Quantitative study of the interfacial intermixing and segregation effects across the wetting layer of Ga(As,Sb)-capped InAs quantum dots

Luna, E.; Beltrán, Ana M.; Sánchez, Ana; Molina, S. I.

doi:10.1063/1.4731790

Cited by 4 publications

(3 citation statements)

References 24 publications

(37 reference statements)

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“…Moreover, a slight interface broadening (≈0.5-1.0 ML) is introduced by the need to orient the interface slightly away from the edge-on condition in order to bring the 002 reflection close to the Bragg condition. [19] Despite these practical concerns, it is significant that the present estimates of interfacial width made using the g 002 DFTEM technique are similar to measurements from other materials systems using different methods, such as EELS [19,27] or atom probe tomography. [28,29] For example, a Z-contrast imaging study of interfacial intermixing in InAs/GaSb NCA superlattices indicated interfacial widths (10-90% criterion) of 2.69 and 2.11 ML at InAs-on-GaSb and GaSb-on-InAs interfaces, respectively.…”

Section: Discussionmentioning

confidence: 79%

Strategies for Analyzing Noncommon‐Atom Heterovalent Interfaces: The Case of CdTe‐on‐InSb

Luna

Trampert

et al. 2019

Adv Materials Inter

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Semiconductor heterostructures are intrinsic to a wide range of modern‐day electronic devices, such as computers, light‐emitting devices, and photodetectors. Knowledge of chemical interfacial profiles in these structures is critical to the task of optimizing the device performance. This work presents an analysis of the composition profile and strain across the noncommon‐atom heterovalent CdTe/InSb interface, carried out using a combination of electron microscopy imaging techniques. Because of the close atomic numbers of the constituent elements, techniques such as high‐angle annular‐dark‐field and large‐angle bright‐field scanning transmission electron microscopy, as well as electron energy‐loss spectroscopy, give results from the interface region that are inherently difficult to interpret. By contrast, use of the 002 dark‐field imaging technique emphasizes the interface location by comparing differences in structure factors between the two materials. Comparisons of experimental and simulated CdTe‐on‐InSb profiles reveal that the interface is structurally abrupt to within about 1.5 nm (10–90% criterion), while geometric phase analysis based on aberration‐corrected electron microscopy images reveals a minimal level of interfacial strain. The present investigation opens new routes to the systematic investigation of heterovalent interfaces, formed by the combination of other valence‐mismatched material systems.

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Section: Discussionmentioning

confidence: 79%

Strategies for Analyzing Noncommon‐Atom Heterovalent Interfaces: The Case of CdTe‐on‐InSb

Luna

Trampert

et al. 2019

Adv Materials Inter

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“…24 In addition, although this imaging method is aperture-limited, it has been shown elsewhere that detailed analysis of the shape of the composition profiles, supported by structural modeling, allows quantification of the chemical interface, and variations in interface widths and layer thicknesses as small as 0.1 ML can be measured. 25,26…”

Section: Dark-field Imagingmentioning

confidence: 99%

“…This is unlikely to be due to Sb segregation; rather, this non-ideal interface is due to an intrinsic minimum interface width that is dictated by the moleculessurface interaction potential during growth, and can be approximated with a set of sigmoidal functions, as represented by Equation (3). [24][25][26] For layers centered at z ¼ 0, the sigmoidal expressions are…”

Section: Evaluation Of Antimony Segregationmentioning

confidence: 99%

Evaluation of antimony segregation in InAs/InAs1−xSbx type-II superlattices grown by molecular beam epitaxy

Luna

Aoki

et al. 2016

Journal of Applied Physics

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InAs/InAs1−xSbx type II superlattices designed for mid-wavelength infrared photo-detection have been studied using several electron microscopy methods, with specific attention directed towards interface chemical diffusion caused by Sb segregation. Reciprocal-space image analysis using the geometric phase method showed asymmetric interfacial strain profiles at the InAs-on-InAsSb interface. Measurement of local Sb compositional profiles across the superlattices using electron energy-loss spectroscopy and 002 dark-field imaging confirmed asymmetric Sb distribution, with the InAs-on-InAsSb interface being chemically graded. In contrast, the InAsSb-on-InAs interface showed a small intrinsic interface width. Careful evaluation of the experimental Sb composition profiles using a combined segregation and sigmoidal model reached quantitative agreement. Segregation dominated over the sigmoidal growth at the InAs-on-InAsSb interface, and the segregation probability of 0.81 ± 0.01 obtained from the two microscopy techniques agreed well within experimental error. Thus, 81% of Sb atoms from the topmost layers segregated into the next layer during growth causing the interfaces to be broadened over a length of ∼3 nm. This strong Sb segregation occurred throughout the whole superlattice stack, and would likely induce undesirable effects on band-gap engineering, such as blue-shift or broadening of the optical response, as well as weakened absorption.

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Theoretical study of the indium incorporation into III-V compounds revisited: The role of indium segregation and desorption

Pelá

Teles

Marques

et al. 2013

Journal of Applied Physics

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Indium based III-V compounds are very important technological materials. However, the indium incorporation depends on several phenomena, among them, the influence of indium segregation has been the most studied. In this paper, we show that to predict accurately the energy levels of In based III-V quantum structures, besides the indium segregation, the indium desorption must also be considered. In order to verify this assumption, we consider InGaAs/GaAs quantum wells as a benchmark case, and simulate 48 different quantum wells comparing with photoluminescence results.

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Quantitative study of the interfacial intermixing and segregation effects across the wetting layer of Ga(As,Sb)-capped InAs quantum dots

Abstract: Wetting layer states of In As ∕ Ga As self-assembled quantum dot structures: Effect of intermixing and capping layer Quantitative analysis of compositional changes in In Ga As ∕ In Ga As P quantum wells on GaAs induced by intermixing with a low temperature grown InGaP cap layer

Cited by 4 publications

References 24 publications

Strategies for Analyzing Noncommon‐Atom Heterovalent Interfaces: The Case of CdTe‐on‐InSb

Strategies for Analyzing Noncommon‐Atom Heterovalent Interfaces: The Case of CdTe‐on‐InSb

Evaluation of antimony segregation in InAs/InAs1−xSbx type-II superlattices grown by molecular beam epitaxy

Theoretical study of the indium incorporation into III-V compounds revisited: The role of indium segregation and desorption

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