Controlling the shape of InAs self-assembled quantum dots by thin GaAs capping layers

Takehana, K.; Pulizzi, Fabio; Patanè, A.; Henini, M.; Main, P. C.; Eaves, L.; Granados, Daniel; Garcı́a, J.M.

doi:10.1016/s0022-0248(02)02407-7

Cited by 32 publications

(25 citation statements)

References 15 publications

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“…(Saito et al 1999;Takehana et al 2003) This is because an aspect ratio of 0.33 for InAs/GaAs Stranski-Krastanow (SK) QDs is already achievable. (Saito et al, 1999) Hence it is already not far from the optimum aspect ratio of approximately 0.5.…”

Section: Energy Trendsmentioning

confidence: 99%

Effects of size and shape on electronic states of quantum dots

et al. 2007

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A strain-modified, single-band, constant-potential three-dimensional model was applied to study the dependence of electronic states of InAs/GaAs quantum dots (QDs) of different shapes and sizes. The energy trend was found to decrease monotonically with increasing QD size (i.e.E ∼ size −γ ) but exhibited minimum value at aspect ratio of approximately 0.5. The ground state energy for broad tip was found to be always lower than that of narrow tip. Thus, effort to alter the QD shape instead of the aspect ratio is proposed for longer wavelength emission with InAs/GaAs QDs. The energy dependency γ for volume was found to be approximately three times smaller than that for base length and height. A method was proposed to exploit this large difference for growth experimentalists to verify if the capped InAs QDs follow similar increase as the uncapped InAs QDs upon growth parameter variation.

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Section: Energy Trendsmentioning

confidence: 99%

Effects of size and shape on electronic states of quantum dots

et al. 2007

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“…5g). These morphological changes are explained in terms of indium diffusion from the dots into the cap layer [27].…”

Section: Influence Of Thin Gaas Capping Layersmentioning

confidence: 99%

“…Here the effects of growth interruption on the optical and microscopic properties of InAs/GaAs show vertical profile of the dot for each sample [27] self-assembled dots grown by MBE on (100) and (311)B oriented GaAs substrates are described. The growth interruption applied after the deposition of the InAs layer allows the formation of well-developed InAs dots (large dot size).…”

Section: Effects Of Growth Interruptionmentioning

confidence: 99%

Properties and applications of quantum dot heterostructures grown by molecular beam epitaxy

Henini

2006

Nanoscale Res Lett

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One of the main directions of contemporary semiconductor physics is the production and study of structures with a dimension less than two: quantum wires and quantum dots, in order to realize novel devices that make use of low-dimensional confinement effects. One of the promising fabrication methods is to use selforganized three-dimensional (3D) structures, such as 3D coherent islands, which are often formed during the initial stage of heteroepitaxial growth in lattice-mismatched systems. This article is intended to convey the flavour of the subject by focussing on the structural, optical and electronic properties and device applications of self-assembled quantum dots and to give an elementary introduction to some of the essential characteristics.

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“…He suggested that the red shift was attributed to partial relaxation of QD strain allowed by capping, and an additional blue-shift shown in a noisy spectrum taken from 5 nm sample was due to high surface potential. Recently, Joyce et al [17] and Takehana et al [21] discussed evolutions of surface morphology on the basis of anisotropic valley-ridge or ring-shaped feature of InAs QDs developed during GaAs overgrowth using in situ scanning tunneling microscopy and atomic force microscopy (AFM), respectively. It is therefore necessary to more definitely identify some controversial issues on the surface morphology and the energy shift mechanism through a complementary analysis on structural and optical characteristics of near-surface QDs.…”

Section: Introductionmentioning

confidence: 99%