  Heterostructures made of stacked 2D materials with different electronic
properties are studied for their potential in creating multifunctional devices.
Graphene (G) and hexagonal boron nitride (h-BN) van der Waals (vdW) systems
have been extensively researched, including recent studies on synthesizing h-BN
on graphene/SiC(0001) templates. These studies suggest that h-BN encapsulation
could occur in addition to vdW epitaxy. This work presents theoretical research
on G/h-BN heterostructures on SiC(0001) with a carbon buffer layer. The results
show an energetic preference for h-BN encapsulation below a single layer of
graphene: G/h-BN/SiC in bilayer systems and G/h-BN/G/SiC in trilayer systems.
Electronic structure calculations reveal that the linear energy band dispersion
of graphene is maintained in bilayer systems but with Dirac points at different
energy positions due to the varied electron doping level of graphene. In
trilayer systems, the doping level of graphene also depends on the stacking
order. The electronic band structure of G/h-BN/G/SiC features two Dirac points
below the Fermi level but with different energies. Less stable systems like
G/G/h-BN/ and h-BN/G/G/SiC display parabolic bands near the Fermi level.
Additional structural characterizations were performed based on simulations of
C-1s core-level-shift (CLS) and carbon K-edge X-ray absorption near-edge
spectroscopy (XANES) to aid future experimental spectroscopy in these
graphene/h-BN vdW systems.
