The CVD Diamond Nucleation Mechanism on Si Overlaid with sp2 Carbon

1992 ◽  
Vol 242 ◽  
Author(s):  
Pehr E. Pehrsson ◽  
John Glesener ◽  
Arthur A. Morrish
Keyword(s):  
Carbon Fibers ◽  
Necessary Conditions ◽  
Cvd Diamond ◽  
High Energy ◽  
Nucleation Mechanism ◽  
Etch Pits ◽  
Diamond Nucleation ◽  
Spontaneous Nucleation ◽  
Cvd Growth ◽  
Saturated Surface

ABSTRACTRudder et al. [1] observed heavy (>109 cm-2) diamond nucleation on unscratched Si wafers overlaid with carbon fibers during CVD growth. We demonstrate that the nucleation occurs on the edges of etch pits and carbon-rich particles resulting from reaction between the fibers and the substrate. Both the etch pits and the particles satisfy what we consider to be two necessary conditions for ‘spontaneous’ nucleation; a carbon-saturated surface and high energy sites (unsatisfied valencies) at edges and steps.

Transmission Electron Microscopy characterization of epitaxial III-V semiconductor thin films grown on Si(100) by ion-assisted deposition

1990 ◽  
Vol 48 (4) ◽  
pp. 686-687
Author(s):  
L. Hultman ◽  
C.-H. Choi ◽  
R. Kaspi ◽  
R. Ai ◽  
S.A. Barnett
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Irradiation ◽  
High Energy ◽  
Nucleation Mechanism ◽  
Layer By Layer ◽  
Extended Defect ◽  
Island Formation ◽  
Si Substrates ◽  
Transmission Electron

III-V semiconductor films nucleate by the Stranski-Krastanov (SK) mechanism on Si substrates. Many of the extended defects present in the films are believed to result from the island formation and coalescence stage of SK growth. We have recently shown that low (-30 eV) energy, high flux (4 ions per deposited atom), Ar ion irradiation during nucleation of III-V semiconductors on Si substrates prolongs the 1ayer-by-layer stage of SK nucleation, leading to a decrease in extended defect densities. Furthermore, the epitaxial temperature was reduced by >100°C due to ion irradiation. The effect of ion bombardment on the nucleation mechanism was explained as being due to ion-induced dissociation of three-dimensional islands and ion-enhanced surface diffusion.For the case of InAs grown at 380°C on Si(100) (11% lattice mismatch), where island formation is expected after ≤ 1 monolayer (ML) during molecular beam epitaxy (MBE), in-situ reflection high-energy electron diffraction (RHEED) showed that 28 eV Ar ion irradiation prolonged the layer-by-layer stage of SK nucleation up to 10 ML. Otherion energies maintained layer-by-layer growth to lesser thicknesses. The ion-induced change in nucleation mechanism resulted in smoother surfaces and improved the crystalline perfection of thicker films as shown by transmission electron microscopy and X-ray rocking curve studies.

Co-construction of sulfur vacancies and carbon confinement in V5S8/CNFs to induce an ultra-stable performance for half/full sodium-ion and potassium-ion batteries

Nanoscale ◽  
2021 ◽  
Author(s):  
Lihong Xu ◽  
Xiaochuan Chen ◽  
Wenti Guo ◽  
Lingxing Zeng ◽  
Tao Yang ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Anode Materials ◽  
High Energy ◽  
Potassium Ion ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Vanadium Sulfide ◽  
Stable Performance

To construct anode materials for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) with high energy, and long lifespan is significant and still challenging. Here, sulfur-defective vanadium sulfide/carbon fibers composite (D-V5S8/CNFs)...

scholarly journals Nucleation Triggering of Highly Undercooled Xylitol Using an Air Lift Reactor for Seasonal Thermal Energy Storage

2018 ◽  
Author(s):  
Marie DUQUESNE ◽  
Elena PALOMO DEL BARRIO ◽  
Alexandre GODIN
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
High Energy ◽  
Operating Conditions ◽  
High Energy Density ◽  
Bubble Generation ◽  
Spontaneous Nucleation ◽  
Air Lift Reactor ◽  
Air Lift

Xylitol is an organic, non-toxic, biosourced phase change material with high potential for seasonal thermal energy storage material. It has a high energy density, a high and stable undercooling allowing storing solar energy at ambient temperature thus, reducing thermal losses and the risk of spontaneous nucleation (i.e., the risk of losing the stored energy). When the energy is needed, the discharge triggering of the storage system (i.e., Nucleation triggering of highly viscous undercooled Xylitol) is very difficult as well as reaching a sufficient power delivery (i.e., the control of the subsequent crystal growth rates). Both are the mains locks for the use of Xylitol in seasonal energy storage. Different techniques to crystallize highly undercooled Xylitol have hence been considered. It has been proven that nucleation triggering of highly undercooled Xylitol using an air lift reactor would allow reaching performances matching with building applications (i.e., at medium temperatures, below 100 °C). The advantages of this technique compared to other existing techniques to activate the crystallization are discussed. The mechanisms triggering the nucleation are investigated. The air bubble generation, transportation of nucleation sites and subsequent crystallization are discussed to improve the air injection operating conditions.

Single Crystal CVD Diamond Nuclear Detectors

2006 ◽  
Vol 48 ◽  
pp. 103-112 ◽  
Author(s):  
Claudio Manfredotti
Keyword(s):  
Single Crystal ◽  
Time Derivative ◽  
Diamond Films ◽  
Radiation Detectors ◽  
Cvd Diamond ◽  
High Energy ◽  
Neutron Spectrometry ◽  
Free Standing ◽  
Wide Range ◽  
Nuclear Detectors

CVD diamond films have reached in recent years superlative improvements in their “ detector grade “ quality, with a time derivative which was never registered for other similar frontier materials. The basic properties of high quality CVD diamond films make them very interesting for a wide range of radiation detectors : they provide fast signals with very low leakage currents, they are very radiation resistant, they have excellent thermal properties and they can be manufactured as free-standing detectors. The recent availability of single crystal CVD diamond samples of extreme good quality, suitable thickness and surface area has opened new application fields in nuclear detection and dosimetry, such as, for instance, hadron therapy and neutron spectrometry in fusion reactors. At the same time, strip and pixel detectors of unprecedented performances have been successfully realized and exploited in the framework of high energy physics experiments. The paper will review the more recent history of CVD diamond nuclear detectors with respect to material quality, with a particular emphasis on epitaxial single crystals diamond, and the achievements in terms of applications in some different fields.

Diamond nucleation on nickel substrates seeded with non-diamond carbon

1994 ◽  
Vol 9 (5) ◽  
pp. 1063-1066 ◽  
Author(s):  
P.C. Yang ◽  
W. Zhu ◽  
J.T. Glass
Keyword(s):  
Single Crystal ◽  
High Temperatures ◽  
Atomic Hydrogen ◽  
Diamond Films ◽  
Nucleation Mechanism ◽  
Diamond Nucleation ◽  
Carbon Species ◽  
Nickel Substrates

Oriented diamond films have been nucleated on single crystal nickel substrates seeded with non-diamond carbon and annealed at high temperatures in atomic hydrogen. The non-diamond carbon seeds included graphite powders, fullerene (60) powders, and gaseous carbon species. It was found that these different non-diamond carbon powders or species were effective in the enhancement of oriented nucleation of diamond. The morphologies of diamond films were similar regardless of the types of carbon used, suggesting a common nucleation mechanism involved. Based on the experimental observations, a revised model was developed for the oriented nucleation of diamond on Ni.

scholarly journals Phosphorous Doping of Microcrystalline CVD Diamond Using Modified Conditions

2007 ◽  
Vol 1039 ◽  
Author(s):  
Ken Haenen ◽  
Andrada Lazea ◽  
Vincent Mortet ◽  
Jan D'Haen ◽  
Peter Geithner ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Growth Conditions ◽  
Diamond Surfaces ◽  
Cvd Growth ◽  
Oriented Polycrystalline ◽  
Electron Back Scattered Diffraction

AbstractPhosphorous-doping of predominantly (110) oriented polycrystalline CVD diamond films is presented. Incorporation of phosphorous into the diamond grains was accomplished by using novel microwave plasma enhanced chemical vapor deposition (MW PE CVD) growth conditions. The substitutional nature of the phosphorous atom was confirmed by applying the quasi-steady-state photocurrent technique (PC) and cathodoluminescence (CL) measurements at low temperature. Topographical information and the relation between substrate and P-doped film grain orientation was obtained with scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). The optimized growth parameters for P-doped layers on (110) oriented polycrystalline diamond differ substantially from the standard conditions reported in literature for P-doping of single crystalline (111) and (100) oriented diamond surfaces.

scholarly journals Electrical explosion process and amorphous structure of carbon fibers under high-density current pulse igniting intense electron-beam accelerator

2009 ◽  
Vol 27 (3) ◽  
pp. 511-520 ◽  
Author(s):  
Limin Li ◽  
Lie Liu ◽  
Guoxin Cheng ◽  
Lei Chang ◽  
Hong Wan ◽  
...  
Keyword(s):  
Electron Beam ◽  
Current Pulse ◽  
Carbon Fibers ◽  
Electrical Explosion ◽  
High Energy ◽  
High Density ◽  
Density Current ◽  
Explosion Process ◽  
Intense Electron Beam ◽  
Intense Electron

AbstractThe development of pulsed power technology, particularly for inductive energy storage, promotes the extensive discussions of electrical explosion process in high energy density. This paper presents the electrical-explosion behavior of carbon fibers subjected to about 20 kA, ~5 µs high-density current pulse igniting an intense electron beam accelerator. After electrical explosion, and surface rupture, submicron particles, fibrillar and strip-shaped structures were observed, experimentally supporting the microstructure model (skin-core heterogeneity) of carbon fiber. Interestingly, the start and turn-off of the current were followed by radiation pulses with different intensities. It was found that the radiation was focused on the explosion stage which was characterized by an oscillating current. The instabilities of plasma produced during the explosion process play an important role in the microstructure changes of carbon fibers and the radiation generation.

Investigation of Structural Stability in 4H-SiC Structures with Heavy Ion Implanted Interface

2006 ◽  
Vol 527-529 ◽  
pp. 395-398 ◽  
Author(s):  
Augustinas Galeckas ◽  
Anders Hallén ◽  
Adolf Schöner ◽  
Jan Linnros ◽  
P. Pirouz
Keyword(s):  
Imaging Spectroscopy ◽  
Stacking Faults ◽  
Heavy Ion ◽  
High Energy ◽  
Irradiation Damage ◽  
Impurity Atoms ◽  
Nucleation Sites ◽  
Comprehensive Picture ◽  
Cvd Growth ◽  
Homoepitaxial Layers

We investigate the possibility of controlling formation of stacking faults (SFs) at the interface region by implanting the 4H-SiC substrate with low-energy antimony ions (75 keV Sb+) prior to conventional CVD growth of the homoepitaxial layers. This approach is based on the solidsolution hardening concept, according to which interaction of impurity atoms with dislocations makes the motion of the latter more difficult. Photoluminescence imaging spectroscopy is employed to investigate incorporation of Sb+ implants at the buried interface and also to assess its impact on structural degradation. Spectral results are analyzed considering both the onset of n-type doping and irradiation damage. The latter factor was estimated separately from supplementary measurements of high-energy (2.5 MeV H+) proton-irradiated 4H-SiC epilayers. We compare results of optically stimulated SF formation in virgin and Sb implanted regions and provide a comprehensive picture of the defect evolution, including microscopic details of the imminent nucleation sites.

Parameters Optimization of Laser Processing CVD Diamond Film Based on FEM Simulation

2010 ◽  
Vol 426-427 ◽  
pp. 26-29 ◽  
Author(s):  
X.J. Wu ◽  
Feng Xu ◽  
Dun Wen Zuo ◽  
Wen Zhuang Lu ◽  
M. Wang
Keyword(s):  
Temperature Distribution ◽  
Diamond Film ◽  
Laser Processing ◽  
Laser Power ◽  
Scanning Speed ◽  
Cvd Diamond ◽  
High Energy ◽  
Machining Parameters ◽  
Etching Depth ◽  
Cvd Diamond Film

Chemical vapor deposited (CVD) diamond film has a series of outstanding properties. However, it can not be easily machined by conventional technologies available currently for its high hardness and stability. Laser processing diamond film method can be an efficient way to process diamond film because of its high energy density. The mechanisms of laser processing diamond film are thermal oxidation, graphitization and evaporative ablation of graphite. Temperature distribution is of great importance to understand these complex phenomena taking place during the process because different temperatures lead to different physical and chemical changes of diamond. In this paper, the finite element method (FEM) software ANSYS is applied to calculate the temperature distribution. The relation between etching depth and laser machining parameters (laser power and scanning speed) is presented. The proper parameter ranges of laser power and scanning speed for a certain etching depth is also investigated with this method.

CVD diamond nucleation enhanced by ultrasonic pretreatment using diamond and mixture of diamond and TaC powders

2002 ◽  
Vol 11 (9) ◽  
pp. 1683-1689 ◽  
Author(s):  
S.G Wang ◽  
Qing Zhang ◽  
S.F Yoon ◽  
J Ahn ◽  
Q Wang ◽  
...  
Keyword(s):  
Cvd Diamond ◽  
Ultrasonic Pretreatment ◽  
Diamond Nucleation
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