spore: profile
id: indium-phosphide
spore_version: 0.2
family: semiconductor-materials
name: Indium phosphide
abbreviation: InP
role: semiconductor
category: semiconductors
type: inp
summary: |
  Indium phosphide (InP) is a binary III-V semiconductor of one indium atom and one phosphorus atom, sold by Shalomeo as single-crystal substrates. Shalomeo gives a density of 4.81 g/cm3, a band gap of 1.344 eV at 300 K and an electron mobility of 5400 cm2/(V·s) at 300 K. Most InGaAs devices are grown on InP, because In0.53Ga0.47As matches its lattice (Wikipedia). PubChem's ECHA summary classifies InP as a cancer hazard (H350) in most of the reports that give hazard codes.
best_for: Substrates for InGaAs photodiodes and detectors, and for high-speed electronics and telecom devices, where a band gap of 1.344 eV and an electron mobility of 5400 cm2/(V·s) at 300 K are the reasons to choose it
weakest_at: 'Supply and toxicity: the United States imports all of its indium, China produced 70% of world indium (USGS), and PubChem''s ECHA summary gives H350 (May cause cancer) for 98.1% of reports that list codes'
identity:
  formula: InP, one indium atom and one phosphorus atom in a zinc-blende crystal
  cas: 22398-80-7
  crystal_system: cubic
  source: shalomeo-inp
  where: Basic Properties table of the Shalomeo page (crystal structure Tetrahedral(M4), lattice constant a = 5.869 Å); cubic from the Surfacenet crystal properties; zinc blende and CAS 22398-80-7 from the Wikipedia infobox
tags:
  environments: []
  stresses: []
  applications:
    - electronics-and-chips
    - optics-and-cameras
    - solar-arrays
properties:
  - benchmark: density
    label: Density of InP single crystal
    value: 4.81
    unit: g/cm3
    scope: material
    conditions:
      form: InP single crystal (substrate product)
      temperature: not stated on the page
    method: Value printed in a substrate supplier's basic properties table
    status: ground
    source: shalomeo-inp
    where: Basic Properties table, row Density
  - benchmark: melting_point
    label: Melting point, InP (Shalomeo)
    value: 1062
    unit: °C
    scope: material
    conditions:
      form: InP single crystal
      pressure: not stated on the page
    method: Value printed in a substrate supplier's basic properties table
    status: ground
    note: Wikipedia's infobox also prints 1,062 °C. Surfacenet prints 1330 °C for the same material (next entry). The two values disagree and both are kept.
    source: shalomeo-inp
    where: Basic Properties table, row Melt Point
  - benchmark: melting_point
    label: Melting point, InP (Surfacenet, (100) block)
    value: 1330
    unit: °C
    scope: material
    conditions:
      orientation: (100)
      page_note: degree sign is garbled on the page
    method: Value printed on a materials data page under the crystal properties block for the (100) orientation
    status: ground
    note: Disagrees with the 1062 °C from Shalomeo and Wikipedia. The disagreement is not resolved here.
    source: surfacenet-inp
    where: Crystal properties, (100) block, melting point row
  - benchmark: band_gap
    label: Band gap of InP at 300 K
    value: 1.344
    unit: eV
    scope: material
    conditions:
      temperature: 300 K
    method: Value printed in a substrate supplier's basic properties table
    status: ground
    note: The Wikipedia infobox describes this gap as direct; the supplier table does not print the gap type.
    source: shalomeo-inp
    where: Basic Properties table, row Bandgap (@300 K)
  - benchmark: electron_mobility
    label: Electron mobility of InP at 300 K
    value: 5400
    unit: cm2/(V·s)
    scope: material
    conditions:
      temperature: 300 K
    method: Value printed in a substrate supplier's basic properties table
    status: ground
    note: Surfacenet gives different figures for undoped N-type (100) and (111) crystal (next two entries). The conditions differ and the values are not reconciled.
    source: shalomeo-inp
    where: Basic Properties table, row Electron Mobility (@300K)
  - benchmark: electron_mobility
    label: Mobility, undoped N-type InP, (100) crystal
    value: 3700
    value_high: 4000
    bound: range
    unit: cm2/ V-S
    scope: material
    conditions:
      orientation: (100)
      doping: undoped, N-type
      temperature: not stated on the page
    method: Range printed on a materials data page under the crystal properties block; the page gives it as mobility for N-type material without naming a temperature
    status: ground
    source: surfacenet-inp
    where: Crystal properties, (100) block, mobility row
  - benchmark: electron_mobility
    label: Mobility, undoped N-type InP, (111) crystal (upper bound)
    value: 3000
    bound: upper
    unit: cm2/ V-S
    scope: material
    conditions:
      orientation: (111)
      doping: undoped, N-type
      temperature: not stated on the page
    method: Upper bound printed on a materials data page (the page prints "< 3000")
    status: ground
    source: surfacenet-inp
    where: Crystal properties, (111) block, mobility row
  - benchmark: thermal_conductivity
    label: Thermal conductivity of InP at 300 K
    value: 0.68
    unit: W/(cm·K)
    scope: material
    conditions:
      temperature: 300 K
    method: Value printed in a substrate supplier's basic properties table
    status: ground
    source: shalomeo-inp
    where: Basic Properties table, row Thermal Conductivity (@300K)
  - benchmark: refractive_index
    label: Refractive index of InP at 632.8 nm
    value: 3.55
    unit: '-'
    scope: material
    conditions:
      wavelength: 632.8nm
    method: Value printed in a substrate supplier's basic properties table
    status: ground
    source: shalomeo-inp
    where: Basic Properties table, row Refractive Index
  - benchmark: lattice_constant
    label: Lattice constant of InP (Shalomeo)
    value: 5.869
    unit: Å
    scope: material
    conditions:
      structure: zinc blende (cubic)
      temperature: not stated on the page
    method: Value printed in a substrate supplier's basic properties table
    status: ground
    note: Surfacenet prints 5.868 Å, and the Wikipedia InGaAs article gives 5.869 Å at 295 K for the In0.53Ga0.47As alloy that matches InP. The values agree within rounding.
    source: shalomeo-inp
    where: Basic Properties table, row Lattice Constant
  - benchmark: lattice_constant
    label: Lattice constant of InP (Surfacenet, (100) block)
    value: 5.868
    unit: Å
    scope: material
    conditions:
      orientation: (100) block
      structure: cubic
      unit_as_printed: A
    method: Value printed on a materials data page under the crystal properties block
    status: ground
    source: surfacenet-inp
    where: Crystal properties, (100) block, crystal structure and lattice constant row
  - benchmark: molar_mass
    label: Molar mass of InP
    value: 145.792
    unit: g/mol
    scope: material
    conditions:
      basis: molecular weight of the InP formula unit
    method: Value printed in a substrate supplier's basic properties table; PubChem prints the same molecular weight (145.792) without a unit
    status: ground
    source: shalomeo-inp
    where: Basic Properties table, row Molar Mass
  - benchmark: electrical_resistivity
    label: Electrical resistivity, (100) InP
    value: 0.03
    value_high: 0.2
    bound: range
    unit: Ohm cm
    scope: material
    conditions:
      orientation: (100)
      doping: not stated on the row
    method: Range printed on a materials data page under the crystal properties block
    status: ground
    note: The page does not tie this resistivity to a doping type, so it is kept apart from the mobility rows.
    source: surfacenet-inp
    where: Crystal properties, (100) block, resistivity row
corrosion:
  - environment: Acids
    headline: The supplier calls indium phosphide slightly soluble in acids; no acid, temperature or exposure time is given.
    effect: 'Shalomeo lists chemical stability as slightly soluble in acids. The statement is qualitative: the page names no acid, concentration, temperature or time, so no corrosion rate can be stated.'
    rating: low
    conditions:
      basis: qualitative chemical-stability statement from a supplier
      acid: not named on the page
    source: shalomeo-inp
    where: Basic Properties table, row Chemical Stability
  - environment: Ionising radiation
    headline: The supplier claims good radiation stability, with no dose or fluence figure.
    effect: Shalomeo lists good radiation stability among the features of its InP substrates and names radiation-resistant solar cells as an application. The page prints no dose, fluence or test result for the claim.
    rating: low
    conditions:
      basis: supplier feature statement with no test given
      dose: not stated on the page
    source: shalomeo-inp
    where: Features statement and application fields
risks:
  hazards:
    - text: PubChem's ECHA summary for indium phosphide (211 company reports from 8 notifications) gives H350 (May cause cancer) for 98.1% of reports that give codes, H361 (Suspected of damaging fertility or the unborn child) for 94.3%, and H372 (Causes damage to organs through prolonged or repeated exposure) for 98.1%. The signal word is Danger.
      ghs:
        - H350
        - H361
        - H372
      source: pubchem-inp
      where: Safety and Hazards, GHS Classification, ECHA C&L Notifications Summary (CID 31170)
    - text: Individual notifications differ. One reads Not Classified, and others list H350 and H372 with the signal word Danger. PubChem notes that the classification varies with impurities, additives and other factors.
      ghs: []
      source: pubchem-inp
      where: Safety and Hazards, GHS Classification, individual notifications
  failure_risks: []
  side_effects: []
  handling:
    - text: Shalomeo packages its InP substrates in class 100 bags inside a class 1000 clean room.
      source: shalomeo-inp
      where: Packaging statement in the product specifications
    - text: No supplier safety data sheet for InP was opened. Get the supplier's sheet before cutting, etching or grinding the material, because the only hazard data here come from the PubChem classification.
      source: pubchem-inp
      where: Safety and Hazards, GHS Classification
  mitigations: []
uses:
  - application: optics-and-cameras
    device: InGaAs photodiodes and detectors grown on InP substrates
    example: Most InGaAs devices are grown on InP substrates. The In0.53Ga0.47As alloy matches the InP lattice at 295 K, GaInAs photodiodes are the preferred choice from 1.1 μm to 1.7 μm, and the 53% indium composition has a cut-off of 1.68 μm at 295 K.
    source: wikipedia-ingaas
    where: Introduction; lattice-matching section; photodiode section
  - application: electronics-and-chips
    device: High-frequency transistors built on InP and InGaAs
    example: Shalomeo says InP performs superiorly in high-power and high-frequency electronics. Wikipedia reports pseudomorphic heterojunction bipolar transistors that could operate at 604 GHz.
    source: wikipedia-inp
    where: Uses section, RF and high-speed electronics paragraph; Shalomeo application statements
  - application: optics-and-cameras
    device: Telecom lasers, photodetectors and receivers
    example: USGS reports that InP lasers and receivers send data through fiber-optic lines in 5G networks, and that InP is used in high-speed photodetectors and laser diodes for optical communications.
    source: usgs-mcs2026-indium
    where: Events, Trends, and Issues
  - application: solar-arrays
    device: Radiation-resistant solar cells
    example: Shalomeo lists radiation-resistant solar cells among the application fields of its InP substrates. The page prints no cell efficiency and no radiation dose.
    source: shalomeo-inp
    where: Product and application statements
supply:
  - subject: Indium (the metal used to make InP)
    producers:
      - country: China
        share_percent: 69.1
        year: 2025
      - country: Korea, Republic of
        share_percent: 16.4
        year: 2025
      - country: Japan
        share_percent: 5.9
        year: 2025
      - country: Canada
        share_percent: 3.6
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (final list, November 2025)
        listed: true
      - list: EU critical raw materials list (European Commission page)
        listed: false
    recycling: 'USGS: indium is most commonly recovered from ITO scrap in Japan and the Republic of Korea; the quantity recovered from scrap is not available.'
    substitutes:
      - 'USGS: the substitutes it names are for indium tin oxide coatings (antimony tin oxide, carbon nanotubes, PEDOT, copper or silver nanowires, graphene), not for InP wafers.'
    source: usgs-mcs2026-indium
    where: World Refinery Production and Capacity table, 2025e (world total 1,100 metric tons; shares calculated by Space Mushroom from China 760, Korea 180, Japan 65 and Canada 40 tons); Events, Trends, and Issues (China 70% of the world total, as printed); Recycling; Substitutes
documents:
  - title: 'Wikipedia: Indium phosphide (formula, crystal structure, manufacturing, uses)'
    type: database
    url: https://en.wikipedia.org/wiki/Indium_phosphide
    year: 2026
  - title: 'Shalomeo: InP single crystal substrates, product page (specifications and basic properties)'
    type: datasheet
    url: https://www.shalomeo.com/Ceramic-Substrates/InP-Semi-Growth/product-257.html
  - title: 'Surfacenet: Indium phosphide (InP) material properties page'
    type: database
    url: https://surfacenet.de/files/old_version/html/inp.html
  - title: 'PubChem compound record: Indium phosphide (CID 31170), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Indium-phosphide
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Indium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf
    year: 2026
  - title: 'USGS: About the 2025 List of Critical Minerals'
    type: report
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
  - title: 'European Commission: Critical raw materials'
    type: report
    url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
    year: 2024
  - title: 'Wikipedia: Indium gallium arsenide (lattice matching to InP, photodiode range)'
    type: database
    url: https://en.wikipedia.org/wiki/Indium_gallium_arsenide
    year: 2026
gaps:
  - No space flight, vacuum, thermal-cycling or radiation-dose result for InP was found. The space statements come from one supplier (good radiation stability, radiation-resistant solar cells) and carry no numbers.
  - Space group, dielectric constant, thermal expansion and effective masses were not found on any page opened. The Ioffe Institute semiconductor table returned a certificate error and could not be opened.
  - Carrier concentration, mobility ratio and dislocation density for undoped, S-doped, Zn-doped and Fe-doped InP are printed on the Shalomeo page without units, and Surfacenet flattens the exponents, so none is recorded.
  - 'Melting point is not resolved: 1062 °C (Shalomeo, Wikipedia) against 1330 °C (Surfacenet, degree sign garbled). Both are recorded.'
  - 'Electron mobility is not resolved: 5400 cm2/(V·s) at 300 K (Shalomeo) against 3700 to 4000 cm2/ V-S for undoped N-type (100) crystal (Surfacenet). The conditions differ.'
  - Atomic weights of indium and phosphorus were not printed on any page opened, so the recipe parts carry atom counts only.
  - The Wikipedia manufacturing section gives a temperature for the white-phosphorus route. It is not recorded as a property because Wikipedia is used here for composition and history only, so the story describes the route without the figure.
  - Phosphorus supply, crustal abundance of indium and the indium price were not recorded. The USGS 2026 summary prints the 2025 U.S. warehouse price as 370 and as 390 dollars per kilogram in different places, so neither is used.
  - No supplier safety data sheet for InP was opened (the American Elements page returned HTTP 403). Hazard data rest on the PubChem ECHA summary, and no toxicology values are recorded.
  - Corrosion and ageing are described only by a qualitative supplier statement about acids and one about radiation stability. No oxidation, humidity or thermal ageing study was opened.
  - Standard designations (UNS, EN, DIN, JIS, ASTM) were not found for InP substrates, so identity.designations is left out.
  - Failure modes, side effects and mitigations for InP devices were not found in the sources read.
  - Molar mass, band gap, electron mobility and lattice constant are not in spores/property-canon.yaml and use snake_case names.
  - No images are added to this profile.
sources:
  wikipedia-inp:
    title: Indium phosphide (Wikipedia)
    url: https://en.wikipedia.org/wiki/Indium_phosphide
    year: 2026
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  shalomeo-inp:
    title: Indium Phosphide (InP) single crystal substrates, InP-Semi-Growth product page (Shalomeo)
    url: https://www.shalomeo.com/Ceramic-Substrates/InP-Semi-Growth/product-257.html
    kind: datasheet
    license: Manufacturer product page (cited, not reproduced)
  surfacenet-inp:
    title: Indium phosphide (InP) material properties (Surfacenet, old-version page)
    url: https://surfacenet.de/files/old_version/html/inp.html
    kind: database
    license: cited, not reproduced
  pubchem-inp:
    title: 'PubChem compound record: Indium phosphide (CID 31170), including ECHA C&L Inventory classification'
    id: CID 31170; CAS 22398-80-7
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Indium-phosphide
    year: 2026
    kind: database
    license: PubChem (NCBI), public domain; ECHA sections attributed in the record
  usgs-mcs2026-indium:
    title: Mineral Commodity Summaries 2026, Indium
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS)
    id: Final 2025 List of Critical Minerals, November 2025
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
  ec-crm:
    title: Critical raw materials (European Commission)
    url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
    year: 2024
    kind: web
    license: European Commission web page
  wikipedia-ingaas:
    title: Indium gallium arsenide (Wikipedia)
    url: https://en.wikipedia.org/wiki/Indium_gallium_arsenide
    year: 2026
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 13
  unreachable: 2
  caveats: 4
  note: 'Written by an AI assistant on 2026-11-01 from pages read in this run: Wikipedia (composition, CAS, manufacturing routes, uses), the Shalomeo and Surfacenet property pages (read through text extraction), PubChem (molecular weight and GHS summary via its data service), the USGS 2026 indium summary (PDF text extracted), the USGS and EU critical-list pages, and the Wikipedia InGaAs article. Unreachable: the Ioffe Institute InP table (certificate error) and American Elements (HTTP 403). Caveats: the Surfacenet melting point and mobility disagree with Shalomeo; the Surfacenet degree sign is garbled; all supplier numbers are one manufacturer''s data.'
story:
  recipe:
    line: 'Indium phosphide is a binary compound of one indium atom and one phosphorus atom, with the formula InP (PubChem). It crystallises in the zinc-blende structure (Wikipedia). Wikipedia lists three routes: reacting white phosphorus with indium iodide at high temperature, direct combination of purified indium and phosphorus at high temperature and pressure, and thermal decomposition of a trialkyl indium compound mixed with phosphine.'
    parts:
      - name: Indium
        symbol: In
        role: The group III element. Indium gallium arsenide replaces part of this indium with gallium so that the alloy matches the InP lattice.
      - name: Phosphorus
        symbol: P
        role: The group V element. One phosphorus atom per formula unit, in the tetrahedral coordination that the supplier table prints.
  risk_groups:
    - title: For people
      level: 2
      verdict: Cancer classification in most reports
      lead: PubChem's ECHA summary classifies indium phosphide as a cancer hazard in most reports that give codes. The classification varies between notifications, and no supplier safety data sheet was opened.
      points:
        - label: Classification
          line: PubChem's ECHA summary covers 211 company reports from 8 notifications. Of the reports that give codes, 98.1% list H350 (May cause cancer), 94.3% list H361 (Suspected of damaging fertility or the unborn child) and 98.1% list H372 (Causes damage to organs through prolonged or repeated exposure). The signal word is Danger.
        - label: Other notifications
          line: One notification reads Not Classified. Others list H350 and H372 with the signal word Danger.
        - label: Wafer packing
          line: Shalomeo packs its substrates in class 100 bags inside a class 1000 clean room. That is the only supplier handling statement that was read.
    - title: In service
      lead: No space failure data for InP were found. The radiation statements that were read carry no numbers.
      points:
        - label: Radiation
          line: Shalomeo says InP has good radiation stability, but it gives no dose, fluence or test result for that claim.
        - label: Surface
          line: Shalomeo gives a surface roughness of Ra ≤5 Å for polished substrates, printed as Ra:≤5A.
    - title: Handling and storage
      points:
        - label: Packaging
          line: Shalomeo ships the substrates in class 100 bags inside a class 1000 clean room. Keep them in those bags until use.
  why: Indium phosphide (InP) is a III-V semiconductor, made of indium and phosphorus in a 1:1 ratio, that is sold as a single-crystal substrate. Shalomeo lists its features as high electron mobility, good radiation stability and a large band gap, and gives a band gap of 1.344 eV at 300 K and an electron mobility of 5400 cm2/(V·s) at 300 K. Its main role is as the substrate for indium gallium arsenide, because the In0.53Ga0.47As alloy matches the InP lattice (Wikipedia).
  uses:
    - where: Photodiodes and detectors
      line: Most InGaAs devices are grown on InP substrates. For 1.1 μm to 1.7 μm, GaInAs photodiodes are the preferred choice, and the 53% indium composition has a cut-off of 1.68 μm at 295 K (Wikipedia).
    - where: High-frequency transistors
      line: Shalomeo says InP performs superiorly in high-power and high-frequency electronics. Wikipedia reports pseudomorphic heterojunction bipolar transistors that could operate at 604 GHz.
    - where: Telecom lasers and receivers
      line: USGS reports that InP lasers and receivers send data through fiber-optic lines in 5G networks, and that InP is used in high-speed photodetectors and laser diodes for optical communications.
  can_do:
    - label: Electron speed
      benchmark: electron_mobility
      value: 5400 cm2/(V·s) at 300 K
      line: Electron mobility is 5400 cm2/(V·s) at 300 K (Shalomeo). Surfacenet gives 3700 to 4000 cm2/ V-S for undoped N-type (100) crystal, so the exact figure depends on the material and its conditions.
    - label: Band gap
      benchmark: band_gap
      value: 1.344 eV at 300 K
      line: The band gap is 1.344 eV at 300 K (Shalomeo). The Wikipedia infobox describes this gap as direct.
    - label: Lattice match
      benchmark: lattice_constant
      value: 5.869 Å
      line: The lattice constant is 5.869 Å (Shalomeo). Wikipedia gives 5.869 Å at 295 K for the In0.53Ga0.47As alloy, which matches InP at that temperature.
    - label: Heat conduction
      benchmark: thermal_conductivity
      value: 0.68 W/(cm·K)
      line: Thermal conductivity is 0.68 W/(cm·K) at 300 K (Shalomeo).
  compare: Indium phosphide sits with the other III-V compound semiconductors in this collection. Compared with gallium arsenide, the figures we hold put InP at a smaller band gap and a lower electron mobility at 300 K. InP's main role is as the substrate on which InGaAs devices are grown. The table compares InP with the other semiconductors in this collection on density, band gap and electron mobility.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Band gap
      benchmark: band_gap
    - label: Electron mobility
      benchmark: electron_mobility
  handling:
    - Treat the material as a cancer hazard until the supplier's safety data sheet says otherwise, because PubChem's ECHA summary gives H350 for 98.1% of reports that list codes.
    - Keep substrates in the clean-room bags they are shipped in until use.
    - Get the supplier's safety data sheet before cutting, etching or grinding InP.
  good_for:
    - Substrates for InGaAs detectors and photodiodes, where the InP lattice matches In0.53Ga0.47As at 295 K.
    - High-frequency transistors. Wikipedia reports pseudomorphic transistors that could operate at 604 GHz.
    - Telecom lasers and receivers, which USGS says carry fiber-optic traffic in 5G networks.
  watch_out:
    - 'Cancer classification: PubChem''s ECHA summary gives H350 for 98.1% of reports that list codes.'
    - 'Supply: China produced 70% of world indium (USGS), China added indium to new export restrictions in February 2025, and the United States imports all of its indium.'
    - 'Melting point: 1062 °C from Shalomeo and Wikipedia, but 1330 °C from Surfacenet.'
    - No space flight or radiation-dose data for InP were found, so the space case rests on supplier statements.
  verdict: InP is the lattice-matched substrate for InGaAs detectors and a fast-electron material for high-frequency and telecom devices. The supplier and database pages agree on density, band gap and lattice constant, but they disagree on the melting point, and the mobility figures need their conditions. The cancer classification and dependence on Chinese indium supply are the points to watch. This profile has no space flight data.