Improving the growth of monolayer CVD-graphene over polycrystalline iron sheets

2017 ◽  
Vol 41 (12) ◽  
pp. 5066-5074 ◽  
Author(s):  
M. P. Lavin-Lopez ◽  
M. Fernandez-Diaz ◽  
L. Sanchez-Silva ◽  
J. L. Valverde ◽  
A. Romero
Keyword(s):  
Graphene Film ◽  
Monolayer Graphene ◽  
Iron Foil ◽  
High Quality ◽  
Polycrystalline Iron ◽  
Cvd Graphene

A high quality graphene film, mostly composed of monolayer graphene, was successfully grown on polycrystalline iron foil by atmospheric CVD process using methane as carbonaceous source.

Highly-Sensitive Graphene Nano-Ribbon-Base Strain Sensor

2016 ◽  
Author(s):  
Shinichirou Sasaki ◽  
Meng Yang ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Graphene Film ◽  
Copper Substrate ◽  
Strain Sensor ◽  
Sensitive Strain ◽  
Bending Test ◽  
Synthesis Process ◽  
Monolayer Graphene ◽  
Large Area ◽  
High Quality ◽  
Highly Sensitive

Large-area and high-quality monolayer graphene was synthesized in order to fabricate a graphene-base highly sensitive strain sensor. A rapid LPCVD (Low Pressure Chemical vaper deposition) synthesis process of monolayer graphene was developed by using acetylene as a resource gas. To synthesize high-quality single-crystal graphene, the surface of copper substrate was strongly orientated to (111) crystallographic plane. By optimizing the concentration of acetylene gas by diluting hydrogen, the high quality of monolayer single-crystalline graphene film was successfully grown on the copper substrate. A strain sensor was fabricated using the graphene-coated Cu foils by applying the MEMS process and reactive ion etching (RIE). Then, the sensor was transferred onto a polydimethysiloxane (PDMS) substrate. Tree-dimensional bending test was performed to investigate the piezoresistive property of the patterned graphene nano-ribbon. It was confirmed that the highly sensitive strain sensor was obtained when the width of the nano-ribbon was thinner than 70 nm.

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 high-quality monolayer graphene by low-power plasma

2019 ◽  
Vol 19 (1) ◽  
pp. 44-49
Author(s):  
Hyo-Ki Hong ◽  
Na Yeon Kim ◽  
Aram Yoon ◽  
Suk Woo Lee ◽  
Jungmin Park ◽  
...  
Keyword(s):  
Low Power ◽  
Monolayer Graphene ◽  
High Quality

scholarly journals Solar-blind ultraviolet photodetector based on graphene/vertical Ga2O3 nanowire array heterojunction

Nanophotonics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 1557-1562 ◽  
Author(s):  
Tao He ◽  
Yukun Zhao ◽  
Xiaodong Zhang ◽  
Wenkui Lin ◽  
Kai Fu ◽  
...  
Keyword(s):  
Response Times ◽  
Nanowire Array ◽  
Graphene Film ◽  
Fast Response ◽  
Nanowire Arrays ◽  
Monolayer Graphene ◽  
Ultraviolet Photodetector ◽  
Solar Blind ◽  
Decay Times ◽  
First Time

AbstractIn this paper, a solar-blind ultraviolet photodetector (PD) based on the graphene/vertical Ga2O3 nanowire array heterojunction was proposed and demonstrated. To the best of our knowledge, it is the first time that vertical Ga2O3 nanowire arrays have been realized. Ga2O3 nanowires were obtained by thermally oxidizing GaN nanowires grown by molecular beam epitaxy on n-doped Si substrate. Then, a monolayer graphene film was transferred to Ga2O3 nanowires to form the graphene/vertical Ga2O3 nanowire array heterojunction and transparent electrodes. The fabricated device exhibited a responsivity (R) of 0.185 A/W and rejection ratio (R258 nm/R365 nm) of 3×104 at the bias of −5 V. Moreover, the fast response times of this PD were 9 and 8 ms for the rise and decay times under 254 nm illumination, respectively, which are attributed to the unique properties of nanowire arrays and the graphene/vertical Ga2O3 nanowire array heterojunction structure.

scholarly journals Upscaling high-quality CVD graphene devices to 100 micron-scale and beyond

2017 ◽  
Vol 110 (11) ◽  
pp. 113502 ◽  
Author(s):  
Timothy J. Lyon ◽  
Jonas Sichau ◽  
August Dorn ◽  
Amaia Zurutuza ◽  
Amaia Pesquera ◽  
...  
Keyword(s):  
High Quality ◽  
Cvd Graphene ◽  
Graphene Devices

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.

Evanescent wave absorption sensor based on tapered multimode fiber coated with monolayer graphene film

2016 ◽  
Vol 366 ◽  
pp. 275-281 ◽  
Author(s):  
Hengwei Qiu ◽  
Saisai Gao ◽  
Peixi Chen ◽  
Zhen Li ◽  
Xiaoyun Liu ◽  
...  
Keyword(s):  
Evanescent Wave ◽  
Graphene Film ◽  
Monolayer Graphene ◽  
Multimode Fiber ◽  
Wave Absorption

Strong Adsorption of Al-Doped Bilayer Graphene Toward Anticancer Cisplatin

NANO ◽  
2018 ◽  
Vol 13 (06) ◽  
pp. 1850068
Author(s):  
Guo-Qing Li ◽  
Meng Zhang ◽  
Wei Li
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Bilayer Graphene ◽  
Monolayer Graphene ◽  
Hollow Site ◽  
High Quality ◽  
Functional Theory ◽  
Strong Adsorption ◽  
Atom Interaction ◽  
Cl Atom

The adsorption of cisplatin on pristine monolayer graphene (MLG), pristine bilayer graphene (BLG) and Al-doped BLG (Al-BLG) was investigated using density functional theory. The obtained results showed that pristine MLG and pristine BLG were not sensitive to cisplatin. Adsorption energy can be primarily influenced by the atomic species rather than the adsorption position. Moreover, it is strong chemisorption of hollow-site Al-BLG (H-Al-BLG) toward cisplatin. The most stable configurations are the Pt or Cl atom interaction with the Al atom of H-Al-BLG. In conclusion, H-Al-BLG is a kind of potential high quality delivery carrier for anticancer cisplatin.

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