scholarly journals Growth of Ordered Graphene Ribbons by Sublimation Epitaxy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 449
Author(s):  
Shuxian Cai ◽  
Xingfang Liu ◽  
Xin Zheng ◽  
Zhonghua Liu
Keyword(s):  
Substrate Surface ◽  
Graphene Film ◽  
Graphene Ribbon ◽  
High Quality ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Few Layer Graphene

Ordered graphene ribbons were grown on the surface of 4° off-axis 4H-SiC wafers by sublimation epitaxy, and characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and micro-Raman spectroscopy (μ-Raman). SEM showed that there were gray and dark ribbons on the substrate surface, and AFM further revealed that these ordered graphene ribbons had clear stepped morphologies due to surface step-bunching. It was shown by μ-Raman that the numbers of graphene layers of these two types of regions were different. The gray region was composed of mono- or bilayer ordered graphene ribbon, while the dark region was of tri- or few-layer ribbon. Meanwhile, ribbons were all homogeneous and had a width up to 40 μm and a length up to 1000 μm, without micro defects such as grain boundaries, ridges, or mono- and few-layer graphene mixtures. The results of this study are useful for optimized growth of high-quality graphene film on silicon carbide crystal.

Synthesis of Few-Layer Graphene on Copper Using a Low-Cost Atmospheric Thermal Chemical Vapour Deposition System with Methane and Forming Gas

Nano Hybrids ◽  
2016 ◽  
Vol 10 ◽  
pp. 1-13
Author(s):  
M.S. Shamsudin ◽  
S.J. Fishlock ◽  
M. Rusop ◽  
S.M. Sanip ◽  
Suan Hui Pu
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Low Cost ◽  
Graphene Film ◽  
Chemical Vapour ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Atomic Force ◽  
Temperature Deposition ◽  
Few Layer Graphene

Graphene has attracted wide interest across a range of applications due to its electrical, mechanical and optical properties. The use of a low-cost, table-top chemical vapour deposition system to deposit few-layer graphene onto copper is reported in this work. Characterisation of the graphene is performed using Raman spectroscopy and atomic force microscopy. The results show that few-layer graphene can be deposited at 1000 °C using CH4 as a carbon precursor, and 5% H2, 95% N2 forming gas as a diluent. The effects of deposition temperature, deposition time, and forming gas addition on graphene film quality was studied experimentally. An increase in graphene quality was observed when forming gas was added during deposition.

scholarly journals Preparation of Colloidal Dispersions of Graphene Sheets in Organic Solvents by Using Ball Milling

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Weifeng Zhao ◽  
Furong Wu ◽  
Hang Wu ◽  
Guohua Chen
Keyword(s):  
Organic Solvents ◽  
Colloidal Suspension ◽  
Colloidal Dispersions ◽  
Graphene Sheets ◽  
Graphite Nanosheets ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Atomic Force ◽  
Transmission Electron ◽  
Few Layer Graphene

A top-down method was developed for producing colloidal dispersions of graphene sheets. Graphite nanosheets comprising hundreds of carbon layers were dispersed and gently ball-milled to exfoliate into graphene in a variety of organic solvents. After 30 hours of the shear-force-dominated grinding and a subsequent 4000 r.p.m. of centrifugation, single- and few-layer graphene sheets were readily prepared and homogeneously and stably suspended in the good solvent medium which possesses a surface tension value close to 40 mJm−2, such as inN,N-dimethylformamide, at a concentration up to 0.08 mg ml−1, achieving a yield higher than 32.0 wt%. The graphene materials in the colloidal suspension were characterized using scanning and transmission electron microscopy and atomic force microscopy.

Graphene Layers on Silicon Carbide Studied by Raman Spectroscopy

2008 ◽  
Vol 600-603 ◽  
pp. 567-570 ◽  
Author(s):  
Jonas Röhrl ◽  
Martin Hundhausen ◽  
Konstantin V. Emtsev ◽  
Thomas Seyller ◽  
Lothar Ley
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Light Scattering ◽  
Graphene Layer ◽  
Monolayer Graphene ◽  
Spectroscopy Study ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Micro Raman Spectroscopy ◽  
Few Layer Graphene

We present a micro-Raman spectroscopy study on single- and few layer graphene (FLG) grown on the silicon terminated surface of 6H-silicon carbide (SiC). On the basis of the 2D-line (light scattering from two phonons close to the K-point in the Brillouin zone) we distinguish graphene mono- from bilayers or few layer graphene. Monolayers have a 2D-line consisting of only one component, whereas more than one component is observed for thicker graphene layers. Compared to the graphite the monolayer graphene lines are shifted to higher frequencies. We tentatively ascribe the corresponding phonon hardening to strain in the first graphene layer.

Solid Phase Growth of Graphene on Silicon Carbide by Nickel Silicidation: Graphene Formation Mechanisms

2014 ◽  
Vol 778-780 ◽  
pp. 1162-1165
Author(s):  
Enrique Escobedo-Cousin ◽  
Konstantin Vassilevski ◽  
Toby Hopf ◽  
Nicholas Wright ◽  
Anthony G. O'Neill ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Solid Phase ◽  
Formation Mechanisms ◽  
Layer By Layer ◽  
Phase Growth ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Atomic Force ◽  
High Temperature Stage ◽  
Few Layer Graphene

This work presents experimental evidence of the formation mechanisms of few-layer graphene (FLG) films on SiC by nickel silicidation. FLG is formed by annealing of a 40 nm thick Ni layer on 6H-SiC at 1035ºC for 60 s, resulting in a Ni2Si layer which may be capped by any Ni that did not react during annealing. It has been proposed that FLG forms on top of the Ni during the high temperature stage. In contrast, during cooling, carbon atoms which were released during the silicidation reaction may diffuse back towards the Ni2Si/SiC interface to form a second FLG film. After annealing, layer-by-layer de-processing was carried out in order to unequivocally identify the FLG at each location using Atomic force microscopy (AFM) and Raman spectroscopy.

Direct growth of etch pit-free GaN crystals on few-layer graphene

RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1343-1349 ◽  
Author(s):  
Seung Jin Chae ◽  
Yong Hwan Kim ◽  
Tae Hoon Seo ◽  
Dinh Loc Duong ◽  
Seung Mi Lee ◽  
...  
Keyword(s):  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
High Quality ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Etch Pit ◽  
Direct Growth ◽  
Metal Organic ◽  
Few Layer Graphene

We report high-quality GaN crystals grown directly on graphene layers without a buffer layer by metal–organic chemical vapour deposition.

Simple, Fast and Cost-Effective Electrochemical Synthesis of Few Layer Graphene Nanosheets

NANO ◽  
2015 ◽  
Vol 10 (02) ◽  
pp. 1550019 ◽  
Author(s):  
Sumanta Kumar Sahoo ◽  
Archana Mallik
Keyword(s):  
Graphene Nanosheets ◽  
Pyrolytic Graphite ◽  
Cost Effective ◽  
Graphite Sheet ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Green Approach ◽  
Atomic Force ◽  
Absorbance Peak ◽  
Few Layer Graphene

We report an efficient and green approach for mass production of few layered graphene nanosheets (FLGNSs) by intercalation and exfoliation of pyrolytic graphite sheet in a simple protic, H 2 SO 4 electrolyte. The as-prepared FLGNSs at the optimum intercalate concentration of 0.5 M H 2 SO 4 is able to produce large domain of lateral dimension of 11–26 μm consisting of 4–6 stacked graphene layers, as confirmed by field emission scanning electron microscopy and atomic force microscopy, respectively. Surface oxygenation and a characteristic absorbance peak at 228 nm are well observed for electrochemical exfoliated FLGNSs from Fourier transform infrared spectroscopy and UV–Vis spectra respectively. (002) planes of the obtained graphene sheets have been confirmed from X-ray diffraction pattern. The characteristic Raman bands have been observed at 1354 cm-1 and 1590 cm-1 in the exfoliated FLGNSs.

Surface Corrugation and Stacking Misorientation in Multilayers of Graphene on Nickel

2011 ◽  
Vol 178-179 ◽  
pp. 125-129 ◽  
Author(s):  
Vito Raineri ◽  
Corrado Bongiorno ◽  
Salvatore di Franco ◽  
Raffaella Lo Nigro ◽  
Emanuele Rimini ◽  
...  
Keyword(s):  
Film Formation ◽  
Graphene Film ◽  
Thermal Processes ◽  
Grown Film ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Transmission Electron ◽  
Thin Polycrystalline

Graphene films were grown on thin polycrystalline Ni using a buried amorphous carbon (a-C) layer as C source. Rapid thermal processes (RTP) at temperatures from 600 to 800°C were used to promote C diffusion into Ni and its subsequent segregation on Ni surface, during the sample cool down. RTP at 800°C was the optimal condition for graphene film formation. Micro-Raman spectroscopy showed that the grown film is mostly composed by multilayers of graphene. Atomic force microscopy showed that the film presents peculiar corrugations (wrinkles), isotropically oriented and with heights ranging from from ~1 to ~15 nm. Selected area diffraction by transmission electron microscopy on the MLG membranes shows a rotational disorder between the stacked graphene layers.

scholarly journals Формирование графена на поликристаллическом никеле

2019 ◽  
Vol 89 (11) ◽  
pp. 1756
Author(s):  
А.Б. Логинов ◽  
И.В. Божьев ◽  
С.Н. Бокова-Сирош ◽  
Е.Д. Образцова ◽  
Р.Р. Исмагилов ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Graphene Film ◽  
Sample Surface ◽  
Reaction Chamber ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Bubble Structure ◽  
Few Layer Graphene ◽  
Methane Pyrolysis

The results of graphene layers formation on Ni surface due to methane pyrolysis are presented in this work. The investigation was carried out using technique that allows controlling morphology of the sample surface with high spatial resolution. This technique includes the use of scanning tunnel microscope (STM) introduced inside the reaction chamber which allows to get rid of atmosphere gases impact. Bubble structure of obtained few-layer graphene film with typical diameter about 100 nm was observed. It was found that local morphology of these bubbles can be easily changed by increasing tunnel voltage applied to the STM tip.

Sign in / Sign up

Export Citation Format

Share Document