Suppression of InAs∕GaAs quantum dot decomposition by the incorporation of a GaAsSb capping layer

Ulloa, JM José Maria; Drouzas, I.; Koenraad, PM Paul; Mowbray, D. J.; Steer, M. J.; Hy, Liu; Hopkinson, M.

doi:10.1063/1.2741608

Cited by 92 publications

(75 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus we can reliably distinguish between Sb and In atoms in the respective polarities. 37 In Fig. 2 we show the distribution of In and Sb around the QD island.…”

Section: Methodsmentioning

confidence: 99%

“…33 Furthermore the GaAsSb capping offers an additional degree of freedom as emission can come from type II band alignment. 16,34 The properties of Ga͑In͒AsSb capping layers have been investigated theoretically 35,36 and experimentally 37,38 showing that like InGaAs the large lattice constant of GaAsSb acts as a SRL providing a mechanism for redshifting the emission wavelength. Such a modified strain difference between the QD and SRL can also induce differences in the island size.…”

Section: Role Of Segregation In Inas/gaas Quantum Dot Structures Cappmentioning

confidence: 99%

See 1 more Smart Citation

Role of segregation in InAs/GaAs quantum dot structures capped with a GaAsSb strain-reduction layer

et al. 2009

Self Cite

View full text Add to dashboard Cite

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: We report a combined experimental and theoretical analysis of Sb and In segregation during the epitaxial growth of InAs self-assembled quantum dot structures covered with a GaSbAs strain-reducing capping layer. Cross-sectional scanning tunneling microscopy shows strong Sb and In segregation which extends through the GaAsSb and into the GaAs matrix. We compare various existing models used to describe the exchange of group III and V atoms in semiconductors and conclude that commonly used methods that only consider segregation between two adjacent monolayers are insufficient to describe the experimental observations. We show that a three-layer model originally proposed for the SiGe system ͓D. J. Godbey and M. G. Ancona, J. Vac. Sci. Technol. A 15, 976 ͑1997͔͒ is instead capable of correctly describing the extended diffusion of both In and Sb atoms. Using atomistic modeling, we present strain maps of the quantum dot structures that show the propagation of the strain into the GaAs region is strongly affected by the shape and composition of the strain-reduction layer.

show abstract

“…Thus we can reliably distinguish between Sb and In atoms in the respective polarities. 37 In Fig. 2 we show the distribution of In and Sb around the QD island.…”

Section: Methodsmentioning

confidence: 99%

Section: Role Of Segregation In Inas/gaas Quantum Dot Structures Cappmentioning

confidence: 99%

Role of segregation in InAs/GaAs quantum dot structures capped with a GaAsSb strain-reduction layer

et al. 2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…27,28 Various shapes of GaAs 1−y Sb y QDs have been reported, including a lens 29 or a pyramid with a graded In concentration. 30 Notably, the hole wave function is expected to be composed of two segments localized in the minima of the piezoelectric potential.…”

Section: -25mentioning

confidence: 99%

“…The pyramidal QD is adopted from Ref. 30 and has the shape of a pyramid with the base length of 22 nm, height of 8 nm, and the trumpet indium composition profile within the pyramid. For the other structures we assume QDs composed of pure InAs.…”

Section: Realistic Quantum Dotsmentioning

confidence: 99%

Excitonic fine structure splitting in type-II quantum dots

2015

View full text Add to dashboard Cite

Excitonic fine structure splitting in quantum dots is closely related to the lateral shape of the wave functions. We have studied theoretically the fine structure splitting in InAs quantum dots with a type-II confinement imposed by a GaAsSb capping layer. We show that very small values of the fine structure splitting comparable with the natural linewidth of the excitonic transitions are achievable for realistic quantum dot morphologies despite the structural elongation and the piezoelectric field. For example, varying the capping layer thickness allows for a fine tuning of the splitting energy. The effect is explained by a strong sensitivity of the hole wave function to the morphology of the structure and a mutual compensation of the electron and hole anisotropies. The oscillator strength of the excitonic transitions in the studied quantum dots is comparable to those with a type-I confinement which makes the dots attractive for quantum communication technology as emitters of polarization-entangled photon pairs.

show abstract

“…The most common capping materials used for the reduction of strain inside dots are InGaAs (Dasika et al, 2009;Kim et al, 2003) and GaAsSb (Haxha et al, 2009;Bozkhurt et al, 2011;Ulloa et al, 2007;Akahane et al, 2004), sometimes InAlAs or some combination of these materials is used (Liu et al, 2005;Kong et al,2008). Strain reducing layers covering InAs dots are used to shift the emission wavelength to 1.3 µm and 1.55 µm, typical of optical fibre communication.…”

Section: Strain Reducing Capping Layersmentioning

confidence: 99%

Capping of InAs/GaAs Quantum Dots for GaAs Based Lasers

Hospodková¹

2012

Quantum Dots - A Variety of New Applications

View full text Add to dashboard Cite

Suppression of InAs∕GaAs quantum dot decomposition by the incorporation of a GaAsSb capping layer

Cited by 92 publications

References 22 publications

Role of segregation in InAs/GaAs quantum dot structures capped with a GaAsSb strain-reduction layer

Role of segregation in InAs/GaAs quantum dot structures capped with a GaAsSb strain-reduction layer

Excitonic fine structure splitting in type-II quantum dots

Capping of InAs/GaAs Quantum Dots for GaAs Based Lasers

Contact Info

Product

Resources

About