Effect of a lattice-matched GaAsSb capping layer on the structural properties of InAs/InGaAs/InP quantum dots

Abstract

Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers)Please check the document version of this publication:• A submitted manuscript is the author's 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 ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. The influence of a lattice-matched GaAsSb capping layer on the structural properties of self-assembled InAs quantum dots ͑QDs͒ grown on InP substrates is studied on the atomic scale by cross-sectional scanning tunneling microscopy. While lattice-matched In 0.53 Ga 0.47 As-capped QDs are clearly truncated pyramids, GaAs 0.51 Sb 0.49 -capped QDs grown under the same conditions look like full pyramids and exhibit a larger height, indicating that capping with GaAsSb reduces dot decomposition. Since there are no differences in strain between the two capping layers, this behavior is most likely related to the surfactant effect of Sb, which stabilizes the growth front and avoids adatom migration.

Scanning probe microscopy and spectroscopy of colloidal semiconductor nanocrystals and assembled structures

“…In such a way, the overall shape of the quantum dot, the atomic structure of the wetting layers and dot, and the presence and effect of doping atoms can be studied. The solid that contains the self-assembled quantum dots can be cleaved under ultrahigh-vacuum conditions, enabling cross-sectional microscopy and energy-level spectroscopy (refs , , , , − , − , − , , and − ). Recently, cross-sectional microscopy has been combined with atom probe tomography, which allows one to make detailed cross sections of the atomic structure of the quantum dot combined with tunneling spectroscopy.…”

Structural and optical changes induced by incorporation of antimony into InAs/GaAs(001) quantum dots

“…11 Several research groups have studied the use of GaAsSb strain reducing layers on top of InAs QDs. [12][13][14][15][16] Because of the strong segregation of Sb during GaAsSb growth on GaAs, the first monolayer ͑ML͒ on top of the QDs have a very low Sb content. 17 Here we report on the changes induced by solid source Sb deposition ͑without codeposition of Ga or As͒, after InAs QD formation and immediately before QD capping with…”

Competitive carrier interactions influencing the emission dynamics of GaAsSb-capped InAs quantum dots

“…The larger QW lattice constant compared to GaAs reduces the strain induced in the QDs during the capping process, preserving the shape, and reducing the decomposition of the dots. [4][5][6] Moreover, contrary to other strain-relieving layers, GaAsSb QW with 14% Sb keeps the confining potential of both electrons and holes essentially identical to that of InAs QDs in GaAs matrix. This limits the carrier thermal escape from the QDs and consequently leads to optimized emission intensity and spectral width, 7,8 although the spatial localization of the holes is reduced.…”