Sala, D.E.M. orcid.org/0000-0001-8116-8830 and Klenovsky, P. orcid.org/0000-0003-1914-164X (2023) Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications. New Journal of Physics, 25. 113012. ISSN 1367-2630
Abstract
We study (In,Ga)(As,Sb)/GaAs quantum dots (QDs) embedded in a GaP (100) matrix, which are overgrown by a thin GaSb capping layer with variable thickness. QD samples are studied by temperature-dependent photoluminescence, and we observe that the QD emission shows anomalous temperature dependence, i.e. increase of energy with temperature increase from 10 K to ∼70 K, followed by energy decrease for larger temperatures. With the help of fitting of luminescence spectra by Gaussian bands with energies extracted from eight band $\textbf{k}\cdot\textbf{p}$ theory with multiparticle corrections calculated using the configuration interaction method, we explain the anomalous temperature dependence as mixing of momentum direct and indirect exciton states. We also find that the k-indirect electron–hole transition in type-I regime at temperatures ${\lt} 70$ K is optically more intense than k-direct. Furthermore, we identify a band alignment change from type-I to type-II for QDs overgrown by more than one monolayer of GaSb. Finally, we predict the retention time of (In,Ga)(As,Sb)/GaAs/AlP/GaP QDs capped with GaSb layers with varying thickness, for usage as storage units in the QD-Flash nanomemory concept and observe that by using only a 2 ML-thick GaSb capping layer, the projected storage time surpasses the non-volatility limit of ten years.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 The Author(s). Published by IOP Publishing Ltd on behalf of the Institute of Physics and Deutsche Physikalische Gesellschaft. Original Content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. https://creativecommons.org/licenses/by/4.0/ |
Keywords: | quantum dot; nanomemory; photoluminescence; k · p method; configuration interaction; antimonides |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 14 Nov 2023 11:26 |
Last Modified: | 14 Nov 2023 11:26 |
Status: | Published |
Publisher: | IOP Publishing |
Refereed: | Yes |
Identification Number: | 10.1088/1367-2630/ad0856 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:205250 |