Fig. 1
Interlayer epitaxy of wafer-scale AB-BLG films by CVD on shell-core structured liquid Pt3Si/solid Pt substrate. a, b EDS maps of the Si Kα1 peak overlapped with the corresponding scanning electron microscopy (SEM) images of the surface (a) and cross section (b) of the substrate. Note that the Si element is distributed on the very surface and the grain boundaries of the Pt foil, forming a shell-core structure. c XRD pattern of the substrate (on log scale), showing the coexistence of Pt and Pt3Si. d–f Optical images showing the formation process of BLG. d A monolayer graphene (MLG) film obtained after 10 min growth at 1100 °C. e A MLG film with the second layer domains obtained after slow cooling for 4 h. f A continuous BLG film obtained after slow cooling for 6 h. The cooling rate keeps 12.5 °C h−1. g Photograph of two ~1.5 × 3.5 cm2 CVD-grown AB-BLG films on a 2-inch SiO2/Si wafer. h Transmittance spectra of a BLG film on a quartz substrate measured by UV-vis-NIR spectroscopy (measurement area: 0.5 × 0.5 cm2). Inset shows a photograph of a quartz substrate partially covered by a BLG film. i High-resolution transmission electron microscopy (HRTEM) image of a folded edge of the BLG film, showing a well-defined interlayer spacing of ~0.34 nm. Scale bars: a, b, d, e, f 100 μm; h 10 μm; i 2 nm
