Khan Asir Intisar, Chakraborty Trisha, Acharjee Niloy, Subrina Samia
Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, 1205, Bangladesh.
Sci Rep. 2017 Nov 27;7(1):16347. doi: 10.1038/s41598-017-16650-5.
The structural and electronic properties of stanene/hexagonal boron nitride (Sn/h-BN) heterobilayer with different stacking patterns are studied using first principle calculations within the framework of density functional theory. The electronic band structure of different stacking patterns shows a direct band gap of ~30 meV at Dirac point and at the Fermi energy level with a Fermi velocity of ~0.53 × 10 ms. Linear Dirac dispersion relation is nearly preserved and the calculated small effective mass in the order of 0.05m suggests high carrier mobility. Density of states and space charge distribution of the considered heterobilayer structure near the conduction and the valence bands show unsaturated π orbitals of stanene. This indicates that electronic carriers are expected to transport only through the stanene layer, thereby leaving the h-BN layer to be a good choice as a substrate for the heterostructure. We have also explored the modulation of the obtained band gap by changing the interlayer spacing between h-BN and Sn layer and by applying tensile biaxial strain to the heterostructure. A small increase in the band gap is observed with the increasing percentage of strain. Our results suggest that, Sn/h-BN heterostructure can be a potential candidate for Sn-based nanoelectronics and spintronic applications.
在密度泛函理论框架内，采用第一性原理计算方法研究了具有不同堆叠模式的锡烯/六方氮化硼（Sn/h-BN）异质双层的结构和电子性质。不同堆叠模式的电子能带结构在狄拉克点和费米能级处显示出约30 meV的直接带隙，费米速度约为0.53×10 m/s。线性狄拉克色散关系几乎得以保留，计算得到的约0.05m量级的小有效质量表明载流子迁移率较高。所考虑的异质双层结构在导带和价带附近的态密度和空间电荷分布显示出锡烯不饱和的π轨道。这表明电子载流子预计仅通过锡烯层传输，从而使得h-BN层成为异质结构衬底的良好选择。我们还通过改变h-BN与Sn层之间的层间距以及对异质结构施加拉伸双轴应变，探索了对所得带隙的调制。随着应变百分比的增加，观察到带隙有小幅增加。我们的结果表明，Sn/h-BN异质结构可能是基于Sn的纳米电子学和自旋电子学应用的潜在候选材料。
