scholarly journals Synthesis of High-Density Indium Oxide Nanowires with Low Electrical Resistivity

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2100
Author(s):  
Yu-Yang Chen ◽  
Shu-Meng Yang ◽  
Kuo-Chang Lu
Keyword(s):  
Electron Microscopy ◽  
Electrical Resistivity ◽  
Indium Oxide ◽  
Chemical Vapor ◽  
Average Diameter ◽  
High Density ◽  
Oxide Nanowires ◽  
Transmission Electron ◽  
Unintentional Doping ◽  
High Resolution Tem

In this study, indium oxide nanowires of high-density were synthesized by chemical vapor deposition (CVD) through a vapor–liquid–solid (VLS) mechanism without carrier gas. The indium oxide nanowires possess great morphology with an aspect ratio of over 400 and an average diameter of 50 nm; the length of the nanowires could be over 30 μm, confirmed by field-emission scanning electron microscopy (SEM). Characterization was conducted with X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence spectrum (PL). High-resolution TEM studies confirm that the grown nanowires were single crystalline c-In2O3 nanowires of body-centered cubic structures. The room temperature PL spectrum shows a strong peak around 2.22 eV, originating from the defects in the crystal structure. The electrical resistivity of a single indium oxide nanowire was measured to be 1.0 × 10−4 Ω⋅cm, relatively low as compared with previous works, which may result from the abundant oxygen vacancies in the nanowires, acting as unintentional doping.

THE DEPOSITION AND CONTROL OF SELF ASSEMBLED SILICON NANO ISLANDS ON CRYSTALLINE SILICON

2008 ◽  
Vol 18 (04) ◽  
pp. 901-910
Author(s):  
RAGNAR KIEBACH ◽  
ZHENRUI YU ◽  
MARIANO ACEVES-MIJARES ◽  
DONGCAI BIAN ◽  
JINHUI DU
Keyword(s):  
Electron Microscopy ◽  
Integrated Circuit ◽  
Crystalline Silicon ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Density ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
And Control ◽  
Circuit Technology

The formation of nano sized Si structures during the annealing of silicon rich oxide (SRO) films was investigated. These films were synthesized by low pressure chemical vapor deposition (LPCVD) and used as precursors, a post-deposition thermal annealing leads to the formation of Si nano crystals in the SiO 2 matrix and Si nano islands ( Si nI ) at c-Si /SRO interface. The influences of the excess Si concentration, the incorporation of N in the SRO precursors, and the presence of a Si concentration gradient on the Si nI formation were studied. Additionally the influence of pre-deposition substrate surface treatments on the island formation was investigated. Therefore, the substrate surface was mechanical scratched, producing high density of net-like scratches on the surface. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) were used to characterize the synthesized nano islands. Results show that above mentioned parameters have significant influences on the Si nIs . High density nanosized Si islands can epitaxially grow from the c-Si substrate. The reported method is very simple and completely compatible with Si integrated circuit technology.

Controlled Growth of Carbon Spheres by Chemical Vapor Deposition Based on Anodic Aluminum Oxide Nano-Template

2012 ◽  
Vol 184-185 ◽  
pp. 924-927
Author(s):  
Lei Shan Chen ◽  
Cun Jing Wang ◽  
Gai Rong Chen
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Anodic Aluminum Oxide ◽  
Chemical Vapor ◽  
Average Diameter ◽  
Carbon Spheres ◽  
Aao Template ◽  
Graphene Layers ◽  
Anodic Aluminum ◽  
Transmission Electron

The reactions were carried out by decomposing acetylene at 1000 °C in a two-stage furnace system for 10 min. In the first furnace no catalyst was placed and an AAO template with the average diameter about 50 nm was placed in the second furnace whose temperature was designed to be 500 °C, 600 °C and 700 °C. The samples were characterized by scanning electron microscopy and high resolution transmission electron microscopy. The results show that carbon spheres with average diameter about 50 nm on the AAO template surface were obtained when the temperature of the second furnace was designed to be 700 °C. These carbon spheres are composed of unclosed graphene layers with an interlayer distance of 0.33–0.35 nm between the layers.

Study on Nanometer Size Structures in the Cr-Mo Electroplated Layer Using Transmission Electron Microscopy and Positron Lifetime Measurement

2011 ◽  
Vol 675-677 ◽  
pp. 247-250 ◽  
Author(s):  
Yoshio Tanita ◽  
Daiji Matsui ◽  
Hiroshi Fukushima
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dark Field Image ◽  
Dark Field ◽  
High Density ◽  
Positron Annihilation Lifetime ◽  
Small Crystal ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Crystal Grains

Micro- and nano-structures of the Cr-Mo electroplated layers were studied mainly by Transmission Electron Microscopy (TEM), High Resolution TEM (HRTEM) and Positron Annihilation Lifetime Spectroscopy (PALS). These electroplated layers which were deposited in Cr-Mo electrolyte containing an organic sulfonic acid, showed surface structures having severe ups and downs of small crystal grains. Both selected area diffraction and dark-field image of TEM confirmed the presence of very small crystal grains of less than 50 nm. These small crystal grains exhibited textured structure when the electrolyte contained an organic sulfonic catalyst. PALS results indicated the presence of high density nano-size voids, and HRTEM analysis confirmed the presence of high density voids of 1 nm to 2 nm in diameter. Size and density of these nano-voids increased with the amount of catalyst in the electrolyte.

Synthesis and Cathodoluminescence of β-Ga2O3 Nanowires with Holes

2008 ◽  
Vol 8 (3) ◽  
pp. 1284-1287
Author(s):  
Xitian Zhang ◽  
Zhuang Liu ◽  
Suikong Hark
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vapor Deposition ◽  
Gallium Oxide ◽  
Chemical Vapor ◽  
Oxide Nanowires ◽  
X Ray ◽  
Transmission Electron ◽  
Reactive Surfaces ◽  
Scanning Electron

Gallium oxide nanowires were synthesized on Si (001) substrate by chemical vapor deposition, using a Ga/Ga2O3 mixture as a precursor and Au as a catalyst. The structure of the as-synthesized products was examined by X-ray powder diffraction and high-resolution transmission electron microscopy, and found to be monoclinic β-Ga2O3. The morphologies of the β-Ga2O3 nanowires were characterized by scanning electron microscopy. The majority of the nanowires contain holes along their length, but a few were also found without holes. The holes are believed to be formed by the reaction of adsorbed Ga droplets on reactive terminating surfaces of the nanowires. For nanowires where these reactive surfaces are not exposed, the reaction of Ga is retarded. Cathodoluminescence (CL) of the nanowires was measured. Three emission bands centered at 376, 454, and 666 nm, respectively, were observed.

High-density aligned carbon nanotubes with uniform diameters

2003 ◽  
Vol 18 (7) ◽  
pp. 1686-1690 ◽  
Author(s):  
P. J. Cao ◽  
Y. S. Gu ◽  
H. W. Liu ◽  
F. Shen ◽  
Y. G. Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
High Density ◽  
Large Area ◽  
Transmission Electron ◽  
Area 7 ◽  
Aligned Carbon Nanotubes ◽  
High Resolution Tem ◽  
Electron Energy Loss

A new method was found to synthesize large-area (7 × 15 mm2), high-density (higher than 109 cm−2), aligned carbon nanotubes (CNTs) with uniform diameters on a silica wafer. Ferrocene/melamine mixtures were pyrolyzed through a three-step process in an Ar atmosphere in a single-stage furnace. The structure and composition of the CNTs were investigated by scanning electron microscopy, transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and electron energy-loss spectroscopy (EELS). It was found that these nanotubes have uniform outer diameters of about 22 nm and varying lengths from 10 to 40 μm. High-resolution TEM images showed that CNT is composed of graphite-like layers arranged in a stacked-cup-like structure. XPS results showed that the layer covering the tops of the aligned CNTs consists of carbon and iron. The EELS spectrum showed that these tubes are pure carbon.

Transmission Electron Microscopy of Hydrogen-Induced Defects in Low Temperature Epitaxial Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
G. B. Anderson ◽  
C. C. Tsai ◽  
R. Thompson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Chemical Vapor ◽  
Dimensional Structure ◽  
Epitaxial Silicon ◽  
Hydrogen Dilution ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Induced Defects

ABSTRACTHydrogen is commonly used in crystalline Si for passivation of defects and impurities. When single crystal Si undergoes a post-hydrogenation step, hydrogen-induced platelets have been shown to form in the first 100 nm of the Si. The same hydrogen platelets occur in homoepitaxial Si grown by low temperature (350°C or below) plasma-enhanced chemical vapor deposition with hydrogen dilution. This study has used transmission electron microscopy (TEM) to examine the structure of these hydrogen-induced platelets. TEM has shown that the platelets generally grow in tne (111) crystal planes of the Si. The size of the platelets, which ranges from 5 to 100 nm, increases with growth temperature but the density of platelets decrease at higher growth temperatures. The hydrogen platelets are not confined to the epitaxial Si layer only but also grow into the substrate. High resolution TEM shows the platelets dilate the silicon lattice by approximately 60% of a Si <111> plane. TEM has also shown that platelets cause no net displacement of the local Si lattice. Tilting experiments performed in the TEM show that the platelets are composed of a circular two-dimensional structure. Our results indicate that the hydrogen-induced platelets found in low temperature epitaxial Si are structurally the same as those seen in crystalline Si that has undergone post-hydrogenation processes.

Heteroepitaxy of diamond on c-BN: Growth mechanisms and defect characterization

1994 ◽  
Vol 9 (7) ◽  
pp. 1849-1865 ◽  
Author(s):  
Alberto Argoitia ◽  
John C. Angus ◽  
Jing S. Ma ◽  
Long Wang ◽  
Pirouz Pirouz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cubic Boron Nitride ◽  
Three Dimensional ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Defect Characterization ◽  
Cross Sectional ◽  
Transmission Electron ◽  
High Resolution Tem

Diamond films grown on {100}, {111} boron-terminated, and nitrogen-terminated facets of cubic boron nitride (c-BN) single crystals were characterized by Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The evolution of morphology and microstructure of the diamond films at different stages during the growth process were followed by SEM investigation. The results indicate that diamond growth proceeds by nucleation of oriented three-dimensional islands followed by their coalescence. Cross-sectional TEM specimens were prepared from thick (over 10 μm) continuous diamond films grown on {111} boron-terminated surfaces. Selected-area diffraction and high resolution TEM images show that the diamond film has a parallel orientation relationship with respect to the substrate. Characteristic defects, common to diamond films obtained by chemical vapor deposition on other substrates, are also discussed.

Characterization of Carbon Nanofibers/ ZrO2 Ceramic Matrix Composite

2013 ◽  
Vol 58 (2) ◽  
pp. 459-463 ◽  
Author(s):  
A. Duszová ◽  
J. Morgiel ◽  
Z. Bastl ◽  
J. Mihály ◽  
J. Dusza
Keyword(s):  
Electron Microscopy ◽  
Ceramic Matrix Composite ◽  
Chemical Vapor ◽  
Average Diameter ◽  
High Resolution Electron Microscopy ◽  
Outer Diameter ◽  
Transmission Electron ◽  
Resolution Electron ◽  
The Matrix ◽  
20 Nm

Carbon micro/nanofibers prepared by catalytic chemical vapor deposition have been characterized in the form of powders and in the form of filaments, intercorporated in the matrix of ZrO2. Scanning electron microscopy, transmission electron microscopy, high resolution electron microscopy, electron spectroscopy for chemical analysis and Raman spectroscopy have been used. The outer diameter of the fibers varied from 50 nm to 600 nm with an average diameter of 120 nm, length from several micrometers to several tens of micrometers and inner diameters from 20 nm to 230 nm. Two types of fibers have been identified; cylindrical which consists of a distinct graphite layers parallel to the fiber axes and bamboo - shaped fibers with walls which are built from domains with different orientations of graphite layers. The fibers contain 99.05 at.% carbon and 0.95 at.% oxygen with a binding energy of O (1s) electrons of 532.7 e V which corresponds to carbon in C-O bonds. In the first-order Raman spectra, the position of the band G was found at 1600 cm-1 and D at 1282 cm-1. The CNFs in ZrO2 + CNFs composite have been relatively well dispersed, however clusters of CNFs together with porosity are present as a result of the difficulty of dispersing, too. TEM and HREM revealed that the CNFs are usually located at the grain boundaries of ZrO2 in the form of undamaged nanofibers or disordered graphite.

Transmission Electron Microscopy (TEM) Specimen Preparation Technique using Focused Ion Beam (FIB): Application to Material Characterization of Chemical Vapor Deposition of Tungsten (W) and Tungsten Silicides (WSix)

1997 ◽  
Author(s):  
K. Doong ◽  
J.-M. Fu ◽  
Y.-C. Huang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Transmission Electron

Abstract The specimen preparation technique using focused ion beam (FIB) to generate cross-sectional transmission electron microscopy (XTEM) samples of chemical vapor deposition (CVD) of Tungsten-plug (W-plug) and Tungsten Silicides (WSix) was studied. Using the combination method including two axes tilting[l], gas enhanced focused ion beam milling[2] and sacrificial metal coating on both sides of electron transmission membrane[3], it was possible to prepare a sample with minimal thickness (less than 1000 A) to get high spatial resolution in TEM observation. Based on this novel thinning technique, some applications such as XTEM observation of W-plug with different aspect ratio (I - 6), and the grain structure of CVD W-plug and CVD WSix were done. Also the problems and artifacts of XTEM sample preparation of high Z-factor material such as CVD W-plug and CVD WSix were given and the ways to avoid or minimize them were suggested.

Low Temperature Large Scale CVD Synthesis of Nano Onion-Like Fullerenes

2012 ◽  
Vol 490-495 ◽  
pp. 3211-3214 ◽  
Author(s):  
Lei Shan Chen ◽  
Cun Jing Wang
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Aluminum Hydroxide ◽  
Large Scale ◽  
Iron Catalyst ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Naoh Solution ◽  
Synthesis Reactions

Synthesis reactions were carried out by chemical vapor deposition using iron catalyst supported on aluminum hydroxide at 400 °C and 420 °C, in the presence of argon as carrier gas and acetylene as carbon source. The aluminum hydroxide support was separated by refluxing the samples in 40% NaOH solution for 2 h and 36% HCl solution for 24 h, respectively. The samples were characterized by field-emission scanning electron microscopy, energy dispersive spectroscopy, high-resolution transmission electron microscopy and X-ray diffraction. The results show that carbon nanotubes were the main products at 420 °C, while large scale high purity nano onion-like fullerenes encapsulating Fe3C, with almost uniform sizes ranging from 10-50 nm, were obtained at the low temperature of 400 °C.

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