Scanning probe analysis of twisted graphene grown on a graphene/silicon carbide template

2021 ◽  
Author(s):  
Yao Yao ◽  
Ryota Negishi ◽  
Daisuke Takajo ◽  
Makoto Takamura ◽  
Yoshitaka Taniyasu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Growth Temperature ◽  
Chemical Vapor ◽  
Epitaxial Graphene ◽  
Scanning Tunneling ◽  
Atomic Force ◽  
Graphene Island ◽  
Grown Graphene ◽  
Few Layer Graphene ◽  
Twisted Graphene

Abstract Overlayer growth of graphene on an epitaxial graphene/silicon carbide (SiC) as a solid template by ethanol chemical vapor deposition is performed over a wide growth temperature range from 900 ºC to 1450 ºC. Structural analysis using atomic force and scanning tunneling microscopies reveal that graphene islands grown at 1300 ºC form hexagonal twisted bilayer graphene as a single crystal. When the growth temperature exceeds 1400 ºC, the grown graphene islands show a circular shape. Moreover, moiré patterns with different periods are observed in a single graphene island. This means that the graphene islands grown at high temperature are composed of several graphene domains with different twist angles. From these results, we conclude that graphene overlayer growth on the epitaxial graphene/SiC solid at 1300 ºC effectively synthesizes the twisted few-layer graphene with a high crystallinity.

Epitaxial Graphene Growth on 6H-SiC (0001) Substrate by Confinement Controlled Sublimation of Silicon Carbide

2013 ◽  
Vol 709 ◽  
pp. 62-65
Author(s):  
Tian Min Lei ◽  
Peng Fei Deng ◽  
Yu Ming Zhang ◽  
Hui Guo
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Surface Morphology ◽  
Field Emission ◽  
Growth Temperature ◽  
High Growth ◽  
Epitaxial Graphene ◽  
Large Area ◽  
Atomic Force ◽  
Electronic Microscope

Large area epitaxial graphene (EG) layers are synthesized on 6H-SiC (0001) by annealing at 1500 °C for 5 min in a closed graphite chamber at low vacuum of 10-3 mbar and its 2D band in Raman spectra can be satisfactorily fitted by a single Lorentzian. From Raman spectroscopy, measurements indicate that too high growth temperature is to the disadvantage of the formation of graphene. The results of atomic force microscope (AFM) and field-emission scanning electronic microscope (FE-SEM) reveal the surface morphology of graphene is related with its growth temperature.

Synthesis and Bio-Compatibility Study of Thermal-CVD Grown Graphene

2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660016
Author(s):  
Mayukh Chakravarty ◽  
Rishi Sharma ◽  
Kumar Amit ◽  
Neelima Sharma ◽  
S. K. Pradhan
Keyword(s):  
Chemical Vapor ◽  
Compatibility Study ◽  
Thermal Cvd ◽  
Cvd Method ◽  
Atomic Force ◽  
Number Of Layers ◽  
Potential Applications ◽  
Grown Graphene ◽  
Sbf Solution ◽  
Bio Compatibility

Graphene based nanomaterials have attracted tremendous attention for their potential applications in various fields. In the present investigation, the growth of graphene on silicon substrate using thermal chemical vapor deposition (Thermal-CVD) method has been reported and the biocompatibility of obtained yield has been critically assessed. Raman spectra confirm the formation of graphene which was found to be the best to obtain minimal number of layers of graphene. Three prominent peaks have been observed at approximately 1360[Formula: see text]cm[Formula: see text] (D Peak), 1595[Formula: see text]cm[Formula: see text] (G Peak) and 2700[Formula: see text]cm[Formula: see text] (2D Peak). Haemolysis test and simulated body fluid (SBF) test are performed to check the biocompatibility of the synthesized graphene samples. Atomic force micrographs of the samples are taken prior and after soaking them in SBF solution to study their interaction with the fluid. Haemolysis percentage is determined using UV-Vis to determine the hemocompatible nature of the samples. The results of haemolysis and SBF test demonstrated that Thermal-CVD grown graphene samples are biocompatible.

Blue/White Emission from Hydrogenated Amorphous Silicon Carbide Films Prepared by PECVD

2009 ◽  
Vol 1153 ◽  
Author(s):  
Volodymyr Ivashchenko ◽  
Andrey Vasin ◽  
L. A. Ivashchenko ◽  
P. L. Skrynskyy
Keyword(s):  
Silicon Carbide ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Substrate Bias ◽  
Double Peak ◽  
Hydrogenated Silicon ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
The One

AbstractPhotoluminescence (PL) from hydrogenated silicon carbide (SiC:H) films is studied at room temperature. The films were deposited by plasma-enhanced chemical vapor (PECVD) technique with and without substrate bias using methyltrichlorosilane as a main precursor. After the deposition the samples were annealed at various temperatures in vacuum. The films were characterized by atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The samples deposited without substrate bias (series A) were amorphous, whereas the samples deposited with negative substrate bias -100V (series B) were nanocrystalline. The one-peak (470 nm) and double-peak (415 and 437 nm) PL structures of the as-deposited samples A and B were observed, respectively. Annealing strongly enhanced intensity of PL of the samples B and trandformed PL spectrum from double-peak into broad featureless band with intensity at about 470 nm. The blue PL in as-deposited films B is supposed to be assigned to the radiative recombination in the sites located at the nanocrystallite surface, whereas the photo excitation of carries mostly occurs in nanocrystallite cores. A further increase in annealing temperature causes hydrogen effusion, which leads to an increase of the concentration of non-raidative recombination centers associated with dangling-bonds and as a result, to the quenching of PL.

scholarly journals Thermal decomposition and chemical vapor deposition: a comparative study of multi-layer growth of graphene on SiC(000-1)

MRS Advances ◽  
2016 ◽  
Vol 1 (55) ◽  
pp. 3667-3672 ◽  
Author(s):  
D. Convertino ◽  
A. Rossi ◽  
V. Miseikis ◽  
V. Piazza ◽  
C. Coletti
Keyword(s):  
Thermal Decomposition ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Large Scale ◽  
Chemical Vapor ◽  
Layer Growth ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Atomic Force ◽  
Grown Graphene

ABSTRACTThis work presents a comparison of the structural, chemical and electronic properties of multi-layer graphene grown on SiC(000-1) by using two different growth approaches: thermal decomposition and chemical vapor deposition (CVD). The topography of the samples was investigated by using atomic force microscopy (AFM), and scanning electron microscopy (SEM) was performed to examine the sample on a large scale. Raman spectroscopy was used to assess the crystallinity and electronic behavior of the multi-layer graphene and to estimate its thickness in a non-invasive way. While the crystallinity of the samples obtained with the two different approaches is comparable, our results indicate that the CVD method allows for a better thickness control of the grown graphene.

Etching of 4° and 8° 4H-SiC Using Various Hydrogen-Propane Mixtures in a Commercial Hot-Wall CVD Reactor

2007 ◽  
Vol 556-557 ◽  
pp. 513-516 ◽  
Author(s):  
Kok Keong Lew ◽  
Brenda L. VanMil ◽  
Rachael L. Myers-Ward ◽  
Ronald T. Holm ◽  
Charles R. Eddy ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Partial Pressure ◽  
Growth Temperature ◽  
Chemical Vapor ◽  
Surface Damage ◽  
Step Bunching ◽  
Force Microscopy ◽  
Atomic Force ◽  
Stepped Surface ◽  
Higher Temperature

Hydrogen etching of 4H-SiC has been performed in a hot-wall chemical vapor deposition reactor to reduce surface damage and to create a bilayer-stepped surface morphology, optimal for initiation of growth on 4H-SiC substrates offcut 4° and 8° towards the <11-20> direction. To understand how step bunching evolves during the ramp to growth temperature, samples were etched ending at temperatures from 1400 to 1580°C under 0, 2 or 10 sccm of propane (C3H8) addition to hydrogen. Initial exploratory growth of 5 μm thick epilayers on the 4° etched surfaces are also discussed. Atomic force microscopy (AFM) and Nomarski microscopy were employed to investigate changes in the surface morphology. The 8° substrates subjected to H2-C3H8 etching up to growth temperature routinely exhibited bilayer steps. However, when the 4° substrates were etched with a 10 sccm C3H8 flow, considerable step bunching was observed. At 1450°C, with a 10 sccm of C3H8 flow (partial pressure is 1.25x10-5 bar), step bunching started with the formation of ribbon-like steps. Progression to higher temperature etches have shown the coalescence of the ribbons into larger macro-steps up to 30 nm in height. Etching 4° substrates under 2 sccm of C3H8 (partial pressure is 2.5x10-6 bar) or in pure H2 up to 1500°C results in minimal step bunching.

Heteropolytype Growth of Beta Silicon Carbide on Alpha Silicon Carbide by Low Pressure Chemical Vapor Deposition at 1150 C

1992 ◽  
Vol 281 ◽  
Author(s):  
K. J. Irvine ◽  
M. G. Spencer ◽  
V. A. Dmitriev
Keyword(s):  
Silicon Carbide ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Growth Temperature ◽  
Vapor Deposition ◽  
Critical Thickness ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Temperature Growth ◽  
Pressure Chemical

ABSTRACTWe report on the low temperature growth of heteropolytype junctions of 3C-SiC on 6H-SiC by low pressure chemical vapor deposition. In this work we have observed the epitaxial layers to be single crystal below a critical thickness limit which depends on growth temperature. Films thicker than this limit are polycrystalline. At 1150 C we have found the critical thickness to be approximately 2500 angstroms.

Morphology of Optically Transparent Cubic Silicon Carbide Prepared by Chemical Vapor Deposition

1996 ◽  
Vol 423 ◽  
Author(s):  
Michael W. Russell ◽  
Jaime A. Freitas ◽  
James E. Butler
Keyword(s):  
Silicon Carbide ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Nucleation Density ◽  
X Ray Diffraction ◽  
Electron Microscopies ◽  
Atomic Force ◽  
Pressure Chemical ◽  
Cubic Silicon Carbide

AbstractCrystals of cubic silicon carbide (3C-SiC) were grown in an RF-induction furnace on graphite substrates by atmospheric pressure chemical vapor deposition (APCVD) from a single precursor, methyltrichlorosilane (MTS) in hydrogen. The deposits were characterized by micro-Raman spectroscopy, x-ray diffraction, and atomic force and scanning electron microscopies. Above ˜1600°C preferential 〈110〉 growth directions were identified for the majority of the crystals. At intermediate deposition temperatures (1600–1700°C) the dominant morphology consisted of yellow prismatic crystals heavily twinned along {111 }and {111} At substrate temperatures exceeding ˜1750°C hexagonally-shaped {1111} oriented 3C-SiC platelets were formed with alternating {001 }/{ 101} edges. The dependence of nucleation density, film morphology and film orientation on deposition conditions will be discussed with emphasis on the growth of high quality single crystals of 3C-SiC.

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