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