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Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation
In this study, we theoretically investigate the response of a germanium thin film under femtosecond pulsed laser irradiation. Electron and lattice temperatures, as well as material-specific optical properties such as dielectric function and reflectivity, were calculated during the irradiation using...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9657278/ https://www.ncbi.nlm.nih.gov/pubmed/36364560 http://dx.doi.org/10.3390/nano12213786 |
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author | Abdelmalek, Ahmed Kotsedi, Lebogang Bedrane, Zeyneb Amara, El-Hachemi Girolami, Marco Maaza, Malik |
author_facet | Abdelmalek, Ahmed Kotsedi, Lebogang Bedrane, Zeyneb Amara, El-Hachemi Girolami, Marco Maaza, Malik |
author_sort | Abdelmalek, Ahmed |
collection | PubMed |
description | In this study, we theoretically investigate the response of a germanium thin film under femtosecond pulsed laser irradiation. Electron and lattice temperatures, as well as material-specific optical properties such as dielectric function and reflectivity, were calculated during the irradiation using an extended two-temperature model coupled with the carrier density rate equation and the Drude model. Melting and ablation fluence thresholds were also predicted, resulting in 0.14 J cm(−2) and 0.35 J cm(−2), respectively. An ultrafast change in both optical and thermal properties was detected upon laser irradiation. Results also indicate that thermal melting occurs after germanium takes on a metallic character during irradiation, and that the impact ionization process may have a critical role in the laser-induced thermal effect. Therefore, we suggest that the origin of the thermal modification of germanium surface under femtosecond laser irradiation is mostly due the impact ionization process and that its effect becomes more important when increasing the laser fluence. |
format | Online Article Text |
id | pubmed-9657278 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-96572782022-11-15 Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation Abdelmalek, Ahmed Kotsedi, Lebogang Bedrane, Zeyneb Amara, El-Hachemi Girolami, Marco Maaza, Malik Nanomaterials (Basel) Article In this study, we theoretically investigate the response of a germanium thin film under femtosecond pulsed laser irradiation. Electron and lattice temperatures, as well as material-specific optical properties such as dielectric function and reflectivity, were calculated during the irradiation using an extended two-temperature model coupled with the carrier density rate equation and the Drude model. Melting and ablation fluence thresholds were also predicted, resulting in 0.14 J cm(−2) and 0.35 J cm(−2), respectively. An ultrafast change in both optical and thermal properties was detected upon laser irradiation. Results also indicate that thermal melting occurs after germanium takes on a metallic character during irradiation, and that the impact ionization process may have a critical role in the laser-induced thermal effect. Therefore, we suggest that the origin of the thermal modification of germanium surface under femtosecond laser irradiation is mostly due the impact ionization process and that its effect becomes more important when increasing the laser fluence. MDPI 2022-10-27 /pmc/articles/PMC9657278/ /pubmed/36364560 http://dx.doi.org/10.3390/nano12213786 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Abdelmalek, Ahmed Kotsedi, Lebogang Bedrane, Zeyneb Amara, El-Hachemi Girolami, Marco Maaza, Malik Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation |
title | Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation |
title_full | Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation |
title_fullStr | Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation |
title_full_unstemmed | Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation |
title_short | Optical and Thermal Behavior of Germanium Thin Films under Femtosecond Laser Irradiation |
title_sort | optical and thermal behavior of germanium thin films under femtosecond laser irradiation |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9657278/ https://www.ncbi.nlm.nih.gov/pubmed/36364560 http://dx.doi.org/10.3390/nano12213786 |
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