Department of Physics, Henan Normal University, Xinxiang 453007, People's Republic of China.
Nanotechnology. 2017 May 12;28(19):195702. doi: 10.1088/1361-6528/aa68d8. Epub 2017 Mar 23.
In a fast developing field, it has been found that van der Waals heterostructures can overcome the weakness of single two-dimensional layered materials and extend their electronic and optoelectronic applications. Through first-principles methods, the studied MoS/stanene heterostructure preserves high-speed carrier characteristics and opens the direct band gap. Simultaneously, the band alignment shows that the electrons transfer from stanene to MoS, which forms an internal electric field. As an effective strategy, the out-of-plane strain remarkably changes the band gaps of the heterostructure and enhances its carrier concentration. In addition, the combined effects of the internal and external electric fields can further open the band gaps and induce a direct-to-indirect gap transition in the heterostructure. More interestingly, when the external electric field is equal to the reverse internal one, the heterostructure regains a Dirac cone. Our results show that the MoS/stanene heterostructure has potential applications in high-speed optoelectronic devices.
在快速发展的领域中，已经发现范德华异质结构可以克服单个二维层状材料的弱点，并扩展其电子和光电子应用。通过第一性原理方法，研究的 MoS/stanene 异质结构保持了高速载流子特性，并开辟了直接带隙。同时，能带排列表明电子从 stanene 转移到 MoS，从而形成内部电场。作为一种有效的策略，面外应变显著改变了异质结构的能带隙并增强了其载流子浓度。此外，内部和外部电场的组合效应可以进一步打开能带隙并诱导异质结构中的直接到间接带隙转变。更有趣的是，当外部电场等于反向内部电场时，异质结构恢复了狄拉克锥。我们的结果表明，MoS/stanene 异质结构在高速光电子器件中有潜在的应用。
