Structural defects in cubic semiconductors characterized by aberration-corrected scanning transmission electron microscopy

Dasilva, Yadira Arroyo Rojas; Kozak, Roksolana; Erni, Rolf; Rossell, Marta D.

doi:10.1016/j.ultramic.2016.09.015

Cited by 32 publications

(10 citation statements)

References 64 publications

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“…Some occasional stacking faults along {111} planes are found in the structure (red arrows in Figure 3d2−d4), which correspond to Frank partial dislocations. 60 In the case of stacking faults that are not parallel to the substrate, they appear after several nanometers above the interface with the substrate and propagate until the top of the NW. Upon reaching the top facet of the NW, they create a step feature as depicted in Figure 3d3.…”

Section: Nano Lettersmentioning

confidence: 99%

“…A longitudinal cross-section TEM lamella is prepared to investigate defect propagation along the NW. Some occasional stacking faults along {111} planes are found in the structure (red arrows in Figure d2–d4), which correspond to Frank partial dislocations . In the case of stacking faults that are not parallel to the substrate, they appear after several nanometers above the interface with the substrate and propagate until the top of the NW.…”

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confidence: 99%

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Selectivity Map for Molecular Beam Epitaxy of Advanced III–V Quantum Nanowire Networks

et al. 2018

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Selective-area growth is a promising technique for enabling of the fabrication of the scalable III–V nanowire networks required to test proposals for Majorana-based quantum computing devices. However, the contours of the growth parameter window resulting in selective growth remain undefined. Herein, we present a set of experimental techniques that unambiguously establish the parameter space window resulting in selective III–V nanowire networks growth by molecular beam epitaxy. Selectivity maps are constructed for both GaAs and InAs compounds based on in situ characterization of growth kinetics on GaAs(001) substrates, where the difference in group III adatom desorption rates between the III–V surface and the amorphous mask area is identified as the primary mechanism governing selectivity. The broad applicability of this method is demonstrated by the successful realization of high-quality InAs and GaAs nanowire networks on GaAs, InP, and InAs substrates of both (001) and (111)B orientations as well as homoepitaxial InSb nanowire networks. Finally, phase coherence in Aharonov–Bohm ring experiments validates the potential of these crystals for nanoelectronics and quantum transport applications. This work should enable faster and better nanoscale crystal engineering over a range of compound semiconductors for improved device performance.

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Section: Nano Lettersmentioning

confidence: 99%

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confidence: 99%

Selectivity Map for Molecular Beam Epitaxy of Advanced III–V Quantum Nanowire Networks

et al. 2018

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“…This is preferable by far to the alternative procedure of forming a circuit with a fixed number of vectors that is placed on the experimental (i.e. deformed) image [ 14 ], since the latter procedure cannot easily be applied in multiply-twinned crystals or grain boundaries.…”

Section: Burgers Vectorsmentioning

confidence: 99%

Stable Defects in Semiconductor Nanowires

et al. 2018

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Semiconductor nanowires are commonly described as being defect-free due to their ability to expel mobile defects with long-range strain fields. Here, we describe previously undiscovered topologically protected line defects with null Burgers vector that, unlike dislocations, are stable in nanoscale crystals. We analyze the defects present in semiconductor nanowires in regions of imperfect crystal growth, i.e., at the nanowire tip formed during consumption of the droplet in self-catalyzed vapor-liquid-solid growth and subsequent vapor-solid shell growth. We use a form of the Burgers circuit method that can be applied to multiply twinned material without difficulty. Our observations show that the nanowire microstructure is very different from bulk material, with line defects either (a) trapped by locks or other defects, (b) arranged as dipoles or groups with a zero total Burgers vector, or (c) have a zero Burgers vector. We find two new line defects with a null Burgers vector, formed from the combination of partial dislocations in twinned material. The most common defect is the three-monolayer high twin facet with a zero Burgers vector. Studies of individual nanowires using cathodoluminescence show that optical emission is quenched in defective regions, showing that they act as strong nonradiative recombination centers.

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“…The white lines in the image show the 5‐ and 7‐member rings that are commonly associated with Lomer dislocations. [ 35 ]…”

Section: Resultsmentioning

confidence: 99%

Impact of Individual Structural Defects in GaAs Solar Cells: A Correlative and In Operando Investigation of Signatures, Structures, and Effects

Chen

McKeon

Zhang

et al. 2020

Advanced Optical Materials

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Defects usually degrade device performance. Thus, many techniques and effort are devoted to studying semiconductor defects. However, it is rarely known: i) how individual defects affect device performance; ii) how the impact depends on the device operating conditions; iii) how the impact varies from one defect to another; and iv) how these variations are correlated to the microscopic‐scale defect structure. To address these crucial questions, an array of correlative and spatially resolved techniques, including electroluminescence, photoluminescence, Raman, I–V characteristics, and high‐resolution electron microscopy, are used to characterize dislocation defects in GaAs solar cells. Significantly, the study is carried out in a series mode and in operando. This approach provides quantitative and definitive correlation between the atomistic structure of defects and their explicit effects on device performance, thus giving unprecedented insight into defect physics.

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Structural defects in cubic semiconductors characterized by aberration-corrected scanning transmission electron microscopy

Cited by 32 publications

References 64 publications

Selectivity Map for Molecular Beam Epitaxy of Advanced III–V Quantum Nanowire Networks

Selectivity Map for Molecular Beam Epitaxy of Advanced III–V Quantum Nanowire Networks

Stable Defects in Semiconductor Nanowires

Impact of Individual Structural Defects in GaAs Solar Cells: A Correlative and In Operando Investigation of Signatures, Structures, and Effects

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