Layers dependent dielectric properties of two dimensional hexagonal boron nitridenanosheets

Two dimensional (2D) boron nitride (h-BN) nanosheets are well known as their tunable electric properties and well compatible with graphene. Studying the dielectric properties carefully is essential for their promised applications. Most previous first principle studies treated 2D h-BN as a strict 2D system, where the contribution of ion polarization is neglected. The results show obvious deviation from experimental values, and the situations are worse with the stacking layer increasing. Thus, in present works, the dielectric properties of 2D h-BN nanosheets are studied with involving the ion contributions appropriately. The evolution of dielectric performance with stacking layers varying is also studied. Obvious layer dependent anisotropic dielectric properties are predicted, which reaches the bulk h-BN level as the thickness approaching 5.8nm (20L). There should be a balance between dielectric properties and the thickness (stacking layers) for the dielectric applications of 2D h-BN nanosheets.