Hexagonal Boron Nitride Monolayers as Protective Barriers for Graphene during Thermal Annealing

In this study, we investigate the behavior of CVD-grown monolayer hexagonal boron nitride (h-BN) as a protective barrier on top of CVD-grown monolayer graphene during the removal of poly-(methyl methacrylate) (PMMA) residues by thermal annealing in air. We use a combination of Raman spectroscopy, optical microscopy, and atomic force microscopy to measure the damage of graphene and the efficacy of air annealing as a cleaning method. Our experimental findings demonstrate the effectiveness of h-BN as a protective barrier against graphene damage at temperatures up to 500 °C compared with bare graphene.