Oriented Si nanowires grown via an SLS mechanism

1999 ◽  
Vol 581 ◽  
Author(s):  
Y. J. Xing ◽  
Z. H. Xi ◽  
Q. L. Hang ◽  
H. F. Yan ◽  
S. Q. Feng ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Silicon Nanowires ◽  
Large Scale ◽  
Whisker Growth ◽  
Ambient Pressure ◽  
Si Nanowires ◽  
Vapor Liquid Solid ◽  
Selected Area Electron Diffraction ◽  
Uniform Diameter ◽  
Solid Liquid

ABSTRACTHighly oriented silicon nanowires were grown on Si (111) substrate via a solid-liquid-solid (SLS) mechanism. Unlike the well known vapor-liquid-solid (VLS) mechanism of whisker growth, no gaseous or liquid Si source was supplied during growth. Ni was used as the liquid forming agent and mixture of H2 and Ar was introduced in the experiment. Oriented silicon nanowires grew at 950°C and the ambient pressure kept at about 200 Torr. The oriented silicon nanowires have a length around I il m and uniform diameter about 25nm. Selected area electron diffraction showed that silicon nanowires are completely amorphous. The approach used here is simple and controllable, and may be useful in large-scale synthesis of various nanowires.

Controlled Growth of Amorphous Silicon Nanowires Via a Solid-Liquid-Solid (SLS) Mechanism

1999 ◽  
Vol 581 ◽  
Author(s):  
H. F. Yan ◽  
Y. J. Xing ◽  
Q. L. Hang ◽  
D. P. Yu ◽  
J. Xu ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Silicon Nanowires ◽  
Whisker Growth ◽  
Average Diameter ◽  
Si Substrate ◽  
Large Area ◽  
Vapor Liquid Solid ◽  
Silicon Source ◽  
20 Nm ◽  
Solid Liquid

ABSTRACTAmorphous silicon nanowires (a-SiNW's) with average diameter around 20 nm were synthesized at about 950° C under an Ar/H2 atmosphere on large area of a (11) Si substrate without supplying any gaseous or liquid Si sources. The Si substrate, deposited with a layer of Ni of about 40 nm thick, served itself as a silicon source for the growth of the a-SiNWs. Different from the well-known vapor-liquid-solid (VLS) for conventional whisker growth, it was found that growth of the a-SiNWs was controlled by a solid-liquid-solid mechanism, which is analogous to the VLS model.

PATTERNED GROWTH OF Si NANOWIRES: A COMPARATIVE STUDY OF VLS AND SLS

2010 ◽  
Vol 09 (03) ◽  
pp. 145-150 ◽  
Author(s):  
M. F. ZIA ◽  
J. ALI ◽  
A. NAWEED ◽  
A. S. BHATTI ◽  
S. NASEEM
Keyword(s):  
Silicon Nanowires ◽  
External Source ◽  
Growth Conditions ◽  
Si Nanowires ◽  
Experimental Conditions ◽  
Patterned Growth ◽  
Gaas Substrates ◽  
Different Temperatures ◽  
Ar Gas ◽  
Solid Liquid

In this paper, we report morphology of silicon nanowires ( Si - NWs ) grown on various surfaces and patterned substrates using Vapor–Liquid–Solid (VLS) and Solid–Liquid–Solid (SLS) techniques. It is observed that the growth conditions are critical in controlling the dimensions of wires in both techniques. In addition to this, it is also demonstrated that Si - NWs are essentially different grown on Si or GaAs substrates. For growth of Si - NWs by VLS, Si powder was evaporated in a tube furnace under Ar flow while substrates were kept at different temperatures. In SLS, experimental conditions were identical except that no external source was used. Si - NWs thus grown showed dependence on the flow rate of Ar gas and the temperature of the substrate. Interestingly, instead of only radial nannowires (NWs), nanobelts and tapered NWs were also grown on patterned Au -catalyzed GaAs surface. In the end, the analysis on the basis of existing theories of NW growth is presented. Optical properties of Si - NWs are also briefly discussed.

scholarly journals Vapor–Liquid–Solid Growth of Small- and Uniform-Diameter Silicon Nanowires at Low Temperature from Si2H6

2008 ◽  
Vol 1 (1) ◽  
pp. 014003 ◽  
Author(s):  
Saeed Akhtar ◽  
Koichi Usami ◽  
Yoshishige Tsuchiya ◽  
Hiroshi Mizuta ◽  
Shunri Oda
Keyword(s):  
Low Temperature ◽  
Silicon Nanowires ◽  
Vapor Liquid Solid ◽  
Uniform Diameter ◽  
Vapor Liquid Solid Growth ◽  
Vapor Liquid

A systematic study of silicon nanowires array fabricated through metal-assisted chemical etching

2020 ◽  
Vol 92 (3) ◽  
pp. 30402
Author(s):  
Shiying Zhang ◽  
Zhenhua Li ◽  
Qingjun Xu
Keyword(s):  
Electron Microscopy ◽  
Silicon Nanowires ◽  
Chemical Etching ◽  
Optimal Solution ◽  
Solution Concentration ◽  
Etching Time ◽  
Si Nanowires ◽  
Selected Area Electron Diffraction ◽  
Initial Silicon ◽  
Metal Assisted Chemical Etching

Aligned and uniform silicon nanowires (SiNWs) arrays were fabricated with good controllability and reproducibility by metal-assisted chemical etching in aqueous AgNO3/HF etching solutions in atmosphere. The SiNWs formed on silicon were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), high-resolution transmission electron microscopy (HRTEM) and selected-area electron diffraction (SAED). The results show that the as-prepared SiNWs are perfectly single crystals and the axial orientation of the Si nanowires is identified to be parallel to the [111] direction, which is identical to the initial silicon wafer. In addition, a series of experiments were conducted to study the effects of etching conditions such as solution concentration, etching time, and etching temperature on SiNWs. And the optimal solution concentrations for SiNWs have been identified. The formation mechanism of silicon nanowires and silver dendrites were also discussed.

scholarly journals Odd electron diffraction patterns in silicon nanowires and silicon thin films explained by microtwins and nanotwins

2009 ◽  
Vol 42 (2) ◽  
pp. 242-252 ◽  
Author(s):  
Cyril Cayron ◽  
Martien Den Hertog ◽  
Laurence Latu-Romain ◽  
Céline Mouchet ◽  
Christopher Secouard ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Silicon Nanowires ◽  
Si Nanowires ◽  
Silicon Thin Films ◽  
Transmission Electron ◽  
Diffraction Patterns

Odd electron diffraction patterns (EDPs) have been obtained by transmission electron microscopy (TEM) on silicon nanowires grownviathe vapour–liquid–solid method and on silicon thin films deposited by electron beam evaporation. Many explanations have been given in the past, without consensus among the scientific community: size artifacts, twinning artifacts or, more widely accepted, the existence of new hexagonal Si phases. In order to resolve this issue, the microstructures of Si nanowires and Si thin films have been characterized by TEM, high-resolution transmission electron microscopy (HRTEM) and high-resolution scanning transmission electron microscopy. Despite the differences in the geometries and elaboration processes, the EDPs of the materials show great similarities. The different hypotheses reported in the literature have been investigated. It was found that the positions of the diffraction spots in the EDPs could be reproduced by simulating a hexagonal structure withc/a= 12(2/3)1/2, but the intensities in many EDPs remained unexplained. Finally, it was established that all the experimental data,i.e.EDPs and HRTEM images, agree with a classical cubic silicon structure containing two microstructural defects: (i) overlapping Σ3 microtwins which induce extra spots by double diffraction, and (ii) nanotwins which induce extra spots as a result of streaking effects. It is concluded that there is no hexagonal phase in the Si nanowires and the Si thin films presented in this work.

Enantiomorph identification and stacking faults in κ-(BEDT-TTF)2Cu(NCS)2by convergent-beam electron diffraction

2009 ◽  
Vol 42 (3) ◽  
pp. 433-441 ◽  
Author(s):  
Satoshi Fujio ◽  
Katsushi Tanaka ◽  
Haruyuki Inui ◽  
Rintaro Ueji ◽  
Naoto Sumida ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Ambient Pressure ◽  
Stacking Faults ◽  
Incident Beam ◽  
Convergent Beam Electron Diffraction ◽  
Beam Electron ◽  
Left Handed ◽  
Selected Area Electron Diffraction ◽  
The Right ◽  
Convergent Beam

The convergent-beam electron diffraction (CBED) method proposed recently for enantiomorph identification has been successfully applied to an ambient-pressure superconductor κ-(BEDT-TTF)2Cu(NCS)2[BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene]. Enantiomorph identification (either the left-handed or right-handed form within the space groupP21) of each crystal grown of κ-(BEDT-TTF)2Cu(NCS)2was achieved at ambient temperature without the need to cool the specimens. Enantiomorph identification was possible within the framework of the proposed method only by taking an additional selected-area electron diffraction pattern to eliminate the ambiguity of 180° rotation of the relevant CBED pattern about the incident beam. In the present study, all four specimens investigated exhibit the right-handed form.

Large Scale Synthesis of Silicon Nanowires by Laser Ablation

1998 ◽  
Vol 526 ◽  
Author(s):  
Y.H. Tang ◽  
Y.F. Zhang ◽  
C.S. Lee ◽  
N. Wang ◽  
D.P. Yu ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Silicon Nanowires ◽  
Large Scale ◽  
High Growth ◽  
High Growth Rate ◽  
Laser Source ◽  
Si Nanowires ◽  
Laser Ablation Method ◽  
Large Scale Synthesis ◽  
Krf Excimer Laser

AbstractQuasi one-dimensional materials have attracted considerable attention in recent years because of its potential to both fundamental physics and nanoelectronic applications. More recently, we have achieved large scale synthesis of silicon nanowires (SINW) at a high growth rate by laser ablation of Si target at 1200 °C. The laser source was a pulsed KrF excimer laser and the Si targets were made by pressing Si powder of 5 microns in size. 50 sccm Ar was used as a carrying gas flowing from the side near the Si target towards a water-cooled copper finger. Si nanowires have been grown with diameters ranging from 3 to 43 nm and several hundreds microns in length after 2 hours of laser ablation of Si target. The SLNWs were analyzed by XRD, Raman, EDS, TEM and HRTEM. Successful large scale synthesis of SINW by laser ablation extends the pulsed laser ablation method from depositing thin films to synthesis of nanowires.

Pollutant Identification by Selected Area Electron Diffraction

1974 ◽  
Vol 32 ◽  
pp. 532-533
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson ◽  
C. W. Walker
Keyword(s):  
Thermal Treatment ◽  
Electron Diffraction ◽  
Sample Preparation ◽  
Crystal Structures ◽  
Water Samples ◽  
Environmental Samples ◽  
Short Review ◽  
Selected Area Electron Diffraction ◽  
Multiple Component

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.

Bimolecular and Monomolecular Lipid Films: Selected Area Electron Diffraction

1969 ◽  
Vol 27 ◽  
pp. 338-339
Author(s):  
Robert M. Glaeser ◽  
David W. Deamer
Keyword(s):  
Electron Diffraction ◽  
Membrane Structure ◽  
Molecular Organization ◽  
Membrane Material ◽  
X Ray Diffraction ◽  
Membrane Systems ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Lipid Films ◽  
Ultimate Objective

In the investigation of the molecular organization of cell membranes it is often supposed that lipid molecules are arranged in a bimolecular film. X-ray diffraction data obtained in a direction perpendicular to the plane of suitably layered membrane systems have generally been interpreted in accord with such a model of the membrane structure. The present studies were begun in order to determine whether selected area electron diffraction would provide a tool of sufficient sensitivity to permit investigation of the degree of intermolecular order within lipid films. The ultimate objective would then be to apply the method to single fragments of cell membrane material in order to obtain data complementary to the transverse data obtainable by x-ray diffraction.

The structure of amorphous and polycrystalline materials using energy-filtered RDF analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1190-1191
Author(s):  
David Cockayne ◽  
David McKenzie
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Density Function ◽  
Electron Diffraction Pattern ◽  
Polycrystalline Materials ◽  
Nearest Neighbour ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Reduced Density ◽  
System F

The technique of Electron Reduced Density Function (RDF) analysis has ben developed into a rapid analytical tool for the analysis of small volumes of amorphous or polycrystalline materials. The energy filtered electron diffraction pattern is collected to high scattering angles (currendy to s = 2 sinθ/λ = 6.5 Å-1) by scanning the selected area electron diffraction pattern across the entrance aperture to a GATAN parallel energy loss spectrometer. The diffraction pattern is then converted to a reduced density function, G(r), using mathematical procedures equivalent to those used in X-ray and neutron diffraction studies.Nearest neighbour distances accurate to 0.01 Å are obtained routinely, and bond distortions of molecules can be determined from the ratio of first to second nearest neighbour distances. The accuracy of coordination number determinations from polycrystalline monatomic materials (eg Pt) is high (5%). In amorphous systems (eg carbon, silicon) it is reasonable (10%), but in multi-element systems there are a number of problems to be overcome; to reduce the diffraction pattern to G(r), the approximation must be made that for all elements i,j in the system, fj(s) = Kji fi,(s) where Kji is independent of s.

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