Nanocrystalline Graphite Growth on Sapphire by Carbon Molecular Beam Epitaxy

Abstract

We report the fabrication of nanocrystalline graphite films on sapphire substrates of various cutting directions by using solid carbon source molecular beam epitaxy. Raman spectra show a systematic change from amorphous carbon to nanocrystalline graphite with a cluster diameter of several nanometers, depending on the growth temperature. The symmetry of the substrate seems to have little effect on the film quality. Simulations suggest that the strong bonding between carbon and oxygen may lead to orientational disorders. Transport measurements show a Dirac-like peak and a carrier type change by the gate voltage.

Solid-source growth and atomic-scale characterization of graphene on Ag(111)

“…The presence of monolayer graphene is also suggested by the symmetric 2D band (full width at half maximum (FWHM) ¼ 42 cm À 1 ) in the Raman data 28 . As seen in other studies, the growth of graphene from atomic carbon is not selflimiting [29][30][31] , with large one-dimensional objects appearing at higher coverages (Supplementary Fig. S4c).…”

Carbon molecular beam epitaxy on various semiconductor substrates

“…Typical thickness of carbon film was 3-5 nm. Other details about the growth procedure can be found elsewhere [6].…”

“…Molecular beam epitaxy (MBE) has been used for this purpose by several groups, and direct depositions of graphitic carbon by MBE on semiconductors and insulators, such as Si(1 1 1), SiC, and Al 2 O 3 were reported recently [1][2][3][4][5][6][7]. Experiments have shown the existence of honeycomb ordering and Dirac cones [2,4], and even a Dirac-like peak has been observed in the transport measurements [6], showing the potential of graphene growth by MBE. Therefore, it is timely to study the growth behavior of carbon on other substrates.…”

SnO2 Nanoparticles Decorated 2D Wavy Hierarchical Carbon Nanowalls with Enhanced Photoelectrochemical Performance

“…However, the G peak position of the asfabricated films grown at 0 W and 20 W has been shifted to 1598 and 1596 cm −1 , respectively. This shifting and wide FWHM G suggest that the structures may be due to the indigenousness of nanocrystalline graphitic features of 2D-CNW [14]. Indeed, the corresponding G peak position becomes less prominent as P rf increases which indicates the formation of larger sized graphitic clusters as evidenced from FESEM results.…”