Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells
Chromium (Cr) can degrade silicon wafer-based solar cell efficiencies at concentrations as low as 10¹⁰cm⁻³. In this contribution, we employ synchrotron-based X-ray fluorescence microscopy to study chromium distributions in multicrystalline silicon in as-grown material and after phosphorous diffusion...
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American Institute of Physics (AIP)
2018
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| Online Access: | http://hdl.handle.net/1721.1/118922 https://orcid.org/0000-0002-5353-0780 https://orcid.org/0000-0001-9352-8741 https://orcid.org/0000-0002-4609-9312 https://orcid.org/0000-0001-8345-4937 |
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| author | Coletti, Gianluca Lai, Barry Jensen, Mallory Ann Hofstetter, Jasmin Morishige, Ashley Elizabeth Fenning, David P Buonassisi, Anthony |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Coletti, Gianluca Lai, Barry Jensen, Mallory Ann Hofstetter, Jasmin Morishige, Ashley Elizabeth Fenning, David P Buonassisi, Anthony |
| author_sort | Coletti, Gianluca |
| collection | MIT |
| description | Chromium (Cr) can degrade silicon wafer-based solar cell efficiencies at concentrations as low as 10¹⁰cm⁻³. In this contribution, we employ synchrotron-based X-ray fluorescence microscopy to study chromium distributions in multicrystalline silicon in as-grown material and after phosphorous diffusion. We complement quantified precipitate size and spatial distribution with interstitial Cr concentration and minority carrier lifetime measurements to provide insight into chromium gettering kinetics and offer suggestions for minimizing the device impacts of chromium. We observe that Cr-rich precipitates in as-grown material are generally smaller than iron-rich precipitates and that Cr[subscript i] point defects account for only one-half of the total Cr in the as-grown material. This observation is consistent with previous hypotheses that Cr transport and CrSi₂ growth are more strongly diffusion-limited during ingot cooling. We apply two phosphorous diffusion gettering profiles that both increase minority carrier lifetime by two orders of magnitude and reduce [Cr[subscript i]] by three orders of magnitude to 10¹⁰cm⁻³. Some Cr-rich precipitates persist after both processes, and locally high [Cr[subscript i]] after the high-temperature process indicates that further optimization of the chromium gettering profile is possible. |
| first_indexed | 2024-09-23T09:38:25Z |
| format | Article |
| id | mit-1721.1/118922 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T09:38:25Z |
| publishDate | 2018 |
| publisher | American Institute of Physics (AIP) |
| record_format | dspace |
| spelling | mit-1721.1/1189222022-09-26T12:48:18Z Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells Coletti, Gianluca Lai, Barry Jensen, Mallory Ann Hofstetter, Jasmin Morishige, Ashley Elizabeth Fenning, David P Buonassisi, Anthony Massachusetts Institute of Technology. Department of Mechanical Engineering Jensen, Mallory Ann Hofstetter, Jasmin Morishige, Ashley Elizabeth Fenning, David P Buonassisi, Anthony Chromium (Cr) can degrade silicon wafer-based solar cell efficiencies at concentrations as low as 10¹⁰cm⁻³. In this contribution, we employ synchrotron-based X-ray fluorescence microscopy to study chromium distributions in multicrystalline silicon in as-grown material and after phosphorous diffusion. We complement quantified precipitate size and spatial distribution with interstitial Cr concentration and minority carrier lifetime measurements to provide insight into chromium gettering kinetics and offer suggestions for minimizing the device impacts of chromium. We observe that Cr-rich precipitates in as-grown material are generally smaller than iron-rich precipitates and that Cr[subscript i] point defects account for only one-half of the total Cr in the as-grown material. This observation is consistent with previous hypotheses that Cr transport and CrSi₂ growth are more strongly diffusion-limited during ingot cooling. We apply two phosphorous diffusion gettering profiles that both increase minority carrier lifetime by two orders of magnitude and reduce [Cr[subscript i]] by three orders of magnitude to 10¹⁰cm⁻³. Some Cr-rich precipitates persist after both processes, and locally high [Cr[subscript i]] after the high-temperature process indicates that further optimization of the chromium gettering profile is possible. United States. Department of Energy (Contract DE-EE0005314) National Science Foundation (U.S.) (Contract EEC-1041895) United States. Department of Energy (Contract EEC-1041895) National Science Foundation (U.S.) (Grant 1122374) 2018-11-06T17:27:03Z 2018-11-06T17:27:03Z 2015-05 2015-04 2018-10-31T15:53:52Z Article http://purl.org/eprint/type/JournalArticle 0003-6951 1077-3118 http://hdl.handle.net/1721.1/118922 Jensen, Mallory Ann et al. “Synchrotron-Based Analysis of Chromium Distributions in Multicrystalline Silicon for Solar Cells.” Applied Physics Letters 106, 20 (May 2015): 202104 © 2015 AIP Publishing LLC https://orcid.org/0000-0002-5353-0780 https://orcid.org/0000-0001-9352-8741 https://orcid.org/0000-0002-4609-9312 https://orcid.org/0000-0001-8345-4937 http://dx.doi.org/10.1063/1.4921619 Applied Physics Letters Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf American Institute of Physics (AIP) Other repository |
| spellingShingle | Coletti, Gianluca Lai, Barry Jensen, Mallory Ann Hofstetter, Jasmin Morishige, Ashley Elizabeth Fenning, David P Buonassisi, Anthony Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells |
| title | Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells |
| title_full | Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells |
| title_fullStr | Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells |
| title_full_unstemmed | Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells |
| title_short | Synchrotron-based analysis of chromium distributions in multicrystalline silicon for solar cells |
| title_sort | synchrotron based analysis of chromium distributions in multicrystalline silicon for solar cells |
| url | http://hdl.handle.net/1721.1/118922 https://orcid.org/0000-0002-5353-0780 https://orcid.org/0000-0001-9352-8741 https://orcid.org/0000-0002-4609-9312 https://orcid.org/0000-0001-8345-4937 |
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