scholarly journals Bi Incorporation and Segregation in the MBE-Grown GaAs-(Ga,Al)As-Ga(As,Bi) Core-Shell Nanowires

2021 ◽  
Author(s):  
Janusz Sadowski ◽  
Anna Kaleta ◽  
Serhii Kryvyi ◽  
Dorota Janaszko ◽  
Bogusława Kurowska ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Flux Ratio ◽  
Growth Conditions ◽  
Nanowire Growth ◽  
Core Shell ◽  
Zinc Blende ◽  
Transmission Electron ◽  
Shell Nanowires

Abstract Incorporation of Bi into GaAs-(Ga,Al)As-Ga(As,Bi) core-shell nanowires grown by molecular beam epitaxy is studied with transmission electron microscopy. Nanowires are grown on GaAs(100) substrates with Au-droplet assisted mode. Bi-doped shells are grown at low temperature (300 °C) with a close to stoichiometric Ga/As flux ratio. At low Bi fluxes, the Ga(As,Bi) shells are smooth, with Bi completely incorporated into the shells. Higher Bi fluxes (Bi/As flux ratio ~ 4%) led to partial segregation of Bi as droplets on the nanowires sidewalls, preferentially located at the nanowire segments with wurtzite structure. We demonstrate that such Bi droplets on the sidewalls act as catalysts for the growth of branches perpendicular to the GaAs trunks. Due to the tunability between zinc-blende and wurtzite polytypes by changing the nanowire growth conditions, this effect enables fabrication of branched nanowire architectures with branches generated from selected (wurtzite) nanowire segments.

Unveiling hidden epitaxial interfaces in novel SnO2/Zn2SnO4 core–shell nanowires with a multi-domain shield via cross-sectional transmission electron microscopy

CrystEngComm ◽  
2019 ◽  
Vol 21 (12) ◽  
pp. 1895-1902 ◽  
Author(s):  
Bojia Xu ◽  
Baobao Cao
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Core Shell ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Shell Nanowires

Hidden epitaxial interfaces were revealed via cross-sectional TEM study of novel quasi-hexagonal SnO2/Zn2SnO4 core–shell nanowires.

A transmission electron microscopy investigation of SiC films grown on SiC substrates by solid-source molecular beam epitaxy

1999 ◽  
Vol 14 (8) ◽  
pp. 3226-3236 ◽  
Author(s):  
U. Kaiser ◽  
I. Khodos ◽  
P. D. Brown ◽  
A. Chuvilin ◽  
M. Albrecht ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Transmission Electron ◽  
Microscopy Investigation ◽  
Substrate Surfaces ◽  
Step Flow Growth ◽  
Sic Films

The relationship between the defect microstructure of SiC films grown by solid-source molecular-beam epitaxy on 4H and 6H–SiC substrates and their growth conditions, for substrate temperatures ranging between 950 and 1300 °C, has been investigated by a combination of transmission electron microscopy and atomic force microscopy. The results demonstrate that the formation of defective cubic films is generally found to occur at temperatures below 1000 °C. At temperatures above 1000 °C our investigations prove that simultaneous supply of C and Si in the step-flow growth mode on vicinal 4H and 6H substrate surfaces results in defect-free hexagonal SiC layers, and defect-free cubic SiC can be grown by the alternating deposition technique. The controlled overgrowth of hexagonal on top of cubic layers is demonstrated for thin layer thicknesses.

Fabrication of Gold Nanotubes from Removable MgO Nanowires Templates

2008 ◽  
Vol 8 (11) ◽  
pp. 5715-5719 ◽  
Author(s):  
Hyoun Woo Kim ◽  
Jong Woo Lee ◽  
Mesfin A. Kebede ◽  
Hyo Sung Kim ◽  
Buddhudu Srinivasa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Metallic Structures ◽  
X Ray ◽  
Transmission Electron ◽  
Shell Nanowires ◽  
Scanning Electron

We have prepared MgO/Au core–shell nanowires, subsequently demonstrating the fabrication of Au nanotubes by using MgO nanowires as a sacrificial template. The samples were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. MgO nanowires were coated with a conformal layer of Au via sputtering. By etching away the MgO core in aqueous (NH3)2SO4 solution, hollow nanotube-like structures of Au were readily obtained. This approach offers a potentially useful route for the fabrication of a variety of hollow metallic structures.

scholarly journals Mechanical, Electrical, and Crystallographic Property Dynamics of Bent and Strained Ge/Si Core–Shell Nanowires As Revealed by in situ Transmission Electron Microscopy

Nano Letters ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 7238-7246 ◽  
Author(s):  
Chao Zhang ◽  
Dmitry G. Kvashnin ◽  
Laure Bourgeois ◽  
Joseph F. S. Fernando ◽  
Konstantin Firestein ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Core Shell ◽  
Transmission Electron ◽  
Crystallographic Property ◽  
Shell Nanowires

Controlled Growth of GaAs/AlAs(111)B Superlattices

1992 ◽  
Vol 263 ◽  
Author(s):  
J.E. Angelo ◽  
J.W. Hoehn ◽  
A.M. Dabiran ◽  
P.I. Cohen ◽  
W.W. Gerberich
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Defect Structure ◽  
Molecular Beam ◽  
Substantial Reduction ◽  
Flux Ratio ◽  
Cross Sectional ◽  
Temperature Growth ◽  
Transmission Electron

ABSTRACTIn this study, transmission electron microscopy (TEM) was used to investigate the growthconditions which produce the highest quality GaAs(111)B films by molecular beam epitaxy (MBE). Low-temperature growth using both As4 and arsine as an As2 source produced highly twinned structures, although the use of As4 provided for a smoother surface and slightly different defect structure. Two distinct twin boundaries, (112)A and (112)B, were identified by cross-sectional transmission electron microscopy (XTEM). The (112)A defect could be over-grown by a subsequent high temperature growth but the roughness associated with the (112)B defects only increased with further growth. High temperature growth of GaAs and AlAs films, while maintaining the GaAs(11)surface reconstruction, resulted in substantial reduction in the number of twins boundaries. We also found that GaAs(111)B layer quality and surface morphology can be further improved by a high temperature growth with low arsenic to Ga flux ratio of I to 1.5 ona slightly misoriented substrate.

Tin-Doping Induced Defects in GaAs Films Grown by Molecular Beam Epitaxy

1984 ◽  
Vol 41 ◽  
Author(s):  
S. H. Chen ◽  
P. Enquist ◽  
C. B. Carter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Surface Region ◽  
Growth Conditions ◽  
Near Surface ◽  
Transmission Electron ◽  
Gaas Films ◽  
Induced Defects

AbstractHeavily Sn-doped GaAs films have been grown by molecular-beam epitaxy and found to contain single-crystal Sn particles situated in the near-surface region of the epilayer GaAs. The morphology and chemical composition of the particles have been examined by using cross-section transmission electron microscopy combined with energy-dispersive x-ray spectroscopy. Different growth conditions were used to study the Sn-particle formation and high-resolution transmission electron microscopy was used to investigate microstructures. The observations are discussed in terms of several models previously proposed for these phenomena.

scholarly journals Epitaxial Growth of Ordered In-Plane Si and Ge Nanowires on Si (001)

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 788
Author(s):  
Jian-Huan Wang ◽  
Ting Wang ◽  
Jian-Jun Zhang
Keyword(s):  
Electron Microscopy ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Core Shell ◽  
High Quality ◽  
Quantum Devices ◽  
Wafer Scale ◽  
Transmission Electron ◽  
Controllable Growth

Controllable growth of wafer-scale in-plane nanowires (NWs) is a prerequisite for achieving addressable and scalable NW-based quantum devices. Here, by introducing molecular beam epitaxy on patterned Si structures, we demonstrate the wafer-scale epitaxial growth of site-controlled in-plane Si, SiGe, and Ge/Si core/shell NW arrays on Si (001) substrate. The epitaxially grown Si, SiGe, and Ge/Si core/shell NW are highly homogeneous with well-defined facets. Suspended Si NWs with four {111} facets and a side width of about 25 nm are observed. Characterizations including high resolution transmission electron microscopy (HRTEM) confirm the high quality of these epitaxial NWs.

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