Comparison and stability of the low-index surfaces of c-BN by first-principles

Using first-principles method based on density functional theory, we have comparatively studied surface relaxation, surface energy, and electronic structure of the low-index surfaces (001), (110), and (111) of c-BN. The calculated surface energy indicated c-BN (110) was the most stable surface over the range of nitrogen chemical potential. It was consistent with the relaxation result that (110) surface showed the smallest contraction/expansion effect. According to density of states, which revealed the nature of stability, the surface electronic structure was mainly impacted by the first-layer atomic orbitals.