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...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 in- terlayer 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.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0202300)the National Natural Science Foundation of China(Grant Nos.61390501 and 61471337)+2 种基金the National Basic Research Program of China(Grant No.2013CBA01600)the CAS Pioneer Hundred Talents Programthe Beijing Nova Program,China(Grant No.Z181100006218023)
文摘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 in- terlayer 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.
