  Graphene and boron nitride (GPBN) heterostructures provide a viable way to
realize tunable bandgap, promising new opportunities in graphene-based
nanoelectronic and optoelectronic devices. In the present study, we
investigated the interplay between vacancies and graphene/h-BN interfaces in
monolayer GPBN heterostructures. The energetics and kinetics of monovacancies
and divacancies in monolayer GPBN heterostructures were examined using
first-principle calculations. The interfaces were shown to be preferential
locations for vacancy segregation. Meanwhile the kinetics of vacancies was
found to be noticeably modified at interfaces, evidenced by the Minimum Energy
Paths (MEPs) and associated migration barriers calculations. The role of
interfacial bonding configurations, energy states and polarization on the
formation and diffusion of vacancies were discussed. Additionally we
demonstrated that it is important to recognize the dissimilarities in the
diffusion prefactor for different vacancies for accurate determination of the
vacancy diffusion coefficient. Our results provide essential data for the
modeling of vacancies in GPBN heterostructures, and important insights towards
the precise engineering of defects, interfaces and quantum domains in the
design of GPBN-based devices.
