Controlled growth of large area multilayer graphene on copper by chemical vapour deposition

Abstract

The growth of nearly full coverage of multilayer graphene on the surface of a 99.8% purity copper foil has been experimentally studied. It has been shown that the film thickness can be controlled by a single parameter, the growth time, and growth can be extended until nearly full coverage of more than one layer graphene over the copper surface. The results are supported by scanning electron microscopy and Raman analysis together with optical transmittance and sheet resistance measurements. It has been verified that silicon oxide impurity particles within the copper act as catalysts and the seeds of multilayer graphene islands. The linear increase of the average thickness of graphene to the growth time has been attributed to the interplay between the mean distance between the impurities on the surface and the molecular mean free path in the process gas. A qualitative model is proposed to explain the microscopic mechanism of the multilayer growth on copper. These results contribute to the understanding of the chemical vapour deposition growth kinetics towards the objective of large area high quality graphene production with tuneable layer thickness.

Direct growth of graphene on Ge(100) and Ge(110) via thermal and plasma enhanced CVD

“…1 b) as multilayer islands on a fully closed monolayer film. Similar to literature 42 , 43 some white dots are present in the SEM image, which are most likely related to an oxidation process of Ge as described in a recent study 17 . Obviously, the graphene film is defective with an I D / I G ratio of 0.7.…”

Spontaneous Nucleation and Growth of Graphene Flakes on Copper Foil in the Absence of External Carbon Precursor in Chemical Vapor Deposition

“…These particles are a compound of silicon and oxygen, originated from the quartz tube of the furnace. 17,39−41 It can be clearly seen that SiO x particles are never sited at the center of GFs at the earlier stages of graphene growth. Therefore, we infer that silicon oxide particles are not the initial cause of graphene nucleation.…”

Contamination-free graphene by chemical vapor deposition in quartz furnaces

“…identified the contaminants as SiO 2 clusters and indicated the phase transition of quartz (occurring during the CVD process) as responsible for the contamination process: SiO 2 is emitted from the quartz tube when Cu atoms (originating from the Cu substrates during heating) diffuse inside the tube walls at the α/β quartz phase transition temperature (573 °C) 37 . Other authors attributed the SiO x contamination to the presence of silicon (Si) in the bulk of the Cu substrates, which in their view would emerge during the growth process and contaminate the graphene surface 38 . A third group linked the presence of SiO 2 clusters on graphene to the reaction of hot hydrogen with the quartz reactor 39 : During the annealing of the Cu substrate the hot part of the tube furnace would be etched by H 2 gas, depositing SiO 2 on the substrate.…”