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Dark Current Analysis on GeSn p-i-n Photodetectors
Group IV alloys of GeSn have been extensively investigated as a competing material alternative in shortwave-to-mid-infrared photodetectors (PDs). The relatively large defect densities present in GeSn alloys are the major challenge in developing practical devices, owing to the low-temperature growth...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10490798/ https://www.ncbi.nlm.nih.gov/pubmed/37687985 http://dx.doi.org/10.3390/s23177531 |
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author | Ghosh, Soumava Sun, Greg Morgan, Timothy A. Forcherio, Gregory T. Cheng, Hung-Hsiang Chang, Guo-En |
author_facet | Ghosh, Soumava Sun, Greg Morgan, Timothy A. Forcherio, Gregory T. Cheng, Hung-Hsiang Chang, Guo-En |
author_sort | Ghosh, Soumava |
collection | PubMed |
description | Group IV alloys of GeSn have been extensively investigated as a competing material alternative in shortwave-to-mid-infrared photodetectors (PDs). The relatively large defect densities present in GeSn alloys are the major challenge in developing practical devices, owing to the low-temperature growth and lattice mismatch with Si or Ge substrates. In this paper, we comprehensively analyze the impact of defects on the performance of GeSn p-i-n homojunction PDs. We first present our theoretical models to calculate various contributing components of the dark current, including minority carrier diffusion in p- and n-regions, carrier generation–recombination in the active intrinsic region, and the tunneling effect. We then analyze the effect of defect density in the GeSn active region on carrier mobilities, scattering times, and the dark current. A higher defect density increases the dark current, resulting in a reduction in the detectivity of GeSn p-i-n PDs. In addition, at low Sn concentrations, defect-related dark current density is dominant, while the generation dark current becomes dominant at a higher Sn content. These results point to the importance of minimizing defect densities in the GeSn material growth and device processing, particularly for higher Sn compositions necessary to expand the cutoff wavelength to mid- and long-wave infrared regime. Moreover, a comparative study indicates that further improvement of the material quality and optimization of device structure reduces the dark current and thereby increases the detectivity. This study provides more realistic expectations and guidelines for evaluating GeSn p-i-n PDs as a competitor to the III-V- and II-VI-based infrared PDs currently on the commercial market. |
format | Online Article Text |
id | pubmed-10490798 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-104907982023-09-09 Dark Current Analysis on GeSn p-i-n Photodetectors Ghosh, Soumava Sun, Greg Morgan, Timothy A. Forcherio, Gregory T. Cheng, Hung-Hsiang Chang, Guo-En Sensors (Basel) Article Group IV alloys of GeSn have been extensively investigated as a competing material alternative in shortwave-to-mid-infrared photodetectors (PDs). The relatively large defect densities present in GeSn alloys are the major challenge in developing practical devices, owing to the low-temperature growth and lattice mismatch with Si or Ge substrates. In this paper, we comprehensively analyze the impact of defects on the performance of GeSn p-i-n homojunction PDs. We first present our theoretical models to calculate various contributing components of the dark current, including minority carrier diffusion in p- and n-regions, carrier generation–recombination in the active intrinsic region, and the tunneling effect. We then analyze the effect of defect density in the GeSn active region on carrier mobilities, scattering times, and the dark current. A higher defect density increases the dark current, resulting in a reduction in the detectivity of GeSn p-i-n PDs. In addition, at low Sn concentrations, defect-related dark current density is dominant, while the generation dark current becomes dominant at a higher Sn content. These results point to the importance of minimizing defect densities in the GeSn material growth and device processing, particularly for higher Sn compositions necessary to expand the cutoff wavelength to mid- and long-wave infrared regime. Moreover, a comparative study indicates that further improvement of the material quality and optimization of device structure reduces the dark current and thereby increases the detectivity. This study provides more realistic expectations and guidelines for evaluating GeSn p-i-n PDs as a competitor to the III-V- and II-VI-based infrared PDs currently on the commercial market. MDPI 2023-08-30 /pmc/articles/PMC10490798/ /pubmed/37687985 http://dx.doi.org/10.3390/s23177531 Text en © 2023 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 Ghosh, Soumava Sun, Greg Morgan, Timothy A. Forcherio, Gregory T. Cheng, Hung-Hsiang Chang, Guo-En Dark Current Analysis on GeSn p-i-n Photodetectors |
title | Dark Current Analysis on GeSn p-i-n Photodetectors |
title_full | Dark Current Analysis on GeSn p-i-n Photodetectors |
title_fullStr | Dark Current Analysis on GeSn p-i-n Photodetectors |
title_full_unstemmed | Dark Current Analysis on GeSn p-i-n Photodetectors |
title_short | Dark Current Analysis on GeSn p-i-n Photodetectors |
title_sort | dark current analysis on gesn p-i-n photodetectors |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10490798/ https://www.ncbi.nlm.nih.gov/pubmed/37687985 http://dx.doi.org/10.3390/s23177531 |
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