Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications
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...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/ad0856 |
| _version_ | 1827766205189980160 |
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| author | Elisa Maddalena Sala Petr Klenovský |
| author_facet | Elisa Maddalena Sala Petr Klenovský |
| author_sort | Elisa Maddalena Sala |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-11T11:39:24Z |
| format | Article |
| id | doaj.art-3765bda100f545f1aec2b1ee3dcce7b8 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-11T11:39:24Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-3765bda100f545f1aec2b1ee3dcce7b82023-11-10T08:49:43ZengIOP PublishingNew Journal of Physics1367-26302023-01-01251111301210.1088/1367-2630/ad0856Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applicationsElisa Maddalena Sala0https://orcid.org/0000-0001-8116-8830Petr Klenovský1https://orcid.org/0000-0003-1914-164XCenter for Nanophotonics, Institute for Solid State Physics, Technische Universität Berlin , Berlin 10623, Germany; EPSRC National Epitaxy Facility, The University of Sheffield , North Campus, Broad Lane, S3 7HQ Sheffield, United Kingdom; Department of Electronic and Electrical Engineering, The University of Sheffield , North Campus, Broad Lane, S3 7HQ Sheffield, United KingdomDepartment of Condensed Matter Physics, Faculty of Science, Masaryk University , Kotlářská 267/2, 61137 Brno, Czech Republic; Czech Metrology Institute , Okružní 31, 63800 Brno, Czech RepublicWe 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.https://doi.org/10.1088/1367-2630/ad0856quantum dotnanomemoryphotoluminescenceK.p methodconfiguration interactionantimonides |
| spellingShingle | Elisa Maddalena Sala Petr Klenovský 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 quantum dot nanomemory photoluminescence K.p method configuration interaction antimonides |
| title | Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications |
| title_full | Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications |
| title_fullStr | Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications |
| title_full_unstemmed | Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications |
| title_short | Anomalous luminescence temperature dependence of (In,Ga)(As,Sb)/GaAs/GaP quantum dots overgrown by a thin GaSb capping layer for nanomemory applications |
| title_sort | anomalous luminescence temperature dependence of in ga as sb gaas gap quantum dots overgrown by a thin gasb capping layer for nanomemory applications |
| topic | quantum dot nanomemory photoluminescence K.p method configuration interaction antimonides |
| url | https://doi.org/10.1088/1367-2630/ad0856 |
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