Optically induced charging effects in self-assembled<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Ga</mml:mi><mml:mi mathvariant="normal">Sb</mml:mi><mml:mo>∕</mml:mo><mml:mi mathvariant="normal">Ga</mml:mi><mml:mi mathvariant="normal">As</mml:mi></mml:mrow></mml:math>quantum dots

Hayne, Manus; Razinkova, O; Bersier, S; Heitz, R.; Müller‐Kirsch, L.; Geller, M.; Bimberg, D.; Moshchalkov, Victor

doi:10.1103/physrevb.70.081302

Cited by 21 publications

(24 citation statements)

References 19 publications

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“…According to the experiments, the sample has an unintentional residual carbon doping (C-doping) [32] of volume density n A . The carbon binding energy E A is about 26.7 meV, so that thermal activation can be neglected at the temperature of the experiments (7 K).…”

Section: Discussionmentioning

confidence: 99%

“…Powerdependent studies and photon-correlation measurements [24] were performed to identify the two lines as a neutral exciton X, at the energy E X = 1.2736 eV, and a charged exciton at the energy E X + = 1.2752 eV. Moreover, the photoluminescence of the GaAs barrier (not shown here) shows an emission line at 1.495 eV resulting from the radiative recombination of the free electrons in the barrier with the holes bound to the carbon acceptors that are the unintentional impurities which appear during the sample growth [32]. These impurities are notably responsible for the presence of residual holes in the sample.…”

Section: Phenomenology Of the Optical Gate Effectmentioning

confidence: 99%

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Photoneutralization and slow capture of carriers in quantum dots probed by resonant excitation spectroscopy

et al. 2013

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We investigate experimentally and theoretically the resonant emission of single InAs/GaAs quantum dots in a planar microcavity. Due to the presence of at least one residual charge in the quantum dots, the resonant excitation of the neutral exciton is blocked. The influence of the residual doping on the initial quantum dots charge state is analyzed, and the resonant emission quenching is interpreted as a Coulomb blockade effect. The use of an additional non-resonant laser in a specific low power regime leads to the carrier draining in quantum dots and allows an efficient optical gating of the exciton resonant emission. A detailed population evolution model, developed to describe the carrier draining and the optical gate effect, perfectly fits the experimental results in the steady state and dynamical regimes of the optical gate with a single set of parameters. We deduce that ultra-slow Auger-and phonon-assisted capture processes govern the carrier draining in quantum dots with relaxation times in the 1 -100 µs range. We conclude that the optical gate acts as a very sensitive probe of the quantum dots population relaxation in an unprecedented slow-capture regime.

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Section: Discussionmentioning

confidence: 99%

Section: Phenomenology Of the Optical Gate Effectmentioning

confidence: 99%

Photoneutralization and slow capture of carriers in quantum dots probed by resonant excitation spectroscopy

et al. 2013

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“…5 The exclusive confinement of holes and their large localization energy makes GaSb/GaAs QDs particularly interesting for charge storage devices. [6][7][8] GaSb/GaAs QDs were first grown using molecular beam epitaxy 2,9 and later by metal-organic chemical vapor epitaxy, 10,11 followed by optical characterization, 9,[12][13][14][15] cross-section scanning electron microscopy investigations, 16 and deep-level transient spectroscopy (DLTS) studies, 17,18 accompanied by numerical calculations. [19][20][21] The various investigations have been performed on different samples.…”

Section: Introductionmentioning

confidence: 99%

Linking structural and electronic properties of high-purity self-assembled GaSb/GaAs quantum dots

et al. 2012

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Hayne, M. (2012). Linking structural and electronic properties of high-purity self-assembled GaSb/GaAs quantum dots. Physical Review B, 86(3) Please check the document version of this publication:• A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal.If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement: www.tue.nl/taverne Take down policyIf you believe that this document breaches copyright please contact us at: openaccess@tue.nl providing details and we will investigate your claim. We present structural, electrical, and theoretical investigations of self-assembled type-II GaSb/GaAs quantum dots (QDs) grown by molecular beam epitaxy. Using cross-sectional scanning tunneling microscopy (X-STM) the morphology of the QDs is determined. The QDs are of high purity (∼100% GaSb content) and have most likely the shape of a truncated pyramid. The average heights of the QDs are 4-6 nm with average base lengths between 9 and 14 nm. Samples with a QD layer embedded into a pn-diode structure are studied with deep-level transient spectroscopy (DLTS), yielding a hole localization energy in the QDs of 609 meV. Based on the X-STM results the electronic structure of the QDs is calculated using 8-band k·p theory. The theoretical localization energies are found to be in good agreement with the DLTS results. Our results also allow us to estimate how variations in size and shape of the dots influence the hole localization energy.

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“…OICD was first seen in the twodimensional electron gas of δ-doped GaAs/AlGaAs quantum wells 28 and heterojunctions 29 and then later in type-II QDs. 27 Here we present the unique result of OICD in both the wetting layer (WL; at low temperature) and QD/QRs (above room temperature). This remarkable observation allows the temperature induced migration of holes to different nanostructures to be observed.…”

Section: Introductionmentioning

confidence: 99%

“…However, in a few cases, redshifts of the QD emission energy with increasing laser power have been seen and explained by optically induced charge depletion (OICD). 27 This paper details the results of a study into OICD in a GaSb/GaAs QD/QR sample. OICD was first seen in the twodimensional electron gas of δ-doped GaAs/AlGaAs quantum wells 28 and heterojunctions 29 and then later in type-II QDs.…”

Section: Introductionmentioning

confidence: 99%

Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings

et al. 2013

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We present the results of photoluminescence (PL) measurements on a type-II GaSb/GaAs quantum dot/ring sample as a function of temperature (2 to 400 K) and over six orders of magnitude of incident laser excitation power. Optically induced charge depletion (OICD) was seen in both the wetting layer (WL) and quantum dots/rings but with remarkably different temperature dependent behavior. Holes originating from background acceptors migrate out of the WL as the sample temperature is raised to 30 K, while the onset of a blueshift in the PL from quantum rings, signaling their thermally induced charging with holes, is only observed at temperatures above 300 K. The presence of dark dots as a hidden reservoir for acceptor holes at the intermediate temperatures is proposed to explain this anomalous behavior. Due to the deep localization potential of GaSb/GaAs, thermalization of acceptor holes between dark dots and bright rings only occurs above room temperature. A rate equation model is presented which successfully replicates the main features of OICD observed here and in previous reports.

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Optically induced charging effects in self-assembledGaSb∕GaAsquantum dots

Cited by 21 publications

References 19 publications

Photoneutralization and slow capture of carriers in quantum dots probed by resonant excitation spectroscopy

Photoneutralization and slow capture of carriers in quantum dots probed by resonant excitation spectroscopy

Linking structural and electronic properties of high-purity self-assembled GaSb/GaAs quantum dots

Hole migration and optically induced charge depletion in GaSb/GaAs wetting layers and quantum rings

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