Theoretical Study on Origin of CVD Growth Direction Difference in Graphene/hBN Heterostructures

The origin of chemical vapor deposition (CVD) growth direction difference in graphene/hexagonal boron nitride (hBN) het erostructures is theoretically studied. The study is focused on the advance in energy gain by H termination of the bare hBN N edge on the Cu(111) surface comparing with that of the bare graphene edge. It is found that the difference in the van der Waals correction method affects largely the advance. However, when the most reliable van der Waals correction of the vdw-DF2-B86R method is used, the results consist with our speculation stating that the edge termination of the existing island rather automatically changes depending on whether the island is graphene or hBN. Thus, it is proposed that the graphene island edge is automatically bare and the hBN island edge is automatically terminated by H during the CVD growth.

Automated summary

The origin of growth direction difference in graphene/hexagonal boron nitride (hBN) heterostructures during chemical vapor deposition (CVD) is theoretically studied. The study focuses on the energy gain with H termination of the bare hBN N edge on the Cu(111) surface compared to the bare graphene edge. The results indicate that the van der Waals correction method greatly affects the differences observed, and the most reliable method supports the speculation that the edge termination of existing islands automatically changes depending on whether it is graphene or hBN.