Fig. 4: High-quality hexagonal-island-merged monolayer hBN on Cu(111) substrates.
From: Single-crystal hBN Monolayers from Aligned Hexagonal Islands
a Schematic of the growth process of monolayer hBN merged from well-aligned hexagonal-shaped hBN islands in oxygen-assisted chemical vapor deposition (CVD) synthesis. b–d SEM images of the as-grown hBN film showing hexagonal-shaped islands (b, c), with white dashed lines indicating the alignment of the hexagonal islands, and a fully merged, continuous monolayer hBN film (d) on Cu(111) foil. The inset in (d) is a magnified view of the hBN wrinkle area. e Photograph of as-grown single-crystal monolayer hBN on Cu(111) foil with areas of 25 × 70 mm2. f, g X-ray photoelectron spectroscopy (XPS) spectra measured on as-grown hexagonal-island-merged monolayer hBN film on Cu(111) substrate. h Optical image of the as-grown monolayer hBN after transferring onto 90 nm SiO2/Si substrates. i Raman map of the intensity of the hBN E2g band measured on the marked region in (h). j Typical Raman spectrum of as-grown hexagonal-island-merged hBN film after transferring onto SiO2/Si substrates.
