Strain engineering of self-organized InAs quantum dots

Guffarth, F.; Heitz, R.; Schliwa, A.; Stier, O.; Ledentsov, N. N.; Kovsh, A. R.; Ustinov, V. M.; Bimberg, D.

doi:10.1103/physrevb.64.085305

Cited by 134 publications

(82 citation statements)

References 24 publications

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“…Therefore, we attribute the former to the dots in the upper layer ͑ground and first excited state transitions in one population of dots in that layer observed due to the state filling effect͒ and the latter to the lower layer of dots, i.e., ground and first excited state transitions again. Such an InGaAs capinduced redshift has been already observed previously in similar structures, 21,22 and the details of its origin will not be discussed here. However, we would like to focus on the properties of the WL QW related part of the spectra.…”

Section: Resultsmentioning

confidence: 67%

“…The inclusion of the tunneling does not cause any significant changes besides the appearance of some additional transitions with low oscillator strength ͑occurring between the electrons localized mostly in one QW and holes in the other͒, which are not manifested in the spectra or are just superimposed with one of the strong transitions and could not be resolved within the inhomogeneous line broadening ͑which is of the order of 10-15 meV͒. The energy of the ground state heavy hole transition of the upper layer calculated for the nominal parameters ͑23.6% of the In content in cap͒ is redshifted in comparison with the experimental value ͑by approximately 15 meV͒, which could be a signature of the cap layer decomposition ͑and the overestimation of the effective In content in the cap layer͒; i.e., some of the In atoms of the cap layer join the dots during the cap deposition 21,30,31 ͑a process which is typically reflected in the increase in the dots height or In content and will be a subject of an independent paper͒. In other words, one would need to decrease the In content of the cap to get an agreement with the experimental value of the ground state transitions.…”

Section: -5mentioning

confidence: 99%

“…The former will not be analyzed in this paper, and the main effects related to them have been discussed recently in the literature. 21 As far as the WL QW is concerned, there are at least two major changes expected: modification of the confinement potential ͑into the steplike QW͒ and some influence on the intermixing degree of the WL. Figure 8͑b͒ shows the In content profile across the WLs for the sample with the highest nominal In content ͑of about 23.6%͒.…”

Section: -mentioning

confidence: 99%

“…However, a process known as "cap layer decomposition" cannot be excluded. 21 We have performed the energy level calculations for such a QW consisting of a WL and InGaAs cap including the In content profile from Fig. 8͑b͒.…”

Section: -mentioning

confidence: 99%

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Wetting layer states of InAs∕GaAs self-assembled quantum dot structures: Effect of intermixing and capping layer

Sęk

Ryczko

Motyka

et al. 2007

Journal of Applied Physics

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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 publicationCitation for published version (APA): Sek, G., Ryczko, K., Motyka, M., Andrzejewski, J., Wysocka, K., Misiewicz, J., ... Patriarche, G. (2007). Wetting layer states of InAs/GaAs self-assembled quantum dot structures. Effect of intermixing and capping layer. Journal of Applied Physics, 101(6), 063539-1/7. [063539]. DOI: 10.1063/1.2711146 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 authors present a modulated reflectivity study of the wetting layer ͑WL͒ states in molecular beam epitaxy grown InAs/ GaAs quantum dot ͑QD͒ structures designed to emit light in the 1.3-1.5 m range. A high sensitivity of the technique has allowed the observation of all optical transitions in the QD system, including low oscillator strength transitions related to QD ground and excited states, and the ones connected with the WL quantum well ͑QW͒. The support of WL content profiles, determined by transmission electron microscopy, has made it possible to analyze in detail the real WL QW confinement potential which was then used for calculating the optical transition energies. We could conclude that in spite of a very effective WL QW intermixing, mainly due to the Ga-In exchange process ͑causing the reduction of the maximum indium content in the WL layer to about 35% from nominally deposited InAs͒, the transition energies remain almost unaffected. The latter effect could be explained in effective mass envelope function calculations taking into account the intermixing of the QW interfaces described within the diffusion model. We have followed the WL-...

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Section: Resultsmentioning

confidence: 67%

Section: -5mentioning

confidence: 99%

Section: -mentioning

confidence: 99%

Section: -mentioning

confidence: 99%

See 2 more Smart Citations

Wetting layer states of InAs∕GaAs self-assembled quantum dot structures: Effect of intermixing and capping layer

Sęk

Ryczko

Motyka

et al. 2007

Journal of Applied Physics

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“…Sample A consists of a single QD layer, samples B and C contain small InAs seed QDs and either a single active layer of InAs QDs, separated by a 36 ML thick GaAs spacer from the seed QDs, or a five-fold stack of InAs QDs with 45 ML thick GaAs spacers between all layers. Sample D contains a three-fold stack of InAs QD layers, each overgrown by an In 0.13 Ga 0.87 As quantum well and a 110 ML thick GaAs spacer [12]. Sample E was prepared using metal-organic vapor phase epitaxy and has a single In 0.2 Ga 0.8 As QD layer in GaAs matrix [43].…”

Section: Phonon Interactionmentioning

confidence: 99%