Selective growth of zinc blende, wurtzite and hybrid SiC nanowires via a simple chemical vapor deposition route

CrystEngComm ◽  
2019 ◽  
Vol 21 (32) ◽  
pp. 4740-4746 ◽  
Author(s):  
Jingbo He ◽  
Bo Sun ◽  
Yong Sun ◽  
Chengxin Wang
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
The Other ◽  
Phase Growth ◽  
Wurtzite Phase ◽  
Flow Rates ◽  
Sic Nanowires ◽  
Zinc Blende ◽  
Simple Chemical

3C-SiC, 2H-SiC and their hybrid nanowires were synthesized in a controllable manner via changing CH4 flow rates. It is found that higher CH4 supply facilitates the wurtzite phase growth, while the other phases formed when decreasing the flow rate.

Silicon carbide nanowires grown on 4H-SiC substrates by chemical vapor deposition

2009 ◽  
Vol 1178 ◽  
Author(s):  
Siva Kotamraju ◽  
Bharat Krishnan ◽  
Yaroslav Koshka ◽  
Siddarth Sundaresan ◽  
Hany Issa ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Precursor Chemistry ◽  
Metal Catalyst ◽  
X Ray Diffraction ◽  
Flow Rates ◽  
Sic Nanowires ◽  
Wide Range ◽  
Vls Growth

AbstractIn this work, SiC nanowires (NWs) were grown by chemical vapor deposition (CVD) on commercial 4H-SiC substrates. The growth was conducted in an inductively heated hot wall CVD reactor traditionally used for homoepitaxy of 4H-SiC, operating at 150 Torr with H2 as the carrier gas. The growth experiments utilized the precursor chemistry that previously enabled the so-called low-temperature homoepitaxial growth of SiC – SiCl4 as the silicon precursor and CH3Cl as the carbon precursor. Vapor-liquid-solid (VLS) growth mode was employed. Two metal catalysts Au and Ni were used for NW growth in a wide range of growth temperatures from below 10500C to above 13000C. It was established that high precursor flow rates favor the regular epitaxial growth (though disturbed by the presence of the islands of the metal catalyst) at temperatures above 12000C. Reduction of the precursor flow rates and the growth temperature caused formation of micro-needles and eventually NWs. NW diameters in the range from below 10 to 100 nm were observed using scanning electron microscopy. Only SiC phase with no presence of Si, even for the growth temperatures down to 10500C, was confirmed by X-ray diffraction.

Synthesis of greenish phosphorus on carbon substrate

2021 ◽  
Author(s):  
Haipeng Wang ◽  
Cheng Liu ◽  
HuiLi Wang ◽  
Xinpeng Han ◽  
Shaojie Zhang ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Formation Mechanism ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Carbon Substrate ◽  
Deposition Method ◽  
Critical Factors ◽  
Simple Chemical

One of the phosphorus allotropes called greenish phosphorus was successfully synthesized by simple chemical vapor deposition method. We revealed that the critical factors in the formation mechanism of greenish phosphorus...

A Three-Dimensional Analysis of Particle Deposition for the Modified Chemical Vapor Deposition (MCVD) Process

1992 ◽  
Vol 114 (3) ◽  
pp. 735-742 ◽  
Author(s):  
Y. T. Lin ◽  
M. Choi ◽  
R. Greif
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Particle Deposition ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Secondary Flows ◽  
Circumferential Direction ◽  
Forced Flow ◽  
Flow Rates ◽  
Entry Length

A study has been made of the deposition of particles that occurs during the modified chemical vapor deposition (MCVD) process. The three-dimensional conservation equations of mass, momentum, and energy have been solved numerically for forced flow, including the effects of buoyancy and variable properties in a heated, rotating tube. The motion of the particles that are formed is determined from the combined effects resulting from thermophoresis and the forced and secondary flows. The effects of torch speed, rotational speed, inlet flow rate, tube radius, and maximum surface temperature on deposition are studied. In a horizontal tube, buoyancy results in circumferentially nonuniform temperature and velocity fields and particle deposition. The effect of tube rotation greatly reduces the nonuniformity of particle deposition in the circumferential direction. The process is chemical-reaction limited at larger flow rates and particle-transport limited at smaller flow rates. The vertical tube geometry has also been studied because its symmetric configuration results in uniform particle deposition in the circumferential direction. The “upward” flow condition results in a large overall deposition efficiency, but this is also accompanied by a large “tapered entry length.”

TRANSPORT PROPERTIES OF CrO2 (100) FILM GROWN ON TiO2 BY A SIMPLE ATMOSPHERE PRESSURE CHEMICAL VAPOR DEPOSITION

2014 ◽  
Vol 21 (04) ◽  
pp. 1450055
Author(s):  
LIANG XIE ◽  
JIN ZHI ZHANG ◽  
NAI YI CUI ◽  
HONG GUANG ZHANG
Keyword(s):  
Chemical Vapor Deposition ◽  
Temperature Dependence ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Residual Resistivity ◽  
Low Field ◽  
Oriented Film ◽  
Critical Wavelength ◽  
Simple Chemical ◽  
Pressure Chemical

Epitaxial CrO 2 (100)-oriented film was successfully fabricated on TiO 2 (100) substrate by a simple chemical vapor deposition in a two-zone furnace with oxygen flow from a CrO 3 precursor. The transport measurements show that the CrO 2 film is metallic with a small residual resistivity 4 μΩ cm down to 0.6 K. The temperature dependence of resistivity was best described by a phenomenological expression ρ(T) = ρ0 + AT2 exp (-Δ/T) over the range of 0.6–300 K with Δ = 123.6 K. The magnetization of the film becomes saturated in a relatively low field with a small coercive field. The temperature dependence of magnetization shows Bloch's T3/2 law and the slope of the curve suggests a critical wavelength of λΔ ~ 26.6 Å beyond which spin-flip scattering becomes important.

Temperature-Induced Structure and Morphological Transformation in SnS Prepared by a Chemical Vapor Deposition Method

2014 ◽  
Vol 513-517 ◽  
pp. 286-290 ◽  
Author(s):  
Ren Fu Zhuo ◽  
Yi Nong Wang ◽  
De Yan ◽  
Xiao Yong Xu ◽  
Zhi Guo Wu
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Morphological Transformation ◽  
Simple Chemical ◽  
Different Temperatures ◽  
Sns Thin Films ◽  
Induced Structure ◽  
Made In

SnS thin films were deposited at different temperatures on silicon and quartz plates through directly elementary reaction via a simple chemical vapor deposition (CVD) process. The as-prepared products have a transformation of morphology from plate-like to granule-like when the temperature increased. A mechanism involving two competitive factors, surface energy and binding energy, was proposed to understand their growth. The products prepared at low temperature were single crystal while the films made in high temperature are polycrystal, the optical band gap (1.2~2.1ev) and the Sn:S atom ratios increases as the deposited temperature increases.

The Effects of Hydrogen Flowrate during Pre-Annealing on Graphene Growth by Chemical Vapor Deposition Using Methanol as a Liquid Carbon Precursor

2019 ◽  
Vol 290 ◽  
pp. 107-112
Author(s):  
Raed Abdalrheem ◽  
Fong Kwong Yam ◽  
Abdul Razak Ibrahim ◽  
Khi Poay Beh ◽  
Hwee San Lim ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Light Transmittance ◽  
High Hydrogen ◽  
Flow Rates ◽  
Hydrogen Flow ◽  
Number Of Layers ◽  
Crystallite Sizes ◽  
Grown Graphene

Studying an influence of several parameters on Chemical Vapor Deposition (CVD) used for graphene synthesis is crucial to optimizing the graphene quality to be Compatible with advanced devices. The effect of different hydrogen (H2) flow-rates (0, 50, 100, 150, 200, 250, and 300 sccm) during the pre-annealing process on CVD grown graphene have been reported. This study revealed that hydrogen flow rates during annealing changed the surface roughness/smoothness of the copper substrates. For high hydrogen flow rates, the smoothing effect was increased. Furthermore, the annealed graphene samples emerged a deferent number of layers because of morphological surface changes. According to Raman D- to G-band intensity ratios (ID/IG), the graphene quality was influenced by the annealing hydrogen flowrate. The visible light transmittance values of the grown graphene samples confirmed a few number of layers (mono to seven-layer). Mostly, the samples which annealed under moderate hydrogen flow rates showed less defects intensities and higher crystallite sizes.

Investigation of Thin Film Growth of B12As2 by Chemical Vapor Deposition

2003 ◽  
Vol 764 ◽  
Author(s):  
R. Nagarajan ◽  
J.H. Edgar ◽  
J. Pomeroy ◽  
M. Kuball ◽  
T. Aselage
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Thin Film Growth ◽  
X Ray Diffraction ◽  
Flow Rates ◽  
X Ray ◽  
Effects Of Temperature ◽  
Reactant Flow

AbstractThe chemical vapor deposition of icosahedral boron arsenide, B12As2, on 6H-SiC (0001) (on and off-axis) substrates was studied using hydrides as the reactants. The effects of temperature and reactant flow rates on the phases deposited and the crystal quality were determined. The growth rate increased with temperature from 1.5μm/h at 1100°C to 5 μm/h at 1400°C and decreased thereafter. X-ray diffraction revealed that the deposits were amorphous when the deposition temperature is below 1150° C. Above 1150°C, smooth B12As2 films were formed on 6H-SiC substrates with an orientation of (0001) B12As2 parallel to 6H-SiC (0001). Raman spectroscopy confirmed the strongly c-axis oriented nature of B12As2 film on 6H-SiC.

Phase Control of Ga2O3 Thin Films Grown by Metal-Organic Chemical Vapor Deposition

2019 ◽  
Vol 954 ◽  
pp. 72-76
Author(s):  
Ze Qi Li ◽  
Zi Min Chen ◽  
Wei Qu Chen ◽  
Gang Wang
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Flow Rates ◽  
Growth Method ◽  
Metal Organic ◽  
Step Growth ◽  
Organic Chemical Vapor Deposition

In this paper, Ga2O3 thin films were grown on c-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD). There was phase transition for samples grown with different flow rates of triethyl-gallium (TEGa) and deionized water (H2O). It is found that ε-Ga2O3 is difficult to coalesce and the phase mixture by β­Ga2O3 takes place if the flow rates of TEGa and H2O are too high. However, by using multiple-step growth method, the film became fully coalesced. High-quality ε-Ga2O3 thin film with atomically flat surface and multilayer morphology was obtained.

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