Figure 4. Characterization of
monolayer and bilayer graphene
synthesized by C-ion implantation. a) Schematic sketch of physically
peeling off the Cu-Ni alloy using a thermal release tape. b) Raman
spectra of the monolayer graphene grown on SiO2, Si,
glass, and sapphire substrates, synthesized by C-ion implantation with a
fluence of 4 × 1015 atoms/cm2. c)
Raman spectra of the monolayer and
bilayer graphene structures on SiO2 substrate,
respectively. The
monolayer (bilayer) graphene
synthesized by C ion implantation with a fluence of 4 ×
1015 (8 × 1015)
atoms/cm2. d, g) STM of the monolayer and bilayer
graphene, respectively, and the insets correspond to the enlarged images
of the selected regions. e, h) SAED patterns of the monolayer and
bilayer graphene and HR-TEM image revealing that the graphene is
monolayer and bilayer, respectively, and the inserts show the profiles
of diffraction spot intensities along a line in e) and h), respectively.
f, i) Raman I2D/IG peak intensity ratio
maps obtained from the monolayer and bilayer graphene films,
respectively.