scholarly journals Fabrication and Characterization of ZnS/Diamond-Like Carbon Core-Shell Nanowires

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Jung Han Kim ◽  
Seul Cham Kim ◽  
Do Hyun Kim ◽  
Kyu Hwan Oh ◽  
Woong-Ki Hong ◽  
...  
Keyword(s):  
Optical Properties ◽  
Coating Layer ◽  
Wavelength Region ◽  
Chemical Vapor ◽  
Diamond Like Carbon ◽  
Core Shell ◽  
Face Centered Cubic ◽  
Infrared Wavelength ◽  
Dlc Coating ◽  
Shell Nanowires

We fabricated ZnS/diamond-like carbon (DLC) core-shell heterostructure nanowire using a simple two-step process: the vapor-liquid-solid method combined with radio frequency plasma enhanced chemical vapor deposition (rf PECVD). As a core nanowire, ZnS nanowires with face-centered cubic structure were synthesized with a sputtered Au thin film, which exhibit a length and a diameter of ~10 μm and ~30–120 nm . After rf PECVD for DLC coating, The length and width of the dense ZnS/DLC core-shell nanowires were a range of ~10 μm  and 50–150 nm , respectively. In addition, ZnS/DLC core-shell nanowires were characterized with scanning transmission electron microscopy. From the results, the products have flat and uniform DLC coating layer on ZnS nanowire in spite of high residual stress induced by the high sp3fraction. To further understanding of the DLC coating layer, Raman spectroscopy was employed with ZnS/DLC core-shell nanowires, which reveals two Raman bands at 1550 cm−1(G peak) and 1330 cm−1(D peak). Finally, we investigated the optical properties from ultraviolet to infrared wavelength region using ultraviolet-visible (UV-Vis) and Fourier transform infrared (FT-IR) spectrometry. Related to optical properties, ZnS/DLC core-shell nanowires exhibit relatively lower absorbance and higher IR transmittance than that of ZnS nanowires.

scholarly journals Synthesis of SiC/SiO2 core–shell nanowires with good optical properties on Ni/SiO2/Si substrate via ferrocene pyrolysis at low temperature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bo-Yu Chen ◽  
Chong-Chi Chi ◽  
Wen-Kuang Hsu ◽  
Hao Ouyang
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Stacking Faults ◽  
Chemical Vapor ◽  
Approximate Model ◽  
Decomposition Temperature ◽  
Core Shell ◽  
Si Substrate ◽  
Hydrocarbon Gases ◽  
Shell Nanowires

AbstractIn this study, the high-density SiC/SiO2 core–shell nanowires were synthesized on the nickel coated SiO2 (100 nm)/Si substrate by chemical vapor deposition (CVD) method with ferrocene precursor at temperature 1000 °C compared to previous studies (1300–1600 °C). The present work provides an efficient strategy for the production of SiC/SiO2 nanowires with uniform morphology and good optical properties, where the Ni layer plays important roles for this fabrication at low temperature which reduces the decomposition temperature of hydrocarbon gases and improves the growth quality of SiC nanowires. The as-synthesized SiC/SiO2 nanowires consist of single crystal 3C structures as well as 3C structures with defects along [111] direction. In the photoluminescence (PL) spectrum, the SiC/SiO2 core–shell nanowires revealed an obvious blueshift. The blueshift is due to the formation of nanoscale silicon carbide polytypism caused by the stacking faults in 3C–SiC and the nanoscale polytypism also caused the transition from indirect to direct bandgap which explains why the stacking faults percentage in SiC confirmed from X-ray diffraction (XRD) is 19%, but ultimately makes the strongest emission intensity. Finally, the PL characteristics are further improved by changing the diameter of the SiC nanowire and etching and an approximate model followed by the vapor–liquid–solid (VLS) mechanism was proposed to explain the possible growth mechanism of the SiC/SiO2 nanowires.

Regulating the electronic and optical properties of GaN/InN core/shell nanowires: A first-principles study

2020 ◽  
Vol 34 (25) ◽  
pp. 2050214 ◽  
Author(s):  
Chang Liu ◽  
Enling Li ◽  
Tuo Peng ◽  
Kaifei Bai ◽  
Yanpeng Zheng ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Core Shell ◽  
First Principles Calculations ◽  
Electronic And Optical Properties ◽  
Gan Nanowires ◽  
The Core ◽  
Light Region ◽  
Calculation Results ◽  
Shell Nanowires

In this paper, electronic and optical properties of GaN/InN core/shell nanowires (CSNWs) have been theoretically investigated through the first principles calculations. The binding energy of In and N atoms on surface of six crystal planes along the [Formula: see text]-axis of GaN nanowires are all negative, which indicate that In and N atoms can be effectively deposited on the surface of GaN nanowires and preparing GaN/InN CSNWs is feasible theoretically. Calculation results of electronic properties indicate that the core/shell ratio and diameter of GaN/InN CSNWs have significant effect on the band structure, bandgap can be effectively adjusted when keeping the number of GaN layers unchanged and changing the number of InN layers. Moreover, with the increase in the number of InN layers, the absorption spectrum of GaN/InN CSNW has significant redshift and few weak absorption peaks appear in the visible light region.

Vertically aligned ZnO–ZnGa2O4 core–shell nanowires: from synthesis to optical properties

2012 ◽  
Vol 14 (4) ◽  
Author(s):  
Miao Zhong ◽  
Yanbo Li ◽  
Takero Tokizono ◽  
Maojun Zheng ◽  
Ichiro Yamada ◽  
...  
Keyword(s):  
Optical Properties ◽  
Core Shell ◽  
Vertically Aligned ◽  
Shell Nanowires

Cutting Performance of Diamond-Like Carbon Coated Tool in Cutting of Aluminum Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 368-373 ◽  
Author(s):  
Tadahiro Wada
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Tool Wear ◽  
Cutting Force ◽  
Coating Layer ◽  
Cutting Performance ◽  
Diamond Like Carbon ◽  
Dlc Coating ◽  
Coated Tool ◽  
Alloy 6061

In cutting aluminum alloy 6061, continuous chips have a negative influence on the machining operation. Usually, Pb is added in order to break continuous chips. However, from the standpoint of environmental protection, it is necessary to improve chip breakability without adding Pb. One effective measure is improving chip breakability by adding Si in aluminum alloy 6061. However, the influence of Si content on tool wear has not been fully examined. In this study, in order to clarify the influence of a diamond-like carbon (DLC) coating layer on cutting performance, aluminum alloys having different Si contents were turned. The substrate of the tool material was high speed steel (1.4%C). The chip configuration, cutting force and tool wear were experimentally investigated. The following results were obtained: (1) The DLC coating layer was effective for decreasing the cutting force. (2) In cutting Al-2mass%Si alloy, the wear progress of the DLC-coated tool was slower than that of the un-coated tool. The length of a chip with the DLC-coated tool was shorter than that with the un-coated tool.

Optical properties and carrier dynamics of ensembles of InP nanowires grown on non-single-crystal platforms

2009 ◽  
Vol 1178 ◽  
Author(s):  
Takehiro Onishi ◽  
Andrew J. Lohn ◽  
Nobuhiko P. Kobayashi
Keyword(s):  
Optical Properties ◽  
Single Crystal ◽  
Quartz Substrate ◽  
Chemical Vapor ◽  
Blue Shift ◽  
Growth Direction ◽  
Longitudinal Optical ◽  
Face Centered Cubic ◽  
Single Crystal Surfaces ◽  
Face Centered

AbstractOptically active InP nanowires were grown on a quartz substrate covered with a layer (100 nm) of hydrogenated amorphous silicon (a-Si:H) by metalorganic chemical vapor deposition (MOCVD), demonstrating that single-crystal semiconductor nanowires can be formed on non-single-crystal surfaces. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, cathodoluminescence (CL), and photoluminescence (PL) were used to characterize the structural and optical properties of the nanowires. The nanowires on a-Si:H grew in random directions with high density. The XRD suggests that nanowires having either hexagonal-close-packed or face-centered cubic lattices co-exist. The Raman spectrum shows peaks associated with transverse optical (TO) and longitudinal optical (LO) branches of InP. The CL intensity does not vary signi?cantly along the growth direction and appears to be originated from the entire structure of the nanowire when probed at various positions. The CL data suggests that recombination is slow enough to allow the carriers to diffuse the complete length of the nanowires (˜2 m in length) before recombining. The PL spectrum suggested the nanowire had a part that contributes to the observed blue shift while the other part had nearly bulk feature in their structure.

Study on Optical Properties of Type-II SnO2/ZnS Core/Shell Nanowires

2011 ◽  
Vol 115 (15) ◽  
pp. 7225-7229 ◽  
Author(s):  
Xiuqing Meng ◽  
Fengmin Wu ◽  
Jingbo Li
Keyword(s):  
Optical Properties ◽  
Core Shell ◽  
Type Ii ◽  
Shell Nanowires
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