Copper indium gallium selenide CIGS
CuIn(1-x)Ga(x)Se2, a solid solution of copper indium selenide (x = 0) and copper gallium selenide (x = 1) · tetragonal, I42d
Copper indium gallium selenide (CIGS, CuIn(1-x)Ga(x)Se2) is a thin-film solar absorber whose band gap runs from 1.0 eV to 1.7 eV as gallium replaces indium, per the Wikipedia infobox.
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
1.0 to 1.7 eV
Thin absorber
1 to 2 µm
Laboratory efficiency
23.6% on glass
Recipe, share of the weight
- Cu not statedCopper
- In not statedIndium
- Ga not statedGallium
- Se not statedSelenium
Best for
Thin, flexible photovoltaic absorbers on light substrates: laboratory cells printed at 17.7% on steel, 16.2% on aluminium and 20.4% on polymer foil (no years given)
Weakest at
Space evidence: no flight record was found; the NASA ground tests give UV power retention, but the proton and electron results are only qualitative, and no humidity data were found
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: CIGS
| Property | Value | Basis |
|---|---|---|
| Density | 5.7 g/cm³ | 1 sourced value |
| Melting point | 990 to 1,070 °C | 1 sourced value |
What is the density of Copper indium gallium selenide (CIGS)?
Copper indium gallium selenide (CIGS) has a density of 5.7 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the melting point of Copper indium gallium selenide (CIGS)?
Copper indium gallium selenide (CIGS) has a melting point of 990 to 1,070 °C. The source and test conditions are listed in the properties table on this page.
What is Copper indium gallium selenide (CIGS) used for?
Uses recorded in the sources include Thin-film photovoltaic module on a flexible substrate; Commercial thin-film modules; Space power (proposed; no flight data in the sources read).
Why it exists
Copper indium gallium selenide (CIGS) is a thin-film photovoltaic absorber with the formula CuIn(1-x)Ga(x)Se2, a solid solution between copper indium selenide and copper gallium selenide. The Wikipedia article says it is best known as the absorber in thin-film solar cells, and that deposition on flexible substrates makes flexible, lightweight solar panels possible. For space, the same article says CIGS cells show high radiation tolerance and are promising candidates for space applications, but it gives no dose or flight figures. No flight record was found in the sources read for this profile.
Where it's used
Thin-film photovoltaic modules
The Wikipedia article says CIGS is best known as the absorber in thin-film solar cells, and that its deposition on flexible substrates enables flexible, lightweight panels.
Commercial thin-film modules
The article prints a 17.8% efficiency for a Solar Frontier module of 900 cm2 and a 17.4% aperture efficiency for a MiaSole module, the latter confirmed by Fraunhofer in 2019. It gives no test conditions for either.
Space power, proposed
The article says CIGS cells show high radiation tolerance and are promising candidates for space applications. No flight or dose data are given in the sources read.
Recipe
CuIn(1-x)Ga(x)Se2, a solid solution of copper indium selenide (x = 0) and copper gallium selenide (x = 1)
CIGS is a solid solution of copper indium selenide (CuInSe2) and copper gallium selenide (CuGaSe2), written CuIn(1-x)Ga(x)Se2 with x running from 0 to 1. The Wikipedia article says the film is made by co-evaporating or co-sputtering copper, gallium and indium onto a substrate and then annealing it in selenium vapour, or by sputtering metal layers and then selenizing them.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Copper Cu | not stated | The metal cation that sits on one of the two cation sites in the chalcopyrite structure; the article lists copper in the formula. |
| Indium In | not stated | Sets the larger end of the band gap (about 1.0 eV in CuInSe2, per the article). |
| Gallium Ga | not stated | Raises the band gap toward about 1.7 eV in CuGaSe2, per the article. |
| Selenium Se | not stated | The anion that completes the tetrahedral bonding in the chalcopyrite structure. |
Weight shares are as printed in the sources.
What it can do
Band gap
1.0 to 1.7 eV
measured
The band gap changes continuously with composition, from about 1.0 eV for copper indium selenide to about 1.7 eV for copper gallium selenide (Wikipedia infobox and lead section).
Thin absorber
1 to 2 µm
measured
The absorber layer is 1 to 2 µm thick, per the comparison section of the Wikipedia solar-cell article. That thin layer is what allows the flexible, lightweight deposition described above.
Laboratory efficiency
23.6% on glass
A laboratory cell on glass is printed at 23.6% (about 0.9 cm2, no year given). The properties section gives 23.64% as a 2024 claim without test conditions.
How it compares
CIGS is one of the thin-film photovoltaic absorbers. The USGS selenium chapter names amorphous silicon and cadmium telluride as the two principal competitors with CIGS in thin-film cells. The sources read give CIGS a band gap of 1.0 to 1.7 eV and a 1 to 2 µm absorber, but no side-by-side efficiency, cost or lifetime comparison with those two materials, so none is made here. The 2002 NASA-hosted conference paper on the sulfide variant CIGS2 reported 8.84% AM0 efficiency on 127 µm stainless steel foil. That is a different compound and is not treated as a CIGS value.
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 | CIGS |
|---|---|
| Thermal behavior and safety | |
| Melting point across the CIGS composition range | 990 to 1070 °C2 |
| Physical and electrical | |
| Density, CIGS (encyclopedia infobox value) | 5.7 g/cm³1 |
| CIGS absorber layer thickness | 1 to 2 µm7 |
| Temperature behavior | |
| Chalcopyrite to zincblende transition temperature | 805 to 1045 °C6 |
| Other measurements | |
| Band gap across the CIGS composition range | 1 to 1.7 eV3 |
| Lattice constant a, tetragonal chalcopyrite cell | 0.56 to 0.58 nm4 |
| Lattice constant c, tetragonal chalcopyrite cell | 1.1 to 1.15 nm5 |
Why choose it, and why not
Good for
- Thin, flexible absorbers: 1 to 2 µm layers on glass, steel, aluminium or polymer foil, with laboratory cells at 17.7% on steel, 16.2% on aluminium and 20.4% on polymer foil (no years given).
- Light panels: the article says flexible deposition enables flexible, lightweight solar panels.
Watch out for
- The efficiency figures conflict: 23.6% in the table and 23.64% in the text, with no year or test condition for either.
- No flight record was found. NASA ground tests give UV power retention, but the proton and electron results are qualitative.
- Supply is concentrated: China supplies 70% of world indium and 99% of primary low-purity gallium, and produced 53% of refined selenium in 2025 (USGS).
CIGS is a thin, flexible absorber with a band gap of 1.0 to 1.7 eV and laboratory efficiencies from 16.2% to 23.6%. The sources read here show no flight record and no quantified proton or electron performance; NASA ground tests give 86.5% UV power retention for a CORIN-coated CIGS cell, so treat it as a candidate for space power, not a proven one.
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.
| Measurement | CIGS |
|---|---|
| Thermal behavior and safety | |
| Rapid thermal cycling range used on CIGS cells | -55 to 125 °C19 |
| Lifetime and stability | |
| Power retention of a bare CIGS cell after simulated UV | 70 %16 |
| Power retention of a CIGS cell with a CORIN coating after simulated UV | 86.5 %17 |
| Power retention of a CIGS cell with CORIN and cerium oxide after simulated UV | 91.6 %18 |
| Other measurements | |
| Laboratory cell efficiency, CIGS on soda-lime glass | 23.6 %8 |
| Claimed record efficiency, 2024 (text of the properties section) | 23.64 %9 |
| Laboratory cell efficiency, CIGS on steel substrate | 17.7 %10 |
| Laboratory cell efficiency, CIGS on aluminium substrate | 16.2 %11 |
| Laboratory cell efficiency, CIGS on flexible polymer foil | 20.4 %12 |
| Large-area production module efficiency, NREL | 13.8 %13 |
| Production module efficiency, Solar Frontier | 17.8 %14 |
| Production module aperture efficiency, MiaSole | 17.4 %15 |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, CIGS (encyclopedia infobox value) | Value printed in the Wikipedia infobox, which cites no source for it | composition CuIn(1-x)Ga(x)Se2, one value printed for x = 0 to 1temperature 25 °Cpressure 100 kPa (standard state, per infobox footnote)printed as ~5.7 g/cm3 | An encyclopedia figure with no cited measurement; use it only as an approximate reference. |
| 2 | Melting point across the CIGS composition range | Range printed in the Wikipedia infobox, which cites Tinoco et al. 1991 (Phys. Status Solidi A 124(2), 427) as reference 1 | composition x = 0 (CuInSe2) to x = 1 (CuGaSe2)pressure not stated | — |
| 3 | Band gap across the CIGS composition range | Range printed in the Wikipedia infobox, citing Tinoco et al. 1991 as reference 1; the lead section gives the same two end values without a reference | composition x = 0 (CIS) to x = 1 (CGS)temperature not stated | Short snake_case name; no band-gap name exists in the canonical property file. |
| 4 | Lattice constant a, tetragonal chalcopyrite cell | Range printed in the Wikipedia infobox; no reference is shown for it | composition x = 0 to 1crystal tetragonal chalcopyrite | — |
| 5 | Lattice constant c, tetragonal chalcopyrite cell | Range printed in the Wikipedia infobox; no reference is shown for it | composition x = 0 to 1crystal tetragonal chalcopyrite | — |
| 6 | Chalcopyrite to zincblende transition temperature | Values printed in the structure section, citing Tinoco et al. 1991 as reference 1 | composition x = 1 gives 805 °C; x = 0 gives 1045 °Ctransition chalcopyrite to zincblende on heating | — |
| 7 | CIGS absorber layer thickness | Range printed in the comparison section of the Wikipedia solar-cell article | layer CIGS absorber | Short snake_case name; no absorber-thickness name exists in the canonical property file. |
| 8 | Laboratory cell efficiency, CIGS on soda-lime glass | Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, with the lab named as Uppsala University and Evolar | substrate glasscell area about 0.9 cm2test not statedyear not printed in the table | Not a canonical property name. The properties section gives a different figure (23.64%, see next entry) and the page does not reconcile the two. |
| 9 | Claimed record efficiency, 2024 (text of the properties section) | Figure printed in the properties section as: In 2024 a CIGS efficiency record of 23.64% was claimed | cell not statedtest not stated | Differs from the table value of 23.6%; both are printed on the page. The page gives no cell condition or source for this claim. |
| 10 | Laboratory cell efficiency, CIGS on steel substrate | Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to Empa | substrate steeltest not statedyear not printed in the table | — |
| 11 | Laboratory cell efficiency, CIGS on aluminium substrate | Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to Empa | substrate aluminiumtest not statedyear not printed in the table | — |
| 12 | Laboratory cell efficiency, CIGS on flexible polymer foil | Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to Empa | substrate flexible polymer foiltest not statedyear not printed in the table | — |
| 13 | Large-area production module efficiency, NREL | Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to NREL | format large-area (meter-square) production paneltest not statedyear not printed | A module figure, listed here under scope cell because the scope field allows only material or cell. |
| 14 | Production module efficiency, Solar Frontier | Value printed in the conversion-efficiency section of the Wikipedia solar-cell article | module area 900 cm2test not statedyear not printed | A module figure, listed here under scope cell because the scope field allows only material or cell. |
| 15 | Production module aperture efficiency, MiaSole | Value printed in the Wikipedia solar-cell article, Sputtering section, as confirmed by Fraunhofer in 2019 | basis aperture areaconfirmed by Fraunhofer, printed as 2019 | A module figure, listed here under scope cell because the scope field allows only material or cell. |
| 16 | Power retention of a bare CIGS cell after simulated UV | Measured by NASA Marshall in its simulated UV test; printed as a bound, not a single figure | lamp xenon arc lamp, 230 to 400 nmexposure up to 2,000 equivalent sun-hourscoating none | Paper says 70% or less; the companion slides say 70% power retention at best. Not a canonical property name. |
| 17 | Power retention of a CIGS cell with a CORIN coating after simulated UV | Measured by NASA Marshall in its simulated UV test | lamp xenon arc lamp, 230 to 400 nmexposure 1,578 equivalent sun-hourscoating CORIN | Not a canonical property name. The NASA slides print the same figure for coated CIGS. |
| 18 | Power retention of a CIGS cell with CORIN and cerium oxide after simulated UV | Measured by NASA Marshall in its simulated UV test | lamp xenon arc lamp, 230 to 400 nmexposure not stated for this resultcoating CORIN with cerium oxide | Not a canonical property name. The paper gives no exposure for this result. The NASA slides print the same figure for coated CIGS. |
| 19 | Rapid thermal cycling range used on CIGS cells | Rapid thermal shock chamber at NASA Marshall; the range is the test range, not a rating | cycles 100coating bare and CORIN-coated CIGS; some samples with a separately cast anti-reflection layer | Test range, not a rated service limit. Not a canonical property name. |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Electron irradiation (space radiation, laboratory test) | not rated | Electron irradiation has only a minimal effect on CIGS cell performance, according to the Wikipedia article.1 |
| Proton irradiation at high dose (space radiation, laboratory test) | not rated | High doses of proton irradiation degrade CIGS optical and electrical properties; the article gives no dose.2 |
| Humidity, moisture and damp-heat exposure | not rated | No moisture or humidity data were found in the sources read.3 |
| Ultraviolet exposure (xenon arc lamp, 230 to 400 nm, laboratory test) | not rated | Bare CIGS cells fell to 70% power or less in simulated UV, mainly through open circuit voltage; a CORIN coating kept more of it.4 |
| Proton irradiation at 50 to 700 keV (laboratory test, NASA Marshall) | not rated | Bare CIGS cells degraded in 50 keV protons; coated CIGS cells kept their power.5 |
| 1 MeV electron irradiation (laboratory test, NASA Marshall) | not rated | CIGS kept its power through every 1 MeV electron exposure in the NASA Marshall test; IMM slightly degraded and single junction GaAs was strongly affected.6 |
| Rapid thermal cycling, -55 to +125 °C (laboratory test, NASA Marshall) | not rated | CORIN-coated CIGS cells performed well in thermal cycling; the anti-reflection coating delaminated.7 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Electron irradiation (space radiation, laboratory test) | The article says studies show that electron irradiation causes only minimal impact to the performance of the solar cells. It gives no fluence, electron energy or measured change in efficiency. | dose not statedenergy not statedcell not stated |
| 2 | Proton irradiation at high dose (space radiation, laboratory test) | The article says high doses of proton irradiation degrade the optical and electrical properties of CIGS cells and reduce efficiency. It also says the damage can be recovered by thermal annealing, when displaced atoms return to their original sites at moderate temperatures. No temperature is given. | dose high doses, not quantifiedanneal temperature moderate, not quantified |
| 3 | Humidity, moisture and damp-heat exposure | The article has no passages on moisture, humidity, damp-heat testing, light soaking or operating lifetime in years. This entry records a gap in the data, not a result. | basis absence of data in the source read |
| 4 | Ultraviolet exposure (xenon arc lamp, 230 to 400 nm, laboratory test) | NASA Marshall found that bare CIGS cells degraded to 70% power or less after the UV exposure, mainly in open circuit voltage. A CORIN coating kept 86.5% power through 1,578 equivalent sun-hours, and CORIN with cerium oxide kept 91.6%. The paper gives no ageing rate beyond these figures. | lamp xenon arc lamp, 230 to 400 nmexposure up to 2,000 equivalent sun-hourscells bare and coated CIGS from the LISA-T arrays |
| 5 | Proton irradiation at 50 to 700 keV (laboratory test, NASA Marshall) | NASA Marshall exposed IMM and CIGS cells to 50, 100, 500 and 700 keV protons. Bare CIGS cells degraded rapidly in the 50 keV exposure, while coated CIGS cells maintained power retention through all proton exposures. The paper prints no retained-power percentage for the proton tests. | energy 50, 100, 500 and 700 keVcells bare and coated CIGS |
| 6 | 1 MeV electron irradiation (laboratory test, NASA Marshall) | The paper says CIGS maintained power retention through all exposures, and that coatings had little effect on durability. It prints no power percentage for CIGS in the electron test, and the fluence range is not copied here. | energy 1 MeV electronsfacility NASA MSFC Combined Environmental Effects Facility, Pelletron accelerator |
| 7 | Rapid thermal cycling, -55 to +125 °C (laboratory test, NASA Marshall) | NASA Marshall cycled bare and coated CIGS cells between -55 and +125 °C for 100 cycles. CORIN-coated CIGS performed well. CIGS cells with a separately cast anti-reflection layer delaminated, and the paper says that process has been improved but not yet tested. | range -55 to +125 °Ccycles 100coating CORIN; CORIN with an anti-reflection layer |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The sources read here do not classify a finished CIGS cell. The one hazard they name is hydrogen selenide, used in one manufacturing route.
- Finished cell
- The sources read here give no safety classification for a finished CIGS cell or module, and no safety data sheet was read.
- Hydrogen selenide in production
- The article says H2Se, used in one selenization route, is highly toxic and an environmental hazard. That sentence carries a citation-needed tag.
- Cadmium buffer
- The buffer layer is typically cadmium sulfide, deposited by chemical bath deposition. The article says some CIGS cells contain no cadmium at all.
If a cell is over-irradiated
These are the only failure routes the sources describe, and none is quantified.
- Proton dose
- The article says high doses of proton irradiation degrade the optical and electrical properties of CIGS cells and reduce their efficiency. No dose is given.
- Annealing recovery
- The article says the damage can be recovered by thermal annealing, when displaced atoms return to their original sites at moderate temperatures. No temperature is given.
Test details
The original wording and numbers from the sources, for readers who want them.
Handling and storage
- The article gives no handling instructions for CIGS powder, targets or cells. Where H2Se is used in selenization, the article says it is highly toxic and should be handled under process controls.
Supply and geography
How common the raw materials are and where they come from.
Indium
Not found in the sources read for this profile.
- Top producers (2025)
- China 70%
- Recycling
- USGS: indium is most commonly recovered from ITO scrap in Japan and the Republic of Korea; the quantity recovered was not available.
Gallium
Not found in the sources read for this profile.
- Top producers (2025)
- China 99%
- Recycling
- USGS: old scrap none; new scrap from GaAs device manufacture was reprocessed at one facility in New York.
Selenium
Not found in the sources read for this profile.
- Top producers (2025)
- China 53%
- Recycling
- USGS: insignificant; most scrap from electronic materials is exported for recovery of contained selenium.
- Substitutes
- USGS: amorphous silicon and cadmium telluride are the two principal competitors with CIGS in thin-film photovoltaic cells.
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: copper-indium-gallium-selenide
spore_version: 0.2
family: semiconductor-materials
name: Copper indium gallium selenide
abbreviation: CIGS
role: thin-film photovoltaic absorber
category: energy
type: solar-cells
summary: |
Copper indium gallium selenide (CIGS, CuIn(1-x)Ga(x)Se2) is a thin-film solar absorber whose band gap runs from 1.0 eV to 1.7 eV as gallium replaces indium, per the Wikipedia infobox. The absorber layer is 1 to 2 µm thick and can be deposited on flexible polyimide or metal foil. A laboratory cell on glass is printed at 23.6% (about 0.9 cm2, no year given). The sources read for this profile contain no flight record and no quantified proton or electron test result. NASA Marshall ground tests of thin-film array cells give 86.5% UV power retention for a CORIN-coated CIGS cell.
best_for: 'Thin, flexible photovoltaic absorbers on light substrates: laboratory cells printed at 17.7% on steel, 16.2% on aluminium and 20.4% on polymer foil (no years given)'
weakest_at: 'Space evidence: no flight record was found; the NASA ground tests give UV power retention, but the proton and electron results are only qualitative, and no humidity data were found'
identity:
formula: CuIn(1-x)Ga(x)Se2, a solid solution of copper indium selenide (x = 0) and copper gallium selenide (x = 1)
crystal_system: tetragonal
space_group: I42d
source: wiki-cigs
where: Infobox, Chemical formula, Crystal structure and Space group; the space group and lattice constants carry no reference in the infobox
tags:
applications:
- solar-arrays
stresses:
- total-radiation-dose
properties:
- benchmark: density
label: Density, CIGS (encyclopedia infobox value)
value: 5.7
unit: g/cm3
scope: material
conditions:
composition: CuIn(1-x)Ga(x)Se2, one value printed for x = 0 to 1
temperature: 25 °C
pressure: 100 kPa (standard state, per infobox footnote)
printed_as: ~5.7 g/cm3
method: Value printed in the Wikipedia infobox, which cites no source for it
status: ground
note: An encyclopedia figure with no cited measurement; use it only as an approximate reference.
source: wiki-cigs
where: Infobox, Density
- benchmark: melting_point
label: Melting point across the CIGS composition range
value: 990
value_high: 1070
bound: range
unit: °C
scope: material
conditions:
composition: x = 0 (CuInSe2) to x = 1 (CuGaSe2)
pressure: not stated
method: Range printed in the Wikipedia infobox, which cites Tinoco et al. 1991 (Phys. Status Solidi A 124(2), 427) as reference 1
status: ground
source: wiki-cigs
where: Infobox, Melting point (printed as 1,070 to 990 °C)
- benchmark: band_gap
label: Band gap across the CIGS composition range
value: 1
value_high: 1.7
bound: range
unit: eV
scope: material
conditions:
composition: x = 0 (CIS) to x = 1 (CGS)
temperature: not stated
method: Range printed in the Wikipedia infobox, citing Tinoco et al. 1991 as reference 1; the lead section gives the same two end values without a reference
status: ground
note: Short snake_case name; no band-gap name exists in the canonical property file.
source: wiki-cigs
where: Infobox, Band gap; lead section
- benchmark: lattice_constant_a
label: Lattice constant a, tetragonal chalcopyrite cell
value: 0.56
value_high: 0.58
bound: range
unit: nm
scope: material
conditions:
composition: x = 0 to 1
crystal: tetragonal chalcopyrite
method: Range printed in the Wikipedia infobox; no reference is shown for it
status: ground
source: wiki-cigs
where: Infobox, Lattice constant (printed as a = 0.56-0.58 nm)
- benchmark: lattice_constant_c
label: Lattice constant c, tetragonal chalcopyrite cell
value: 1.1
value_high: 1.15
bound: range
unit: nm
scope: material
conditions:
composition: x = 0 to 1
crystal: tetragonal chalcopyrite
method: Range printed in the Wikipedia infobox; no reference is shown for it
status: ground
source: wiki-cigs
where: Infobox, Lattice constant (printed as c = 1.10-1.15 nm)
- benchmark: phase_transition_temperature
label: Chalcopyrite to zincblende transition temperature
value: 805
value_high: 1045
bound: range
unit: °C
scope: material
conditions:
composition: x = 1 gives 805 °C; x = 0 gives 1045 °C
transition: chalcopyrite to zincblende on heating
method: Values printed in the structure section, citing Tinoco et al. 1991 as reference 1
status: ground
source: wiki-cigs
where: Structure section
- benchmark: conversion_efficiency
label: Laboratory cell efficiency, CIGS on soda-lime glass
value: 23.6
unit: '%'
scope: cell
conditions:
substrate: glass
cell_area: about 0.9 cm2
test: not stated
year: not printed in the table
method: Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, with the lab named as Uppsala University and Evolar
status: ground
note: Not a canonical property name. The properties section gives a different figure (23.64%, see next entry) and the page does not reconcile the two.
source: wiki-cigs-solar
where: Conversion efficiency table, row Lab cells on glass
- benchmark: conversion_efficiency
label: Claimed record efficiency, 2024 (text of the properties section)
value: 23.64
unit: '%'
scope: cell
conditions:
cell: not stated
test: not stated
method: 'Figure printed in the properties section as: In 2024 a CIGS efficiency record of 23.64% was claimed'
status: ground
note: Differs from the table value of 23.6%; both are printed on the page. The page gives no cell condition or source for this claim.
source: wiki-cigs-solar
where: Properties section
- benchmark: conversion_efficiency
label: Laboratory cell efficiency, CIGS on steel substrate
value: 17.7
unit: '%'
scope: cell
conditions:
substrate: steel
test: not stated
year: not printed in the table
method: Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to Empa
status: ground
source: wiki-cigs-solar
where: Conversion efficiency table, row Lab cells on steel
- benchmark: conversion_efficiency
label: Laboratory cell efficiency, CIGS on aluminium substrate
value: 16.2
unit: '%'
scope: cell
conditions:
substrate: aluminium
test: not stated
year: not printed in the table
method: Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to Empa
status: ground
source: wiki-cigs-solar
where: Conversion efficiency table, row Lab cells on aluminium
- benchmark: conversion_efficiency
label: Laboratory cell efficiency, CIGS on flexible polymer foil
value: 20.4
unit: '%'
scope: cell
conditions:
substrate: flexible polymer foil
test: not stated
year: not printed in the table
method: Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to Empa
status: ground
source: wiki-cigs-solar
where: Conversion efficiency table, row Lab cells on polymer
- benchmark: conversion_efficiency
label: Large-area production module efficiency, NREL
value: 13.8
unit: '%'
scope: cell
conditions:
format: large-area (meter-square) production panel
test: not stated
year: not printed
method: Value printed in the conversion-efficiency table of the Wikipedia solar-cell article, credited to NREL
status: ground
note: A module figure, listed here under scope cell because the scope field allows only material or cell.
source: wiki-cigs-solar
where: Conversion efficiency table, module row NREL
- benchmark: conversion_efficiency
label: Production module efficiency, Solar Frontier
value: 17.8
unit: '%'
scope: cell
conditions:
module_area: 900 cm2
test: not stated
year: not printed
method: Value printed in the conversion-efficiency section of the Wikipedia solar-cell article
status: ground
note: A module figure, listed here under scope cell because the scope field allows only material or cell.
source: wiki-cigs-solar
where: Conversion efficiency section, module list
- benchmark: conversion_efficiency
label: Production module aperture efficiency, MiaSole
value: 17.4
unit: '%'
scope: cell
conditions:
basis: aperture area
confirmed_by: Fraunhofer, printed as 2019
method: Value printed in the Wikipedia solar-cell article, Sputtering section, as confirmed by Fraunhofer in 2019
status: ground
note: A module figure, listed here under scope cell because the scope field allows only material or cell.
source: wiki-cigs-solar
where: Sputtering of metallic layers section
- benchmark: absorber_thickness
label: CIGS absorber layer thickness
value: 1
value_high: 2
bound: range
unit: µm
scope: material
conditions:
layer: CIGS absorber
method: Range printed in the comparison section of the Wikipedia solar-cell article
status: ground
note: Short snake_case name; no absorber-thickness name exists in the canonical property file.
source: wiki-cigs-solar
where: Comparison, Conventional crystalline silicon section
- benchmark: uv_power_retention
label: Power retention of a bare CIGS cell after simulated UV
value: 70
unit: '%'
scope: cell
conditions:
lamp: xenon arc lamp, 230 to 400 nm
exposure: up to 2,000 equivalent sun-hours
coating: none
method: Measured by NASA Marshall in its simulated UV test; printed as a bound, not a single figure
status: ground
note: Paper says 70% or less; the companion slides say 70% power retention at best. Not a canonical property name.
source: nasa-msfc-2017-paper
where: Section II.B, Ultraviolet Radiation (bare CIGS degraded to 70% or less, mainly in open circuit voltage)
- benchmark: uv_power_retention
label: Power retention of a CIGS cell with a CORIN coating after simulated UV
value: 86.5
unit: '%'
scope: cell
conditions:
lamp: xenon arc lamp, 230 to 400 nm
exposure: 1,578 equivalent sun-hours
coating: CORIN
method: Measured by NASA Marshall in its simulated UV test
status: ground
note: Not a canonical property name. The NASA slides print the same figure for coated CIGS.
source: nasa-msfc-2017-paper
where: Section II.B, Ultraviolet Radiation (CORIN kept the CIGS cell power at 86.5% through 1,578 ESH)
- benchmark: uv_power_retention
label: Power retention of a CIGS cell with CORIN and cerium oxide after simulated UV
value: 91.6
unit: '%'
scope: cell
conditions:
lamp: xenon arc lamp, 230 to 400 nm
exposure: not stated for this result
coating: CORIN with cerium oxide
method: Measured by NASA Marshall in its simulated UV test
status: ground
note: Not a canonical property name. The paper gives no exposure for this result. The NASA slides print the same figure for coated CIGS.
source: nasa-msfc-2017-paper
where: Section II.B, Ultraviolet Radiation (CORIN with cerium oxide kept the CIGS cell power at 91.6%)
- benchmark: thermal_cycle_temperature
label: Rapid thermal cycling range used on CIGS cells
value: -55
value_high: 125
bound: range
unit: °C
scope: cell
conditions:
cycles: 100
coating: bare and CORIN-coated CIGS; some samples with a separately cast anti-reflection layer
method: Rapid thermal shock chamber at NASA Marshall; the range is the test range, not a rating
status: ground
note: Test range, not a rated service limit. Not a canonical property name.
source: nasa-msfc-2017-paper
where: Section II.E, Thermal Cycling (cycled between -55 and +125 °C for 100 cycles)
corrosion:
- environment: Electron irradiation (space radiation, laboratory test)
headline: Electron irradiation has only a minimal effect on CIGS cell performance, according to the Wikipedia article.
effect: The article says studies show that electron irradiation causes only minimal impact to the performance of the solar cells. It gives no fluence, electron energy or measured change in efficiency.
rating: unknown
conditions:
dose: not stated
energy: not stated
cell: not stated
source: wiki-cigs-solar
where: Radiation tolerance section
- environment: Proton irradiation at high dose (space radiation, laboratory test)
headline: High doses of proton irradiation degrade CIGS optical and electrical properties; the article gives no dose.
effect: The article says high doses of proton irradiation degrade the optical and electrical properties of CIGS cells and reduce efficiency. It also says the damage can be recovered by thermal annealing, when displaced atoms return to their original sites at moderate temperatures. No temperature is given.
rating: unknown
conditions:
dose: high doses, not quantified
anneal_temperature: moderate, not quantified
source: wiki-cigs-solar
where: Radiation tolerance section
- environment: Humidity, moisture and damp-heat exposure
headline: No moisture or humidity data were found in the sources read.
effect: The article has no passages on moisture, humidity, damp-heat testing, light soaking or operating lifetime in years. This entry records a gap in the data, not a result.
rating: unknown
conditions:
basis: absence of data in the source read
source: wiki-cigs-solar
where: Whole article read; no section covers these topics
- environment: Ultraviolet exposure (xenon arc lamp, 230 to 400 nm, laboratory test)
headline: Bare CIGS cells fell to 70% power or less in simulated UV, mainly through open circuit voltage; a CORIN coating kept more of it.
effect: NASA Marshall found that bare CIGS cells degraded to 70% power or less after the UV exposure, mainly in open circuit voltage. A CORIN coating kept 86.5% power through 1,578 equivalent sun-hours, and CORIN with cerium oxide kept 91.6%. The paper gives no ageing rate beyond these figures.
rating: unknown
conditions:
lamp: xenon arc lamp, 230 to 400 nm
exposure: up to 2,000 equivalent sun-hours
cells: bare and coated CIGS from the LISA-T arrays
source: nasa-msfc-2017-paper
where: Section II.B, Ultraviolet Radiation
- environment: Proton irradiation at 50 to 700 keV (laboratory test, NASA Marshall)
headline: Bare CIGS cells degraded in 50 keV protons; coated CIGS cells kept their power.
effect: NASA Marshall exposed IMM and CIGS cells to 50, 100, 500 and 700 keV protons. Bare CIGS cells degraded rapidly in the 50 keV exposure, while coated CIGS cells maintained power retention through all proton exposures. The paper prints no retained-power percentage for the proton tests.
rating: unknown
conditions:
energy: 50, 100, 500 and 700 keV
cells: bare and coated CIGS
source: nasa-msfc-2017-paper
where: Section II.D, Proton Radiation
- environment: 1 MeV electron irradiation (laboratory test, NASA Marshall)
headline: CIGS kept its power through every 1 MeV electron exposure in the NASA Marshall test; IMM slightly degraded and single junction GaAs was strongly affected.
effect: The paper says CIGS maintained power retention through all exposures, and that coatings had little effect on durability. It prints no power percentage for CIGS in the electron test, and the fluence range is not copied here.
rating: unknown
conditions:
energy: 1 MeV electrons
facility: NASA MSFC Combined Environmental Effects Facility, Pelletron accelerator
source: nasa-msfc-2017-paper
where: Section II.C, Electron Radiation
- environment: Rapid thermal cycling, -55 to +125 °C (laboratory test, NASA Marshall)
headline: CORIN-coated CIGS cells performed well in thermal cycling; the anti-reflection coating delaminated.
effect: NASA Marshall cycled bare and coated CIGS cells between -55 and +125 °C for 100 cycles. CORIN-coated CIGS performed well. CIGS cells with a separately cast anti-reflection layer delaminated, and the paper says that process has been improved but not yet tested.
rating: unknown
conditions:
range: '-55 to +125 °C'
cycles: 100
coating: CORIN; CORIN with an anti-reflection layer
source: nasa-msfc-2017-paper
where: Section II.E, Thermal Cycling; Section III, Discussion
risks:
hazards:
- text: Hydrogen selenide (H2Se) is used in one selenization route. The article calls it highly toxic and an environmental hazard; that sentence carries a citation-needed tag.
ghs: []
source: wiki-cigs-solar
where: Production, Film production, Selenization section
- text: The buffer layer is typically cadmium sulfide, deposited by chemical bath deposition. The article says some CIGS cells contain no cadmium at all, and that a cadmium-free buffer removes the cadmium impact.
ghs: []
source: wiki-cigs-solar
where: Structure section; Properties section, Figure 1 caption; Sputtering of metallic layers followed by selenization section
- text: Elemental selenium (CAS 7782-49-2, the element in CIGS) carries signal word Danger with H301 (Toxic if swallowed), H331 (Toxic if inhaled), H373 (May cause damage to organs through prolonged or repeated exposure) and H413 (May cause long lasting harmful effects to aquatic life), per a selenium safety data sheet. That SDS is for the element, not for finished CIGS.
ghs:
- H301
- H331
- H373
- H413
source: chemicalbook-selenium-sds
where: Section 2, Hazard statements and Label elements
failure_risks: []
handling:
- text: The article gives no handling instructions for CIGS powder, targets or cells. Where H2Se is used in selenization, the article says it is highly toxic and should be handled under process controls.
source: wiki-cigs-solar
where: Production, Selenization section
mitigations: []
uses:
- application: solar-arrays
device: Thin-film photovoltaic module on a flexible substrate
example: The Wikipedia article says CIGS is best known as the absorber in thin-film solar cells, and that deposition on flexible substrates enables flexible, lightweight solar panels.
source: wiki-cigs
where: Applications section
- application: solar-arrays
device: Commercial thin-film modules
example: The Wikipedia article prints a 17.8% efficiency for a Solar Frontier module of 900 cm2 and a 17.4% aperture efficiency for a MiaSole module, the latter confirmed by Fraunhofer in 2019; no test conditions are given for either.
source: wiki-cigs-solar
where: Conversion efficiency section, module list; Sputtering section
- application: solar-arrays
device: Space power (proposed; no flight data in the sources read)
example: The Wikipedia article says CIGS solar cells exhibit high radiation tolerance, making them promising candidates for space applications. It gives no dose or flight result.
source: wiki-cigs-solar
where: Radiation tolerance section
supply:
- subject: Indium
abundance: Not found in the sources read for this profile.
producers:
- country: China
share_percent: 70
year: 2025
critical_lists: []
recycling: 'USGS: indium is most commonly recovered from ITO scrap in Japan and the Republic of Korea; the quantity recovered was not available.'
substitutes: []
source: usgs-mcs2026-indium
where: 'Events, Trends, and Issues (China 70% of the world total); Recycling; Import Sources (United States, 2021-24: Republic of Korea 25%, Japan 22%, China 12%, Canada 11%). The chapter has no critical-list statement.'
- subject: Gallium
abundance: Not found in the sources read for this profile.
producers:
- country: China
share_percent: 99
year: 2025
critical_lists: []
recycling: 'USGS: old scrap none; new scrap from GaAs device manufacture was reprocessed at one facility in New York.'
substitutes: []
source: usgs-mcs2026-gallium
where: Domestic Production and Use; Events, Trends, and Issues (China 99% of worldwide primary low-purity gallium production); Recycling. The chapter has no critical-list statement.
- subject: Selenium
abundance: Not found in the sources read for this profile.
producers:
- country: China
share_percent: 53
year: 2025
critical_lists: []
recycling: 'USGS: insignificant; most scrap from electronic materials is exported for recovery of contained selenium.'
substitutes:
- 'USGS: amorphous silicon and cadmium telluride are the two principal competitors with CIGS in thin-film photovoltaic cells.'
source: usgs-mcs2026-selenium
where: Domestic Production and Use (lists thin-film CIGS solar cells among selenium uses); Events, Trends, and Issues (China 53% of estimated global production); World Refinery Production table (2025 world total 3,800 t); Recycling; Substitutes
documents:
- title: 'USGS Mineral Commodity Summaries 2026: Indium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Gallium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-gallium.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Selenium'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-selenium.pdf
year: 2026
- title: 'NASA NTRS 20030000597: CIGS2 Thin-Film Solar Cells on Flexible Foils for Space Power (conference abstract, CIGS2 sulfide variant)'
type: paper
url: https://ntrs.nasa.gov/citations/20030000597
year: 2002
- title: 'NASA NTRS 20170005334: Simulated Space Environmental Effects on Thin Film Solar Array Components (LISA-T, paper)'
type: paper
url: https://ntrs.nasa.gov/citations/20170005334
year: 2017
- title: 'NASA NTRS 20170005333: Simulated Space Environmental Effects on Thin Film Solar Array Components (ASEC, May 2017, slides)'
type: report
url: https://ntrs.nasa.gov/citations/20170005333
year: 2017
- title: 'ChemicalBook: Selenium, chemical safety data sheet (CAS 7782-49-2)'
type: sds
url: https://www.chemicalbook.com/msds/selenium.htm
year: 2026
gaps:
- 'Flight: the brief names a flight of CIGS without a coverglass on a small satellite and NASA GRC work. The NASA Marshall LISA-T sources read in this run (NTRS 20170005333 and 20170005334) are ground simulations and report no flight result, so the file makes no flight claim.'
- NASA NTRS 20030000597 covers CIGS2, CuIn(1-x)Ga(x)S2, the sulfide variant, not CIGS selenide. Its figures (8.84% AM0 efficiency on 127 µm stainless steel foil, 9.26% AM1.5, 2002) are not used as CIGS values. The abstract gives no radiation, flexibility or flight test data.
- 'Radiation: the Wikipedia article gives no dose, fluence or electron energy. NASA Marshall (NTRS 20170005334) gives UV power retention for bare and coated CIGS; its proton and electron results are qualitative, with fluence ranges printed only as exponents and not copied here. No post-irradiation efficiency for CIGS was found.'
- 'Humidity, damp-heat, light soaking and operating lifetime: no source read gives any of these for CIGS. Thermal cycling is covered by NASA Marshall (NTRS 20170005334) with the cycle range and cell outcomes only.'
- Density (5.7 g/cm3) and the crystal-structure values come from an encyclopedia infobox. The infobox cites no measurement for the density and no reference for the space group or lattice constants. No datasheet or laboratory paper for CIGS was read.
- 'Efficiency: the Wikipedia table gives no year or test condition. The properties section gives 23.64% for a 2024 claim, which does not match the 23.6% in the table, and the page does not reconcile them.'
- 'Not found: thermal conductivity, specific heat, thermal expansion, elastic modulus, electrical resistivity and refractive index for CIGS.'
- 'Hazards: the PubChem pages for selenium, indium and gallium returned a browser verification page, so no GHS classification was read from PubChem. A ChemicalBook selenium SDS was read for the elemental form only (CAS 7782-49-2). No safety data sheet for CIGS, indium or gallium was read.'
- 'Hydrogen selenide: the article''s sentence on its toxicity carries a citation-needed tag.'
- 'Critical-mineral lists: the USGS 2026 indium, gallium and selenium chapters read here contain no critical-list statement. The USGS critical-mineral list and the EU list were not checked for these three elements.'
- 'Crustal abundance of indium, gallium and selenium: not found in the sources read.'
- 'Recycling of CIGS modules and end-of-life handling: not found in any source read.'
- 'Atomic weights for the recipe parts: not read from a fetched page, so none are given.'
- 'Designations (UNS, EN, ASTM or other codes) for CIGS: none printed on a page read.'
- 'Media: no images added.'
- 'Sources: nine read in total (two Wikipedia pages, NASA NTRS 20030000597, three USGS chapters, two NASA NTRS 2017 records and one selenium SDS). Not reached: RSC open-access CIGS paper (403), Springer JOM 2019 simulation (login redirect), Ioffe 2015 CIGS paper (certificate error), American Elements CIGS page (403), Sigma-Aldrich selenium SDS (timeout), JAXA record (503).'
- 'Verification caveat: the Wikipedia and NTRS figures were read through a summarising fetch, not checked line by line against the page text. Spot-check them before publication.'
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 19
unreachable: 10
caveats: 4
note: 'Written by an AI assistant on 2026-11-01 from two Wikipedia pages and one NASA NTRS abstract (read through a summarising fetch) and three USGS Mineral Commodity Summaries 2026 chapters (text extracted with pdftotext). Deepen pass on 2026-11-01 added two NASA NTRS 2017 LISA-T records (full text via pdftotext) and a ChemicalBook selenium SDS (fetched). Unreachable in that pass: RSC, Springer, Ioffe, American Elements, Sigma-Aldrich, JAXA. Unreachable: PubChem pages for selenium, indium and gallium (browser verification page); the NREL efficiency chart (domain not resolvable). Caveats: the NTRS figures are for CIGS2, not CIGS; the density has no cited measurement; the efficiency table has no years; the flight claim in the brief is unconfirmed.'
story:
recipe:
line: CIGS is a solid solution of copper indium selenide (CuInSe2) and copper gallium selenide (CuGaSe2), written CuIn(1-x)Ga(x)Se2 with x running from 0 to 1. The Wikipedia article says the film is made by co-evaporating or co-sputtering copper, gallium and indium onto a substrate and then annealing it in selenium vapour, or by sputtering metal layers and then selenizing them.
parts:
- name: Copper
symbol: Cu
role: The metal cation that sits on one of the two cation sites in the chalcopyrite structure; the article lists copper in the formula.
- name: Indium
symbol: In
share: 1 - x of the group III sites
role: Sets the larger end of the band gap (about 1.0 eV in CuInSe2, per the article).
- name: Gallium
symbol: Ga
share: x of the group III sites
role: Raises the band gap toward about 1.7 eV in CuGaSe2, per the article.
- name: Selenium
symbol: Se
role: The anion that completes the tetrahedral bonding in the chalcopyrite structure.
risk_groups:
- title: For people
verdict: No hazard classification read for a finished cell
lead: The sources read here do not classify a finished CIGS cell. The one hazard they name is hydrogen selenide, used in one manufacturing route.
points:
- label: Finished cell
line: The sources read here give no safety classification for a finished CIGS cell or module, and no safety data sheet was read.
- label: Hydrogen selenide in production
line: The article says H2Se, used in one selenization route, is highly toxic and an environmental hazard. That sentence carries a citation-needed tag.
- label: Cadmium buffer
line: The buffer layer is typically cadmium sulfide, deposited by chemical bath deposition. The article says some CIGS cells contain no cadmium at all.
- title: If a cell is over-irradiated
lead: These are the only failure routes the sources describe, and none is quantified.
points:
- label: Proton dose
line: The article says high doses of proton irradiation degrade the optical and electrical properties of CIGS cells and reduce their efficiency. No dose is given.
- label: Annealing recovery
line: The article says the damage can be recovered by thermal annealing, when displaced atoms return to their original sites at moderate temperatures. No temperature is given.
why: Copper indium gallium selenide (CIGS) is a thin-film photovoltaic absorber with the formula CuIn(1-x)Ga(x)Se2, a solid solution between copper indium selenide and copper gallium selenide. The Wikipedia article says it is best known as the absorber in thin-film solar cells, and that deposition on flexible substrates makes flexible, lightweight solar panels possible. For space, the same article says CIGS cells show high radiation tolerance and are promising candidates for space applications, but it gives no dose or flight figures. No flight record was found in the sources read for this profile.
uses:
- where: Thin-film photovoltaic modules
line: The Wikipedia article says CIGS is best known as the absorber in thin-film solar cells, and that its deposition on flexible substrates enables flexible, lightweight panels.
- where: Commercial thin-film modules
line: The article prints a 17.8% efficiency for a Solar Frontier module of 900 cm2 and a 17.4% aperture efficiency for a MiaSole module, the latter confirmed by Fraunhofer in 2019. It gives no test conditions for either.
- where: Space power, proposed
line: The article says CIGS cells show high radiation tolerance and are promising candidates for space applications. No flight or dose data are given in the sources read.
can_do:
- label: Band gap
benchmark: band_gap
value: 1.0 to 1.7 eV
line: The band gap changes continuously with composition, from about 1.0 eV for copper indium selenide to about 1.7 eV for copper gallium selenide (Wikipedia infobox and lead section).
- label: Thin absorber
benchmark: absorber_thickness
value: 1 to 2 µm
line: The absorber layer is 1 to 2 µm thick, per the comparison section of the Wikipedia solar-cell article. That thin layer is what allows the flexible, lightweight deposition described above.
- label: Laboratory efficiency
benchmark: conversion_efficiency
value: 23.6% on glass
line: A laboratory cell on glass is printed at 23.6% (about 0.9 cm2, no year given). The properties section gives 23.64% as a 2024 claim without test conditions.
compare: CIGS is one of the thin-film photovoltaic absorbers. The USGS selenium chapter names amorphous silicon and cadmium telluride as the two principal competitors with CIGS in thin-film cells. The sources read give CIGS a band gap of 1.0 to 1.7 eV and a 1 to 2 µm absorber, but no side-by-side efficiency, cost or lifetime comparison with those two materials, so none is made here. The 2002 NASA-hosted conference paper on the sulfide variant CIGS2 reported 8.84% AM0 efficiency on 127 µm stainless steel foil. That is a different compound and is not treated as a CIGS value.
compare_rows:
- label: Density
benchmark: density
- label: Melting point
benchmark: melting_point
- label: Absorber thickness
benchmark: absorber_thickness
handling:
- The sources read give no handling instructions for CIGS powder, targets or cells. Obtain the supplier's safety data sheet before handling any of these.
- The selenium SDS (ChemicalBook, elemental selenium) prints the precautionary statements "Avoid breathing dust/fume/gas/mist/vapours/spray." and "Call a POISON CENTER or doctor/physician." These apply to the element until a CIGS SDS is read.
- Where H2Se is used in selenization, the article calls it highly toxic. Use the process controls the producer applies.
- Older designs use a cadmium sulfide buffer; some cells are cadmium-free, so check the buffer type before handling spent cells.
good_for:
- 'Thin, flexible absorbers: 1 to 2 µm layers on glass, steel, aluminium or polymer foil, with laboratory cells at 17.7% on steel, 16.2% on aluminium and 20.4% on polymer foil (no years given).'
- 'Light panels: the article says flexible deposition enables flexible, lightweight solar panels.'
watch_out:
- 'The efficiency figures conflict: 23.6% in the table and 23.64% in the text, with no year or test condition for either.'
- No flight record was found. NASA ground tests give UV power retention, but the proton and electron results are qualitative.
- 'Supply is concentrated: China supplies 70% of world indium and 99% of primary low-purity gallium, and produced 53% of refined selenium in 2025 (USGS).'
verdict: CIGS is a thin, flexible absorber with a band gap of 1.0 to 1.7 eV and laboratory efficiencies from 16.2% to 23.6%. The sources read here show no flight record and no quantified proton or electron performance; NASA ground tests give 86.5% UV power retention for a CORIN-coated CIGS cell, so treat it as a candidate for space power, not a proven one.
sources:
wiki-cigs:
title: Copper indium gallium selenide (Wikipedia article)
url: https://en.wikipedia.org/wiki/Copper_indium_gallium_selenide
year: 2026
kind: web
license: CC BY-SA 4.0 (cited, not reproduced)
wiki-cigs-solar:
title: Copper indium gallium selenide solar cells (Wikipedia article)
url: https://en.wikipedia.org/wiki/Copper_indium_gallium_selenide_solar_cells
year: 2026
kind: web
license: CC BY-SA 4.0 (cited, not reproduced)
ntrs-20030000597:
title: CIGS2 Thin-Film Solar Cells on Flexible Foils for Space Power
id: NASA NTRS 20030000597; 17th Space Photovoltaic Research and Technology Conference, 2002 (abstract only)
url: https://ntrs.nasa.gov/citations/20030000597
year: 2002
kind: paper
license: NASA NTRS record (cited, not reproduced)
usgs-mcs2026-indium:
title: 'Mineral Commodity Summaries 2026: Indium'
id: USGS, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-indium.pdf
year: 2026
kind: report
license: Public domain (U.S. Government work)
usgs-mcs2026-gallium:
title: 'Mineral Commodity Summaries 2026: Gallium'
id: USGS, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-gallium.pdf
year: 2026
kind: report
license: Public domain (U.S. Government work)
usgs-mcs2026-selenium:
title: 'Mineral Commodity Summaries 2026: Selenium'
id: USGS, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-selenium.pdf
year: 2026
kind: report
license: Public domain (U.S. Government work)
nasa-msfc-2017-paper:
title: Simulated Space Environmental Effects on Thin Film Solar Array Components (LISA-T, paper)
id: NASA NTRS 20170005334; NASA Marshall Space Flight Center; no date printed in the text read, year taken from the NTRS record
url: https://ntrs.nasa.gov/citations/20170005334
year: 2017
kind: paper
license: NASA NTRS record (cited, not reproduced)
nasa-msfc-2017-slides:
title: Simulated Space Environmental Effects on Thin Film Solar Array Components (ASEC, May 2017, slides)
id: NASA NTRS 20170005333
url: https://ntrs.nasa.gov/citations/20170005333
year: 2017
kind: report
license: NASA NTRS record (cited, not reproduced)
chemicalbook-selenium-sds:
title: 'ChemicalBook: Selenium, chemical safety data sheet (CAS 7782-49-2)'
id: accessed 2026-11-01; no date printed on the page
url: https://www.chemicalbook.com/msds/selenium.htm
year: 2026
kind: web
license: Cited, not reproduced
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 |
|---|---|---|---|---|
| Copper indium gallium selenide (Wikipedia article) | web | 2026 | 8 values | |
| Copper indium gallium selenide solar cells (Wikipedia article) | web | 2026 | 17 values | |
| CIGS2 Thin-Film Solar Cells on Flexible Foils for Space Power | paper | 2002 | 0 values | |
| Mineral Commodity Summaries 2026: Indium | report | 2026 | 1 value | |
| Mineral Commodity Summaries 2026: Gallium | report | 2026 | 1 value | |
| Mineral Commodity Summaries 2026: Selenium | report | 2026 | 1 value | |
| Simulated Space Environmental Effects on Thin Film Solar Array Components (LISA-T, paper) | paper | 2017 | 8 values | |
| Simulated Space Environmental Effects on Thin Film Solar Array Components (ASEC, May 2017, slides) | report | 2017 | 0 values | |
| ChemicalBook: Selenium, chemical safety data sheet (CAS 7782-49-2) | web | 2026 | 1 value |
Updated