Silicon Si
Si, elemental silicon, supplied as single-crystal wafers grown by Czochralski (CZ) or float-zone (FZ) methods
Silicon is the element Si, used as single-crystal wafers for chips and as the base material of most solar cells.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Act as a semiconductor
1.12 eV
Carry heat
150 W/(m·K)
Weight
2.328 g/cm3
Recipe, share of the weight
- Si 100%Silicon
Best for
Semiconductor wafers: a 1.12 eV band gap at 300 K and a well-documented resistivity range from doping
Weakest at
Light emission and heat flow: an indirect band gap (not stated in the sources read) and thermal conductivity of 150 W/(m·K), well below metals
Risk at a glance
- People Low. Low concern in the aggregate; check the supplier SDS for
- If it fails No data. No failure risks recorded
- Corrosion Low. Silicon forms a thin native oxide in air at room temperature.
Quick facts: Si
| Property | Value | Basis |
|---|---|---|
| Density | 2.33 g/cm³ | 1 sourced value |
| Thermal conductivity | 150 W/(m·K) | 2 sourced values across conditions |
| Melting point | 1,415 °C | 1 sourced value |
What is the density of Silicon?
Silicon has a density of 2.33 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Silicon?
Silicon has a thermal conductivity of 150 W/(m·K). The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the melting point of Silicon?
Silicon has a melting point of 1,415 °C. The source and test conditions are listed in the properties table on this page.
What is Silicon used for?
Uses recorded in the sources include Single-crystal silicon wafer substrate; Semiconductor chips; Silicon solar cell.
Why it exists
Silicon is the semiconductor used for chips and, in the user brief, for solar cells. The sources read here give its density as 2.328 g/cm3, its band gap as 1.12 eV at 300 K, and its melting point as 1415 °C. Its electrical properties change with doping, which is why suppliers sell it as wafers across a wide resistivity range.
Where it's used
Wafers
Single-crystal silicon is sold as wafers grown by Czochralski or float-zone methods. The supplier table covers resistivity from 0.001 to 50 Ω·cm for CZ boron-doped grades, and from 0.01 to 10000 Ω·cm for float-zone grades.
Recipe
Si, elemental silicon, supplied as single-crystal wafers grown by Czochralski (CZ) or float-zone (FZ) methods
Silicon is the element Si, atomic weight 28.085 (PubChem). Commercial single crystals are made by the Czochralski process: polysilicon is melted at just above its melting point in a silica crucible under 10 to 200 mbar of argon, a seed is dipped in and slowly pulled, and the crystal is grown to diameters up to 300 mm. The LMU review says about 95 % of world silicon single-crystal production uses this process.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Silicon Si | 100% | Element. The crystal is pure silicon, doped with boron or phosphorus to set resistivity. |
Weight shares are as printed in the sources.
What it can do
Act as a semiconductor
1.12 eV
measured
At 300 K the band gap is 1.12 eV in one table and 1.1242 eV in another, so the two sources agree to about one per cent.
Carry heat
150 W/(m·K)
measured
The printed thermal conductivity is 150 W/(m·K) with no temperature stated, or 1.5 W/(cm·°C) at 300 K in a second table.
Weight
2.328 g/cm3
measured
Density is printed as 2.328 g/cm3.
How it compares
Intrinsic silicon at 300 K has a resistivity of 230000 Ω·cm, while a CZ boron-doped grade can be as low as 0.001 Ω·cm. Doping changes the resistance by many orders of magnitude. The intrinsic carrier concentration is printed as 1.0e10 cm-3 in one source and 1.45e10 cm-3 in another, both at 300 K. Check which edition a design rule is based on.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | Si | Ge | SiGe | As | B |
|---|---|---|---|---|---|
| Thermal behavior and safety | |||||
| Melting pointValue printed in a materials property table | 1415 °C | 937 °C | no data | 817 °C | 2075 °C |
| Thermal conductivityValue printed in a materials property table | 150 W/(m·K) | 58.62 W/(m·K) | no data | 50 W m-1 K-1 | 27 W/(m·K) |
| Thermal conductivity (300 K table)Value printed in a materials property table | 1.5 W/(cm·°C) | 58.62 W/(m·K) | no data | 50 W m-1 K-1 | 27 W/(m·K) |
| Physical and electrical | |||||
| DensityValue printed in a materials property table | 2.328 g/cm³ | 5.327 g/cm³ | 4.31 g/cm³ | 5727 kg/m3 | 2.35 g/cm³ |
| Intrinsic resistivityValue printed in a materials property table | 2.3×10^5 Ω·cm | 47 Ω·cm | no data | no data | no data |
| Effective density of states, conduction bandValue printed in a materials property table | 3×10^19 cm-3 | no data | no data | no data | no data |
| Effective density of states, valence bandValue printed in a materials property table | 1×10^19 cm-3 | no data | no data | no data | no data |
| Resistivity range, CZ boron-doped (p-type) waferSupplier resistivity range for the grade | 0.001 Ω·cm1 | no data | no data | no data | no data |
| Resistivity range, CZ phosphorus-doped (n-type) waferSupplier resistivity range for the grade | 1 Ω·cm2 | no data | no data | no data | no data |
| Resistivity range, float-zone waferSupplier resistivity range for the grade | 0.01 Ω·cm | no data | no data | no data | no data |
| Other measurements | |||||
| Lattice constantValue printed in a materials property table | 0.5431 nm | 5.646 Å | no data | 376 pm | no data |
| Energy band gap (table at 300 K)Value printed in a materials property table | 1.12 eV | 0.66 eV | no data | no data | no data |
| Energy band gap (no temperature stated)Value printed in a materials property table | 1.124 eV | 0.66 eV | no data | no data | no data |
| Intrinsic carrier concentration (300 K table)Value printed in a materials property table | 1.45×10^10 cm-3 | no data | no data | no data | no data |
| Intrinsic carrier concentration (updated values)Value printed in a materials property table | 1×10^10 cm-3 | no data | no data | no data | no data |
| Electron drift mobilityValue printed in a materials property table | 1500 cm²/(V·s) | 3900 cm²/(V·s) | no data | no data | no data |
| Hole drift mobilityValue printed in a materials property table | 475 cm²/(V·s) | 1900 cm²/(V·s) | no data | no data | no data |
| Relative permittivityValue printed in a materials property table | 11.7 dimensionless | no data | no data | no data | no data |
| Dielectric constant (300 K table)Value printed in a materials property table | 11.9 dimensionless | no data | no data | no data | no data |
| Carbon concentration, CZ siliconSupplier specification | 0.5 ppma | no data | no data | no data | no data |
| Oxygen concentration, CZ siliconSupplier specification, standard grade | 24 ppma | no data | no data | no data | no data |
Why choose it, and why not
Good for
- label: Wafers with a set resistivity line: Doping sets the resistivity, and suppliers quote it as a range per dopant and growth method.
Watch out for
- label: Mixed sources line: Some values carry no temperature, so compare only figures that state the same condition.
- label: Thermal conductivity line: At 150 W/(m·K) silicon conducts heat far less well than copper, a fact that matters for thermal control.
Silicon is a well-documented semiconductor. Its band gap, density and melting point are printed in more than one source, and its resistivity is set by doping. Its hazards are low in the PubChem aggregate. Radiation numbers and acid or alkali corrosion are not covered by the sources read here.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Resistivity range, CZ boron-doped (p-type) wafer | — | dopant boron, p-typegrowth Czochralski (CZ)temperature not stated | — |
| 2 | Resistivity range, CZ phosphorus-doped (n-type) wafer | — | dopant phosphorus, n-typegrowth Czochralski (CZ)temperature not stated | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Ambient air, room temperature | low | Silicon forms a thin native oxide in air at room temperature.1 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Ambient air, room temperature | A 2013 J. Phys. Chem. C paper on oxidation of silicon gives a native oxide about 10 Å (1 nm) thick and calls it a poor dielectric, so it is usually removed before oxidation for microelectronics. | basis Thickness from the paper; the low rating is the assistant's reading of a thin oxide, not a printed rating |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The PubChem aggregate for silicon is mostly "not classified" (3,142 of 3,263 reports). A minority of reports give H228 (flammable solid) and H320 (eye irritation). Low concern in the aggregate; check the supplier SDS for the form
- Silicon as a substance
- PubChem's aggregate lists H228 and H320 from a small share of reports. No exposure limit was read in this run, so none is given here.
If it fails
Failure routes found in the sources are about the wafer grade, not about hazards.
- Wrong resistivity
- A supplier gives CZ boron-doped wafers a resistivity range of 0.001 to 50 Ω·cm, so the grade has to be chosen for the device, or the wafer will not behave as intended.
- Oxygen content
- CZ silicon carries oxygen in the range 24 to 38 ppma under ASTM F121-76, a value the supplier lists as standard.
Handling and storage
- Keep to the grade
- Choose the growth method and dopant from the supplier table. The sources read here give no storage advice.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Wafer grade mismatch: a supplier gives CZ boron-doped wafers a resistivity range | Wafer grade mismatch: a supplier gives CZ boron-doped wafers a resistivity range of 0.001 to 50 Ω·cm, so the wrong dopant or growth method changes the device behaviour. |
Handling and storage
- Keep away from heat, sparks and open flames, as the PubChem GHS entry for the flammable-solid class advises. The entry is an aggregate and applies to the form handled; check the supplier SDS for wafer or powder.
Supply and geography
How common the raw materials are and where they come from.
Silicon metal and silicon materials (feedstock for chips, solar-grade polysilicon, aluminium alloys and silicones)
World and domestic resources are abundant; the source of silicon is silica (quartzite).
- Top producers (2025)
- China 87%, Brazil 3.9%, Norway 2.8%
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
Show the full YAML
spore: profile
id: silicon
spore_version: 0.2
family: semiconductor-materials
name: Silicon
abbreviation: Si
role: semiconductor
category: semiconductors
type: silicon
summary: |
Silicon is the element Si, used as single-crystal wafers for chips and as the base material of most solar cells. The sources read for this profile give a density of 2.328 g/cm3, a band gap of 1.12 eV at 300 K, a melting point of 1415 °C and a relative permittivity of 11.9 at 300 K. Its electrical behaviour depends strongly on doping: a supplier table gives CZ boron-doped wafers a resistivity range of 0.001 to 50 Ω·cm.
best_for: 'Semiconductor wafers: a 1.12 eV band gap at 300 K and a well-documented resistivity range from doping'
weakest_at: 'Light emission and heat flow: an indirect band gap (not stated in the sources read) and thermal conductivity of 150 W/(m·K), well below metals'
identity:
formula: Si, elemental silicon, supplied as single-crystal wafers grown by Czochralski (CZ) or float-zone (FZ) methods
source: pveducation
where: Atomic weight row and Section 9 Material Properties (atomic weight printed as 28.09)
tags:
environments: []
stresses: []
applications:
- electronics-and-chips
- solar-arrays
properties:
- benchmark: density
label: Density
value: 2.328
unit: g/cm3
scope: material
conditions:
temperature: not stated on the page
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row Density (ρ)
- benchmark: lattice_constant
label: Lattice constant
value: 0.543095
unit: nm
scope: material
conditions:
temperature: not stated on the page
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row Lattice constant
- benchmark: bandgap
label: Energy band gap (table at 300 K)
value: 1.12
unit: eV
scope: material
conditions:
temperature: 300 K (table title)
method: Value printed in a materials property table
status: ground
source: eesemi
where: Table Properties of Silicon (Si), Germanium (Ge), and Gallium Arsenide (GaAs) at 300 deg K, row Energy Gap at 300K
- benchmark: bandgap
label: Energy band gap (no temperature stated)
value: 1.1242
unit: eV
scope: material
conditions:
temperature: not stated on the page
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row Energy bandgap (EG)
- benchmark: intrinsic_carrier_concentration
label: Intrinsic carrier concentration (300 K table)
value: 14500000000
unit: cm-3
scope: material
conditions:
temperature: 300 K (table title)
method: Value printed in a materials property table
status: ground
source: eesemi
where: Table at 300 deg K, row Intrinsic Carrier Concentration
- benchmark: intrinsic_carrier_concentration
label: Intrinsic carrier concentration (updated values)
value: 10000000000
unit: cm-3
scope: material
conditions:
temperature: 300 K
basis: 'footnote: updated values from Sproul, Green and Zhao (1990) and Sproul and Green (1991)'
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row Intrinsic carrier concentration (ni) at 300K
- benchmark: electron_mobility
label: Electron drift mobility
value: 1500
unit: cm2/(V·s)
scope: material
conditions:
temperature: 300 K (table title)
type: drift mobility, doping not stated
method: Value printed in a materials property table
status: ground
source: eesemi
where: Table at 300 deg K, row Mobility (Drift), electrons
- benchmark: hole_mobility
label: Hole drift mobility
value: 475
unit: cm2/(V·s)
scope: material
conditions:
temperature: 300 K (table title)
type: drift mobility, doping not stated
method: Value printed in a materials property table
status: ground
source: eesemi
where: Table at 300 deg K, row Mobility (Drift), holes
- benchmark: intrinsic_resistivity
label: Intrinsic resistivity
value: 230000
unit: Ω·cm
scope: material
conditions:
temperature: 300 K (table title)
doping: intrinsic, undoped
method: Value printed in a materials property table
status: ground
source: eesemi
where: Table at 300 deg K, row Intrinsic Resistivity (printed as 2.3 x 10^5)
- benchmark: relative_permittivity
label: Relative permittivity
value: 11.7
unit: dimensionless
scope: material
conditions:
temperature: not stated on the page
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row Relative permittivity (εr)
- benchmark: relative_permittivity
label: Dielectric constant (300 K table)
value: 11.9
unit: dimensionless
scope: material
conditions:
temperature: 300 K (table title)
method: Value printed in a materials property table
status: ground
source: eesemi
where: Table at 300 deg K, row Dielectric Constant (no unit printed)
- benchmark: melting_point
label: Melting point
value: 1415
unit: °C
scope: material
conditions:
basis: melting point as printed, no pressure or purity stated
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row Melting point
- benchmark: thermal_conductivity
label: Thermal conductivity
value: 150
unit: W/(m·K)
scope: material
conditions:
temperature: not stated on the page
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row Thermal conductivity (printed as 1.5 W cm-1K-1 and 150 W m-1K-1)
- benchmark: thermal_conductivity
label: Thermal conductivity (300 K table)
value: 1.5
unit: W/(cm·°C)
scope: material
conditions:
temperature: 300 K
method: Value printed in a materials property table
status: ground
source: eesemi
where: Table at 300 deg K, row Thermal Conductivity at 300 K
- benchmark: effective_density_of_states
label: Effective density of states, conduction band
value: 30000000000000000000
unit: cm-3
scope: material
conditions:
temperature: not stated on the page
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row NC
- benchmark: effective_density_of_states
label: Effective density of states, valence band
value: 10000000000000000000
unit: cm-3
scope: material
conditions:
temperature: not stated on the page
method: Value printed in a materials property table
status: ground
source: pveducation
where: Section 9 Material Properties, row NV
- benchmark: resistivity_range
label: Resistivity range, CZ boron-doped (p-type) wafer
value: 0.001
value_high: 50
unit: Ω·cm
scope: material
conditions:
dopant: boron, p-type
growth: Czochralski (CZ)
temperature: not stated
method: Supplier resistivity range for the grade
status: ground
source: elcat
where: Dopant table, row Boron (p-type Si:B), CZ
- benchmark: resistivity_range
label: Resistivity range, CZ phosphorus-doped (n-type) wafer
value: 1
value_high: 50
unit: Ω·cm
scope: material
conditions:
dopant: phosphorus, n-type
growth: Czochralski (CZ)
temperature: not stated
method: Supplier resistivity range for the grade
status: ground
source: elcat
where: Dopant table, row Phosphorus (n-type Si:P), CZ
- benchmark: resistivity_range
label: Resistivity range, float-zone wafer
value: 0.01
value_high: 10000
unit: Ω·cm
scope: material
conditions:
growth: float-zone (FZ) and CFZ
temperature: not stated
method: Supplier resistivity range for the grade
status: ground
source: elcat
where: Dopant table, FZ/CFZ rows for boron and phosphorus
- benchmark: carbon_concentration
label: Carbon concentration, CZ silicon
value: 0.5
unit: ppma
scope: material
conditions:
growth: Czochralski (CZ)
limit: maximum
method: Supplier specification
status: ground
source: elcat
where: Carbon concentration row, CZ silicon
- benchmark: oxygen_concentration
label: Oxygen concentration, CZ silicon
value: 24
value_high: 38
unit: ppma
scope: material
conditions:
growth: Czochralski (CZ)
standard: ASTM F121-76
method: Supplier specification, standard grade
status: ground
source: elcat
where: Oxygen concentration row, CZ silicon
corrosion:
- environment: Ambient air, room temperature
headline: Silicon forms a thin native oxide in air at room temperature.
effect: A 2013 J. Phys. Chem. C paper on oxidation of silicon gives a native oxide about 10 Å (1 nm) thick and calls it a poor dielectric, so it is usually removed before oxidation for microelectronics.
rating: low
conditions:
basis: Thickness from the paper; the low rating is the assistant's reading of a thin oxide, not a printed rating
source: khalilov-jpcc-2013
where: Abstract (native oxide thickness about 10 Å); Introduction, paragraph 2 (up to 1 nm, poor dielectric)
risks:
hazards:
- text: PubChem aggregates GHS reports for silicon from 3,263 company reports. Most reports (3,142) say it does not meet GHS hazard criteria. The rest give H228 (flammable solid) and H320 (causes eye irritation), signal word Danger.
ghs:
- 'H228: Flammable solid'
- 'H320: Causes eye irritation'
source: pubchem-si
where: Safety and Hazards, GHS Classification (CID 5461123)
- text: Precautionary statements listed with the GHS entry include P210 (keep away from heat, sparks and open flames), P280 (protective gloves) and P305+P351+P338 (eye rinsing).
ghs: []
source: pubchem-si
where: Safety and Hazards, GHS Classification precautionary statements
failure_risks:
- source: elcat
where: Dopant table, rows for boron and phosphorus, CZ
mode: 'Wafer grade mismatch: a supplier gives CZ boron-doped wafers a resistivity range'
consequence: 'Wafer grade mismatch: a supplier gives CZ boron-doped wafers a resistivity range of 0.001 to 50 Ω·cm, so the wrong dopant or growth method changes the device behaviour.'
side_effects: []
handling:
- text: Keep away from heat, sparks and open flames, as the PubChem GHS entry for the flammable-solid class advises. The entry is an aggregate and applies to the form handled; check the supplier SDS for wafer or powder.
source: pubchem-si
where: Safety and Hazards, precautionary statements P210
mitigations: []
uses:
- application: electronics-and-chips
device: Single-crystal silicon wafer substrate
example: Wafers grown by Czochralski or float-zone methods, sold by resistivity grade
source: elcat
where: Wafer specification page, product range
- application: electronics-and-chips
device: Semiconductor chips
example: Silicon metal is further processed into semiconductor-grade polysilicon for chips; the LMU review says CZ single crystal is the raw material for microelectronics
source: usgs-si-2026
where: Domestic Production and Use paragraph; LMU review, introduction
- application: solar-arrays
device: Silicon solar cell
example: NASA reports that Si solar cells are the most important case in its displacement-damage analysis, which models proton damage to cells
source: nasa-tp-2004-213338
where: Section 9, Quantifying low energy proton effects
supply:
- subject: Silicon metal and silicon materials (feedstock for chips, solar-grade polysilicon, aluminium alloys and silicones)
abundance: World and domestic resources are abundant; the source of silicon is silica (quartzite).
producers:
- country: China
share_percent: 87
year: 2025
basis: 'computed: 4,000 kt of 4,600 kt world silicon metal (USGS table, World Production)'
- country: Brazil
share_percent: 3.9
year: 2025
basis: 'computed: 180 kt of 4,600 kt'
- country: Norway
share_percent: 2.8
year: 2025
basis: 'computed: 130 kt of 4,600 kt'
us_position: 'US silicon metal imports were an estimated 180 kt in 2025, against 117 kt in 2024. Total net import reliance for ferrosilicon and silicon metal was above 50 % in 2025e. Silicon metal imports 2021 to 2024: Brazil 38 %, Canada 29 %, Norway 12 %.'
source: usgs-si-2026
where: Salient Statistics; Events, Trends, and Issues; Import Sources; World Production table
media: []
documents:
- title: EL-CAT silicon data sheet (CZ and FZ specifications)
type: datasheet
url: https://www.el-cat.com/dscsi.htm
- title: USGS Mineral Commodity Summaries 2026, Silicon
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silicon.pdf
- title: PubChem record for silicon (CID 5461123), GHS classification and identifiers
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/Silicon
- title: NASA TP-2004-213338, Displacement Damage Effects in Solar Cells, Mining Damage
type: report
url: https://ntrs.nasa.gov/api/citations/20050071537/downloads/20050071537.pdf
- title: Khalilov et al., New Mechanism for Oxidation of Native Silicon Oxide, J. Phys. Chem. C 2013
type: paper
url: https://medialibrary.uantwerpen.be/oldcontent/container2642/files/jpcc13newmechanisms.pdf
- title: Single-Crystal Growth of Silicon (Czochralski process), LMU Munich
type: paper
url: https://www.cup.lmu.de/ac/kluefers/homepage/publ_pdf/czochralski_engl.pdf
gaps:
- 'Indirect or direct band gap type: not stated in the sources read.'
- 'Crystal structure and space group: pveducation says the crystal structure is not named on its page; no other source read.'
- 'Electron and hole mobility at doping levels other than undoped: the pveducation mobility tables gave units only.'
- 'Corrosion in acids or alkalis (HF, KOH etch): not read in this run.'
- 'Float-zone process steps: not read in this run; only the CZ process is sourced.'
- 'Radiation damage: the NASA report gives the method and says Si solar cells are the key case, but its numeric values are in figures that were not readable as text, so no radiation number is given.'
- 'Crystal structure (diamond cubic): not confirmed on a fetched page in this run.'
- 'Critical-mineral list status: the EU and USGS critical lists were not checked for silicon in this run.'
- Intrinsic carrier concentration disagrees between sources (1.0e10 vs 1.45e10 cm-3 at 300 K); both are listed with their source.
- NIST WebBook silicon page gave only an Antoine vapour-pressure equation; no property from it was used.
- 'Only three sources were reached: ioffe.ru could not be fetched (TLS certificate error), and the Columbia lecture PDF and the microchemicals wafer PDF could not be read.'
sources:
pveducation:
title: PVEducation, General Properties of Silicon (Section 9, Material Properties)
url: https://www.pveducation.org/pvcdrom/materials/general-properties-of-silicon
kind: web
license: page content, cited as published
eesemi:
title: EE Semi, Properties of Silicon (Si), Germanium (Ge), and Gallium Arsenide (GaAs) at 300 deg K
url: https://www.eesemi.com/sigegaas.htm
kind: web
license: page content, cited as published
elcat:
title: EL-CAT, Silicon data sheet (CZ and FZ dopant, resistivity and specification tables)
url: https://www.el-cat.com/dscsi.htm
kind: datasheet
license: page content, cited as published
usgs-si-2026:
title: USGS Mineral Commodity Summaries 2026, Silicon
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silicon.pdf
kind: report
license: public domain (USGS), cited as published
pubchem-si:
title: PubChem, Silicon (CID 5461123), GHS classification
url: https://pubchem.ncbi.nlm.nih.gov/compound/Silicon
kind: database
license: public domain (NCBI), cited as published
nasa-tp-2004-213338:
title: NASA/TP-2004-213338, Displacement Damage Effects in Solar Cells, Mining Damage (S.R. Messenger)
url: https://ntrs.nasa.gov/api/citations/20050071537/downloads/20050071537.pdf
kind: report
license: public domain (NASA), cited as published
khalilov-jpcc-2013:
title: Khalilov et al., New Mechanism for Oxidation of Native Silicon Oxide, J. Phys. Chem. C 2013, 117, 9819-9825
url: https://medialibrary.uantwerpen.be/oldcontent/container2642/files/jpcc13newmechanisms.pdf
kind: paper
license: author copy, cited as published
lmu-cz-2008:
title: Single-Crystal Growth of Silicon (Czochralski process), LMU Munich, English version
url: https://www.cup.lmu.de/ac/kluefers/homepage/publ_pdf/czochralski_engl.pdf
kind: paper
license: author copy, cited as published
license: CC-BY-4.0
checked_values: 21
updated: '2026-10-19'
story:
risk_groups:
- title: For people
lead: The PubChem aggregate for silicon is mostly "not classified" (3,142 of 3,263 reports). A minority of reports give H228 (flammable solid) and H320 (eye irritation). Low concern in the aggregate; check the supplier SDS for the form
level: 1
verdict: Low concern in the aggregate; check the supplier SDS for
points:
- label: Silicon as a substance
line: PubChem's aggregate lists H228 and H320 from a small share of reports. No exposure limit was read in this run, so none is given here.
- title: If it fails
lead: Failure routes found in the sources are about the wafer grade, not about hazards.
points:
- label: Wrong resistivity
line: A supplier gives CZ boron-doped wafers a resistivity range of 0.001 to 50 Ω·cm, so the grade has to be chosen for the device, or the wafer will not behave as intended.
- label: Oxygen content
line: CZ silicon carries oxygen in the range 24 to 38 ppma under ASTM F121-76, a value the supplier lists as standard.
- title: Handling and storage
points:
- label: Keep to the grade
line: Choose the growth method and dopant from the supplier table. The sources read here give no storage advice.
recipe:
line: 'Silicon is the element Si, atomic weight 28.085 (PubChem). Commercial single crystals are made by the Czochralski process: polysilicon is melted at just above its melting point in a silica crucible under 10 to 200 mbar of argon, a seed is dipped in and slowly pulled, and the crystal is grown to diameters up to 300 mm. The LMU review says about 95 % of world silicon single-crystal production uses this process.'
parts:
- name: Silicon
symbol: Si
share_percent: 100
atomic_weight: 28.085
role: Element. The crystal is pure silicon, doped with boron or phosphorus to set resistivity.
source: pubchem-si
where: Compound record, Molecular Weight (CID 5461123)
why: Silicon is the semiconductor used for chips and, in the user brief, for solar cells. The sources read here give its density as 2.328 g/cm3, its band gap as 1.12 eV at 300 K, and its melting point as 1415 °C. Its electrical properties change with doping, which is why suppliers sell it as wafers across a wide resistivity range.
uses:
- where: Wafers
line: Single-crystal silicon is sold as wafers grown by Czochralski or float-zone methods. The supplier table covers resistivity from 0.001 to 50 Ω·cm for CZ boron-doped grades, and from 0.01 to 10000 Ω·cm for float-zone grades.
can_do:
- label: Act as a semiconductor
value: 1.12 eV
benchmark: bandgap
line: At 300 K the band gap is 1.12 eV in one table and 1.1242 eV in another, so the two sources agree to about one per cent.
- label: Carry heat
value: 150 W/(m·K)
benchmark: thermal_conductivity
line: The printed thermal conductivity is 150 W/(m·K) with no temperature stated, or 1.5 W/(cm·°C) at 300 K in a second table.
- label: Weight
value: 2.328 g/cm3
benchmark: density
line: Density is printed as 2.328 g/cm3.
compare: Intrinsic silicon at 300 K has a resistivity of 230000 Ω·cm, while a CZ boron-doped grade can be as low as 0.001 Ω·cm. Doping changes the resistance by many orders of magnitude. The intrinsic carrier concentration is printed as 1.0e10 cm-3 in one source and 1.45e10 cm-3 in another, both at 300 K. Check which edition a design rule is based on.
good_for:
- 'label: Wafers with a set resistivity line: Doping sets the resistivity, and suppliers quote it as a range per dopant and growth method.'
watch_out:
- 'label: Mixed sources line: Some values carry no temperature, so compare only figures that state the same condition.'
- 'label: Thermal conductivity line: At 150 W/(m·K) silicon conducts heat far less well than copper, a fact that matters for thermal control.'
verdict: Silicon is a well-documented semiconductor. Its band gap, density and melting point are printed in more than one source, and its resistivity is set by doping. Its hazards are low in the PubChem aggregate. Radiation numbers and acid or alkali corrosion are not covered by the sources read here.
handling:
- Silicon wafers are made to a resistivity grade. Pick the dopant and growth method from the supplier table, and check the supplier SDS for the form handled.
compare_rows:
- scope: material
label: Density
benchmark: density
- scope: material
label: Melting point
benchmark: melting_point
- scope: material
label: Thermal conductivity
benchmark: thermal_conductivity
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| PVEducation, General Properties of Silicon (Section 9, Material Properties) | web | 10 values | ||
| EE Semi, Properties of Silicon (Si), Germanium (Ge), and Gallium Arsenide (GaAs) at 300 deg K | web | 7 values | ||
| EL-CAT, Silicon data sheet (CZ and FZ dopant, resistivity and specification tables) | datasheet | 7 values | ||
| USGS Mineral Commodity Summaries 2026, Silicon | report | 2 values | ||
| PubChem, Silicon (CID 5461123), GHS classification | database | 3 values | ||
| NASA/TP-2004-213338, Displacement Damage Effects in Solar Cells, Mining Damage (S.R. Messenger) | report | 1 value | ||
| Khalilov et al., New Mechanism for Oxidation of Native Silicon Oxide, J. Phys. Chem. C 2013, 117, 9819-9825 | paper | 1 value | ||
| Single-Crystal Growth of Silicon (Czochralski process), LMU Munich, English version | paper | 0 values |