Thermal Stability of Thin hexagonal Boron Nitride grown by MOVPE on Epigraphene

Abstract

International audiencePassivating graphene with a layer of hexagonal boron nitride (hBN) is known to protect it from environment effects that degrade its mobility. However, BN is hard to grow on graphene because of the lack of surface dangling bonds. Here, we report the growth of thin BN films (down to 10 nm) on monolayer epigraphene grown on silicon carbide single-crystal substrates using metal-organic vapor phase epitaxy (MOVPE). The BN film has continuous coverage on the epigraphene surface, with smooth morphology. Particles consisting of layered BN are also observed on the surface with a higher density at the step edges. High-Resolution Scanning Transmission Electron Microscopy reveals high structural quality BN layers, with a clean and abrupt interface with graphene. The BN/epigraphene/SiC heterostructure is stable up to high temperature (1550 oC), and annealing improves its crystallinity. These results show that MOVPE growth technique has a potential for large-scale production of BN fully coated graphene and high-temperature applications