scholarly journals Preparation of Copper Surface for the Synthesis of Single-Layer Graphene

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1071
Author(s):  
Ivan Kondrashov ◽  
Maxim Komlenok ◽  
Pavel Pivovarov ◽  
Sergey Savin ◽  
Elena Obraztsova ◽  
...  
Keyword(s):  
Copper Foil ◽  
Single Layer ◽  
Chemical Vapor ◽  
Copper Surface ◽  
Single Layer Graphene ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Additional Layer ◽  
Graphene Synthesis ◽  
Few Layer Graphene

Chemical vapor deposition synthesis of graphene on copper foil from methane is the most promising technology for industrial production. However, an important problem of the formation of the additional graphene layers during synthesis arises due to the strong roughness of the initial copper foil. In this paper, various approaches are demonstrated to form a smooth copper surface before graphene synthesis to reduce the amount of few layer graphene islands. Six methods of surface processing of copper foils are studied and the decrease of the roughness from 250 to as low as 80 nm is achieved. The correlation between foil roughness and the formation of the additional layer is demonstrated. Under optimized conditions of surface treatment, the content of the additional graphene layer drops from 9 to 2.1%. The quality and the number of layers of synthesized graphene are analyzed by Raman spectroscopy, scanning electron microscopy and measurements of charge mobility.

scholarly journals Influence of Different Copper Treatment on the Formation of Single-Layer Graphene by CVD Method

2020 ◽  
Vol 4 (1) ◽  
pp. 14
Author(s):  
Ivan Kondrashov ◽  
Maxim Komlenok ◽  
Pavel Pivovarov ◽  
Sergei Savin ◽  
Elena Obraztsova ◽  
...  
Keyword(s):  
Copper Foil ◽  
Single Layer ◽  
Chemical Vapor ◽  
Copper Surface ◽  
Single Layer Graphene ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Graphene Synthesis ◽  
Number Of Layers ◽  
Optimized Conditions

Chemical vapor deposition synthesis of graphene on copper foil from methane is the most promising technology for industrial production. However, an important problem of the formation of the second and subsequent graphene layers during synthesis arises due to the strong roughness of the initial copper foil. Here we demonstrate the various approaches to prepare a smooth copper surface before graphene synthesis to reduce the formation of multi-layer graphene islands. Six methods of surface processing of copper foils are studied, and the decrease of the roughness from 250 to as low as 80 nm is achieved. The correlation between roughness and the formation of multi-layer graphene is demonstrated. Under optimized conditions of surface treatment, the content of the multi-layer graphene islands drops from 9% to 2.1%. The quality and the number of layers of synthesized graphene are analyzed by Raman spectroscopy, scanning electron microscopy, and measurements of charge mobility.

scholarly journals Spectral Monitoring CH/C2Ratio of Methane Plasma for Growing Single-Layer Graphene on Cu

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Shih-Hao Chan ◽  
Shih-Fang Liao ◽  
Hung-Pin Chen ◽  
Hung-Sen Wei ◽  
Sheng-Hui Chen ◽  
...  
Keyword(s):  
Single Layer ◽  
Emission Spectra ◽  
Chemical Vapor ◽  
Active Species ◽  
Single Layer Graphene ◽  
Plasma Power ◽  
Layer Graphene ◽  
Graphene Synthesis ◽  
Initial Stage ◽  
Flowing Hydrogen

Single-layer graphene was grown on copper at a low temperature of 600°C by plasma-assisted thermal chemical vapor deposition. Its growth mechanism was discussed with reference to the emission spectra of the plasma. The methane plasma produces the active species (Hx, CHx, and Cx) without the addition of flowing hydrogen, and the amounts of hydrogen-containing species can be controlled by varying the plasma power. The effective distance was found between the plasma initial stage and the deposition stage for the single-layer graphene synthesis. The results reveal that high-quality graphene can be synthesized using methane plasma at a suitable plasma power.

scholarly journals Restoring self-limited growth of single-layer graphene on copper foil via backside coating

Nanoscale ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 5094-5101 ◽  
Author(s):  
Nicolas Reckinger ◽  
Marcello Casa ◽  
Jeroen E. Scheerder ◽  
Wout Keijers ◽  
Matthieu Paillet ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Copper Foil ◽  
Single Layer ◽  
Chemical Vapor ◽  
Single Layer Graphene ◽  
Graphene Sheets ◽  
Tungsten Coating ◽  
Limited Growth ◽  
Layer Graphene

Backside tungsten coating of copper foils allows for the chemical vapor deposition of exclusively single-layer graphene sheets.

scholarly journals Single-Layer Graphene Synthesis on a Al2O3(0001)/Cu(111) Template Using Chemical Vapor Deposition

2016 ◽  
Vol 5 (11) ◽  
pp. Q3060-Q3066 ◽  
Author(s):  
Ken Verguts ◽  
Nandi Vrancken ◽  
Bart François Vermeulen ◽  
Cedric Huyghebaert ◽  
Herman Terryn ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Single Layer ◽  
Chemical Vapor ◽  
Single Layer Graphene ◽  
Layer Graphene ◽  
Graphene Synthesis

scholarly journals Characterizing the maximum number of layers in chemically exfoliated graphene

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Péter Szirmai ◽  
Bence G. Márkus ◽  
Julio C. Chacón-Torres ◽  
Philipp Eckerlein ◽  
Konstantin Edelthalhammer ◽  
...  
Keyword(s):  
Single Layer ◽  
Vapour Phase ◽  
Single Layer Graphene ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Exfoliated Graphene ◽  
Upper Limit ◽  
Number Of Layers ◽  
Graphene Flakes ◽  
Few Layer Graphene

AbstractAn efficient route to synthesize macroscopic amounts of graphene is highly desired and bulk characterization of such samples, in terms of the number of layers, is equally important. We present a Raman spectroscopy-based method to determine the typical upper limit of the number of graphene layers in chemically exfoliated graphene. We utilize a controlled vapour-phase potassium intercalation technique and identify a lightly doped stage, where the Raman modes of undoped and doped few-layer graphene flakes coexist. The spectra can be unambiguously distinguished from alkali doped graphite, and modeling with the typical upper limit of the layers yields an upper limit of flake thickness of five layers with a significant single-layer graphene content. Complementary statistical AFM measurements on individual few-layer graphene flakes find a consistent distribution of the layer numbers.

scholarly journals Methane as an effective hydrogen source for single-layer graphene synthesis on Cu foil by plasma enhanced chemical vapor deposition

Nanoscale ◽  
2013 ◽  
Vol 5 (3) ◽  
pp. 1221 ◽  
Author(s):  
Yong Seung Kim ◽  
Jae Hong Lee ◽  
Young Duck Kim ◽  
Sahng-Kyoon Jerng ◽  
Kisu Joo ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Single Layer ◽  
Chemical Vapor ◽  
Single Layer Graphene ◽  
Layer Graphene ◽  
Graphene Synthesis ◽  
Cu Foil ◽  
Effective Hydrogen

scholarly journals Possible pair-graphene structures govern the thermodynamic properties of arbitrarily stacked few-layer graphene

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Sun ◽  
Kenta Kirimoto ◽  
Tsuyoshi Takase ◽  
Daichi Eto ◽  
Shohei Yoshimura ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Lattice Deformation ◽  
Stable Pair ◽  
Stick Slip ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Stacking Order ◽  
Few Layer Graphene

AbstractThe thermodynamic properties of few-layer graphene arbitrarily stacked on LiNbO3 crystal were characterized by measuring the parameters of a surface acoustic wave as it passed through the graphene/LiNbO3 interface. The parameters considered included the propagation velocity, frequency, and attenuation. Mono-, bi-, tri-, tetra-, and penta-layer graphene samples were prepared by transferring individual graphene layers onto LiNbO3 crystal surfaces at room temperature. Intra-layer lattice deformation was observed in all five samples. Further inter-layer lattice deformation was confirmed in samples with odd numbers of layers. The inter-layer lattice deformation caused stick–slip friction at the graphene/LiNbO3 interface near the temperature at which the layers were stacked. The thermal expansion coefficient of the deformed few-layer graphene transitioned from positive to negative as the number of layers increased. To explain the experimental results, we proposed a few-layer graphene even–odd layer number stacking order effect. A stable pair-graphene structure formed preferentially in the few-layer graphene. In even-layer graphene, the pair-graphene structure formed directly on the LiNbO3 substrate. Contrasting phenomena were noted with odd-layer graphene. Single-layer graphene was bound to the substrate after the stable pair-graphene structure was formed. The pair-graphene structure affected the stacking order and inter-layer lattice deformation of few-layer graphene substantially.

Thermal Conductivity Reduction in Few-Layer Graphene

2011 ◽  
Author(s):  
Dhruv Singh ◽  
Jayathi Y. Murthy ◽  
Timothy S. Fisher
Keyword(s):  
Thermal Conductivity ◽  
Weak Coupling ◽  
Phonon Scattering ◽  
Single Layer ◽  
Acoustic Mode ◽  
Single Layer Graphene ◽  
Boltzmann Transport ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Few Layer Graphene

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. The highly restrictive selection rule that leads to a high thermal conductivity of ZA phonons in single-layer graphene is only weakly broken with the addition of multiple layers, and ZA phonons still dominate thermal conductivity. We also find that the decrease in thermal conductivity is mainly caused by decreased contributions of the higher-order overtones of the fundamental out-of-plane acoustic mode. Moreover, the extent of reduction is largest when going from single to bilayer graphene and saturates for four layers. The results compare remarkably well over the entire temperature range with measurements of of graphene and graphite.

Surface-Confined Single-Layer Covalent Organic Framework on Single-Layer Graphene Grown on Copper Foil

2014 ◽  
Vol 126 (36) ◽  
pp. 9718-9722 ◽  
Author(s):  
Lirong Xu ◽  
Xin Zhou ◽  
Wei Quan Tian ◽  
Teng Gao ◽  
Yan Feng Zhang ◽  
...  
Keyword(s):  
Copper Foil ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Covalent Organic Framework ◽  
Layer Graphene ◽  
Organic Framework

Image Processing To Aid in Graphene Detection

2014 ◽  
Vol 1702 ◽  
Author(s):  
Ryan D. Gorby ◽  
Lihong (Heidi) Jiao
Keyword(s):  
Image Processing ◽  
Single Layer ◽  
Optical Microscope ◽  
Single Layer Graphene ◽  
Camera System ◽  
Layer Graphene ◽  
Sophisticated Equipment ◽  
Processing Software ◽  
Image Processing Software ◽  
Few Layer Graphene

ABSTRACTQualitative techniques for the detection of graphene on a Si/SiO2 substrate, without the use of sophisticated equipment, are presented. Once calibrated, this technique can be used to detect Single Layer Graphene (SLG) and Few Layer Graphene (FLG) with the use of an inexpensive optical microscope (OM), OM camera system, and image processing software. This technique could be transferred to graphene deposited on other substrates or other 2-D materials with minor updates to mathematical theory.

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