Growth and Raman spectroscopy of thickness-controlled rotationally faulted multilayer graphene

We report the growth of thickness-controlled rotationally faulted multilayer graphene (rf-MLG) on Ni foils by low-pressure chemical vapor deposition and their characterization by micro-Raman spectroscopy. The surface morphology and thickness were investigated by scanning electron microscopy, X-ray diffraction, and transmittance measurements. These results have revealed that the thickness of rf-MLG can be effectively controlled by the thickness of the Ni foil rather than the flow rate of CH4, H-2, Ar. In Raman spectroscopy measurements, we observed most Raman peaks of the graphitic materials. Raman spectra can be categorized into four patterns and show systematic behaviors. Especially, the in-plane (similar to 1880 cm(-1), similar to 2035 cm(-1)) and out-of-plane (similar to 1750 cm(-1)) modes are successfully analyzed to explain the dimensionality of rf-MLG as in the twisted (or rotated) bilayer graphene. In addition, it is found that the two peaks at similar to 1230 cm(-1) and similar to 2220 cm(-1) well reflect the properties of the in-plane mode. The peak intensities of the above four in-plane modes are proportional to that of 2D band, indicating that they share the common Raman resonance process. (C) 2018 Elsevier Ltd. All rights reserved.