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Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature
Epitaxially grown quantum dots (QDs) are established as quantum emitters for quantum information technology, but their operation under ambient conditions remains a challenge. Therefore, we study photoluminescence (PL) emission at and close to room temperature from self-assembled strain-free GaAs qua...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8001385/ https://www.ncbi.nlm.nih.gov/pubmed/33802007 http://dx.doi.org/10.3390/nano11030690 |
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author | Ranasinghe, Leonardo Heyn, Christian Deneke, Kristian Zocher, Michael Korneev, Roman Hansen, Wolfgang |
author_facet | Ranasinghe, Leonardo Heyn, Christian Deneke, Kristian Zocher, Michael Korneev, Roman Hansen, Wolfgang |
author_sort | Ranasinghe, Leonardo |
collection | PubMed |
description | Epitaxially grown quantum dots (QDs) are established as quantum emitters for quantum information technology, but their operation under ambient conditions remains a challenge. Therefore, we study photoluminescence (PL) emission at and close to room temperature from self-assembled strain-free GaAs quantum dots (QDs) in refilled AlGaAs nanoholes on (001)GaAs substrate. Two major obstacles for room temperature operation are observed. The first is a strong radiative background from the GaAs substrate and the second a significant loss of intensity by more than four orders of magnitude between liquid helium and room temperature. We discuss results obtained on three different sample designs and two excitation wavelengths. The PL measurements are performed at room temperature and at T = 200 K, which is obtained using an inexpensive thermoelectric cooler. An optimized sample with an AlGaAs barrier layer thicker than the penetration depth of the exciting green laser light (532 nm) demonstrates clear QD peaks already at room temperature. Samples with thin AlGaAs layers show room temperature emission from the QDs when a blue laser (405 nm) with a reduced optical penetration depth is used for excitation. A model and a fit to the experimental behavior identify dissociation of excitons in the barrier below T = 100 K and thermal escape of excitons from QDs above T = 160 K as the central processes causing PL-intensity loss. |
format | Online Article Text |
id | pubmed-8001385 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-80013852021-03-28 Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature Ranasinghe, Leonardo Heyn, Christian Deneke, Kristian Zocher, Michael Korneev, Roman Hansen, Wolfgang Nanomaterials (Basel) Article Epitaxially grown quantum dots (QDs) are established as quantum emitters for quantum information technology, but their operation under ambient conditions remains a challenge. Therefore, we study photoluminescence (PL) emission at and close to room temperature from self-assembled strain-free GaAs quantum dots (QDs) in refilled AlGaAs nanoholes on (001)GaAs substrate. Two major obstacles for room temperature operation are observed. The first is a strong radiative background from the GaAs substrate and the second a significant loss of intensity by more than four orders of magnitude between liquid helium and room temperature. We discuss results obtained on three different sample designs and two excitation wavelengths. The PL measurements are performed at room temperature and at T = 200 K, which is obtained using an inexpensive thermoelectric cooler. An optimized sample with an AlGaAs barrier layer thicker than the penetration depth of the exciting green laser light (532 nm) demonstrates clear QD peaks already at room temperature. Samples with thin AlGaAs layers show room temperature emission from the QDs when a blue laser (405 nm) with a reduced optical penetration depth is used for excitation. A model and a fit to the experimental behavior identify dissociation of excitons in the barrier below T = 100 K and thermal escape of excitons from QDs above T = 160 K as the central processes causing PL-intensity loss. MDPI 2021-03-10 /pmc/articles/PMC8001385/ /pubmed/33802007 http://dx.doi.org/10.3390/nano11030690 Text en © 2021 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 (http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) ). |
spellingShingle | Article Ranasinghe, Leonardo Heyn, Christian Deneke, Kristian Zocher, Michael Korneev, Roman Hansen, Wolfgang Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature |
title | Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature |
title_full | Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature |
title_fullStr | Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature |
title_full_unstemmed | Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature |
title_short | Luminescence from Droplet-Etched GaAs Quantum Dots at and Close to Room Temperature |
title_sort | luminescence from droplet-etched gaas quantum dots at and close to room temperature |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8001385/ https://www.ncbi.nlm.nih.gov/pubmed/33802007 http://dx.doi.org/10.3390/nano11030690 |
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