Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers

<p dir="ltr">We investigated the optical and structural properties of vertically coupled InAs/GaAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) and separated by thin GaAs and GaAs<sub>0.94</sub>Sb<sub>0.06</sub> spacer layers (SLs). Atomic force mi...

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محفوظ في:
التفاصيل البيبلوغرافية
المؤلف الرئيسي: Abdelmajid Salhi (9178041) (author)
مؤلفون آخرون: Atef Zekri (14156904) (author), Sultan Alshaibani (12059804) (author), Brahim Aissa (10591619) (author)
منشور في: 2025
الموضوعات:
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author Abdelmajid Salhi (9178041)
author2 Atef Zekri (14156904)
Sultan Alshaibani (12059804)
Brahim Aissa (10591619)
author2_role author
author
author
author_facet Abdelmajid Salhi (9178041)
Atef Zekri (14156904)
Sultan Alshaibani (12059804)
Brahim Aissa (10591619)
author_role author
dc.creator.none.fl_str_mv Abdelmajid Salhi (9178041)
Atef Zekri (14156904)
Sultan Alshaibani (12059804)
Brahim Aissa (10591619)
dc.date.none.fl_str_mv 2025-09-12T15:00:00Z
dc.identifier.none.fl_str_mv 10.1016/j.optmat.2025.117500
dc.relation.none.fl_str_mv https://figshare.com/articles/journal_contribution/Engineering_InAs_quantum_dot_pairs_Tailoring_structural_and_optical_properties_with_GaAs_and_GaAsSb_spacer_layers/31057105
dc.rights.none.fl_str_mv CC BY 4.0
info:eu-repo/semantics/openAccess
dc.subject.none.fl_str_mv Engineering
Materials engineering
Nanotechnology
Physical sciences
Condensed matter physics
Molecular beam epitaxy
Quantum dots pair
GaAsSb
Structural properties
Optical properties
dc.title.none.fl_str_mv Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
dc.type.none.fl_str_mv Text
Journal contribution
info:eu-repo/semantics/publishedVersion
text
contribution to journal
description <p dir="ltr">We investigated the optical and structural properties of vertically coupled InAs/GaAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) and separated by thin GaAs and GaAs<sub>0.94</sub>Sb<sub>0.06</sub> spacer layers (SLs). Atomic force microscopy (AFM) analysis of uncapped samples revealed larger top-layer QDs (TQDs) than seed-layer QDs (SQDs), regardless of the presence of Sb in the thin GaAs SL. Scanning transmission electron microscopy (STEM) confirmed the formation of InAs/GaAs and InAs/GaAsSb QD pairs. With a pure GaAs SL, TQDs were larger than SQDs, as expected. However, Sb incorporation into the GaAs SL increased the size of SQDs, leading to QD pairs with nearly identical dimensions. Power-dependent photoluminescence (PL) at 77 K revealed dual-layer (SQDs and TQDs) contributions to the first two emission peaks in both samples. Notably, while the lowest-energy emission originated from the TQDs in the sample with GaAs SL, it arose from the SQDs in the sample with GaAsSb SL. Additionally, the GaAsSb SL enhanced the PL intensity. Thermal activation energy analysis showed higher activation energies for the SQDs compared to the TQDs, consistent with the energy difference between the SQD emission and the wetting layer. The TQDs exhibited an activation energy of 120 meV in both samples, consistent with carrier escape from the TQDs into nonradiative recombination centers within the GaAs cap layer. These findings demonstrate that Sb incorporation into the GaAs SL enables precise control over the electronic and optical properties of artificial quantum dot (QD) molecules, offering a promising pathway for their integration into high-performance optoelectronic and quantum nanodevices.</p><h2 dir="ltr">Other Information</h2><p dir="ltr">Published in: Optical Materials<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1016/j.optmat.2025.117500" target="_blank">https://dx.doi.org/10.1016/j.optmat.2025.117500</a></p>
eu_rights_str_mv openAccess
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network_acronym_str Manara2
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oai_identifier_str oai:figshare.com:article/31057105
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spelling Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layersAbdelmajid Salhi (9178041)Atef Zekri (14156904)Sultan Alshaibani (12059804)Brahim Aissa (10591619)EngineeringMaterials engineeringNanotechnologyPhysical sciencesCondensed matter physicsMolecular beam epitaxyQuantum dots pairGaAsSbStructural propertiesOptical properties<p dir="ltr">We investigated the optical and structural properties of vertically coupled InAs/GaAs quantum dots (QDs) grown by molecular beam epitaxy (MBE) and separated by thin GaAs and GaAs<sub>0.94</sub>Sb<sub>0.06</sub> spacer layers (SLs). Atomic force microscopy (AFM) analysis of uncapped samples revealed larger top-layer QDs (TQDs) than seed-layer QDs (SQDs), regardless of the presence of Sb in the thin GaAs SL. Scanning transmission electron microscopy (STEM) confirmed the formation of InAs/GaAs and InAs/GaAsSb QD pairs. With a pure GaAs SL, TQDs were larger than SQDs, as expected. However, Sb incorporation into the GaAs SL increased the size of SQDs, leading to QD pairs with nearly identical dimensions. Power-dependent photoluminescence (PL) at 77 K revealed dual-layer (SQDs and TQDs) contributions to the first two emission peaks in both samples. Notably, while the lowest-energy emission originated from the TQDs in the sample with GaAs SL, it arose from the SQDs in the sample with GaAsSb SL. Additionally, the GaAsSb SL enhanced the PL intensity. Thermal activation energy analysis showed higher activation energies for the SQDs compared to the TQDs, consistent with the energy difference between the SQD emission and the wetting layer. The TQDs exhibited an activation energy of 120 meV in both samples, consistent with carrier escape from the TQDs into nonradiative recombination centers within the GaAs cap layer. These findings demonstrate that Sb incorporation into the GaAs SL enables precise control over the electronic and optical properties of artificial quantum dot (QD) molecules, offering a promising pathway for their integration into high-performance optoelectronic and quantum nanodevices.</p><h2 dir="ltr">Other Information</h2><p dir="ltr">Published in: Optical Materials<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1016/j.optmat.2025.117500" target="_blank">https://dx.doi.org/10.1016/j.optmat.2025.117500</a></p>2025-09-12T15:00:00ZTextJournal contributioninfo:eu-repo/semantics/publishedVersiontextcontribution to journal10.1016/j.optmat.2025.117500https://figshare.com/articles/journal_contribution/Engineering_InAs_quantum_dot_pairs_Tailoring_structural_and_optical_properties_with_GaAs_and_GaAsSb_spacer_layers/31057105CC BY 4.0info:eu-repo/semantics/openAccessoai:figshare.com:article/310571052025-09-12T15:00:00Z
spellingShingle Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
Abdelmajid Salhi (9178041)
Engineering
Materials engineering
Nanotechnology
Physical sciences
Condensed matter physics
Molecular beam epitaxy
Quantum dots pair
GaAsSb
Structural properties
Optical properties
status_str publishedVersion
title Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
title_full Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
title_fullStr Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
title_full_unstemmed Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
title_short Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
title_sort Engineering InAs quantum dot pairs: Tailoring structural and optical properties with GaAs and GaAsSb spacer layers
topic Engineering
Materials engineering
Nanotechnology
Physical sciences
Condensed matter physics
Molecular beam epitaxy
Quantum dots pair
GaAsSb
Structural properties
Optical properties