Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Ranasinghe, Leonardo, Heyn, Christian, Deneke, Kristian, Zocher, Michael, Korneev, Roman, Hansen, Wolfgang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
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
_version_ 1783671217493901312
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
work_keys_str_mv AT ranasingheleonardo luminescencefromdropletetchedgaasquantumdotsatandclosetoroomtemperature
AT heynchristian luminescencefromdropletetchedgaasquantumdotsatandclosetoroomtemperature
AT denekekristian luminescencefromdropletetchedgaasquantumdotsatandclosetoroomtemperature
AT zochermichael luminescencefromdropletetchedgaasquantumdotsatandclosetoroomtemperature
AT korneevroman luminescencefromdropletetchedgaasquantumdotsatandclosetoroomtemperature
AT hansenwolfgang luminescencefromdropletetchedgaasquantumdotsatandclosetoroomtemperature