routes of exposure
    - text: PubChem lists the compound Carbon (CID 5462310) under the same formula C; no GHS hazard classification for graphene was read in this run.
      ghs: []
      source: pubchem-carbon
      where: Compound record, Carbon, CID 5462310
  failure_risks:
    - source: yan2015
      where: Section on thermal conductivity of supported graphene
      mode: 'When graphene is supported on a substrate, its heat conduction falls well below '
      consequence: When graphene is supported on a substrate, its heat conduction falls well below the suspended-flake values. A design that relies on the suspended value will under-predict temperatures.
  side_effects: []
  handling:
    - text: Keep dust-generating work inside local exhaust ventilation. The HSE guidance asks for enclosure of the process where possible, and LEV for cutting, sawing and polishing operations.
      source: hsg272
      where: Control of risk, Local exhaust ventilation section
    - text: Weigh powders over a damp sheet of absorbent material and wipe spills with a damp sheet, rather than dry sweeping.
      source: hsg272
      where: Good practice, handling of nanomaterials
    - text: Wear suitable single-use gloves and a lab coat that does not retain dust.
      source: hsg272
      where: Personal protective equipment section
  mitigations:
    - text: Use a risk management programme in the workplace to reduce exposure, and keep records of LEV checks and tests.
      source: hsg272
      where: Control of risk section and LEV section
uses:
  - application: thermal-control
    device: Heat spreader on AlGaN/GaN transistors
    example: Few-layer graphene films exfoliated from highly oriented pyrolytic graphite were transferred onto AlGaN/GaN devices on SiC to spread heat from the transistor hot spot in a proof-of-concept experiment.
    source: yan2015
    where: Section on graphene heat spreaders, experimental demonstration
  - application: thermal-control
    device: Heat spreader on thermal evaluation chips
    example: Single-layer and multilayer graphene grown by CVD on copper and transferred onto thermal evaluation chips with a platinum microheater were tested as heat spreaders.
    source: yan2015
    where: Section on CVD-grown graphene heat spreaders
  - application: electronics-and-chips
    device: Heat spreaders in silicon-on-insulator circuits
    example: Simulations of graphene lateral heat spreaders attached to the side heat sinks of a SOI circuit reduced the simulated hot-spot temperature. These are simulations, not measurements.
    source: yan2015
    where: Section on graphene heat spreaders in SOI circuits (simulation)
supply:
  - subject: Natural graphite (feedstock for graphene and nanoplatelets)
    abundance: USGS reports world reserves of 310,000,000 tons, of which China holds 100,000,000 tons; the rest of the world resources are said to exceed 800 million tons of recoverable graphite.
    producers:
      - country: China
        share_percent: 82
        year: 2025
        note: share of world natural graphite production, 2025 estimate
    critical_lists: []
    import_reliance: 100 percent of US apparent consumption (2021 to 2025e)
    source: usgs-graphite-2026
    where: Mineral Commodity Summaries 2026, Graphite (Natural), Events, Trends and Issues and World Mine Production tables
  - subject: Natural graphite imports to the United States
    abundance: US net import reliance for natural graphite is 100 percent.
    producers:
      - country: China (2021 to 2024 import share)
        share_percent: 46
        year: 2024
      - country: Canada
        share_percent: 13
        year: 2024
      - country: Mozambique
        share_percent: 13
        year: 2024
      - country: Mexico
        share_percent: 12
        year: 2024
    critical_lists: []
    source: usgs-graphite-2026
    where: Mineral Commodity Summaries 2026, Import Sources (2021 to 2024)
media: []
documents:
  - title: 'Graphenea: Graphene properties (manufacturer page)'
    type: datasheet
    url: https://www.graphenea.com/pages/graphene-properties
    year: 2026
  - title: Electronic and Thermal Properties of Graphene (Nanomaterials, 2020, 10(5):926, editorial)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC7279320/
    year: 2020
  - title: 'USGS Mineral Commodity Summaries 2026: Graphite (Natural)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-graphite.pdf
    year: 2026
  - title: 'HSE HSG272: Using nanomaterials at work'
    type: report
    url: https://www.hse.gov.uk/pubns/books/hsg272.pdf
    year: 2013
  - title: 'PubChem compound record: Carbon (CID 5462310)'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Carbon
    year: 2026
  - title: Review of Thermal Properties of Graphene and Few-Layer Graphene (Yan, Nika, Balandin)
    type: paper
    url: https://arxiv.org/abs/1503.01825
    year: 2015
  - title: Phonon Transport in Graphene (Nika, Balandin)
    type: paper
    url: https://arxiv.org/abs/1203.4282
    year: 2012
  - title: Suppression of Multilayer Graphene Patches during CVD Graphene growth on Copper (arXiv:1205.1337)
    type: paper
    url: https://arxiv.org/abs/1205.1337
    year: 2012
  - title: Structure and Synthesis of graphene oxide (arXiv:1901.02274)
    type: paper
    url: https://arxiv.org/abs/1901.02274
    year: 2019
gaps:
  - 'Commercial nanoplatelet datasheets not read: XG Sciences, Sigma-Aldrich and SpecialChem pages returned Cloudflare blocks or no content. Search snippets were not used.'
  - 'Balandin 2008 single-layer thermal conductivity (5300 W/mK) not read: the Nano Letters paper is not on arXiv under a found ID. The 2000 to 5000 W/mK range is from the 2015 review, for suspended flakes.'
  - Oxidation temperature of graphene in air not read from a fetched primary source. The only figure seen was in Wikipedia, which is not used for numbers.
  - Wrinkling and ripple effects on ageing not read from a fetched source.
  - 'Graphene oxide reduction: the review gives only a qualitative statement that oxidised graphite is reduced to graphene. No reduction temperature or method was read.'
  - 'PubChem GHS hazard classification for graphene not read: the PubChem record found is for elemental carbon.'
  - NIOSH nanotechnology pages returned errors. Only the HSE HSG272 guidance was read for exposure control.
  - USGS critical-mineral status of graphite not read in this run.
  - Space or radiation use of graphene not researched in this run.
  - Uses are limited to thermal heat spreading from research papers. No commercial product use was read.
  - Recipe process lines (CVD on copper, graphene oxide reduction) rest on two arXiv papers listed in documents, not on a numeric source. Only the qualitative process is stated.
sources:
  graphenea:
    title: Graphene properties (Graphenea manufacturer page)
    id: Graphenea web page
    url: https://www.graphenea.com/pages/graphene-properties
    year: 2026
    kind: web
    license: Manufacturer web page, cited not reproduced
  rhee2020:
    title: Electronic and Thermal Properties of Graphene (editorial)
    id: doi:10.3390/nano10050926 (Nanomaterials 10(5), 926, PMC7279320); author Kyong Yop Rhee
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC7279320/
    year: 2020
    kind: paper
    license: Open access, as listed by PMC
  usgs-graphite-2026:
    title: 'Mineral Commodity Summaries 2026: Graphite (Natural)'
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-graphite.pdf
    year: 2026
    kind: report
    license: Public domain (US government)
  yan2015:
    title: 'Review of Thermal Properties of Graphene and Few-Layer Graphene: Applications in Electronics'
    id: arXiv:1503.01825; Yan, Nika and Balandin
    url: https://arxiv.org/abs/1503.01825
    year: 2015
    kind: paper
    license: arXiv, as listed
  nika2012:
    title: Phonon Transport in Graphene (invited review)
    id: arXiv:1203.4282; Nika and Balandin
    url: https://arxiv.org/abs/1203.4282
    year: 2012
    kind: paper
    license: arXiv, as listed
  pubchem-carbon:
    title: 'PubChem compound record: Carbon (CID 5462310)'
    id: CID 5462310
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Carbon
    year: 2026
    kind: database
    license: PubChem, public
  hsg272:
    title: Using nanomaterials at work, including carbon nanotubes (CNTs) and other biopersistent high aspect ratio nanomaterials (HARNs), HSG272
    id: HSE HSG272
    url: https://www.hse.gov.uk/pubns/books/hsg272.pdf
    year: 2013
    kind: report
    license: Open Government Licence
  cvd-pulsed-cu:
    title: Suppression of Multilayer Graphene Patches during CVD Graphene growth on Copper
    id: arXiv:1205.1337
    url: https://arxiv.org/abs/1205.1337
    year: 2012
    kind: paper
    license: arXiv, as listed
  go-synthesis:
    title: Structure and Synthesis of graphene oxide
    id: arXiv:1901.02274
    url: https://arxiv.org/abs/1901.02274
    year: 2019
    kind: paper
    license: arXiv, as listed
license: CC-BY-4.0
updated: '2026-10-19'
review:
  status: draft
  method: assistant
  checked_values: 15
  unreachable: 4
  caveats: 3
  note: 'Deepened by an assistant on 2026-10-19 from sources read in this run: USGS MCS 2026 graphite, two Balandin-group reviews on arXiv, a CVD-on-copper paper, a graphene oxide synthesis review, HSE HSG272 and PubChem. Commercial nanoplatelet values were not verified.'
story:
  recipe:
    line: Graphene is a single sheet of carbon atoms, each bonded to three neighbours in a hexagonal lattice with carbon-carbon bonds of 0.142 nm. Few-layer graphene and nanoplatelets are stacks of such sheets. Made by mechanical exfoliation of graphite, by chemical vapour deposition of methane on copper foil, or by oxidising graphite to graphene oxide and then reducing it.
    parts:
      - name: Carbon
        symbol: C
        atoms: 1
        atomic_weight: 12.011
        role: The only element. Each atom bonds to three neighbours in the plane, and the bonds set the strength and stiffness of the sheet.
  risk_groups:
    - title: For people
      level: 1
      verdict: Handle as a precaution
      lead: No exposure limit is set for graphene, and the UK HSE treats nanomaterials as substances of high concern.
      points:
        - label: Inhalation
          line: Dust should be kept out of the air with local exhaust ventilation. Inhalation, skin contact and ingestion are all routes of exposure, and the skin and ingestion effects are little studied.
  why: Graphene is a single sheet of carbon one atom thick. The manufacturer page and the editorial review give very high carrier mobility and stiffness for the ideal single layer. Commercial nanoplatelets are stacks of such sheets, and their real properties depend on layer count and lateral size, which were not verified in this run.
  uses:
    - where: Electronics heat spreading
      line: Experiments placed few-layer graphene films on AlGaN/GaN transistors to spread heat from the hot spot. The review also reports simulations for silicon-on-insulator circuits.
    - where: Thermal test chips
      line: CVD graphene grown on copper has been tested as a heat spreader on thermal evaluation chips.
  can_do:
    - label: Heat conduction
      benchmark: thermal_conductivity
      line: Suspended graphene flakes conduct heat at 2000 to 5000 W/mK at room temperature. On a SiO2/Si substrate the cited value falls to about 600 W/mK, and encased single-layer graphene is cited at about 160 W/mK.
    - label: Stiffness
      benchmark: young_modulus
      line: Ideal single-layer graphene is reported at 1 TPa (editorial review) and 0.5 TPa (manufacturer page). The two sources disagree, so treat the stiffness as a range until a primary measurement is read.
    - label: Carrier mobility
      benchmark: electron_mobility
      line: The manufacturer page gives a theoretical electron mobility limit of 200000 cm2/(V.s) for a single layer, and 40000 cm2/(V.s) with a SiO2 substrate. These are limits, not measured values for a commercial product.
  compare: Ideal single-layer graphene combines a very high theoretical electron mobility with a stiffness near 1 TPa. Commercial nanoplatelets were not read in this run, so this profile does not compare them with other carbon materials.
  compare_rows:
    - scope: material
      label: Electron mobility limit
      benchmark: electron_mobility
    - scope: material
      label: Young modulus
      benchmark: young_modulus
    - scope: material
      label: Thermal conductivity, suspended
      benchmark: thermal_conductivity
  handling:
    - Keep dust-generating work under local exhaust ventilation, and wipe spills with a damp sheet.
    - Wear single-use gloves and a lab coat that does not retain dust. Check the supplier safety data sheet for the product you use.
  good_for:
    - Ideal single-layer electronics and mechanics, where the theoretical limits matter. The numbers here are not measurements on a commercial product.
  watch_out:
    - Only ideal single-layer values are included. Commercial nanoplatelet values were not verified and should not be assumed.
    - The two stiffness sources disagree, 0.5 TPa against 1 TPa.
    - Thermal conduction drops sharply once the sheet is supported on a substrate, so suspended values do not describe a device.
  verdict: Graphene has very high ideal single-layer values on the sources read here. For a commercial nanoplatelet choice, the product datasheet has to be read first.