Theoretical investigation of the hBN(0001)/cBN(111) interface

The interface between the (0001) surface of the hexagonal boron nitride (hBN) and the (111) surface of the cubic boron nitride (cBN) is studied through first principles plane-wave pseudopotentials within the density functional theory. Four different structural models for the pseudomorphic growth of the cBN on hBN have been investigated, two with tetrahedral and two with hexagonal arrangements of the atoms at the interface. The interfaces with N-terminated cBN(111) surface are seen to have the lowest formation energies. The studied interface models present a metallic character, with the levels at Fermi energy spatially confined in the interface region. The band offsets show type I band lineups, with large valence and conduction band discontinuities.