Plastic and Elastic Strain Fields in GaAs/Si Core–Shell Nanowires

Conesa‐Boj, Sonia; Boioli, Francesca; Russo-Averchi, Eleonora; Dunand, S.; Heiß, Martin; Rüffer, Daniel; Wyrsch, Nicolas; Ballif, Christophe; Miglio, Leo; Morral, Anna Fontcuberta i

doi:10.1021/nl4046312

Cited by 32 publications

(33 citation statements)

References 55 publications

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“…The corresponding strain fields can be then calculated by tacking the derivative of the displacement field. 31 , 32 In this analysis, the scan distortions introduced during the STEM data acquisition have been corrected (see sections SI and SII for further details about this procedure). The phase image ( Figure 2 d) was calculated for the set of (01–10) lattice fringes ( Figure 2 c), evaluated from the fast Fourier transform (FFT); see Figure 2 b.…”

Section: Strain-dependent Edge Structure In a Mos 2 mentioning

confidence: 99%

Strain-Dependent Edge Structures in MoS₂ Layers

et al. 2017

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Edge structures are low-dimensional defects unavoidable in layered materials of the transition metal dichalcogenides (TMD) family. Among the various types of such structures, the armchair (AC) and zigzag (ZZ) edge types are the most common. It has been predicted that the presence of intrinsic strain localized along these edges structures can have direct implications for the customization of their electronic properties. However, pinning down the relation between local structure and electronic properties at these edges is challenging. Here, we quantify the local strain field that arises at the edges of MoS2 flakes by combining aberration-corrected transmission electron microscopy (TEM) with the geometrical-phase analysis (GPA) method. We also provide further insight on the possible effects of such edge strain on the resulting electronic behavior by means of electron energy loss spectroscopy (EELS) measurements. Our results reveal that the two-dominant edge structures, ZZ and AC, induce the formation of different amounts of localized strain fields. We also show that by varying the free edge curvature from concave to convex, compressive strain turns into tensile strain. These results pave the way toward the customization of edge structures in MoS2, which can be used to engineer the properties of layered materials and thus contribute to the optimization of the next generation of atomic-scale electronic devices built upon them.

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Section: Strain-dependent Edge Structure In a Mos 2 mentioning

confidence: 99%

Strain-Dependent Edge Structures in MoS₂ Layers

et al. 2017

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“…1−4 In addition, the strain induced by the lattice mismatch between Ge and Si (around 4%) modifies the band alignment, 5,6 paving the way to technological applications based on band gap engineering. 7−10 However, the lattice mismatch between Ge and Si results in strain-induced misfit dislocations, 11 severely affecting the carrier mobility.…”

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confidence: 99%

Boosting Hole Mobility in Coherently Strained [110]-Oriented Ge–Si Core–Shell Nanowires

Conesa‐Boj

Koelling

et al. 2017

Nano Lett.

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The ability of core–shell nanowires to overcome existing limitations of heterostructures is one of the key ingredients for the design of next generation devices. This requires a detailed understanding of the mechanism for strain relaxation in these systems in order to eliminate strain-induced defect formation and thus to boost important electronic properties such as carrier mobility. Here we demonstrate how the hole mobility of [110]-oriented Ge–Si core–shell nanowires can be substantially enhanced thanks to the realization of large band offset and coherent strain in the system, reaching values as high as 4200 cm2/(Vs) at 4 K and 1600 cm2/(Vs) at room temperature for high hole densities of 1019 cm–3. We present a direct correlation of (i) mobility, (ii) crystal direction, (iii) diameter, and (iv) coherent strain, all of which are extracted in our work for individual nanowires. Our results imply [110]-oriented Ge–Si core–shell nanowires as a promising candidate for future electronic and quantum transport devices.

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“…To carry out quantitative and qualitative studies, one needs a tool with high spatial resolution and strain sensitivity as well as penetrability through hundreds of atomic layers. While electron imaging methods 3,4 provide unbeatable surface spatial resolution, they have limited penetrability of a few nanometers, and since the electron beam also interacts with an external electric and magnetic field, their application for volumetric and dynamical strain mapping in the volume of nanostructures and heterostructures is greatly hindered. The atom probe tomography (APT) technique can access the information beyond a single cubic nanometer, 5 but one must accept the destruction of the sample in the process.…”

Section: Introductionmentioning

confidence: 99%