Surface Etching During Epitaxial H-Bn Growth On Graphene

The vertically stacked hetero-structure is an important application of two-dimensional materials. In order to avoid contamination during sample transfer and stacking, and to achieve a scalable hexagonal boron nitride (h-BN)/graphene vertical heterostructure, direct growth of a h-BN film on graphene is desirable. However, the growth mechanism of h-BN on graphene is not yet fully understood. Here, we demonstrate the etching growth mechanism of a h-BN film on graphene. X-ray photoemission spectroscopy measurements show the element composition and chemical bonding formation of the pure phase h-BN. Angle-resolved photoemission spectroscopy measurements show the energy dispersion of the h-BN and also reveal the formation of the new R0 degrees graphene. Atomic force microscopy and scanning tunneling microscopy are applied to investigate the surface morphology of the samples. Our study provides a deeper understanding of the growth mechanism of the h-BN film on graphene and shows implication for the further research on h-BN/graphene heterojunctions.