Fast and simultaneous growth of graphene, intermetallic compounds, and silicate on Cu-Ni alloy foils

A graphene bilayer was grown on copper-nickel alloy foils (30 at-% Ni: 70 at-% Cu designated as a 30Ni-70Cu) via an inductively coupled plasma-chemical vapor deposition chamber, and was characterized. The first layer fully covered the foil, while there was partial coverage of the second layer. At the same time, the alloy catalyst produced a compound of magnesium silicate in some regions and of copper sulfide in other regions on which a graphene monolayer simultaneously grew without any discontinuity or boundaries of the 1st graphene monolayer between simultaneous growth and graphene-only growth regions. Compared with Cu foils, the alloy foils led to faster growth of the graphene film in graphene-only growth regions, while maintaining the same quality, homogeneity, and thickness uniformity as a monolayer graphene grown on Cu. Raman spectroscopy and scattering demonstrated that the 2D and D bands of the Raman spectra were in the same position for the monolayer graphene on 30Ni-70Cu regardless of the grown regions and for the graphene on the Cu with a full width at half maximum of ∼38 cm−1 ranging from 30 to 55 cm−1 of 2D, and without a D band in the spectra of the graphene monolayer and bilayer. Thus the resulting graphene growth is affected primarily by the Cu catalyst, partly by the compounds grown simultaneously with the graphene monolayer on the foil surface via thermal reactions of the impurities dissolved in the alloy matrix, and partly by the Ni. The quality of the graphene is dependent on the major composition of Cu catalyst in the alloy foils. On the other hands, the alloying element of Ni governs the growth kinetics unless the alloy foils is covered with the intermetallic compounds and silicate.