scholarly journals Highly uniform monolayer graphene synthesis via a facile pretreatment of copper catalyst substrates using an ammonium persulfate solution

RSC Advances ◽  
2019 ◽  
Vol 9 (36) ◽  
pp. 20871-20878 ◽  
Author(s):  
Hyunhak Jeong ◽  
Wang-Taek Hwang ◽  
Younggul Song ◽  
Jae-Keun Kim ◽  
Youngrok Kim ◽  
...  
Keyword(s):  
Copper Catalyst ◽  
Ammonium Persulfate ◽  
Monolayer Graphene ◽  
Large Area ◽  
Graphene Growth ◽  
Cvd Graphene ◽  
Graphene Synthesis ◽  
Highly Uniform

A facile method for preparing a pretreated copper catalyst substrate for highly uniform, large-area CVD graphene growth is proposed.

scholarly journals Influence of the Total Gas Flow at Different Reaction Times for CVD-Graphene Synthesis on Polycrystalline Nickel

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
M. P. Lavin-Lopez ◽  
J. L. Valverde ◽  
L. Sanchez-Silva ◽  
A. Romero
Keyword(s):  
Reaction Time ◽  
Gas Flow ◽  
Reaction Times ◽  
Monolayer Graphene ◽  
Graphene Monolayer ◽  
Multilayer Graphene ◽  
Reaction Step ◽  
Polycrystalline Nickel ◽  
Cvd Graphene ◽  
Graphene Synthesis

Optimization of the total gas flow (CH4+H2) during the reaction step for different reaction times for CVD-graphene synthesis on polycrystalline nickel foil using an atmospheric pressure set-up is reported. Athickness valuerelated to number of graphene layers in each of the synthesized samples was determined using an Excel-VBA application. This method assigned athickness valuebetween 1 and 1000 and provided information on the percentage of each type of graphene (monolayer, bilayer, and multilayer) deposited onto the polycrystalline nickel sheet. The influence of the total gas flow during the reaction step and the reaction time was studied in detail. Optical microscopy showed that samples were covered with different types of graphene, such as multilayer, few-layer, bilayer, and monolayer graphene. The synthesis variables were optimized according to thethickness valueand the results were verified by Raman spectroscopy. The best conditions were obtained with a reaction temperature of 980°C, a CH4/H2flow rate ratio of 0.07 v/v, a reaction time of 1 minute, and a total gas flow of 80 NmL/min. In the sample obtained under the optimized conditions, 80% of the area was covered with monolayer graphene and less than 1% with multilayer graphene.

Adlayer-free large-area single-crystal CVD graphene growth on copper

2020 ◽  
Vol 31 (24) ◽  
pp. 21821-21831
Author(s):  
Chaitanya Arya ◽  
K. Kanishka H. De Silva ◽  
Masamichi Yoshimura
Keyword(s):  
Single Crystal ◽  
Large Area ◽  
Graphene Growth ◽  
Cvd Graphene

Synthesis of CVD-graphene on rapidly heated copper foils

Nanoscale ◽  
2014 ◽  
Vol 6 (9) ◽  
pp. 4728-4734 ◽  
Author(s):  
Sang-Min Kim ◽  
Jae-Hyun Kim ◽  
Kwang-Seop Kim ◽  
Yun Hwangbo ◽  
Jong-Hyuk Yoon ◽  
...  
Keyword(s):  
Structural Properties ◽  
Mass Production ◽  
Rapid Heating ◽  
Copper Catalyst ◽  
Cvd Graphene ◽  
Copper Foils ◽  
Graphene Synthesis ◽  
Time Required

Rapid heating of a copper catalyst can greatly reduce the time required for CVD-graphene synthesis, which may make the mass production of graphene with good electrical and structural properties possible.

Synthesis of Large-Area and Monolayer of Graphene: Role of Transition Metal Support and Growth Time by CVD Method

2011 ◽  
Vol 306-307 ◽  
pp. 331-335
Author(s):  
Hui Gao ◽  
Yun Fei Wang ◽  
Yan Xia Liu ◽  
Er Qing Xie ◽  
Pulickel M. Ajayan
Keyword(s):  
Graphene Sheet ◽  
Chemical Vapor ◽  
Liquid Hydrocarbon ◽  
Growth Time ◽  
Monolayer Graphene ◽  
Large Area ◽  
Cvd Method ◽  
Graphene Synthesis ◽  
Transmission Electron ◽  
Metal Support

Continuous monolayer graphene sheet with large area has been synthesized via chemical vapor deposition (CVD) method using liquid hydrocarbon as precursor. Synthesis parameters including growth substrate and growth time have been investigated to assess their influence on monolayer graphene synthesis. Raman spectroscopy and high resolution transmission electron microscopy (HRTEM) reveal that the number of layers and quality of graphene sheet depend greatly on the varied synthesis parameter. The study could be used to improve understanding the growth of graphene by CVD method in order to meet the needs of graphene in various electronic applications.

HIGH FREQUENCY GRAPHENE TRANSISTORS USING LARGE-AREA CVD GRAPHENE AND ADVANCED DIELECTRICS

2011 ◽  
Vol 20 (03) ◽  
pp. 669-677
Author(s):  
OSAMA M. NAYFEH ◽  
TONY IVANOV ◽  
JAMES WILSON ◽  
ROBERT PROIE ◽  
MADAN DUBEY
Keyword(s):  
High Frequency ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Hole Mobility ◽  
Monolayer Graphene ◽  
Large Area ◽  
Cvd Graphene ◽  
Ambipolar Behavior ◽  
Chemical Vapor Deposited ◽  
First Time

Graphene transistors using large area chemical-vapor-deposited (CVD) monolayer graphene and advanced dielectric stacks are constructed and examined. Top-gated devices with a SiO 2/ Al 2 O 3 gate-dielectric have a Dirac Point (DP) located at less than 5 V and asymmetric electron/hole mobility. In contrast, devices based on an advanced AlN interfacial layer have a DP located near 0V and a near symmetric carrier mobility- characteristics that could be more suitable for applications that require ambipolar behavior and low-power operation. For the first time, a measured RF cut-off frequency range of 1GHz is measured for top-gated transistors using CVD graphene. The results are of importance for the realization of graphene based, wafer-scale, high frequency electronics.

scholarly journals Decreasing graphene synthesis temperature by catalytic metal engineering and thermal processing

RSC Advances ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 1477-1480
Author(s):  
Li Zheng ◽  
Xinhong Cheng ◽  
Peiyi Ye ◽  
Lingyan Shen ◽  
Qian Wang ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Thermal Processing ◽  
Synthesis Temperature ◽  
Graphene Growth ◽  
Cvd Graphene ◽  
Graphene Synthesis ◽  
Catalytic Metal

The CVD graphene growth temperature can be lowered to 700 °C by copper engineering with carbon implantation.

HIGH FREQUENCY TOP-GATED GRAPHENE RF AMBIPOLAR FETs USING LARGE-AREA CVD GRAPHENE AND ADVANCED DIELECTRICS

2011 ◽  
Vol 1283 ◽  
Author(s):  
Osama M. Nayfeh ◽  
Madan Dubey
Keyword(s):  
Dirac Point ◽  
Gate Dielectric ◽  
Field Effect Transistors ◽  
Hole Mobility ◽  
Monolayer Graphene ◽  
Large Area ◽  
Electron Hole ◽  
Cvd Graphene ◽  
Graphene Fet ◽  
P Type

ABSTRACTAmbipolar top-gated field effect transistors (FETs) based on large area Cu catalyzed CVD-grown monolayer graphene interfaced to advanced dielectrics have been constructed and examined both for their material and electrical qualities. Interfacing of the graphene with novel insulators/substrates could be tailored for the particular application and provide for enhanced device functionality. In contrast to graphene FETs using SiO2-based top-gate dielectric, which show asymmetric electron/hole mobility (with larger hole mobility), and Dirac point shifted to positive levels, FETs constructed using advanced AlN show Dirac point almost near neutral levels and near symmetric electron/hole mobility. The DP is shifted likely due to compensation of the intrinsic p-type doping by n-type doping introduced by the AlN deposition and potentially via a contribution of polarization-induced carrier density. Finally, we demonstrate a top-gated graphene FET with the first observation of RF operation with GHz cut-off frequency based on large area CVD graphene.

Polymer-nanoimprinting route for the construction of large-area Au@Ag plasmonic arrays using as highly-uniform SERS platforms

2021 ◽  
Vol 121 ◽  
pp. 111532
Author(s):  
Wenkuan Che ◽  
Jing Wu ◽  
Mingfei Cheng ◽  
Lu Xu ◽  
Jinghuai Fang
Keyword(s):  
Large Area ◽  
Highly Uniform

Highly uniform manufacturing method for large-area microlens arrays

2017 ◽  
Vol 95 (1-4) ◽  
pp. 99-108 ◽  
Author(s):  
Xiaodong Zhang ◽  
Lihua Li ◽  
Zexiao Li ◽  
Changyuen Chan ◽  
Linlin Zhu ◽  
...  
Keyword(s):  
Large Area ◽  
Microlens Arrays ◽  
Manufacturing Method ◽  
Highly Uniform

scholarly journals Контролируемый синтез графена на меди с использованием метода имплантации атомов отдачи углерода

2019 ◽  
Vol 45 (4) ◽  
pp. 49
Author(s):  
А.Ф. Вяткин
Keyword(s):  
Cooling Rate ◽  
Copper Foil ◽  
Annealing Temperature ◽  
Monolayer Graphene ◽  
Graphene Synthesis ◽  
Graphene Films ◽  
Recoil Atoms

AbstractA method of graphene synthesis on the surface of copper foil by cold implantation of carbon recoil atoms is considered. It is established that monolayer graphene films are formed on the surface of carbon-implanted copper foil under certain conditions (annealing temperature and duration, cooling rate) of postimplantation processing.

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