Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> Alloys
We report on the connection between strain, composition, defect density and the photoluminescence observed before and after annealing at 300 °C for GeSn samples with Sn content of 8% to 10%. Results show how the composition and level of strain influenced the separation between the indirect and direc...
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| Language: | English |
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MDPI AG
2021-07-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/11/8/905 |
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| author | Oluwatobi Olorunsola Hryhorii Stanchu Solomon Ojo Krishna Pandey Abdulla Said Joe Margetis John Tolle Andrian Kuchuk Yuriy I. Mazur Gregory Salamo Shui-Qing Yu |
| author_facet | Oluwatobi Olorunsola Hryhorii Stanchu Solomon Ojo Krishna Pandey Abdulla Said Joe Margetis John Tolle Andrian Kuchuk Yuriy I. Mazur Gregory Salamo Shui-Qing Yu |
| author_sort | Oluwatobi Olorunsola |
| collection | DOAJ |
| description | We report on the connection between strain, composition, defect density and the photoluminescence observed before and after annealing at 300 °C for GeSn samples with Sn content of 8% to 10%. Results show how the composition and level of strain influenced the separation between the indirect and direct optical transitions, while changes in the level of strain also influenced the density of misfit dislocations and surface roughness. The effect of annealing is observed to lower the level of strain, decreasing the energy separation between the indirect and direct optical transitions, while also simultaneously increasing the density of misfit/threading dislocations and surface roughness. The reduction in energy separation leads to an increase of photoluminescence (PL) emission, while the increase of misfit/threading dislocations density and surface roughness results in a decrease of PL. Consequently, the competition between these factors is observed to determine the impact of annealing on the PL. As a result, annealing increases the collected PL for small (≤40 meV) separation between the indirect to direct optical transitions in the as-grown sample while decreases the PL for larger (≥60 meV) separations. More generally, these numbers have a small dependence on the level of strain in the as-grown samples. |
| first_indexed | 2024-03-10T08:54:29Z |
| format | Article |
| id | doaj.art-52cc0d89022f4e5d8b1a6a7e8fdab34a |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-10T08:54:29Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-52cc0d89022f4e5d8b1a6a7e8fdab34a2023-11-22T07:16:38ZengMDPI AGCrystals2073-43522021-07-0111890510.3390/cryst11080905Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> AlloysOluwatobi Olorunsola0Hryhorii Stanchu1Solomon Ojo2Krishna Pandey3Abdulla Said4Joe Margetis5John Tolle6Andrian Kuchuk7Yuriy I. Mazur8Gregory Salamo9Shui-Qing Yu10Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USAMicroelectronics-Photonics Program, University of Arkansas, Fayetteville, AR 72701, USADepartment of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USAMaterial Science and Engineering Program, University of Arkansas, Fayetteville, AR 72701, USAMaterial Science and Engineering Program, University of Arkansas, Fayetteville, AR 72701, USASchool of Electrical, Energy and Computer Engineering, Arizona State University, Tempe, AZ 85287, USASchool of Electrical, Energy and Computer Engineering, Arizona State University, Tempe, AZ 85287, USAInstitute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR 72701, USAInstitute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR 72701, USAInstitute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR 72701, USADepartment of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USAWe report on the connection between strain, composition, defect density and the photoluminescence observed before and after annealing at 300 °C for GeSn samples with Sn content of 8% to 10%. Results show how the composition and level of strain influenced the separation between the indirect and direct optical transitions, while changes in the level of strain also influenced the density of misfit dislocations and surface roughness. The effect of annealing is observed to lower the level of strain, decreasing the energy separation between the indirect and direct optical transitions, while also simultaneously increasing the density of misfit/threading dislocations and surface roughness. The reduction in energy separation leads to an increase of photoluminescence (PL) emission, while the increase of misfit/threading dislocations density and surface roughness results in a decrease of PL. Consequently, the competition between these factors is observed to determine the impact of annealing on the PL. As a result, annealing increases the collected PL for small (≤40 meV) separation between the indirect to direct optical transitions in the as-grown sample while decreases the PL for larger (≥60 meV) separations. More generally, these numbers have a small dependence on the level of strain in the as-grown samples.https://www.mdpi.com/2073-4352/11/8/905germanium tinannealingdirect and indirect optical transitionstrain engineering |
| spellingShingle | Oluwatobi Olorunsola Hryhorii Stanchu Solomon Ojo Krishna Pandey Abdulla Said Joe Margetis John Tolle Andrian Kuchuk Yuriy I. Mazur Gregory Salamo Shui-Qing Yu Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> Alloys Crystals germanium tin annealing direct and indirect optical transition strain engineering |
| title | Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> Alloys |
| title_full | Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> Alloys |
| title_fullStr | Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> Alloys |
| title_full_unstemmed | Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> Alloys |
| title_short | Impact of Long-Term Annealing on Photoluminescence from Ge<sub>1−x</sub>Sn<sub>x</sub> Alloys |
| title_sort | impact of long term annealing on photoluminescence from ge sub 1 x sub sn sub x sub alloys |
| topic | germanium tin annealing direct and indirect optical transition strain engineering |
| url | https://www.mdpi.com/2073-4352/11/8/905 |
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