Van der Waals epitaxy of two-dimensional single-layer h-BN on graphite by molecular beam epitaxy: Electronic properties and band structure

We report on the controlled growth of h-BN/graphite by means of molecular beam epitaxy (MBE). X-ray photoelectron spectroscopy (XPS) suggests an interface without any reaction or intermixing, while the angle resolved photoemission spectroscopy (ARPES) measurements show that the h-BN layers are epitaxially aligned with graphite. A well-defined band structure is revealed by ARPES measurement, reflecting the high quality of the h-BN films. The measured valence band maximum (VBM) located at 2.8 eV below the Fermi level reveals the presence of undoped h-BN films (band gap ~ 6 eV). These results demonstrate that, although only weak van der Waals interactions are present between h-BN and graphite, a long range ordering of h-BN can be obtained even on polycrystalline graphite via van der Waals epitaxy, offering the prospect of large area, single layer h-BN.