Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2
Abstract The chalcopyrite Cu(In,Ga)S2 has gained renewed interest in recent years due to the potential application in tandem solar cells. In this contribution, a combined theoretical and experimental approach is applied to investigate stable and metastable phases forming in CuInS2 (CIS) thin films....
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2022-08-01
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| Series: | Advanced Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/advs.202200848 |
| _version_ | 1797819760415604736 |
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| author | Jes K. Larsen Kostiantyn V. Sopiha Clas Persson Charlotte Platzer‐Björkman Marika Edoff |
| author_facet | Jes K. Larsen Kostiantyn V. Sopiha Clas Persson Charlotte Platzer‐Björkman Marika Edoff |
| author_sort | Jes K. Larsen |
| collection | DOAJ |
| description | Abstract The chalcopyrite Cu(In,Ga)S2 has gained renewed interest in recent years due to the potential application in tandem solar cells. In this contribution, a combined theoretical and experimental approach is applied to investigate stable and metastable phases forming in CuInS2 (CIS) thin films. Ab initio calculations are performed to obtain formation energies, X‐ray diffraction (XRD) patterns, and Raman spectra of CIS polytypes and related compounds. Multiple CIS structures with zinc‐blende and wurtzite‐derived lattices are identified and their XRD/Raman patterns are shown to contain overlapping features, which could lead to misidentification. Thin films with compositions from Cu‐rich to Cu‐poor are synthesized via a two‐step approach based on sputtering from binary targets followed by high‐temperature sulfurization. It is discovered that several CIS polymorphs are formed when growing the material with this approach. In the Cu‐poor material, wurtzite CIS is observed for the first time in sputtered thin films along with chalcopyrite CIS and CuAu‐ordered CIS. Once the wurtzite CIS phase has formed, it is difficult to convert into the stable chalcopyrite polymorph. CuIn5S8 and NaInS2 accommodating In‐excess are found alongside the CIS polymorphs. It is argued that the metastable polymorphs are stabilized by off‐stoichiometry of the precursors, hence tight composition control is required. |
| first_indexed | 2024-03-13T09:27:21Z |
| format | Article |
| id | doaj.art-8c7ce2a6834a448c9dfd8742bb5e8d53 |
| institution | Directory Open Access Journal |
| issn | 2198-3844 |
| language | English |
| last_indexed | 2024-03-13T09:27:21Z |
| publishDate | 2022-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advanced Science |
| spelling | doaj.art-8c7ce2a6834a448c9dfd8742bb5e8d532023-05-26T08:56:00ZengWileyAdvanced Science2198-38442022-08-01923n/an/a10.1002/advs.202200848Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2Jes K. Larsen0Kostiantyn V. Sopiha1Clas Persson2Charlotte Platzer‐Björkman3Marika Edoff4Division of Solar Cell Technology Department of Materials Science and Engineering Uppsala University Box 534 Uppsala SE‐75237 SwedenDivision of Solar Cell Technology Department of Materials Science and Engineering Uppsala University Box 534 Uppsala SE‐75237 SwedenCentre for Materials Science and Nanotechnology/Department of Physics University of Oslo Blindern, Box 1048 Oslo NO‐0316 NorwayDivision of Solar Cell Technology Department of Materials Science and Engineering Uppsala University Box 534 Uppsala SE‐75237 SwedenDivision of Solar Cell Technology Department of Materials Science and Engineering Uppsala University Box 534 Uppsala SE‐75237 SwedenAbstract The chalcopyrite Cu(In,Ga)S2 has gained renewed interest in recent years due to the potential application in tandem solar cells. In this contribution, a combined theoretical and experimental approach is applied to investigate stable and metastable phases forming in CuInS2 (CIS) thin films. Ab initio calculations are performed to obtain formation energies, X‐ray diffraction (XRD) patterns, and Raman spectra of CIS polytypes and related compounds. Multiple CIS structures with zinc‐blende and wurtzite‐derived lattices are identified and their XRD/Raman patterns are shown to contain overlapping features, which could lead to misidentification. Thin films with compositions from Cu‐rich to Cu‐poor are synthesized via a two‐step approach based on sputtering from binary targets followed by high‐temperature sulfurization. It is discovered that several CIS polymorphs are formed when growing the material with this approach. In the Cu‐poor material, wurtzite CIS is observed for the first time in sputtered thin films along with chalcopyrite CIS and CuAu‐ordered CIS. Once the wurtzite CIS phase has formed, it is difficult to convert into the stable chalcopyrite polymorph. CuIn5S8 and NaInS2 accommodating In‐excess are found alongside the CIS polymorphs. It is argued that the metastable polymorphs are stabilized by off‐stoichiometry of the precursors, hence tight composition control is required.https://doi.org/10.1002/advs.202200848disorderpolymorphspolytypesRaman spectrawurtzitezinc‐blende |
| spellingShingle | Jes K. Larsen Kostiantyn V. Sopiha Clas Persson Charlotte Platzer‐Björkman Marika Edoff Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2 Advanced Science disorder polymorphs polytypes Raman spectra wurtzite zinc‐blende |
| title | Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2 |
| title_full | Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2 |
| title_fullStr | Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2 |
| title_full_unstemmed | Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2 |
| title_short | Experimental and Theoretical Study of Stable and Metastable Phases in Sputtered CuInS2 |
| title_sort | experimental and theoretical study of stable and metastable phases in sputtered cuins2 |
| topic | disorder polymorphs polytypes Raman spectra wurtzite zinc‐blende |
| url | https://doi.org/10.1002/advs.202200848 |
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