Graphene nano-flakes on Cu low-index surfaces by density functional theory and molecular dynamics simulations

Balerba, Athanasia K.; Kotanidis, Alexis; Paraskeuas, Angelos; Gialampouki, Martha; Moreno, José Julio Gutiérrez; Evangelakis, G.A.; Lekka, Christina

doi:10.1016/b978-0-12-821495-4.00009-9

Cited by 2 publications

(2 citation statements)

References 59 publications

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“…The tube furnace comprises substrate and catalyst, e.g., a copper plate interfacing with the gas at temperatures in a range of 1000-1300 K. Among possible Cu surfaces, we considered the ideal Cu(111) surface and a temperature of 1300 K. It is important to note that such temperatures are rather close to the melting point of copper (1357 K), which means that surface Cu atoms can be quite mobile. Although there are some theoretical studies in the literature indicating the impact of the mobility of Cu atoms on the coalescence process [76], we neglected these effects in the present work and considered a solid, rigid surface. We used the adsorption rate of both gases, which depends on their partial pressures, system temperature, and dissociative adsorption activation energies (more details in the SI).…”

Section: Methodsmentioning

confidence: 99%

Multiscale Model of CVD Growth of Graphene on Cu(111) Surface

Esmaeilpour

Bügel

Fink

et al. 2023

IJMS

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Due to its outstanding properties, graphene has emerged as one of the most promising 2D materials in a large variety of research fields. Among the available fabrication protocols, chemical vapor deposition (CVD) enables the production of high quality single-layered large area graphene. To better understand the kinetics of CVD graphene growth, multiscale modeling approaches are sought after. Although a variety of models have been developed to study the growth mechanism, prior studies are either limited to very small systems, are forced to simplify the model to eliminate the fast process, or they simplify reactions. While it is possible to rationalize these approximations, it is important to note that they have non-trivial consequences on the overall growth of graphene. Therefore, a comprehensive understanding of the kinetics of graphene growth in CVD remains a challenge. Here, we introduce a kinetic Monte Carlo protocol that permits, for the first time, the representation of relevant reactions on the atomic scale, without additional approximations, while still reaching very long time and length scales of the simulation of graphene growth. The quantum-mechanics-based multiscale model, which links kinetic Monte Carlo growth processes with the rates of occurring chemical reactions, calculated from first principles makes it possible to investigate the contributions of the most important species in graphene growth. It permits the proper investigation of the role of carbon and its dimer in the growth process, thus indicating the carbon dimer to be the dominant species. The consideration of hydrogenation and dehydrogenation reactions enables us to correlate the quality of the material grown within the CVD control parameters and to demonstrate an important role of these reactions in the quality of the grown graphene in terms of its surface roughness, hydrogenation sites, and vacancy defects. The model developed is capable of providing additional insights to control the graphene growth mechanism on Cu(111), which may guide further experimental and theoretical developments.

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Section: Methodsmentioning

confidence: 99%

Multiscale Model of CVD Growth of Graphene on Cu(111) Surface

Esmaeilpour

Bügel

Fink

et al. 2023

IJMS

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“…DFT is used to investigate elementary reactions at atomistic levels and to calculate corresponding energy barriers, which are then utilized by kMC in describing the kinetics of the flake growth. One of the main conclusions of these studies is that on Cu(111) monoatomic and diatomic carbon are the most important candidates, playing a key role for the dominant feeding particle of the growth process (i.e., it was shown that they have low diffusion barriers/high mobility on the surface), yet, to our knowledge, there is no general agreement on this question in the literature [ 24 , 25 , 26 , 27 ]. Carbon trimer was evaluated as an important feeding material on h-BN [ 28 ]; however, on copper it is believed to be much less significant [ 29 ].…”

Section: Introductionmentioning

confidence: 99%

Analytical Model of CVD Growth of Graphene on Cu(111) Surface

et al. 2022

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Although the CVD synthesis of graphene on Cu(111) is an industrial process of outstanding importance, its theoretical description and modeling are hampered by its multiscale nature and the large number of elementary reactions involved. In this work, we propose an analytical model of graphene nucleation and growth on Cu(111) surfaces based on the combination of kinetic nucleation theory and the DFT simulations of elementary steps. In the framework of the proposed model, the mechanism of graphene nucleation is analyzed with particular emphasis on the roles played by the two main feeding species, C and C2. Our analysis reveals unexpected patterns of graphene growth, not typical for classical nucleation theories. In addition, we show that the proposed theory allows for the reproduction of the experimentally observed characteristics of polycrystalline graphene samples in the most computationally efficient way.

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Graphene nano-flakes on Cu low-index surfaces by density functional theory and molecular dynamics simulations

Cited by 2 publications

References 59 publications

Multiscale Model of CVD Growth of Graphene on Cu(111) Surface

Multiscale Model of CVD Growth of Graphene on Cu(111) Surface

Analytical Model of CVD Growth of Graphene on Cu(111) Surface

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