Electronic properties of silicene in BN/silicene van der Waals heterostructures

Abstract

Silicene is a promising 2D Dirac material as a building block for van der\nWaals heterostructures (vdWHs). Here we investigate the electronic properties\nof hexagonal boron nitride/silicene (BN/Si) vdWHs using first-principles\ncalculations. We calculate the energy band structures of BN/Si/BN\nheterostructures with different rotation angles and find that the electronic\nproperties of silicene are retained and protected robustly by the BN layers. In\nBN/Si/BN/Si/BN heterostructure, we find that the band structure near the Fermi\nenergy is sensitive to the stacking configurations of the silicene layers due\nto interlayer coupling. The coupling is reduced by increasing the number of BN\nlayers between the silicene layers and becomes negligible in BN/Si/(BN)3/Si/BN.\nIn (BN)n/Si superlattices, the band structure undergoes a conversion from Dirac\nlines to Dirac points by increasing the number of BN layers between the\nsilicene layers. Calculations of silicene sandwiched by other 2D materials\nreveal that silicene sandwiched by low-carbon-doped boron nitride or HfO2 is\nsemiconducting.\n