The Experts below are selected from a list of 5193 Experts worldwide ranked by ideXlab platform

Rodney S Ruoff - One of the best experts on this subject based on the ideXlab platform.

  • selective mechanical transfer of graphene from seed Copper Foil using rate effects
    ACS Nano, 2015
    Co-Authors: Seung Ryul Na, Rodney S Ruoff, Deji Akinwande, Rui Huang, Kenneth M Liechti
    Abstract:

    A very fast, dry transfer process based on mechanical delamination successfully effected the transfer of large-area, CVD grown graphene on Copper Foil to silicon. This has been achieved by bonding silicon backing layers to both sides of the graphene-coated Copper Foil with epoxy and applying a suitably high separation rate to the backing layers. At the highest separation rate considered (254.0 μm/s), monolayer graphene was completely transferred from the Copper Foil to the target silicon substrate. On the other hand, the lowest rate (25.4 μm/s) caused the epoxy to be completely separated from the graphene. Fracture mechanics analyses were used to determine the adhesion energy between graphene and its seed Copper Foil (6.0 J/m2) and between graphene and the epoxy (3.4 J/m2) at the respective loading rates. Control experiments for the epoxy/silicon interface established a rate dependent adhesion, which supports the hypothesis that the adhesion of the graphene/epoxy interface was higher than that of the grap...

  • Copper oxide as a "self-cleaning" substrate for graphene growth
    Journal of Materials Research, 2014
    Co-Authors: Carl W. Magnuson, Carl A. Ventrice, Hengxing Ji, Richard D Piner, Xianghua Kong, Huifeng Li, Cheng Tan, Rodney S Ruoff
    Abstract:

    Commonly used techniques for cleaning Copper substrates before graphene growth via chemical vapor deposition (CVD), such as rinsing with acetone, nitric, and acetic acid, and high temperature hydrogen annealing still leave residual adventitious carbon on the Copper surface. This residual carbon promotes graphene nucleation and leads to higher nucleation density. We find that Copper with an oxidized surface can act as a self-cleaning substrate for graphene growth by CVD. Under vacuum conditions, Copper oxide thermally decomposes, releasing oxygen from the substrate surface. The released oxygen reacts with the carbon residues on the Copper surface and forms volatile carbon monoxide and carbon dioxide, leaving a clean Copper surface free of carbon for large-area graphene growth. Using oxidized electropolished Copper Foil leads to a reduction in graphene nucleation density by over a factor of 1000 when compared to using chemically cleaned oxygen free Copper Foil.

Shiqiao Qin - One of the best experts on this subject based on the ideXlab platform.

  • growth of millimeter size single crystal graphene on cu Foils by circumfluence chemical vapor deposition
    Scientific Reports, 2015
    Co-Authors: Chaocheng Wang, Wei Chen, Cheng Han, Guang Wang, Binbing Tang, Changxin Tang, Yan Wang, Wennan Zou, Xueao Zhang, Shiqiao Qin
    Abstract:

    A simply and reproducible way is proposed to significantly suppress the nucleation density of graphene on the Copper Foil during the chemical vapor deposition process. By inserting a Copper Foil into a tube with one close end, the nucleation density on the Copper Foils can be reduced by more than five orders of magnitude and an ultra-low nucleation density of ~10 nucleus/cm2 has been achieved. The structural analyses demonstrate that single crystal monolayer graphene with a lateral size of 1.9 mm can be grown on the Copper Foils under the optimized growth condition. The electrical transport studies show that the mobility of such single crystal graphene is around 2400 cm2/Vs.

Shu Yan - One of the best experts on this subject based on the ideXlab platform.

  • rolled electrodeposited Copper Foil with modified surface morphology as anode current collector for high corrosion resistance in lithium ion battery electrolyte
    Surface & Coatings Technology, 2021
    Co-Authors: Jingqi Chen, Yang Zhao, Haitao Gao, Shoudong Chen, Xianghua Liu, Shu Yan
    Abstract:

    Abstract A novel preparation method has been proposed that using electrodeposited Copper Foil as raw material and then performing asymmetrical rolling and surface morphology modification to improve the corrosion resistance of the Copper Foil current collector in lithium-ion battery electrolyte for long-term storage. The results of electrochemical experiments show that the corrosion current density of rolled electrodeposited (RE) Copper Foil is only 10% of that of electrodeposited (ED) Copper Foil. After RE Copper Foil is stored in the electrolyte for 100 days, its capacity retention rate is ~91.2%, which is much higher than 75.6% of ED Copper Foil and 80.8% of rolled Copper Foil. The fraction of low-Σ CSL boundaries of RE Copper Foil is 33.6%, which is much higher than 2.2% for rolled Copper Foil and 8.7% for ED Copper Foil. The large fraction of low-Σ CSL boundaries and disrupted RHABN in RE Copper Foil is an effective structure to inhibit corrosion; Asymmetrical rolling and surface morphology modification significantly increase the compressive residual stress and surface roughness of RE Copper Foil, which can effectively improve the corrosion performance of Copper Foil. The RE Copper Foil with modified surface morphology provides a new idea for the next generation of high-performance lithium-ion battery current collector materials.

Zhongke Wang - One of the best experts on this subject based on the ideXlab platform.

  • mold free fabrication of 3d microfeatures using laser induced shock pressure
    Applied Surface Science, 2013
    Co-Authors: Balasubramanian Nagarajan, Sylvie Castagne, Zhongke Wang
    Abstract:

    Abstract This paper reports on the fabrication of microfeatures on metallic Foils using laser-induced shock forming without the assistance of micromold patterns. A mold-free laser shock forming technique, Flexible Pad Laser Shock Forming (FPLSF) has been developed and demonstrated to fabricate near-spherical microcraters on thin Copper Foils through the laser-generated plasma shock inducing plastic deformation on the Copper Foil. It is found that the crater formation strongly depends on the laser energy fluence applied to ablate an ablative overlay which is on top of the Copper Foil for plasma shock generation. Microfeatures with deformation depth of 80 μm to130 μm and radius of 485 μm to 616 μm were formed on 25 μm thick Copper Foils for the laser fluence of 7.3 J/cm 2 to 20 J/cm 2 while using aluminum Foil as the ablative overlay and silicone rubber as a flexible support instead of a micromold. Fabrication of crater arrays on Copper Foils was also demonstrated successfully.

Lei Liao - One of the best experts on this subject based on the ideXlab platform.