Gallium oxide (beta-Ga2O3) Ga2O3
Ga2O3 (beta polymorph of gallium(III) oxide, two gallium atoms and three oxygen atoms per formula unit) · CAS 12024-21-4
Beta-gallium oxide (beta-Ga2O3) is an ultra-wide-bandgap semiconductor.
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.
Band gap
4.8 eV
Electron mobility
300 cm2/(V·s)
Thermal conductivity
10 to 30 W/mK
Recipe, share of the weight
- Ga not statedGallium
- O not statedOxygen
Best for
Power switching devices where a wide band gap of 4.8 eV and an estimated breakdown field of 8 MV/cm matter (per the 2019 review)
Weakest at
Thermal conductivity of 10 to 30 W/mK (Table 1 of the 2019 review, temperature not stated), and no space or radiation data in the sources read here
Risk at a glance
- People No data. No hazard data recorded
- If it fails No data. No failure risks recorded
- Corrosion No data. No corrosion data recorded
Quick facts: Ga2O3
| Property | Value | Basis |
|---|---|---|
| Density | 5.88 g/cm³ | 1 sourced value |
| Thermal conductivity | 10 to 30 W/(m·K) | 4 sourced values across conditions |
What is the density of Gallium oxide (beta-Ga2O3)?
Gallium oxide (beta-Ga2O3) has a density of 5.88 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Gallium oxide (beta-Ga2O3)?
Gallium oxide (beta-Ga2O3) has a thermal conductivity of 10 to 30 W/(m·K). The range covers 4 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 Gallium oxide (beta-Ga2O3) used for?
Uses recorded in the sources include Field-plated MOSFET (research device in the review); GOOI FET (research device in the review).
Why it exists
Beta-gallium oxide (beta-Ga2O3) is an ultra-wide-bandgap semiconductor. The 2019 review in Journal of Semiconductors gives a band gap of 4.8 eV and an estimated breakdown field of 8 MV/cm. Its Baliga figure of merit is printed as 3200 relative to silicon, which the review uses as a guide to power-device performance. The review also notes that melt-grown substrates could be lower cost. No space or radiation test is taken from the sources read here.
Where it's used
Power transistors (research devices)
The review reports a field-plated MOSFET with a breakdown voltage of 1850 V, and GOOI FETs with an on/off ratio of 10^10. These are laboratory devices described in the review, not commercial parts.
Recipe
Ga2O3 (beta polymorph of gallium(III) oxide, two gallium atoms and three oxygen atoms per formula unit)
Beta-Ga2O3 is gallium(III) oxide, a compound of two gallium atoms and three oxygen atoms. The 2019 review names the stable form beta-Ga2O3.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Gallium Ga | not stated | The metal cation in the oxide. The review gives no process route for the Ga2O3 crystal, so none is described here. |
| Oxygen O | not stated | Bonded to the gallium atoms in the oxide lattice. Oxygen content sets the stoichiometry of the compound. |
Weight shares are as printed in the sources.
What it can do
Band gap
4.8 eV
measured
The review gives a band gap of 4.8 eV in Table 1. The abstract gives a range of 4.5 to 4.8 eV.
Electron mobility
300 cm2/(V·s)
measured
The review gives a carrier mobility of 300 cm2/(V·s) in Table 1. The abstract gives an intrinsic limit of 250 cm2/(V·s).
Thermal conductivity
10 to 30 W/mK
measured
Table 1 of the review gives a thermal conductivity of 10 to 30 W/mK, with no test temperature stated.
How it compares
Table 1 of the review also prints values for silicon, GaAs, 4H-SiC, GaN and diamond. Only the beta-Ga2O3 column is entered in this profile. The Baliga figure of merit relative to silicon is 3200 in Table 1 and more than 3000 in the abstract.
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. Compare every grade in the family.
| Measurement | Ga2O3 |
|---|---|
| Thermal behavior and safety | |
| Thermal conductivity, beta-Ga2O3 (range)Range printed in Table 1 of the review | 10 to 30 W/mK |
| Thermal conductivity, beta-Ga2O3 along [100], room temperature | 10.9 W/mK12 |
| Thermal conductivity, beta-Ga2O3 along [010], room temperature | 27 W/mK13 |
| Thermal conductivity, beta-Ga2O3 along [100], room temperature, 3 omega method | 13 W/mK14 |
| Physical and electrical | |
| Relative density, gallium(III) oxide powder | 5.88 g/mL8 |
| Other measurements | |
| Band gap, beta-Ga2O3 | 4.8 eV1 |
| Critical (breakdown) electric field, beta-Ga2O3 | 8 MV/cm2 |
| Intrinsic electron mobility limit, beta-Ga2O3Value printed in the abstract of the review | 250 cm²/(V·s)3 |
| Carrier mobility, beta-Ga2O3Value printed in Table 1 of the review | 300 cm²/(V·s)4 |
| dielectric constant | 11 -5 |
| Saturation velocity, beta-Ga2O3 | 2 10^7 cm/s6 |
| Baliga figure of merit relative to siliconRatio printed in Table 1 of the review | 3200 -7 |
| Johnson figure of merit relative to silicon, beta-Ga2O3 | 2844 -9 |
| Baliga high-frequency figure of merit relative to silicon, beta-Ga2O3 | 142 -10 |
| Keyes figure of merit relative to silicon, beta-Ga2O3 | 0.2 -11 |
Why choose it, and why not
Good for
- Power switching where a 4.8 eV band gap and an estimated 8 MV/cm breakdown field matter, per the 2019 review.
- Power device research where the review's Baliga figure of merit, 3200 relative to silicon, is the target.
Watch out for
- Thermal conductivity of 10 to 30 W/mK in Table 1, with no test temperature stated.
- The review's abstract and Table 1 disagree on electron mobility, 250 against 300 cm2/(V·s).
- Most device figures in the review are for laboratory devices, not production parts.
Beta-Ga2O3 has a wide band gap of 4.8 eV and an estimated breakdown field of 8 MV/cm in the 2019 review. This profile has no corrosion, radiation or space data, so no space verdict is possible from it.
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 | Band gap, beta-Ga2O3 | Value printed in Table 1 of an open-access review of gallium oxide power devices | polymorph beta-Ga2O3temperature not stated | The abstract of the same review gives a range of 4.5 to 4.8 eV, so the value depends on the source. |
| 2 | Critical (breakdown) electric field, beta-Ga2O3 | Estimated value printed in the abstract and in Table 1 of the review; not a measured breakdown test | polymorph beta-Ga2O3basis described as estimated in the abstract; no test condition given | — |
| 3 | Intrinsic electron mobility limit, beta-Ga2O3 | — | polymorph beta-Ga2O3basis intrinsic limit, as printed in the abstract | Table 1 of the same review gives a carrier mobility of 300 cm2/(V·s), so the abstract and table disagree. Both values are kept. |
| 4 | Carrier mobility, beta-Ga2O3 | — | polymorph beta-Ga2O3temperature not stated | The abstract gives an intrinsic limit of 250 cm2/(V·s), which differs from this table value. |
| 5 | dielectric constant | Value printed in Table 1 of the review (dimensionless) | polymorph beta-Ga2O3temperature not stated | — |
| 6 | Saturation velocity, beta-Ga2O3 | Value printed in Table 1 of the review, in the unit the table prints | polymorph beta-Ga2O3temperature not stated | — |
| 7 | Baliga figure of merit relative to silicon | — | polymorph beta-Ga2O3basis ratio to silicon, where silicon equals 1; not an absolute figuretemperature not stated | The abstract describes this figure of merit as more than 3000 relative to silicon, which is consistent with the table value. |
| 8 | Relative density, gallium(III) oxide powder | Relative density printed in Section 9.1 of the supplier SDS; a supplier value for the powder, not a crystal measurement | form powder, white (Aldrich product 215066)temperature 25 °C | The SDS gives 5.88 g/mL for the powder. No density for a single beta-Ga2O3 crystal is printed in any source read in this run. |
| 9 | Johnson figure of merit relative to silicon, beta-Ga2O3 | Ratio printed in Table 1 of the review, Johnson FOM row | polymorph beta-Ga2O3basis ratio to silicon, where silicon equals 1temperature not stated | — |
| 10 | Baliga high-frequency figure of merit relative to silicon, beta-Ga2O3 | Ratio printed in Table 1 of the review, Baliga High Frequency FOM row | polymorph beta-Ga2O3basis ratio to silicon, where silicon equals 1temperature not stated | — |
| 11 | Keyes figure of merit relative to silicon, beta-Ga2O3 | Ratio printed in Table 1 of the review, Keyes FOM row | polymorph beta-Ga2O3basis ratio to silicon, where silicon equals 1temperature not stated | — |
| 12 | Thermal conductivity, beta-Ga2O3 along [100], room temperature | Time-domain thermoreflectance on single crystals; value printed in the abstract | polymorph beta-Ga2O3direction [100]temperature room temperature | Printed as 10.9 ± 1.0 W/mK. The ± 1.0 is the uncertainty the paper prints. |
| 13 | Thermal conductivity, beta-Ga2O3 along [010], room temperature | Time-domain thermoreflectance on single crystals; value printed in the abstract | polymorph beta-Ga2O3direction [010]temperature room temperature | Printed as 27.0 ± 2.0 W/mK. The ± 2.0 is the uncertainty the paper prints. |
| 14 | Thermal conductivity, beta-Ga2O3 along [100], room temperature, 3 omega method | Electrical 3 omega method on bulk crystals; value printed in the abstract | polymorph beta-Ga2O3direction [100]temperature room temperaturecrystal Czochralski-grown bulk crystals, Mg-doped and undoped | Printed as 13 ± 1 W/mK, the uncertainty the paper prints. It is a second method on a different crystal set from the TDTR values above. |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
Two supplier safety data sheets for gallium(III) oxide disagree. The Aldrich sheet (product 215066) lists no classification, and the ChemicalBook sheet prints the hazard statements H315, H319 and H335.
- Check the supplier sheet
- PubChem returned a reCAPTCHA page and American Elements returned an access error. Check the safety data sheet for the lot you handle before handling powder or wafers.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Reaction with strong oxidizing agents | Contact with strong oxidizing agents, which the Aldrich SDS lists as incompatibleThe SDS gives no reaction products or rates: reactivity and hazardous reactions are 'no data available'. |
| Fire | Exposure to a fireThe SDS says the product does not burn and lists gallium oxides as the special fire hazard. Flash point is 'not applicable'. |
Handling and storage
- Aldrich SDS: provide exhaust ventilation where dust forms, avoid dust formation, keep the container tightly closed in a dry and well-ventilated place, and do not let the product enter drains. Wear gloves and eye protection.
Supply and geography
How common the raw materials are and where they come from.
Gallium (the metal from which Ga2O3 is made)
Average gallium content of bauxite is 50 parts per million (USGS, World Resources)
- Top producers (2025)
- China 99%
- Critical mineral lists
- US: listed, EU: listed
- Recycling
- USGS: old scrap none. Substantial new scrap from GaAs device manufacture is reprocessed to recover high-purity gallium at one facility in New York.
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: gallium-oxide
spore_version: 0.2
family: semiconductor-materials
name: Gallium oxide (beta-Ga2O3)
abbreviation: Ga2O3
role: ultra-wide-bandgap power semiconductor
category: semiconductors
type: ga2o3
summary: |
Beta-gallium oxide (beta-Ga2O3) is an ultra-wide-bandgap semiconductor. The 2019 review in Journal of Semiconductors gives a band gap of 4.8 eV and an estimated critical (breakdown) field of 8 MV/cm for the beta phase. Its Table 1 gives a Baliga figure of merit of 3200 relative to silicon (Si = 1). Table 1 also gives a thermal conductivity of 10 to 30 W/mK. No radiation, space or corrosion test of this material was read in this run.
best_for: Power switching devices where a wide band gap of 4.8 eV and an estimated breakdown field of 8 MV/cm matter (per the 2019 review)
weakest_at: Thermal conductivity of 10 to 30 W/mK (Table 1 of the 2019 review, temperature not stated), and no space or radiation data in the sources read here
identity:
formula: Ga2O3 (beta polymorph of gallium(III) oxide, two gallium atoms and three oxygen atoms per formula unit)
cas: 12024-21-4
source: wiki-ga2o3
where: Identifiers box of the Wikipedia article (CAS number only; no other identifiers taken from it)
tags:
environments: []
stresses: []
applications:
- electronics-and-chips
properties:
- benchmark: band_gap
label: Band gap, beta-Ga2O3
value: 4.8
unit: eV
scope: material
conditions:
polymorph: beta-Ga2O3
temperature: not stated
method: Value printed in Table 1 of an open-access review of gallium oxide power devices
status: ground
note: The abstract of the same review gives a range of 4.5 to 4.8 eV, so the value depends on the source.
source: jos-ga2o3-review
where: Table 1 (material parameters), row Bandgap
- benchmark: breakdown_field
label: Critical (breakdown) electric field, beta-Ga2O3
value: 8
unit: MV/cm
scope: material
conditions:
polymorph: beta-Ga2O3
basis: described as estimated in the abstract; no test condition given
method: Estimated value printed in the abstract and in Table 1 of the review; not a measured breakdown test
status: ground
source: jos-ga2o3-review
where: Abstract; Table 1, row Critical field (EC)
- benchmark: electron_mobility
label: Intrinsic electron mobility limit, beta-Ga2O3
value: 250
unit: cm2/(V·s)
scope: material
conditions:
polymorph: beta-Ga2O3
basis: intrinsic limit, as printed in the abstract
method: Value printed in the abstract of the review
status: ground
note: Table 1 of the same review gives a carrier mobility of 300 cm2/(V·s), so the abstract and table disagree. Both values are kept.
source: jos-ga2o3-review
where: Abstract
- benchmark: electron_mobility
label: Carrier mobility, beta-Ga2O3
value: 300
unit: cm2/(V·s)
scope: material
conditions:
polymorph: beta-Ga2O3
temperature: not stated
method: Value printed in Table 1 of the review
status: ground
note: The abstract gives an intrinsic limit of 250 cm2/(V·s), which differs from this table value.
source: jos-ga2o3-review
where: Table 1 (material parameters), row Carrier mobility
- benchmark: dielectric_constant
value: 11
unit: '-'
scope: material
conditions:
polymorph: beta-Ga2O3
temperature: not stated
method: Value printed in Table 1 of the review (dimensionless)
status: ground
source: jos-ga2o3-review
where: Table 1 (material parameters), row Dielectric constant
- benchmark: thermal_conductivity
label: Thermal conductivity, beta-Ga2O3 (range)
value: 10
value_high: 30
bound: range
unit: W/mK
scope: material
conditions:
polymorph: beta-Ga2O3
temperature: not stated
method: Range printed in Table 1 of the review
status: ground
source: jos-ga2o3-review
where: Table 1 (material parameters), row Thermal conductivity
- benchmark: saturation_velocity
label: Saturation velocity, beta-Ga2O3
value: 2
unit: 10^7 cm/s
scope: material
conditions:
polymorph: beta-Ga2O3
temperature: not stated
method: Value printed in Table 1 of the review, in the unit the table prints
status: ground
source: jos-ga2o3-review
where: Table 1 (material parameters), row Saturation velocity (vsat)
- benchmark: baliga_figure_of_merit
label: Baliga figure of merit relative to silicon
value: 3200
unit: '-'
scope: material
conditions:
polymorph: beta-Ga2O3
basis: ratio to silicon, where silicon equals 1; not an absolute figure
temperature: not stated
method: Ratio printed in Table 1 of the review
status: ground
note: The abstract describes this figure of merit as more than 3000 relative to silicon, which is consistent with the table value.
source: jos-ga2o3-review
where: Table 1 (material parameters), row Baliga FOM (epsilon mu Ec^3), relative to Si
- benchmark: density
label: Relative density, gallium(III) oxide powder
value: 5.88
unit: g/mL
scope: material
conditions:
form: powder, white (Aldrich product 215066)
temperature: 25 °C
method: Relative density printed in Section 9.1 of the supplier SDS; a supplier value for the powder, not a crystal measurement
status: ground
note: The SDS gives 5.88 g/mL for the powder. No density for a single beta-Ga2O3 crystal is printed in any source read in this run.
source: aldrich-215066-sds
where: Section 9.1 (physical and chemical properties), item m, relative density
- benchmark: johnson_figure_of_merit
label: Johnson figure of merit relative to silicon, beta-Ga2O3
value: 2844
unit: '-'
scope: material
conditions:
polymorph: beta-Ga2O3
basis: ratio to silicon, where silicon equals 1
temperature: not stated
method: Ratio printed in Table 1 of the review, Johnson FOM row
status: ground
source: jos-ga2o3-review
where: Table 1, FOM relative to Si section, row Johnson FOM
- benchmark: baliga_high_frequency_figure_of_merit
label: Baliga high-frequency figure of merit relative to silicon, beta-Ga2O3
value: 142
unit: '-'
scope: material
conditions:
polymorph: beta-Ga2O3
basis: ratio to silicon, where silicon equals 1
temperature: not stated
method: Ratio printed in Table 1 of the review, Baliga High Frequency FOM row
status: ground
source: jos-ga2o3-review
where: Table 1, FOM relative to Si section, row Baliga High Frequency FOM
- benchmark: keyes_figure_of_merit
label: Keyes figure of merit relative to silicon, beta-Ga2O3
value: 0.2
unit: '-'
scope: material
conditions:
polymorph: beta-Ga2O3
basis: ratio to silicon, where silicon equals 1
temperature: not stated
method: Ratio printed in Table 1 of the review, Keyes FOM row
status: ground
source: jos-ga2o3-review
where: Table 1, FOM relative to Si section, row Keyes FOM
- benchmark: thermal_conductivity
label: Thermal conductivity, beta-Ga2O3 along [100], room temperature
value: 10.9
unit: W/mK
scope: material
conditions:
polymorph: beta-Ga2O3
direction: '[100]'
temperature: room temperature
method: Time-domain thermoreflectance on single crystals; value printed in the abstract
status: ground
note: Printed as 10.9 ± 1.0 W/mK. The ± 1.0 is the uncertainty the paper prints.
source: guo-2014-tc
where: Abstract
- benchmark: thermal_conductivity
label: Thermal conductivity, beta-Ga2O3 along [010], room temperature
value: 27
unit: W/mK
scope: material
conditions:
polymorph: beta-Ga2O3
direction: '[010]'
temperature: room temperature
method: Time-domain thermoreflectance on single crystals; value printed in the abstract
status: ground
note: Printed as 27.0 ± 2.0 W/mK. The ± 2.0 is the uncertainty the paper prints.
source: guo-2014-tc
where: Abstract
- benchmark: thermal_conductivity
label: Thermal conductivity, beta-Ga2O3 along [100], room temperature, 3 omega method
value: 13
unit: W/mK
scope: material
conditions:
polymorph: beta-Ga2O3
direction: '[100]'
temperature: room temperature
crystal: Czochralski-grown bulk crystals, Mg-doped and undoped
method: Electrical 3 omega method on bulk crystals; value printed in the abstract
status: ground
note: Printed as 13 ± 1 W/mK, the uncertainty the paper prints. It is a second method on a different crystal set from the TDTR values above.
source: handwerg-2014-tc
where: Abstract
uses:
- application: electronics-and-chips
device: Field-plated MOSFET (research device in the review)
example: The review reports a field-plated MOSFET with a breakdown voltage of 1850 V (Fig. 11).
source: jos-ga2o3-review
where: Figure 11 caption
- application: electronics-and-chips
device: GOOI FET (research device in the review)
example: The review reports GOOI FETs with an on/off ratio of 10^10 and a maximum drain current of 1.5 A/mm in depletion mode and 1.0 A/mm in enhancement mode (Fig. 21).
source: jos-ga2o3-review
where: Figure 21 caption
risks:
hazards:
- text: 'Aldrich supplier SDS for gallium(III) oxide, product 215066 (Version 4.3): Sections 2.1 and 2.2 read ''Not a hazardous substance or mixture.'' with no GHS label elements.'
ghs: []
source: aldrich-215066-sds
where: Sections 2.1 and 2.2
- text: ChemicalBook supplier SDS for CAS 12024-21-4 (revision date printed 2026-08-15) prints the hazard statements H315 (causes skin irritation), H319 (causes serious eye irritation) and H335 (may cause respiratory irritation), with the signal word Warning and precautionary statements P261, P271 and P280. This conflicts with the Aldrich SDS, so both are kept.
ghs:
- H315
- H319
- H335
source: chemicalbook-ga2o3-sds
where: GHS hazard statements and precautionary statements block
failure_risks:
- mode: Reaction with strong oxidizing agents
trigger: Contact with strong oxidizing agents, which the Aldrich SDS lists as incompatible
consequence: 'The SDS gives no reaction products or rates: reactivity and hazardous reactions are ''no data available''.'
source: aldrich-215066-sds
where: Sections 10.1, 10.3 and 10.5
- mode: Fire
trigger: Exposure to a fire
consequence: The SDS says the product does not burn and lists gallium oxides as the special fire hazard. Flash point is 'not applicable'.
source: aldrich-215066-sds
where: Sections 3.1, 5.2, 5.4 and 9.1 (flash point)
handling:
- text: 'Aldrich SDS: provide exhaust ventilation where dust forms, avoid dust formation, keep the container tightly closed in a dry and well-ventilated place, and do not let the product enter drains. Wear gloves and eye protection.'
source: aldrich-215066-sds
where: Sections 6.1, 6.2, 7.1, 7.2 and 8.2
supply:
- subject: Gallium (the metal from which Ga2O3 is made)
abundance: Average gallium content of bauxite is 50 parts per million (USGS, World Resources)
producers:
- country: China
share_percent: 99
year: 2025
critical_lists:
- list: USGS 2025 List of Critical Minerals (described as used in semiconductors; no strategic designation printed)
listed: true
- list: EU critical raw materials list (Regulation (EU) 2024/1252, fifth list of 34 critical raw materials)
listed: true
recycling: 'USGS: old scrap none. Substantial new scrap from GaAs device manufacture is reprocessed to recover high-purity gallium at one facility in New York.'
source: usgs-mcs2026-gallium
where: Gallium chapter, Events, Trends, and Issues (China 99% of primary low-purity gallium production); World Resources (bauxite content); Recycling. The year for the 99% share is not printed in that sentence; 2025 is the year of the chapter's own production table.
documents:
- title: A review of the most recent progresses of state-of-art gallium oxide power devices (Journal of Semiconductors 40(1), 011803)
type: paper
url: https://www.jos.ac.cn/en/article/doi/10.1088/1674-4926/40/1/011803
year: 2019
- title: 'USGS Mineral Commodity Summaries 2026: Gallium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-gallium.pdf
year: 2026
- title: Safety Data Sheet, Gallium(III) oxide, Aldrich product 215066 (Version 4.3)
type: sds
url: https://www.physics.purdue.edu/primelab/safety/MSDS/SDS/gallium%20(III)%20oxide%20%20-%20Aldrich.pdf
year: 2014
- title: Chemical Safety Data Sheet MSDS / SDS, gallium(III) oxide (ChemicalBook)
type: sds
url: https://www.chemicalbook.com/msds/galliumiiioxide.htm
year: 2026
- title: Anisotropic Thermal Conductivity in Single Crystal beta-Gallium Oxide (arXiv:1412.7472)
type: paper
url: https://arxiv.org/abs/1412.7472
year: 2014
- title: Temperature-dependent thermal conductivity in Mg-doped and undoped beta-Ga2O3 bulk-crystals (arXiv:1407.4272)
type: paper
url: https://arxiv.org/abs/1407.4272
year: 2014
gaps:
- No oxidation, corrosion or ageing rate for beta-Ga2O3 was found in a source read in this run. The review covers material parameters and devices only. The Aldrich SDS gives only the incompatibility with strong oxidizing agents and storage stability ('Stable under recommended storage conditions').
- No radiation, vacuum, atomic-oxygen or flight result was found. The Wikipedia article says the material is 'thought to be radiation-hard' but gives no numbers, so nothing is taken from it.
- Melting point is not printed in any source read in this run. The Aldrich SDS says 'no data available' and the 2024 IJMMM review page prints no value. The Wikipedia infobox prints a melting point of 1,725 °C from a handbook, but Wikipedia is used here for composition only, so it is not entered. Density of a single crystal is not found; the only density entered is the supplier SDS relative density of the powder.
- Crystal structure (monoclinic, space group C2/m) is on Wikipedia only and is left out under the composition-only rule for that source.
- 'PubChem returned a reCAPTCHA page and American Elements returned HTTP 403, so no PubChem GHS record was read. The two supplier SDS sources read disagree on classification (Aldrich: not hazardous; ChemicalBook: H315, H319, H335). Both are kept.'
- Supply shares are for gallium metal from the USGS chapter. No country share for gallium oxide itself was found.
- Test temperatures for the band gap, mobility, dielectric constant and thermal conductivity are not stated in the review.
- Band gap, breakdown field, electron mobility, saturation velocity and Baliga figure of merit are not in property-canon.yaml. They were added as snake_case names (band_gap, breakdown_field, electron_mobility, saturation_velocity, baliga_figure_of_merit). The Johnson, Baliga high-frequency and Keyes figures of merit were added the same way (johnson_figure_of_merit, baliga_high_frequency_figure_of_merit, keyes_figure_of_merit).
- 'A second source for the band gap, mobility or breakdown field could not be read: the web search budget for this turn ran out, so only the 2019 review and the Wikipedia identifiers were used.'
sources:
jos-ga2o3-review:
title: A review of the most recent progresses of state-of-art gallium oxide power devices
id: doi:10.1088/1674-4926/40/1/011803 (Journal of Semiconductors 40(1), 011803; authors Hong Zhou et al.)
url: https://www.jos.ac.cn/en/article/doi/10.1088/1674-4926/40/1/011803
year: 2019
kind: paper
license: not stated on the page read
wiki-ga2o3:
title: Gallium(III) oxide (Wikipedia, identifiers box)
id: CAS 12024-21-4
url: https://en.wikipedia.org/wiki/Gallium(III)_oxide
year: 2026
kind: web
license: CC BY-SA (Wikipedia)
usgs-mcs2026-gallium:
title: Mineral Commodity Summaries 2026, Gallium
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-gallium.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-crit2025:
title: About the 2025 List of Critical Minerals (USGS, final list of 60 minerals)
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, list of 34 critical raw materials under Regulation (EU) 2024/1252)
id: Regulation (EU) 2024/1252
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
aldrich-215066-sds:
title: Safety Data Sheet, Gallium(III) oxide, Aldrich product 215066 (Version 4.3)
id: Aldrich 215066, CAS 12024-21-4; revision date 06/25/2014, print date 01/15/2016 (as printed)
url: https://www.physics.purdue.edu/primelab/safety/MSDS/SDS/gallium%20(III)%20oxide%20%20-%20Aldrich.pdf
year: 2014
kind: datasheet
license: not stated on the document
chemicalbook-ga2o3-sds:
title: Chemical Safety Data Sheet MSDS / SDS, gallium(III) oxide (ChemicalBook)
id: CAS 12024-21-4; revision date 2026-08-15 (as printed)
url: https://www.chemicalbook.com/msds/galliumiiioxide.htm
year: 2026
kind: datasheet
license: not stated on the page read
guo-2014-tc:
title: Anisotropic Thermal Conductivity in Single Crystal beta-Gallium Oxide (Guo et al.)
id: arXiv:1412.7472
url: https://arxiv.org/abs/1412.7472
year: 2014
kind: paper
license: arXiv (see the paper page)
handwerg-2014-tc:
title: Temperature-dependent thermal conductivity in Mg-doped and undoped beta-Ga2O3 bulk-crystals (Handwerg et al.)
id: arXiv:1407.4272
url: https://arxiv.org/abs/1407.4272
year: 2014
kind: paper
license: arXiv (see the paper page)
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 15
unreachable: 4
caveats: 3
note: Written by an AI assistant on 2026-11-01 and deepened the same day from pages read in this run. Eight property values come from the 2019 review; the density comes from a supplier SDS, and two thermal conductivity values come from arXiv:1412.7472 and one from arXiv:1407.4272. PubChem (reCAPTCHA page), American Elements (HTTP 403), MDPI and NSF PAR (blocked) could not be read. Values have not been re-checked by a second reader.
story:
recipe:
line: Beta-Ga2O3 is gallium(III) oxide, a compound of two gallium atoms and three oxygen atoms. The 2019 review names the stable form beta-Ga2O3.
parts:
- name: Gallium
symbol: Ga
role: The metal cation in the oxide. The review gives no process route for the Ga2O3 crystal, so none is described here.
- name: Oxygen
symbol: O
role: Bonded to the gallium atoms in the oxide lattice. Oxygen content sets the stoichiometry of the compound.
risk_groups:
- title: For people
verdict: Sources conflict
lead: Two supplier safety data sheets for gallium(III) oxide disagree. The Aldrich sheet (product 215066) lists no classification, and the ChemicalBook sheet prints the hazard statements H315, H319 and H335.
points:
- label: Check the supplier sheet
line: PubChem returned a reCAPTCHA page and American Elements returned an access error. Check the safety data sheet for the lot you handle before handling powder or wafers.
why: Beta-gallium oxide (beta-Ga2O3) is an ultra-wide-bandgap semiconductor. The 2019 review in Journal of Semiconductors gives a band gap of 4.8 eV and an estimated breakdown field of 8 MV/cm. Its Baliga figure of merit is printed as 3200 relative to silicon, which the review uses as a guide to power-device performance. The review also notes that melt-grown substrates could be lower cost. No space or radiation test is taken from the sources read here.
uses:
- where: Power transistors (research devices)
line: The review reports a field-plated MOSFET with a breakdown voltage of 1850 V, and GOOI FETs with an on/off ratio of 10^10. These are laboratory devices described in the review, not commercial parts.
can_do:
- label: Band gap
benchmark: band_gap
value: 4.8 eV
line: The review gives a band gap of 4.8 eV in Table 1. The abstract gives a range of 4.5 to 4.8 eV.
- label: Electron mobility
benchmark: electron_mobility
value: 300 cm2/(V·s)
line: The review gives a carrier mobility of 300 cm2/(V·s) in Table 1. The abstract gives an intrinsic limit of 250 cm2/(V·s).
- label: Thermal conductivity
benchmark: thermal_conductivity
value: 10 to 30 W/mK
line: Table 1 of the review gives a thermal conductivity of 10 to 30 W/mK, with no test temperature stated.
compare: Table 1 of the review also prints values for silicon, GaAs, 4H-SiC, GaN and diamond. Only the beta-Ga2O3 column is entered in this profile. The Baliga figure of merit relative to silicon is 3200 in Table 1 and more than 3000 in the abstract.
compare_rows:
- label: Band gap
benchmark: band_gap
- label: Electron mobility
benchmark: electron_mobility
- label: Thermal conductivity
benchmark: thermal_conductivity
handling:
- 'Aldrich SDS (product 215066): provide exhaust ventilation where dust forms, avoid dust formation, keep the container tightly closed in a dry and well-ventilated place, and do not let the product enter drains. The SDS is an older version, so check the current sheet for the lot you have.'
good_for:
- Power switching where a 4.8 eV band gap and an estimated 8 MV/cm breakdown field matter, per the 2019 review.
- Power device research where the review's Baliga figure of merit, 3200 relative to silicon, is the target.
watch_out:
- Thermal conductivity of 10 to 30 W/mK in Table 1, with no test temperature stated.
- The review's abstract and Table 1 disagree on electron mobility, 250 against 300 cm2/(V·s).
- Most device figures in the review are for laboratory devices, not production parts.
verdict: Beta-Ga2O3 has a wide band gap of 4.8 eV and an estimated breakdown field of 8 MV/cm in the 2019 review. This profile has no corrosion, radiation or space data, so no space verdict is possible from it.
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 |
|---|---|---|---|---|
| A review of the most recent progresses of state-of-art gallium oxide power devices | paper | 2019 | 13 values | |
| Gallium(III) oxide (Wikipedia, identifiers box) | web | 2026 | 1 value | |
| Mineral Commodity Summaries 2026, Gallium | report | 2026 | 1 value | |
| About the 2025 List of Critical Minerals (USGS, final list of 60 minerals) | web | 2025 | 0 values | |
| Critical raw materials (European Commission, list of 34 critical raw materials under Regulation (EU) 2024/1252) | web | 2024 | 0 values | |
| Safety Data Sheet, Gallium(III) oxide, Aldrich product 215066 (Version 4.3) | datasheet | 2014 | 5 values | |
| Chemical Safety Data Sheet MSDS / SDS, gallium(III) oxide (ChemicalBook) | datasheet | 2026 | 1 value | |
| Anisotropic Thermal Conductivity in Single Crystal beta-Gallium Oxide (Guo et al.) | paper | 2014 | 2 values | |
| Temperature-dependent thermal conductivity in Mg-doped and undoped beta-Ga2O3 bulk-crystals (Handwerg et al.) | paper | 2014 | 1 value |
Updated