Cadmium telluride (CdTe) CdTe
CdTe · CAS 1306-25-8 · zinc blende, F43m
Cadmium telluride (CdTe) is a zinc-blende compound of cadmium and tellurium with a direct band gap of 1.5 eV at 300 K, per Wikipedia.
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
1.5 eV
Cell efficiency
22.1%
Module efficiency
Up to 19.3%
Ageing
0.3% per year
High-temperature output
5 to 9% more energy
Recipe, share of the weight
- Cd not statedCadmium
- Te not statedTellurium
Best for
Utility-scale thin-film PV built on a high-volume line, where Wikipedia records a direct manufacturing cost of $0.57 per watt in 2013
Weakest at
Cadmium toxicity and tellurium supply: Wikipedia prints GHS codes H302, H312, H332, H410 and H411 for CdTe, and the USGS lists tellurium as a critical mineral that is recovered mainly from copper refining
Risk at a glance
- People No data. No hazard data recorded
- If it fails Moderate. Cadmium release at high temperature
- Corrosion Low. First Solar warrants 0.3% per year degradation and a 30-year linear performance warranty.
Quick facts: CdTe
| Property | Value | Basis |
|---|---|---|
| Density | 5.85 g·cm−3 | 1 sourced value |
| Young's modulus | 52 GPa | 1 sourced value |
| Thermal conductivity | 6.2 W·m/m2·K | 1 sourced value |
| Thermal expansion (CTE) | 0.0000059 /K | 1 sourced value |
| Melting point | 1,041 °C | 1 sourced value |
| Specific heat | 210 J/(kg·K) | 1 sourced value |
What is the density of Cadmium telluride (CdTe)?
Cadmium telluride (CdTe) has a density of 5.85 g·cm−3. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Cadmium telluride (CdTe)?
Cadmium telluride (CdTe) has a thermal conductivity of 6.2 W·m/m2·K. The source and test conditions are listed in the properties table on this page.
What is the coefficient of thermal expansion of Cadmium telluride (CdTe)?
Cadmium telluride (CdTe) has a coefficient of thermal expansion of 0.0000059 /K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Cadmium telluride (CdTe)?
Cadmium telluride (CdTe) has a melting point of 1,041 °C. The source and test conditions are listed in the properties table on this page.
What is the Young's modulus of Cadmium telluride (CdTe)?
Cadmium telluride (CdTe) has a Young's modulus of 52 GPa. The source and test conditions are listed in the properties table on this page.
What is Cadmium telluride (CdTe) used for?
Uses recorded in the sources include Utility-scale thin-film PV plants; Thin-film PV panels made in the United States; Thin-film photovoltaic market share (market context, not one device).
Why it exists
Cadmium telluride (CdTe) is a semiconductor that absorbs sunlight in thin-film solar modules. Wikipedia gives its band gap as 1.5 eV at 300 K. Its importance comes from the module business: First Solar makes CdTe thin-film modules at scale, and Wikipedia says CdTe held 5.1% of worldwide PV production in 2013.
Where it's used
Utility-scale solar plants
Wikipedia lists Agua Caliente, Arizona at 290 MW and Topaz Solar Farm, California at 550 MW, whose construction finished in November 2014.
U.S. manufacturing
USGS reports that the leading domestic CdTe solar-panel maker began production at a fifth facility in mid-2025, with capacity expected to reach about 14 gigawatts per year once ramped up in 2026.
Market share
Wikipedia says CdTe held 5.1% of worldwide PV production and more than half of the thin-film market in 2013.
Recipe
CdTe
CdTe is a compound of one cadmium atom and one tellurium atom per formula unit, in the zinc-blende crystal structure. Wikipedia prints a molar mass of 240.01 g/mol and says CdTe is commercially available as a powder or as crystals, and can be made into nanocrystals. The page names only one production technique, growth of single crystals by HPVB and HPVZM methods.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Cadmium Cd | not stated | The cadmium half of the lattice. Cadmium is a toxic element, and CdTe carries the GHS codes listed in the risks section. |
| Tellurium Te | not stated | The tellurium half of the lattice. Tellurium is recovered mainly as a byproduct of copper refining, according to the USGS. |
Weight shares are as printed in the sources.
What it can do
Band gap
1.5 eV
measured
Wikipedia gives a direct band gap of 1.5 eV at 300 K, which it relates to a band-gap wavelength of about 830 nm.
Cell efficiency
22.1%
Wikipedia reports a record CdTe cell efficiency of 22.1% in February 2016, credited to First Solar.
Module efficiency
Up to 19.3%
First Solar lists its Series 7 module at up to 19.3% efficiency. This is a manufacturer headline, not a measured test with a stated method.
Ageing
0.3% per year
First Solar warrants an annual degradation rate of 0.3% and a 30-year linear performance warranty.
High-temperature output
5 to 9% more energy
Wikipedia says CdTe modules lose about half the performance of crystalline silicon modules at high temperature, yielding 5 to 9% more annual energy.
How it compares
Cadmium telluride is a thin-film semiconductor, and the sources collected here compare it mainly with crystalline silicon. Wikipedia says CdTe modules lose about half the performance of crystalline silicon modules at high temperature, yielding 5 to 9% more annual energy. The USGS says CdTe solar panels compete with crystalline silicon panels. No silicon band gap or silicon efficiency was read in this run, so the comparison stops at what these sources print.
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 | CdTe |
|---|---|
| Thermal behavior and safety | |
| melting point | 1041 °C1 |
| Thermal conductivityInfobox value, unit as printed on the page | 6.2 W·m/m2·K |
| specific heat | 210 J/kg·K3 |
| Physical and electrical | |
| DensityValue in the Wikipedia infobox | 5.85 g·cm−3 |
| Other measurements | |
| boiling point | 1050 °C2 |
| Thermal expansion (CTE) | 5.9×10^-6 /K4 |
| elastic modulusPrinted value for Young's modulus | 52 GPa |
| poissons ratioPrinted value for the Poisson ratio | 0.41 - |
| refractive indexInfobox value, labelled nD on the page | 2.67 - |
| Band gap | 1.5 eV5 |
| Electron mobilityValue printed in the Applications section | 1100 cm²/V·s6 |
| Hole mobilityValue printed in the Applications section | 100 cm²/V·s7 |
| Solubility in water | < 0.1 mg/L8 |
| Lattice constantInfobox value, printed as a = 0.648 nm | 0.648 nm9 |
| Molar massInfobox value | 240 g/mol10 |
Why choose it, and why not
Good for
- Utility-scale thin-film PV: Wikipedia lists plants of 290 MW and 550 MW built with CdTe modules.
- High-temperature energy yield: Wikipedia says CdTe modules yield 5 to 9% more annual energy than crystalline silicon at high temperature.
Watch out for
- Cadmium toxicity: Wikipedia prints H302, H312, H332, H410 and H411 for CdTe, and a NIOSH limit of 0.005 mg/m3 as Cd.
- Tellurium supply: the USGS lists tellurium as critical and says China produced 80% of estimated 2025 global output.
- Efficiency figures: 22.1% is a laboratory record cell, and 19.3% is a manufacturer headline for the Series 7 module, not a field result.
CdTe is a mature thin-film absorber, backed by utility-scale plants and a manufacturer warranty of 0.3% per year degradation. Its main drawbacks are cadmium toxicity and a tellurium supply tied to copper refining. No source in this profile supports a space-flight or radiation-tolerance claim.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Cell-level benchmarks
Values for finished cells. These vary by manufacturer, so read the conditions in the notes. Compare every grade in the family.
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | melting point | Infobox value, printed as 1,041 °C (1,906 °F; 1,314 K) | pressure not printed on the page | — |
| 2 | boiling point | Infobox value, printed as 1,050 °C (1,920 °F; 1,320 K) | pressure not printed on the page | — |
| 3 | specific heat | Infobox value for heat capacity (C), unit as printed on the page | temperature 293 K | — |
| 4 | Thermal expansion (CTE) | Printed on the page as 5.9×10−6/K; written here in the file's exponent form | temperature 293 K | — |
| 5 | Band gap | Infobox value. The page relates it to a band-gap wavelength of about 830 nm | temperature 300 Kgap type direct, printed as @300 K, direct | Not in spores/property-canon.yaml; short snake_case name used. |
| 6 | Electron mobility | — | basis printed with a tilde (~1100 cm2/V·s) in a radiation-detector context | Not in spores/property-canon.yaml. Approximate, as printed. |
| 7 | Hole mobility | — | basis printed with a tilde (~100 cm2/V·s) in a radiation-detector context | Not in spores/property-canon.yaml. Approximate, as printed. |
| 8 | Solubility in water | Footnote to the infobox: the insoluble classification rests on a value below 0.1 mg/L | temperature not printed on the page | Not in spores/property-canon.yaml. |
| 9 | Lattice constant | — | temperature not printed on the page | Not in spores/property-canon.yaml. |
| 10 | Molar mass | — | basis molar mass of the compound as printed | Not in spores/property-canon.yaml. |
| 11 | Record CdTe cell efficiency | Printed on Wikipedia with the company and date; not re-measured here | basis record CdTe cell, laboratorydate February 2016maker First Solar | Not in spores/property-canon.yaml. |
| 12 | Module efficiency, Series 7 | Manufacturer product-page headline; a marketing figure with no test method stated | basis printed as 'Up to 19.3%' efficiencyproduct First Solar Series 7 CdTe module | Not in spores/property-canon.yaml. |
| 13 | Warranted annual degradation rate | Manufacturer warranty figure, not a measured field result | basis manufacturer warranty rate, printed as 0.3% per yearproduct First Solar Series 7 CdTe module | Not in spores/property-canon.yaml. |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Outdoor field operation of a thin-film module (ageing) | low | First Solar warrants 0.3% per year degradation and a 30-year linear performance warranty.1 |
| High operating temperature (module output) | low | Wikipedia says CdTe modules yield 5 to 9% more annual energy than crystalline silicon at high temperature.2 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Outdoor field operation of a thin-film module (ageing) | The Series 7 product page prints a 'Warranted Annual Degradation Rate' of 0.3% per year and a '30 Year Linear Performance Warranty'. Wikipedia says PV modules last 25 to 30 years. These are a manufacturer warranty and a general statement, not a measured field test. | basis manufacturer warranty figureproduct First Solar Series 7 CdTe module |
| 2 | High operating temperature (module output) | The page prints: CdTe modules lose about half the performance of crystalline silicon modules at high temperature, yielding 5–9% more annual energy. The page gives no test temperature or conditions for this statement. | comparison crystalline silicon modulestemperature high temperature, not defined on the page |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
Wikipedia prints GHS hazard codes for CdTe and a NIOSH limit for cadmium. It does not give a verdict on the powder.
- The compound
- Wikipedia prints the GHS hazard codes H302, H312, H332, H410 and H411 for CdTe, under the signal word Warning. A Kurt J. Lesker safety data sheet for the same CAS number prints H302, H312, H332, H400 and H410, also under the signal word Warning.
- Exposure limit
- NIOSH lists 0.005 mg/m3 as Cd as a time-weighted average permissible exposure limit, and an IDLH of 9 mg/m3 as Cd.
If a module overheats
These results come from laboratory heating tests and from air-emission figures on Wikipedia, not from field incidents.
- Lab heating
- In lab tests at about 1100 °C, 0.4 to 0.6% of the cadmium content was released, according to Wikipedia.
- Air emissions
- Wikipedia prints cadmium air emissions of 0.02 to 0.5 grams per GWh of PV electricity.
Handling and storage
- Dust
- Keep airborne cadmium below 0.005 mg/m3 as Cd, the NIOSH limit printed on Wikipedia.
- Recycling
- First Solar recovers up to 95% of semiconductor material and 90% of glass from end-of-life modules, per Wikipedia.
- Water
- Wikipedia gives CdTe as insoluble in water, with a footnote placing the basis below 0.1 mg/L.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Cadmium release at high temperaturemoderate severity | Laboratory heating at about 1100 °C0.4 to 0.6% of the cadmium content was released in these lab tests (Wikipedia prints 0.4–0.6%). |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| Air around the plant and its surroundings | Cadmium air emissions: 0.02 to 0.5 grams per GWh of PV electricity, as printed on Wikipedia. |
Handling and storage
- First Solar recovers up to 95% of semiconductor material and 90% of glass from end-of-life modules, per Wikipedia. Its recycling program began in 2005.
Mitigations
- Keep airborne cadmium below the NIOSH permissible exposure limit of 0.005 mg/m3 as Cd, as printed on Wikipedia.
Supply and geography
How common the raw materials are and where they come from.
Cadmium
The USGS gives the cadmium content of typical zinc ores as about 0.03%, and says cadmium is generally recovered from zinc ores. A crust abundance was not found in the sources read.
- Top producers (2025)
- China 41.3%, Korea, Republic of 18.7%, Canada 5.7%
- Critical mineral lists
- US: not listed, EU: not listed
- Recycling
- USGS: secondary cadmium is mainly recovered from spent NiCd batteries, and CdTe solar panels are named among the scrap from which cadmium can be recycled.
- Substitutes
- USGS: batteries with other chemistries, particularly lithium-ion, can replace NiCd batteries, and zinc-nickel coatings can replace cadmium in many plating applications.
Tellurium
Wikipedia says tellurium's abundance in the Earth's crust is comparable to platinum's. No numeric crust abundance was read in this run.
- Top producers (2025)
- China 80%, Japan 6.1%, Canada 2.8%
- Critical mineral lists
- US: listed, EU: not listed
- Recycling
- USGS: tellurium was recycled from CdTe solar cells in the United States, but the quantity was limited because most of those cells had not reached the end of their useful life.
- Substitutes
- USGS: amorphous silicon and copper indium gallium diselenide are the two principal competitors with CdTe in thin-film photovoltaic cells.
Documents
Datasheets, safety data sheets, papers and standards you can open.
| Document | Type | Year |
|---|---|---|
| USGS Mineral Commodity Summaries 2026: Cadmium | report | 2026 |
| USGS Mineral Commodity Summaries 2026: Tellurium | report | 2026 |
| First Solar Series 7 CdTe module (product page, EMEA) | datasheet | 2026 |
| Kurt J. Lesker safety data sheet, Cadmium Tellurium (pieces), SDS No. 4766 rev. 2 | sds | 2018 |
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: cadmium-telluride
spore_version: 0.2
family: semiconductor-materials
name: Cadmium telluride (CdTe)
abbreviation: CdTe
role: thin-film photovoltaic absorber semiconductor
category: energy
type: solar-cells
summary: |
Cadmium telluride (CdTe) is a zinc-blende compound of cadmium and tellurium with a direct band gap of 1.5 eV at 300 K, per Wikipedia. It is the absorber in the thin-film solar modules made by First Solar, whose Series 7 module is listed at up to 19.3% efficiency. Wikipedia reports a record CdTe cell efficiency of 22.1% in February 2016, credited to First Solar, and says CdTe held 5.1% of worldwide PV production in 2013. No flight or radiation-test record for CdTe was found in the sources read for this profile.
best_for: Utility-scale thin-film PV built on a high-volume line, where Wikipedia records a direct manufacturing cost of $0.57 per watt in 2013
weakest_at: 'Cadmium toxicity and tellurium supply: Wikipedia prints GHS codes H302, H312, H332, H410 and H411 for CdTe, and the USGS lists tellurium as a critical mineral that is recovered mainly from copper refining'
identity:
formula: CdTe
cas: 1306-25-8
crystal_system: zinc blende
space_group: F43m
source: cdte-wiki
where: 'Infobox: formula, CAS number 1306-25-8, crystal structure zinc blende, space group F43m'
tags:
environments: []
stresses:
- extreme-heat
applications:
- solar-arrays
properties:
- benchmark: density
value: 5.85
unit: g·cm−3
scope: material
conditions:
temperature: not printed on the page
method: Value in the Wikipedia infobox
status: ground
source: cdte-wiki
where: Infobox, Density row
- benchmark: melting_point
value: 1041
unit: °C
scope: material
conditions:
pressure: not printed on the page
method: Infobox value, printed as 1,041 °C (1,906 °F; 1,314 K)
status: ground
source: cdte-wiki
where: Infobox, Melting point row; Chemical properties section
- benchmark: boiling_point
value: 1050
unit: °C
scope: material
conditions:
pressure: not printed on the page
method: Infobox value, printed as 1,050 °C (1,920 °F; 1,320 K)
status: ground
source: cdte-wiki
where: Infobox, Boiling point row
- benchmark: thermal_conductivity
value: 6.2
unit: W·m/m2·K
scope: material
conditions:
temperature: 293 K
method: Infobox value, unit as printed on the page
status: ground
source: cdte-wiki
where: Infobox, Thermal conductivity row
- benchmark: specific_heat
value: 210
unit: J/kg·K
scope: material
conditions:
temperature: 293 K
method: Infobox value for heat capacity (C), unit as printed on the page
status: ground
source: cdte-wiki
where: Infobox, Thermochemistry (heat capacity C) row
- benchmark: cte
value: 0.0000059
unit: /K
scope: material
conditions:
temperature: 293 K
method: Printed on the page as 5.9×10−6/K; written here in the file's exponent form
status: ground
source: cdte-wiki
where: Physical properties section, thermal expansion coefficient
- benchmark: elastic_modulus
value: 52
unit: GPa
scope: material
conditions:
temperature: not printed on the page
method: Printed value for Young's modulus
status: ground
source: cdte-wiki
where: Physical properties section, Young's modulus row
- benchmark: poissons_ratio
value: 0.41
unit: '-'
scope: material
conditions:
basis: no unit or temperature printed on the page
method: Printed value for the Poisson ratio
status: ground
source: cdte-wiki
where: Physical properties section, Poisson ratio
- benchmark: refractive_index
value: 2.67
unit: '-'
scope: material
conditions:
wavelength: 10 μm, printed as @10 μm
method: Infobox value, labelled nD on the page
status: ground
source: cdte-wiki
where: Infobox, Refractive index row
- benchmark: band_gap
label: Band gap
value: 1.5
unit: eV
scope: material
conditions:
temperature: 300 K
gap_type: direct, printed as @300 K, direct
method: Infobox value. The page relates it to a band-gap wavelength of about 830 nm
status: ground
note: Not in spores/property-canon.yaml; short snake_case name used.
source: cdte-wiki
where: Infobox, Band gap row; Optical and electronic properties section
- benchmark: electron_mobility
label: Electron mobility
value: 1100
unit: cm2/V·s
scope: material
conditions:
basis: printed with a tilde (~1100 cm2/V·s) in a radiation-detector context
method: Value printed in the Applications section
status: ground
note: Not in spores/property-canon.yaml. Approximate, as printed.
source: cdte-wiki
where: Applications section (electron mobility)
- benchmark: hole_mobility
label: Hole mobility
value: 100
unit: cm2/V·s
scope: material
conditions:
basis: printed with a tilde (~100 cm2/V·s) in a radiation-detector context
method: Value printed in the Applications section
status: ground
note: Not in spores/property-canon.yaml. Approximate, as printed.
source: cdte-wiki
where: Applications section (hole mobility)
- benchmark: water_solubility
label: Solubility in water
value: 0.1
bound: upper
unit: mg/L
scope: material
conditions:
temperature: not printed on the page
method: 'Footnote to the infobox: the insoluble classification rests on a value below 0.1 mg/L'
status: ground
note: Not in spores/property-canon.yaml.
source: cdte-wiki
where: Infobox, Solubility in water row and its footnote
- benchmark: lattice_constant
label: Lattice constant
value: 0.648
unit: nm
scope: material
conditions:
temperature: not printed on the page
method: Infobox value, printed as a = 0.648 nm
status: ground
note: Not in spores/property-canon.yaml.
source: cdte-wiki
where: Infobox, Lattice constant row
- benchmark: molar_mass
label: Molar mass
value: 240.01
unit: g/mol
scope: material
conditions:
basis: molar mass of the compound as printed
method: Infobox value
status: ground
note: Not in spores/property-canon.yaml.
source: cdte-wiki
where: Infobox, Molar mass row
- benchmark: cell_efficiency_record
label: Record CdTe cell efficiency
value: 22.1
unit: '%'
scope: cell
conditions:
basis: record CdTe cell, laboratory
date: February 2016
maker: First Solar
method: Printed on Wikipedia with the company and date; not re-measured here
status: ground
note: Not in spores/property-canon.yaml.
source: cdte-pv-wiki
where: 'Section 3.1, Technology: Cell efficiency'
- benchmark: module_efficiency
label: Module efficiency, Series 7
value: 19.3
bound: upper
unit: '%'
scope: cell
conditions:
basis: printed as 'Up to 19.3%' efficiency
product: First Solar Series 7 CdTe module
method: Manufacturer product-page headline; a marketing figure with no test method stated
status: ground
note: Not in spores/property-canon.yaml.
source: firstsolar-s7
where: Product page intro headline
- benchmark: annual_degradation_rate
label: Warranted annual degradation rate
value: 0.3
unit: '%/year'
scope: cell
conditions:
basis: manufacturer warranty rate, printed as 0.3% per year
product: First Solar Series 7 CdTe module
method: Manufacturer warranty figure, not a measured field result
status: ground
note: Not in spores/property-canon.yaml.
source: firstsolar-s7
where: Product page intro headline and 'More Lifetime Energy per Nameplate Watt' section
corrosion:
- environment: Outdoor field operation of a thin-film module (ageing)
headline: First Solar warrants 0.3% per year degradation and a 30-year linear performance warranty.
effect: The Series 7 product page prints a 'Warranted Annual Degradation Rate' of 0.3% per year and a '30 Year Linear Performance Warranty'. Wikipedia says PV modules last 25 to 30 years. These are a manufacturer warranty and a general statement, not a measured field test.
rating: low
conditions:
basis: manufacturer warranty figure
product: First Solar Series 7 CdTe module
source: firstsolar-s7
where: Product page intro headline; 'More Lifetime Energy per Nameplate Watt' section
- environment: High operating temperature (module output)
headline: Wikipedia says CdTe modules yield 5 to 9% more annual energy than crystalline silicon at high temperature.
effect: 'The page prints: CdTe modules lose about half the performance of crystalline silicon modules at high temperature, yielding 5–9% more annual energy. The page gives no test temperature or conditions for this statement.'
rating: low
conditions:
comparison: crystalline silicon modules
temperature: high temperature, not defined on the page
source: cdte-pv-wiki
where: Section 3.3, Ambient temperature
risks:
hazards:
- text: Wikipedia prints the GHS hazard statements H302, H312, H332, H410 and H411 for cadmium telluride, under the signal word Warning. The page does not print the wording of these statements.
ghs:
- H302
- H312
- H332
- H410
- H411
source: cdte-wiki
where: Safety section, GHS hazard statements row
- text: The Kurt J. Lesker safety data sheet for cadmium telluride (pieces), SDS No. 4766 revision 2, prints the signal word Warning and the hazard statements H302, H312, H332, H400 and H410. It prints H302 as Harmful if swallowed, H312 as Harmful in contact with skin, H332 as Harmful if inhaled, H400 as Very toxic to aquatic life and H410 as Very toxic to aquatic life with long lasting effects. The Wikipedia list above has H411 and no H400, so the two sources differ.
ghs:
- H302
- H312
- H332
- H400
- H410
source: kjlesker-cdte-sds
where: Label elements (signal word and hazard statements); Hazard statements in full at the end of the sheet
- text: 'NIOSH limits printed for cadmium in CdTe: a time-weighted average permissible exposure limit of 0.005 mg/m3 as Cd (listed as 1910.1027), and an IDLH of 9 mg/m3 as Cd. The page gives no numeric REL.'
ghs: []
source: cdte-wiki
where: Safety section, NIOSH PEL, IDLH and REL rows
failure_risks:
- mode: Cadmium release at high temperature
trigger: Laboratory heating at about 1100 °C
consequence: 0.4 to 0.6% of the cadmium content was released in these lab tests (Wikipedia prints 0.4–0.6%).
severity: moderate
source: cdte-pv-wiki
where: Section 6, Environmental and health impact
side_effects:
- text: 'Cadmium air emissions: 0.02 to 0.5 grams per GWh of PV electricity, as printed on Wikipedia.'
affects: Air around the plant and its surroundings
source: cdte-pv-wiki
where: Section 6, Environmental and health impact
handling:
- text: First Solar recovers up to 95% of semiconductor material and 90% of glass from end-of-life modules, per Wikipedia. Its recycling program began in 2005.
source: cdte-pv-wiki
where: Section 5, Recycling
mitigations:
- text: Keep airborne cadmium below the NIOSH permissible exposure limit of 0.005 mg/m3 as Cd, as printed on Wikipedia.
source: cdte-wiki
where: Safety section, NIOSH PEL row
uses:
- application: solar-arrays
device: Utility-scale thin-film PV plants
example: Wikipedia lists Agua Caliente, Arizona at 290 MW and Topaz Solar Farm, California at 550 MW, whose construction finished in November 2014.
source: cdte-pv-wiki
where: Section 7.1, Notable systems
- application: solar-arrays
device: Thin-film PV panels made in the United States
example: USGS reports that the leading domestic CdTe solar-panel maker began production at a fifth facility in mid-2025, with capacity expected to reach about 14 gigawatts per year once ramped up in 2026.
source: usgs-mcs2026-cadmium
where: Events, Trends, and Issues (cadmium chapter)
- application: solar-arrays
device: Thin-film photovoltaic market share (market context, not one device)
example: Wikipedia says CdTe held 5.1% of worldwide PV production and more than half of the thin-film market in 2013.
source: cdte-pv-wiki
where: Introduction (lead)
supply:
- subject: Cadmium
abundance: The USGS gives the cadmium content of typical zinc ores as about 0.03%, and says cadmium is generally recovered from zinc ores. A crust abundance was not found in the sources read.
producers:
- country: China
share_percent: 41.3
year: 2025
- country: Korea, Republic of
share_percent: 18.7
year: 2025
- country: Canada
share_percent: 5.7
year: 2025
critical_lists:
- list: USGS 2025 List of Critical Minerals
listed: false
- list: EU critical raw materials list (European Commission page)
listed: false
recycling: 'USGS: secondary cadmium is mainly recovered from spent NiCd batteries, and CdTe solar panels are named among the scrap from which cadmium can be recycled.'
substitutes:
- 'USGS: batteries with other chemistries, particularly lithium-ion, can replace NiCd batteries, and zinc-nickel coatings can replace cadmium in many plating applications.'
source: usgs-mcs2026-cadmium
where: 'World Refinery Production table, 2025e: China 9,500 t, Korea 4,300 t and Canada 1,300 t of a 23,000 t world total (rounded); shares calculated by Space Mushroom. Recycling; Substitutes. Critical lists from the USGS and EC pages'
- subject: Tellurium
abundance: Wikipedia says tellurium's abundance in the Earth's crust is comparable to platinum's. No numeric crust abundance was read in this run.
producers:
- country: China
share_percent: 80
year: 2025
- country: Japan
share_percent: 6.1
year: 2025
- country: Canada
share_percent: 2.8
year: 2025
critical_lists:
- list: 'USGS 2025 List of Critical Minerals (entry: Tellurium, used in solar cells)'
listed: true
- list: EU critical raw materials list (European Commission page)
listed: false
recycling: 'USGS: tellurium was recycled from CdTe solar cells in the United States, but the quantity was limited because most of those cells had not reached the end of their useful life.'
substitutes:
- 'USGS: amorphous silicon and copper indium gallium diselenide are the two principal competitors with CdTe in thin-film photovoltaic cells.'
source: usgs-mcs2026-tellurium
where: 'Events, Trends, and Issues (China 80% of estimated 2025 global production, as printed); World Refinery Production table, 2025e: Japan 61 t and Canada 28 t of a 1,000 t world total (shares calculated by Space Mushroom); Recycling; Substitutes; USGS 2025 critical list (usgs-crit2025)'
media: []
documents:
- title: 'USGS Mineral Commodity Summaries 2026: Cadmium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cadmium.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Tellurium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tellurium.pdf
year: 2026
- title: First Solar Series 7 CdTe module (product page, EMEA)
type: datasheet
url: https://www.firstsolar.com/en-EMEA/Products/Series-7
year: 2026
- title: Kurt J. Lesker safety data sheet, Cadmium Tellurium (pieces), SDS No. 4766 rev. 2
type: sds
url: https://cores.research.utdallas.edu/files/2023/04/CdTe-MSDS.pdf
year: 2018
gaps:
- No flight record for CdTe was found. The AlSat-1N Wikipedia page, read in this run, does not mention CdTe, so the AlSat-1N flight claim in the brief is not in this file.
- No radiation-tolerance comparison with silicon or III-V cells was found in the sources read, so radiation tolerance is not stated.
- The PubChem record could not be read (the site returned a browser-verification page), so PubChem could not confirm which hazard list is current. The GHS codes come from the Wikipedia safety section and from a Kurt J. Lesker safety data sheet (SDS No. 4766, 2018). The two lists differ on H411 and H400.
- The NREL Best Research-Cell Efficiency chart could not be reached (host did not resolve), so the 22.1% record is the value printed on Wikipedia, not a checked NREL row.
- Elemental atomic weights of cadmium and tellurium are not printed on the pages read, so the recipe parts carry no atomic_weight. The molar mass of 240.01 g/mol is printed.
- Temperature coefficient of power, nominal operating cell temperature and operating temperature range are not printed on the First Solar product page. Its linked Series 7 datasheet was not read.
- No corrosion or chemical-resistance test for CdTe was found. The corrosion section covers only warranted field ageing and the high-temperature output statement.
- No vacuum, thermal-cycling or proton or electron irradiation result for CdTe was found in the sources read.
- Band gap, electron and hole mobility, water solubility, lattice constant, molar mass, record cell efficiency, module efficiency and annual degradation rate are not in spores/property-canon.yaml. Short snake_case names were used.
- The crust abundance of cadmium is not printed in the sources read. The USGS gives only the cadmium content of typical zinc ores (about 0.03%).
- CdZnTe radiation-detector substrates named in the USGS cadmium chapter are a different compound and are not used in this profile.
- No media images were fetched, so the media section is empty.
sources:
cdte-wiki:
title: Cadmium telluride
id: Wikipedia, Cadmium telluride (infobox, physical, optical and safety sections, read 2026-11-01)
url: https://en.wikipedia.org/wiki/Cadmium_telluride
year: 2026
kind: web
license: CC BY-SA 4.0 (Wikipedia)
cdte-pv-wiki:
title: Cadmium telluride photovoltaics
id: Wikipedia, Cadmium telluride photovoltaics (read 2026-11-01)
url: https://en.wikipedia.org/wiki/Cadmium_telluride_photovoltaics
year: 2026
kind: web
license: CC BY-SA 4.0 (Wikipedia)
usgs-mcs2026-cadmium:
title: Mineral Commodity Summaries 2026, Cadmium
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cadmium.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-mcs2026-tellurium:
title: Mineral Commodity Summaries 2026, Tellurium
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tellurium.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, critical raw materials list)
id: European Commission critical raw materials page
url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
year: 2026
kind: web
license: European Commission web page
firstsolar-s7:
title: First Solar Series 7 CdTe module (EMEA product page)
id: First Solar product page, undated; read 2026-11-01
url: https://www.firstsolar.com/en-EMEA/Products/Series-7
year: 2026
kind: datasheet
license: manufacturer web page, linked not reproduced
kjlesker-cdte-sds:
title: 'Safety data sheet: Cadmium Tellurium (pieces), Kurt J. Lesker Company'
id: SDS No. 4766, revision 2, revision date 8/31/2018 (copy hosted by UT Dallas)
url: https://cores.research.utdallas.edu/files/2023/04/CdTe-MSDS.pdf
year: 2018
kind: datasheet
license: supplier safety data sheet, linked not reproduced
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 18
unreachable: 2
caveats: 2
note: 'Read by an AI assistant on 2026-11-01. 18 properties taken from fetched pages. Unreachable in this run: the PubChem record (browser-verification page) and the NREL efficiency chart (host did not resolve). The First Solar datasheet linked from the product page was not read. The AlSat-1N flight claim in the brief was not confirmed.'
story:
recipe:
line: CdTe is a compound of one cadmium atom and one tellurium atom per formula unit, in the zinc-blende crystal structure. Wikipedia prints a molar mass of 240.01 g/mol and says CdTe is commercially available as a powder or as crystals, and can be made into nanocrystals. The page names only one production technique, growth of single crystals by HPVB and HPVZM methods.
parts:
- name: Cadmium
symbol: Cd
role: The cadmium half of the lattice. Cadmium is a toxic element, and CdTe carries the GHS codes listed in the risks section.
- name: Tellurium
symbol: Te
role: The tellurium half of the lattice. Tellurium is recovered mainly as a byproduct of copper refining, according to the USGS.
risk_groups:
- title: For people
verdict: Carries GHS hazard codes (Wikipedia)
lead: Wikipedia prints GHS hazard codes for CdTe and a NIOSH limit for cadmium. It does not give a verdict on the powder.
points:
- label: The compound
line: Wikipedia prints the GHS hazard codes H302, H312, H332, H410 and H411 for CdTe, under the signal word Warning. A Kurt J. Lesker safety data sheet for the same CAS number prints H302, H312, H332, H400 and H410, also under the signal word Warning.
- label: Exposure limit
line: NIOSH lists 0.005 mg/m3 as Cd as a time-weighted average permissible exposure limit, and an IDLH of 9 mg/m3 as Cd.
- title: If a module overheats
lead: These results come from laboratory heating tests and from air-emission figures on Wikipedia, not from field incidents.
points:
- label: Lab heating
line: In lab tests at about 1100 °C, 0.4 to 0.6% of the cadmium content was released, according to Wikipedia.
- label: Air emissions
line: Wikipedia prints cadmium air emissions of 0.02 to 0.5 grams per GWh of PV electricity.
- title: Handling and storage
points:
- label: Dust
line: Keep airborne cadmium below 0.005 mg/m3 as Cd, the NIOSH limit printed on Wikipedia.
- label: Recycling
line: First Solar recovers up to 95% of semiconductor material and 90% of glass from end-of-life modules, per Wikipedia.
- label: Water
line: Wikipedia gives CdTe as insoluble in water, with a footnote placing the basis below 0.1 mg/L.
why: 'Cadmium telluride (CdTe) is a semiconductor that absorbs sunlight in thin-film solar modules. Wikipedia gives its band gap as 1.5 eV at 300 K. Its importance comes from the module business: First Solar makes CdTe thin-film modules at scale, and Wikipedia says CdTe held 5.1% of worldwide PV production in 2013.'
uses:
- where: Utility-scale solar plants
line: Wikipedia lists Agua Caliente, Arizona at 290 MW and Topaz Solar Farm, California at 550 MW, whose construction finished in November 2014.
- where: U.S. manufacturing
line: USGS reports that the leading domestic CdTe solar-panel maker began production at a fifth facility in mid-2025, with capacity expected to reach about 14 gigawatts per year once ramped up in 2026.
- where: Market share
line: Wikipedia says CdTe held 5.1% of worldwide PV production and more than half of the thin-film market in 2013.
can_do:
- label: Band gap
benchmark: band_gap
value: 1.5 eV
line: Wikipedia gives a direct band gap of 1.5 eV at 300 K, which it relates to a band-gap wavelength of about 830 nm.
- label: Cell efficiency
benchmark: cell_efficiency_record
value: 22.1%
line: Wikipedia reports a record CdTe cell efficiency of 22.1% in February 2016, credited to First Solar.
- label: Module efficiency
benchmark: module_efficiency
value: Up to 19.3%
line: First Solar lists its Series 7 module at up to 19.3% efficiency. This is a manufacturer headline, not a measured test with a stated method.
- label: Ageing
benchmark: annual_degradation_rate
value: 0.3% per year
line: First Solar warrants an annual degradation rate of 0.3% and a 30-year linear performance warranty.
- label: High-temperature output
value: 5 to 9% more energy
line: Wikipedia says CdTe modules lose about half the performance of crystalline silicon modules at high temperature, yielding 5 to 9% more annual energy.
compare: Cadmium telluride is a thin-film semiconductor, and the sources collected here compare it mainly with crystalline silicon. Wikipedia says CdTe modules lose about half the performance of crystalline silicon modules at high temperature, yielding 5 to 9% more annual energy. The USGS says CdTe solar panels compete with crystalline silicon panels. No silicon band gap or silicon efficiency was read in this run, so the comparison stops at what these sources print.
compare_rows:
- label: Band gap
benchmark: band_gap
- label: Record cell efficiency
benchmark: cell_efficiency_record
- label: Density
benchmark: density
handling:
- Keep airborne cadmium below the NIOSH permissible exposure limit of 0.005 mg/m3 as Cd (Wikipedia).
- 'Recycle end-of-life modules: First Solar recovers up to 95% of semiconductor material (Wikipedia).'
- Note that lab heating at about 1100 °C released 0.4 to 0.6% of the cadmium content (Wikipedia).
good_for:
- 'Utility-scale thin-film PV: Wikipedia lists plants of 290 MW and 550 MW built with CdTe modules.'
- 'High-temperature energy yield: Wikipedia says CdTe modules yield 5 to 9% more annual energy than crystalline silicon at high temperature.'
watch_out:
- 'Cadmium toxicity: Wikipedia prints H302, H312, H332, H410 and H411 for CdTe, and a NIOSH limit of 0.005 mg/m3 as Cd.'
- 'Tellurium supply: the USGS lists tellurium as critical and says China produced 80% of estimated 2025 global output.'
- 'Efficiency figures: 22.1% is a laboratory record cell, and 19.3% is a manufacturer headline for the Series 7 module, not a field result.'
verdict: CdTe is a mature thin-film absorber, backed by utility-scale plants and a manufacturer warranty of 0.3% per year degradation. Its main drawbacks are cadmium toxicity and a tellurium supply tied to copper refining. No source in this profile supports a space-flight or radiation-tolerance claim.
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 |
|---|---|---|---|---|
| Cadmium telluride | web | 2026 | 19 values | |
| Cadmium telluride photovoltaics | web | 2026 | 7 values | |
| Mineral Commodity Summaries 2026, Cadmium | report | 2026 | 2 values | |
| Mineral Commodity Summaries 2026, Tellurium | 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, critical raw materials list) | web | 2026 | 0 values | |
| First Solar Series 7 CdTe module (EMEA product page) | datasheet | 2026 | 3 values | |
| Safety data sheet: Cadmium Tellurium (pieces), Kurt J. Lesker Company | datasheet | 2018 | 1 value |
Updated