Kinetics of the initial stage of coherent island formation in heteroepitaxial systems

Dubrovskiı̆, V. G.; Cirlin, G. É.; Ustinov, V. M.

doi:10.1103/physrevb.68.075409

Cited by 118 publications

(103 citation statements)

References 21 publications

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“…This comparison clearly confirms a role of surface kinetics of adatoms diffusion for the initial nucleation of QDs. The two processes compete: (1) new dots nucleation after locally overcoming of h crit by the deposition thickness and (2) size increase of nucleated dots by the capture of adatoms diffusing on the surface, while the diffusion is regarded as stress-driven toward the existing dots [8]. The dependence of QDs size on the growth rate V observed in Fig.…”

Section: Resultsmentioning

confidence: 71%

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Efficient Emission from InAlGaAs Single Quantum Dots with Low Lattice Misfit and AlGaAs Indirect Bandgap Barrier

et al. 2016

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We report on molecular beam epitaxy growth and properties of rarely studied quaternary In0.4(Al0.75Ga0.25)0.6As self-assembled quantum dots, which show strong and efficient emission of red light from single quantum dots. The increased yield is, among others, due to efficient energy transfer from indirect band-gap Al0.75Ga0.25As barriers. To maximize photon energy emitted from quantum dots, low In composition, xIn = 0.4 was applied, which also lowered the lattice misfit close to the limit of 2D/3D transition in the Stranski-Krastanov growth mode. Time-resolved micro-photoluminescence shows emission at 650-750 nm. Well-resolved single quantum dot photoluminescence lines (decay time of ≈ 1−2 ns) are observed despite a high concentration ≈ 3 × 10 11 cm −2 of quantum dots. We discuss this observation assuming newly a role of carriers or excitons diffusion/tunneling between quantum dots at high surface concentration of dots and a possible role of lattice disorder inside the dot on the exciton lifetime.

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Section: Resultsmentioning

confidence: 71%

“…[7][8][9], QDs formation occurs via nucleation and growth mode. Initial concentration of QDs formed at the 2D/3D transition critical thickness, h crit , for a relatively small excess thickness of deposited material, h−h crit , is determined mostly by kinetic factors for atoms adsorbed on the surface (adatoms).…”

Section: Resultsmentioning

confidence: 99%

Efficient Emission from InAlGaAs Single Quantum Dots with Low Lattice Misfit and AlGaAs Indirect Bandgap Barrier

et al. 2016

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“…Osipov et al [69,70] and Dubrovskii et al [71][72][73] systematically applied the CNGT, as outlined above, to explain QD formation in lattice-mismatched heteroepitaxy. These authors assumed that an elastically strained epitaxial flat film forms first as the metastable phase with a thickness h significantly exceeding a critical value h eq , below which the film is thermodynamically stable; the corresponding "supersaturation" or superstress is defined in terms of ζ ≡ h/h eq − 1.…”

Section: First-order Phase Transformationmentioning

confidence: 99%

Self-assembly of InAs quantum dots on GaAs(001) by molecular beam epitaxy

Jin

2015

Front. Phys.

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Currently, the nature of self-assembly of three-dimensional epitaxial islands or quantum dots (QDs) in a lattice-mismatched heteroepitaxial growth system, such as InAs/GaAs(001) and Ge/Si(001) as fabricated by molecular beam epitaxy (MBE), is still puzzling. The purpose of this article is to discuss how the self-assembly of InAs QDs in MBE InAs/GaAs(001) should be properly understood in atomic scale. First, the conventional kinetic theories that have traditionally been used to interpret QD self-assembly in heteroepitaxial growth with a significant lattice mismatch are reviewed briefly by examining the literature of the past two decades. Second, based on their own experimental data, the authors point out that InAs QD self-assembly can proceed in distinctly different kinetic ways depending on the growth conditions and so cannot be framed within a universal kinetic theory, and, furthermore, that the process may be transient, or the time required for a QD to grow to maturity may be significantly short, which is obviously inconsistent with conventional kinetic theories. Third, the authors point out that, in all of these conventional theories, two well-established experimental observations have been overlooked: i) A large number of “floating” indium atoms are present on the growing surface in MBE InAs/GaAs(001); ii) an elastically strained InAs film on the GaAs(001) substrate should be mechanically unstable. These two well-established experimental facts may be highly relevant and should be taken into account in interpreting InAs QD formation. Finally, the authors speculate that the formation of an InAs QD is more likely to be a collective event involving a large number of both indium and arsenic atoms simultaneously or, alternatively, a morphological/structural transformation in which a single atomic InAs sheet is transformed into a three-dimensional InAs island, accompanied by the rehybridization from the sp 2-bonded to sp 3-bonded atomic configuration of both indium and arsenic elements in the heteroepitaxial growth system.

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“…The thermodynamic model of coherent island on the flat substrate has already been established by Dubrovskii et al and Osipov et al 5,6 It includes the surface energy, the elastic strain energy, and the attractive energy of the wetting layer. Though their proposed model has successfully explained the nucleation barrier and size distribution of island; however, it fails to take into account the thickness-dependent surface energy of wetting layer, which can not be regarded as constant in practical deposition process.…”

Section: Introductionmentioning

confidence: 99%

“…1,2 Self-assembly of QDs have attracted much interest due to their original physical properties and potential device applications. [2][3][4] Although the main mechanisms of heteroepitaxial growth of QDs on flat substrate have been elucidated, 5,6 the vicinal systems exhibit many different features in the experimental observations which are of vital importance to be investigated theoretically. Controlling the size, shape, and a predictable spatial ordering of QDs on the vicinal substrate remains significant challenges, in part because of a limited understanding of the mechanisms of strain-induced transition from wetting layer to faceted QDs.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic model of coherent island formation on vicinal substrate

Zhang¹,

Yu²,

Sun³

et al. 2014

Journal of Applied Physics

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A thermodynamic model has been proposed to address the formation of coherent island on the vicinal substrate. The morphological transition from square based island to elongated based one with various substrate misorientations is described. The initial stage of nucleation and growth process of islands in Stranski-Krastanow system is studied by taking into account the elastic deformations and the change of energy in the case of two-dimensional growth mode. The theoretical analysis shows the minimum nucleation barrier of island is on the decrease with increment of substrate misorientation, which means the nucleation of island on vicinal substrate is more favorable than that on flat substrate. By using the fitting data of experimental results done by Persichetti et al., [Phys. Rev. Lett. 104, 036104 (2010) A thermodynamic model has been proposed to address the formation of coherent island on the vicinal substrate. The morphological transition from square based island to elongated based one with various substrate misorientations is described. The initial stage of nucleation and growth process of islands in Stranski-Krastanow system is studied by taking into account the elastic deformations and the change of energy in the case of two-dimensional growth mode. The theoretical analysis shows the minimum nucleation barrier of island is on the decrease with increment of substrate misorientation, which means the nucleation of island on vicinal substrate is more favorable than that on flat substrate. By using the fitting data of experimental results done by Persichetti et al., [Phys. Rev. Lett. 104, 036104 (2010) and Phys. Rev. B 82, 121309(R) (2010)], we provide a meaningful explanation of the experimental observations. V C 2014 AIP Publishing LLC. [http://dx

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Kinetics of the initial stage of coherent island formation in heteroepitaxial systems

Cited by 118 publications

References 21 publications

Efficient Emission from InAlGaAs Single Quantum Dots with Low Lattice Misfit and AlGaAs Indirect Bandgap Barrier

Efficient Emission from InAlGaAs Single Quantum Dots with Low Lattice Misfit and AlGaAs Indirect Bandgap Barrier

Self-assembly of InAs quantum dots on GaAs(001) by molecular beam epitaxy

Thermodynamic model of coherent island formation on vicinal substrate

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