The Experts below are selected from a list of 27576 Experts worldwide ranked by ideXlab platform
Richard D Piner - One of the best experts on this subject based on the ideXlab platform.
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growth mechaNism and controlled synthesis of ab stacked bilayer graphene on cu Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D Piner, Rodney S RuoffAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial “90–10” Cu–Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu–Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of 12CH4 and 13CH4) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu–Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for 12C vs13C, and slower cooling rate all produced higher graphene coverage on this type of Cu–Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto...
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Growth mechaNism and controlled synthesis of AB-stacked bilayer graphene on Cu-Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Yujie Ren, Yufeng Hao, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D PinerAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial "90-10" Cu-Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu-Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of (12)CH(4) and (13)CH(4)) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu-Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for (12)C vs(13)C, and slower cooling rate all produced higher graphene coverage on this type of Cu-Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto Si/SiO(2) substrates was controllably synthesized.
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oxidation resistance of graphene coated cu and cu Ni Alloy
ACS Nano, 2011Co-Authors: Shanshan Chen, Richard D Piner, Lola Brown, Mark Levendorf, Sang Yong Ju, Jonathan P Edgeworth, Xuesong Li, Carl W Magnuson, Aruna Velamakanni, Junyong KangAbstract:The ability to protect refined metals from reactive environments is vital to many industrial and academic applications. Current solutions, however, typically introduce several negative effects, including increased thickness and changes in the metal physical properties. In this paper, we demonstrate for the first time the ability of graphene films grown by chemical vapor deposition to protect the surface of the metallic growth substrates of Cu and Cu/Ni Alloy from air oxidation. In particular, graphene prevents the formation of any oxide on the protected metal surfaces, thus allowing pure metal surfaces only one atom away from reactive environments. SEM, Raman spectroscopy, and XPS studies show that the metal surface is well protected from oxidation even after heating at 200 °C in air for up to 4 h. Our work further shows that graphene provides effective resistance against hydrogen peroxide. This protection method offers sigNificant advantages and can be used on any metal that catalyzes graphene growth.
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Synthesis and characterization of large-area graphene and graphite films on commercial Cu-Ni Alloy foils
Nano Letters, 2011Co-Authors: Shanshan Chen, Yujie Ren, Ji Won Suk, Weiwei Cai, Yaping Wu, Junyong Kang, Richard D Piner, Rodney S RuoffAbstract:Controlling the thickness and uNiformity during growth of multilayer graphene is an important goal. Here we report the synthesis of large-area monolayer and multilayer, particularly bilayer, graphene films on Cu-Ni Alloy foils by chemical vapor deposition with methane and hydrogen gas as precursors. The dependence of the iNitial stages of graphene growth rate on the substrate grain orientation was observed for the first time by electron backscattered diffraction and scanNing electron microscopy. The thickness and quality of the graphene and graphite films obtained on such Cu-Ni Alloy foils could be controlled by varying the deposition temperature and cooling rate and were studied by optical microscopy, scanNing electron microscopy, atomic force microscopy, and micro-Raman imaging spectroscopy. The optical and electrical properties of the graphene and graphite films were studied as a function of thickness.
Junyong Kang - One of the best experts on this subject based on the ideXlab platform.
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growth mechaNism and controlled synthesis of ab stacked bilayer graphene on cu Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D Piner, Rodney S RuoffAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial “90–10” Cu–Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu–Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of 12CH4 and 13CH4) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu–Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for 12C vs13C, and slower cooling rate all produced higher graphene coverage on this type of Cu–Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto...
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Growth mechaNism and controlled synthesis of AB-stacked bilayer graphene on Cu-Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Yujie Ren, Yufeng Hao, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D PinerAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial "90-10" Cu-Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu-Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of (12)CH(4) and (13)CH(4)) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu-Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for (12)C vs(13)C, and slower cooling rate all produced higher graphene coverage on this type of Cu-Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto Si/SiO(2) substrates was controllably synthesized.
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oxidation resistance of graphene coated cu and cu Ni Alloy
ACS Nano, 2011Co-Authors: Shanshan Chen, Richard D Piner, Lola Brown, Mark Levendorf, Sang Yong Ju, Jonathan P Edgeworth, Xuesong Li, Carl W Magnuson, Aruna Velamakanni, Junyong KangAbstract:The ability to protect refined metals from reactive environments is vital to many industrial and academic applications. Current solutions, however, typically introduce several negative effects, including increased thickness and changes in the metal physical properties. In this paper, we demonstrate for the first time the ability of graphene films grown by chemical vapor deposition to protect the surface of the metallic growth substrates of Cu and Cu/Ni Alloy from air oxidation. In particular, graphene prevents the formation of any oxide on the protected metal surfaces, thus allowing pure metal surfaces only one atom away from reactive environments. SEM, Raman spectroscopy, and XPS studies show that the metal surface is well protected from oxidation even after heating at 200 °C in air for up to 4 h. Our work further shows that graphene provides effective resistance against hydrogen peroxide. This protection method offers sigNificant advantages and can be used on any metal that catalyzes graphene growth.
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Synthesis and characterization of large-area graphene and graphite films on commercial Cu-Ni Alloy foils
Nano Letters, 2011Co-Authors: Shanshan Chen, Yujie Ren, Ji Won Suk, Weiwei Cai, Yaping Wu, Junyong Kang, Richard D Piner, Rodney S RuoffAbstract:Controlling the thickness and uNiformity during growth of multilayer graphene is an important goal. Here we report the synthesis of large-area monolayer and multilayer, particularly bilayer, graphene films on Cu-Ni Alloy foils by chemical vapor deposition with methane and hydrogen gas as precursors. The dependence of the iNitial stages of graphene growth rate on the substrate grain orientation was observed for the first time by electron backscattered diffraction and scanNing electron microscopy. The thickness and quality of the graphene and graphite films obtained on such Cu-Ni Alloy foils could be controlled by varying the deposition temperature and cooling rate and were studied by optical microscopy, scanNing electron microscopy, atomic force microscopy, and micro-Raman imaging spectroscopy. The optical and electrical properties of the graphene and graphite films were studied as a function of thickness.
Shanshan Chen - One of the best experts on this subject based on the ideXlab platform.
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growth mechaNism and controlled synthesis of ab stacked bilayer graphene on cu Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D Piner, Rodney S RuoffAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial “90–10” Cu–Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu–Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of 12CH4 and 13CH4) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu–Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for 12C vs13C, and slower cooling rate all produced higher graphene coverage on this type of Cu–Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto...
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Growth mechaNism and controlled synthesis of AB-stacked bilayer graphene on Cu-Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Yujie Ren, Yufeng Hao, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D PinerAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial "90-10" Cu-Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu-Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of (12)CH(4) and (13)CH(4)) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu-Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for (12)C vs(13)C, and slower cooling rate all produced higher graphene coverage on this type of Cu-Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto Si/SiO(2) substrates was controllably synthesized.
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oxidation resistance of graphene coated cu and cu Ni Alloy
ACS Nano, 2011Co-Authors: Shanshan Chen, Richard D Piner, Lola Brown, Mark Levendorf, Sang Yong Ju, Jonathan P Edgeworth, Xuesong Li, Carl W Magnuson, Aruna Velamakanni, Junyong KangAbstract:The ability to protect refined metals from reactive environments is vital to many industrial and academic applications. Current solutions, however, typically introduce several negative effects, including increased thickness and changes in the metal physical properties. In this paper, we demonstrate for the first time the ability of graphene films grown by chemical vapor deposition to protect the surface of the metallic growth substrates of Cu and Cu/Ni Alloy from air oxidation. In particular, graphene prevents the formation of any oxide on the protected metal surfaces, thus allowing pure metal surfaces only one atom away from reactive environments. SEM, Raman spectroscopy, and XPS studies show that the metal surface is well protected from oxidation even after heating at 200 °C in air for up to 4 h. Our work further shows that graphene provides effective resistance against hydrogen peroxide. This protection method offers sigNificant advantages and can be used on any metal that catalyzes graphene growth.
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Synthesis and characterization of large-area graphene and graphite films on commercial Cu-Ni Alloy foils
Nano Letters, 2011Co-Authors: Shanshan Chen, Yujie Ren, Ji Won Suk, Weiwei Cai, Yaping Wu, Junyong Kang, Richard D Piner, Rodney S RuoffAbstract:Controlling the thickness and uNiformity during growth of multilayer graphene is an important goal. Here we report the synthesis of large-area monolayer and multilayer, particularly bilayer, graphene films on Cu-Ni Alloy foils by chemical vapor deposition with methane and hydrogen gas as precursors. The dependence of the iNitial stages of graphene growth rate on the substrate grain orientation was observed for the first time by electron backscattered diffraction and scanNing electron microscopy. The thickness and quality of the graphene and graphite films obtained on such Cu-Ni Alloy foils could be controlled by varying the deposition temperature and cooling rate and were studied by optical microscopy, scanNing electron microscopy, atomic force microscopy, and micro-Raman imaging spectroscopy. The optical and electrical properties of the graphene and graphite films were studied as a function of thickness.
Rodney S Ruoff - One of the best experts on this subject based on the ideXlab platform.
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growth mechaNism and controlled synthesis of ab stacked bilayer graphene on cu Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D Piner, Rodney S RuoffAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial “90–10” Cu–Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu–Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of 12CH4 and 13CH4) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu–Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for 12C vs13C, and slower cooling rate all produced higher graphene coverage on this type of Cu–Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto...
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Synthesis and characterization of large-area graphene and graphite films on commercial Cu-Ni Alloy foils
Nano Letters, 2011Co-Authors: Shanshan Chen, Yujie Ren, Ji Won Suk, Weiwei Cai, Yaping Wu, Junyong Kang, Richard D Piner, Rodney S RuoffAbstract:Controlling the thickness and uNiformity during growth of multilayer graphene is an important goal. Here we report the synthesis of large-area monolayer and multilayer, particularly bilayer, graphene films on Cu-Ni Alloy foils by chemical vapor deposition with methane and hydrogen gas as precursors. The dependence of the iNitial stages of graphene growth rate on the substrate grain orientation was observed for the first time by electron backscattered diffraction and scanNing electron microscopy. The thickness and quality of the graphene and graphite films obtained on such Cu-Ni Alloy foils could be controlled by varying the deposition temperature and cooling rate and were studied by optical microscopy, scanNing electron microscopy, atomic force microscopy, and micro-Raman imaging spectroscopy. The optical and electrical properties of the graphene and graphite films were studied as a function of thickness.
Yaping Wu - One of the best experts on this subject based on the ideXlab platform.
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growth mechaNism and controlled synthesis of ab stacked bilayer graphene on cu Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D Piner, Rodney S RuoffAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial “90–10” Cu–Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu–Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of 12CH4 and 13CH4) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu–Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for 12C vs13C, and slower cooling rate all produced higher graphene coverage on this type of Cu–Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto...
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Growth mechaNism and controlled synthesis of AB-stacked bilayer graphene on Cu-Ni Alloy foils
ACS Nano, 2012Co-Authors: Yaping Wu, Yujie Ren, Yufeng Hao, Qingzhi Wu, Junyong Kang, Wei Jiang, Shanshan Chen, Hengxing Ji, Harry Chou, Richard D PinerAbstract:Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial "90-10" Cu-Ni Alloy foil. However, the mechaNism of growth of bilayer graphene on Cu-Ni Alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of (12)CH(4) and (13)CH(4)) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechaNism of graphene growth on Cu-Ni Alloy is by precipitation at the surface from carbon dissolved in the bulk of the Alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for (12)C vs(13)C, and slower cooling rate all produced higher graphene coverage on this type of Cu-Ni Alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto Si/SiO(2) substrates was controllably synthesized.
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Synthesis and characterization of large-area graphene and graphite films on commercial Cu-Ni Alloy foils
Nano Letters, 2011Co-Authors: Shanshan Chen, Yujie Ren, Ji Won Suk, Weiwei Cai, Yaping Wu, Junyong Kang, Richard D Piner, Rodney S RuoffAbstract:Controlling the thickness and uNiformity during growth of multilayer graphene is an important goal. Here we report the synthesis of large-area monolayer and multilayer, particularly bilayer, graphene films on Cu-Ni Alloy foils by chemical vapor deposition with methane and hydrogen gas as precursors. The dependence of the iNitial stages of graphene growth rate on the substrate grain orientation was observed for the first time by electron backscattered diffraction and scanNing electron microscopy. The thickness and quality of the graphene and graphite films obtained on such Cu-Ni Alloy foils could be controlled by varying the deposition temperature and cooling rate and were studied by optical microscopy, scanNing electron microscopy, atomic force microscopy, and micro-Raman imaging spectroscopy. The optical and electrical properties of the graphene and graphite films were studied as a function of thickness.