Growing Properties of Carbon Nanowalls According to the Hydrogen Gas Ratio

2020 ◽  
Vol 20 (11) ◽  
pp. 6835-6838
Author(s):  
Hyeokjoo Choi ◽  
Hyunil Kang ◽  
Young Park ◽  
Jung Hyun Kim ◽  
Wonseok Choi
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Dimensional Structure ◽  
Electrical Characteristics ◽  
Plasma Enhanced Cvd ◽  
Carbon Nanowalls ◽  
Ar Gas ◽  
Gas Ratio ◽  
Si Wafer

In this study, the growth characteristics of carbon nanowalls (CNWs), which are applied to many devices because of their high aspect ratio and excellent electrical characteristics thanks to their two-dimensional structure, were confirmed by changing the ratio of methane (CH4) and hydrogen (H2) therein. In many studies, CNWs were grown using various chemical vapor deposition (CVD) or sputtering methods, with a mixture of CH4 and H2 or argon (Ar) gas. To find the suitable rate, 25 sccm CH4, which is used as the source gas, was first injected into the chamber, and the characteristics were confirmed by changing the amount of H2 gas from 0 to 50 sccm. Ultrasonically cleaned Si wafer was used as the substrate, and the CNW was grown for 10 minutes at microwave power (1300 W, 600°C) using microwave-plasma-enhanced CVD (MPECVD).

scholarly journals Catalyst-Less and Transfer-Less Synthesis of Graphene on Si(100) Using Direct Microwave Plasma Enhanced Chemical Vapor Deposition and Protective Enclosures

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5630
Author(s):  
Rimantas Gudaitis ◽  
Algirdas Lazauskas ◽  
Šarūnas Jankauskas ◽  
Šarūnas Meškinis
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Synthesis Process ◽  
Synthesis Time ◽  
Graphene Layers

In this study, graphene was synthesized on the Si(100) substrates via the use of direct microwave plasma-enhanced chemical vapor deposition (PECVD). Protective enclosures were applied to prevent excessive plasma etching of the growing graphene. The properties of synthesized graphene were investigated using Raman scattering spectroscopy and atomic force microscopy. Synthesis time, methane and hydrogen gas flow ratio, temperature, and plasma power effects were considered. The synthesized graphene exhibited n-type self-doping due to the charge transfer from Si(100). The presence of compressive stress was revealed in the synthesized graphene. It was presumed that induction of thermal stress took place during the synthesis process due to the large lattice mismatch between the growing graphene and the substrate. Importantly, it was demonstrated that continuous horizontal graphene layers can be directly grown on the Si(100) substrates if appropriate configuration of the protective enclosure is used in the microwave PECVD process.

Characterization Analysis According to Growth Temperature of Carbon Nanowall on Metal Coated Substrate for Electrode Application of Energy Storage

2017 ◽  
Vol 904 ◽  
pp. 115-119
Author(s):  
Jong Kug Park ◽  
Won Seok Choi ◽  
Hyun Suk Hwang ◽  
Kyoung Hak Lee ◽  
Jung Hyun Kim ◽  
...  
Keyword(s):  
Energy Storage ◽  
Growth Temperature ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Rf Magnetron Sputtering ◽  
Nickel Layer ◽  
Cross Sectional ◽  
Storage Media ◽  
Carbon Nanowalls ◽  
Core Storage

Secondary cells, which are the core storage media of energy storage systems (ESS), and carbon nanowalls (CNWs), which are expected to improve the performance of supercapacitors while being used as their electrodes, were investigated in this study. CNWs were directly grown on the substrate, and the substrate was a Si wafer with a nickel layer deposited on top of it. The nickel layer was deposited with the RF-magnetron sputtering method using a 4-inch Ni target. The CNWs were grown on the prepared substrate using microwave plasma-enhanced chemical vapor deposition (PECVD). The substrate temperature was changed from 550 to 800°C by 50°C increments to identify the growth characteristics according to the growth temperature. The surficial and cross-sectional images according to the temperature were analyzed using a field emission scanning electron microscope (FE-SEM). It was confirmed that the density of the CNWs increased along with the temperature. Especially, it was confirmed that the density increased dramatically at 750°C or higher.

Fabrication of Metal-Coated Carbon Nanowalls Synthesized by Microwave Plasma Enhanced Chemical Vapor Deposition

2014 ◽  
Vol 14 (12) ◽  
pp. 9189-9193
Author(s):  
Sangjoon Lee ◽  
Won Seok Choi ◽  
Jinsu Yoo ◽  
Dong-Gun Lim ◽  
Hyung Jin Kim ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Carbon Nanowalls ◽  
Coated Carbon

Single Crystal Boron-Doped Diamond Synthesis

2009 ◽  
Vol 1203 ◽  
Author(s):  
Timothy Grotjohn ◽  
Shannon Nicley ◽  
Dzung Tran ◽  
Donnie K. Reinhard ◽  
Michael Becker ◽  
...  
Keyword(s):  
Single Crystal ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Electrical Characteristics ◽  
Temperature Dependent ◽  
Boron Doped Diamond ◽  
Dopant Activation ◽  
Boron Doped ◽  
Boron Dopant ◽  
Boron Acceptor

AbstractThe electrical characteristics of high quality single crystal boron-doped diamond are studied. Samples are synthesized in a high power-density microwave plasma-assisted chemical vapor deposition (CVD) reactor at pressures of 130-160 Torr. The boron-doped diamond films are grown using diborane in the feedgas at concentrations of 1 to 50 ppm. The boron acceptor concentration is investigated using infrared absorption and a four point probe is used to study the conductivity. The temperature dependent conductivity is analyzed to determine the boron dopant activation energy.

(110)-oriented diamond films synthesized by microwave chemical-vapor deposition

1990 ◽  
Vol 5 (11) ◽  
pp. 2469-2482 ◽  
Author(s):  
Koji Kobashi ◽  
Kozo Nishimura ◽  
Koichi Miyata ◽  
Kazuo Kumagai ◽  
Akimitsu Nakaue
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Diamond Films ◽  
Film Surface ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
X Ray ◽  
Bilayer Films

Bilayer diamond films were deposited on Si substrates by microwave-plasma chemical-vapor deposition (CVD) using a methane-hydrogen gas mixture. The first layer was deposited for 3 h using a reaction gas which was composed of 2.5 vol. % methane and 97.5 vol.% hydrogen. The deposited film consisted of very weakly (110)-oriented microcrystalline diamonds as well as amorphous carbon and graphite. In order to remove non-diamond carbons from the film surface, the specimen was treated in hydrogen plasma for 1 h. Finally, a second layer was deposited on the first layer for 14 h using a methane concentration of between 0.2 and 1.6 vol.%. It was found that the x-ray intensity of the (220) diffraction of the bilayer films was much greater than that of the (111) diffraction, indicating that the diamond grains in the second layer were strongly oriented with their crystallographic (110) planes parallel to the substrate surface. X-ray diffraction spectra of bilayer films in which the second layer was deposited for 7, 14, 21, and 35 h using two different methane concentrations, 0.3 and 1.2 vol.%, showed that within periods of up to 21 h, the (220) intensity increased with the deposition time much more quickly than the (111) intensity, indicating that the degree of (110) orientation was further enhanced as the second layer thickness increased. However, the (220) intensity decreased after 21 h, presumably due to thermal randomization. Results of scanning electron microscopy, electron diffraction, and Raman spectroscopy of the bilayer films are also presented.

Characteristic Study of Boron Doped Carbon Nanowalls Films Deposited by Microwave Plasma Enhanced Chemical Vapor Deposition

2016 ◽  
Vol 16 (2) ◽  
pp. 1680-1684 ◽  
Author(s):  
Chunyuan Lu ◽  
Qi Dong ◽  
Kelimu Tulugan ◽  
Yeong Min Park ◽  
Mahendra A. More ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Boron Doped ◽  
Carbon Nanowalls

Control of electrostatic self-assembly seeding of diamond nanoparticles on carbon nanowalls

2021 ◽  
Vol 33 (10) ◽  
pp. 105605
Author(s):  
Lei Huang ◽  
Xiangqing Wu ◽  
Ryota Hijiya ◽  
Kungen Teii
Keyword(s):  
Self Assembly ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Plasma Chemical Vapor Deposition ◽  
Diamond Nanoparticles ◽  
Mean Size ◽  
Zero Degree ◽  
Vertically Aligned ◽  
Carbon Nanowalls ◽  
Diamond Nanoparticle

Abstract Seeding of diamond nanoparticles on vertically-aligned multi-layer graphene, the so-called carbon nanowalls (CNWs), is studied by using deionized water, ethylene glycol, ethanol, and formamide as dispersion mediums. Detonation nanodiamond particles show the smallest mean size and size distribution with a high positive zeta potential when dispersed in ethanol. The contact angle of ethanol on CNWs is almost zero degree, confirming highly wetting behaviour. The diamond nanoparticles dispersed in ethanol are distributed the most uniformly with minimal aggregation on CNWs as opposed to those dispersed in other liquids. The resulting diamond nanoparticle-seeded CNWs, followed by short-term growth in microwave plasma chemical vapor deposition, show a marked decrease in field emission turn-on field down to 1.3 V μm−1 together with a large increase in current density, compared to bare CNWs without diamond seeding. The results provide a way to control the density, size, and uniformity (spacing) of diamond nanoparticles on CNWs and should be applied to fabricate hybrid materials and devices using nanodiamond and nanocarbons.

Effects of Plasma Treatment on Carbon Nanowalls Grown by Microwave Plasma Enhanced Chemical Vapor Deposition

2016 ◽  
Vol 16 (5) ◽  
pp. 5291-5294
Author(s):  
Yong Ho Jung ◽  
Hyunil Kang ◽  
Won Seok Choi ◽  
Yeun-Ho Joung ◽  
Young-Kwan Choi
Keyword(s):  
Chemical Vapor Deposition ◽  
Plasma Treatment ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Carbon Nanowalls

Near-interface characterization of diamond films on silica and silicon

1991 ◽  
Vol 6 (6) ◽  
pp. 1264-1277 ◽  
Author(s):  
D.J. Pickrell ◽  
W. Zhu ◽  
A.R. Badzian ◽  
R.E. Newnham ◽  
R. Messier
Keyword(s):  
Methane Concentration ◽  
Microwave Plasma ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Growth Stages ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Methane Concentrations

The near-interface structure of diamond films grown from a methane and hydrogen gas mixture by microwave plasma enhanced chemical vapor deposition has been studied. Freestanding diamond films grown on both silica and silicon at two different methane concentrations were analyzed by scanning and transmission electron microscopies, electron diffraction, Raman spectroscopy, and secondary ion mass spectroscopy. It was found that the substrate chemistry greatly influenced the nature of the carbon initially deposited on the substrate surface. Diamond formed large flat contact areas on silicon, whereas on silica a particulate type of intermediate layer formed first because of the chemical reactions occurring on and/or with the surface. It was found that the phase content of the films was greatly affected by the methane concentration in hydrogen. At the low (1.0% or less) methane concentrations in hydrogen, phase pure diamond formed; while at the high (5.0%) methane concentration in hydrogen, graphite and disordered carbon were codeposited along with diamond during the early growth stages. Silicon carbide was detected at the diamond interfaces which appeared in discrete areas on silica as opposed to a rather continuous layer as is believed to form on silicon.

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