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

TL;DR

This study uses first-principles calculations to explore how stacking and layer variations in BN/silicene heterostructures affect their electronic properties, revealing robustness and tunability of silicene's electronic structure.

Contribution

It provides detailed insights into the electronic behavior of BN/silicene heterostructures with different stacking configurations and layer numbers, highlighting their potential for electronic applications.

Findings

Silicene's electronic properties are preserved by BN layers.

Interlayer coupling affects band structure near Fermi energy.

Increasing BN layers can convert Dirac lines to Dirac points.

Abstract

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