Preparation and characterization of Ni(111)/graphene/Y2O3(111) heterostructures

Dahal, Arjun; Coy-Diaz, Horacio; Addou, Rafik; Lallo, James; Sutter, Eli; Batzill, Matthias

doi:10.1063/1.4805042

Cited by 21 publications

(26 citation statements)

References 34 publications

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“…The peak position of the CC bond was shifted to lower binding energy by about −0.2, −0.17, −0.1, −0.1, −0.05, and 0 eV for NiCl 2 , CuCl 2 , CoCl 2 , ZnCl 2 , TiCl 3 , and InCl 3 , respectively. The peak shift in the C 1s core‐level position was strongly related to Fermi‐level engineering, suggesting that the observed shift to lower binding energy indicates an increase in the work function of transition‐metal‐doped graphene . The atomic content of carbon and oxygen for each sample is displayed in Fig.…”

Section: Resultsmentioning

confidence: 99%

Effect of transition-metal chlorides on graphene properties

Kwon

Choi

Kim

et al. 2014

Phys. Status Solidi A

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The doping mechanisms of transition-metal chlorides such as NiCl 2 , CuCl 2 , CoCl 2 , ZnCl 2 , TiCl 3 , and InCl 3 in graphene were investigated. The sheet resistance of graphene decreased from 780 to 400-700 V sq. À1 on doping; further, its transmittance at 550 nm also decreased from 97% to 90-96% owing to reduction of metal cations. Both the G and 2D peak in Raman spectra were shifted to higher wavenumbers after metalchloride doping, which indicates a charge transfer from graphene to metal cations. The peak position of the CÀ À À ÀC bond in synchrotron radiation photoemission spectroscopy shifted to lower binding energy, suggesting that the Fermi level of doped graphene was lowered by spontaneous electron transfer between graphene and metal cations. Secondary cut-off spectra showed that the work function of doped graphene increased from 4.32 eV to 4. 88, 4.85, 4.82, 4.81, 4.8, and 4.64 eV upon doping with 20 mM of NiCl 2 , CuCl 2 , CoCl 2 , ZnCl 2 , TiCl 3 , and InCl 3 , respectively. The tendency of an increasing work function is strongly related to the work function value of the bulk metallic state. It is considered that spontaneous electron transfer and strong carbon-chlorine bond formation induce a specific energy-level engineering in doped graphene sheets, thereby increasing its work function and conductivity.

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Section: Resultsmentioning

confidence: 99%

Effect of transition-metal chlorides on graphene properties

Kwon

Choi

Kim

et al. 2014

Phys. Status Solidi A

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“…Indeed, reports of growth on Ni(111) at close to atmospheric pressures (with hydrocarbon partial pressures in the mbar regime) show the formation of inhomogeneous few-layer graphene. 53 , 54 …”

Section: Discussionmentioning

confidence: 99%

Interdependency of Subsurface Carbon Distribution and Graphene–Catalyst Interaction

et al. 2014

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The dynamics of the graphene–catalyst interaction during chemical vapor deposition are investigated using in situ, time- and depth-resolved X-ray photoelectron spectroscopy, and complementary grand canonical Monte Carlo simulations coupled to a tight-binding model. We thereby reveal the interdependency of the distribution of carbon close to the catalyst surface and the strength of the graphene–catalyst interaction. The strong interaction of epitaxial graphene with Ni(111) causes a depletion of dissolved carbon close to the catalyst surface, which prevents additional layer formation leading to a self-limiting graphene growth behavior for low exposure pressures (10–6–10–3 mbar). A further hydrocarbon pressure increase (to ∼10–1 mbar) leads to weakening of the graphene–Ni(111) interaction accompanied by additional graphene layer formation, mediated by an increased concentration of near-surface dissolved carbon. We show that growth of more weakly adhered, rotated graphene on Ni(111) is linked to an initially higher level of near-surface carbon compared to the case of epitaxial graphene growth. The key implications of these results for graphene growth control and their relevance to carbon nanotube growth are highlighted in the context of existing literature.

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“…For the annealed Ni(111) films (Figure e), the height modulation after annealing was only 10 atomic layers, corresponding to approximately 20 Å, on a length scale of 3000 Å. Previous observations with Ni(111) films on other supports, of new holes formed by annealing or even of a complete loss of the metal were not confirmed . The Ir(111) films (Figure d) were even flatter than the Ni(111) films; the Ru(0001) films (Figure f) remained somewhat rougher and showed quite a high density of screw dislocations.…”

Section: Resultsmentioning

confidence: 73%

Single Crystalline Metal Films as Substrates for Graphene Growth

et al. 2017

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Single crystalline metal films deposited on YSZ-buffered Si(111) wafers were investigated with respect to their suitability as substrates for epitaxial graphene. Graphene was grown by CVD of ethylene on Ru(0001), Ir(111), and Ni(111) films in UHV. For analysis a variety of surface science methods were used. By an initial annealing step the surface quality of the films was strongly improved. The temperature treatments of the metal films caused a pattern of slip lines, formed by thermal stress in the films, which, however, did not affect the graphene quality and even prevented wrinkle formation. Graphene was successfully grown on all three types of metal films in a quality comparable to graphene grown on bulk single crystals of the same metals. In the case of the Ni(111) films the originally obtained domain structure of rotational graphene phases could be transformed into a single domain by annealing. This healing process is based on the control of the equilibrium between graphene and dissolved carbon in the film. For the system graphene/Ni(111) the metal, after graphene growth, could be removed from underneath the epitaxial graphene layer by a pure gas phase reaction, using the reaction of CO with Ni to give gaseous Ni(CO) 4 .

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Preparation and characterization of Ni(111)/graphene/Y2O3(111) heterostructures

Cited by 21 publications

References 34 publications

Effect of transition-metal chlorides on graphene properties

Effect of transition-metal chlorides on graphene properties

Interdependency of Subsurface Carbon Distribution and Graphene–Catalyst Interaction

Single Crystalline Metal Films as Substrates for Graphene Growth

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