Structures, Energetics, and Electronic Properties of Multifarious Stacking Patterns for High-Buckled and Low-Buckled Silicene on the MoS2 Substrate
Structures, Energetics, and Electronic Properties of Multifarious Stacking Patterns for High-Buckled and Low-Buckled Silicene on the MoS2 Substrate
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DOI：
10.1021/jp5043359
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发表时间：
2014-08-21
影响因子：
3.7
通讯作者：
Zhao, Mingwen
中科院分区：
文献类型：
--
作者：
Li, Linyang;Zhao, Mingwen
硅烯与衬底材料之间的界面对体系的电子性质起着重要的作用。已经报道了在块状MoS 2表面上合成的高屈曲（HB）硅烯[Adv.Mater. 2014，26，2096-2101]。利用第一性原理计算，我们研究了硅烯和单层MoS 2衬底之间的界面。我们发现硅烯可以通过货车范德华（vdW）相互作用吸附在MoS 2衬底上，形成具有HB或低屈曲（LB）构型的硅烯/MoS 2异质结构。LB硅烯和MoS 2衬底之间的晶格失配导致莫尔超结构的形成。HB硅烯在MoS 2衬底上的异质结构是金属的，而LB硅烯在MoS 2衬底上的异质结构是半导体的，由于界面效应，具有小的带隙。带隙依赖于旋转角度和堆叠模式，而形成能则不依赖。LB硅烯的高载流子迁移率被保留在这些异质结构中。更有趣的是，可以通过施加垂直的外部电场来进一步调节带隙。这些特性有助于硅烯纳米电子器件的制备。
The interfaces between silicene and substrate materials play important roles in the electronic properties of the systems. High-buckled (HB) silicene synthesized on bulk MoS2 surface has been reported [Adv. Mater. 2014, 26, 2096-2101]. Using first-principles calculations, we studied the interfaces between silicene and the monolayer MoS2 substrate. We found that silicene can adsorb on the MoS2 substrate via van der Waals (vdW) interactions forming silicene/MoS2 heterostructures with HB or low-buckled (LB) configuration. The lattice mismatch between LB silicene and the MoS2 substrate leads to the formation of Moire superstructures. The heterostructures of HB silicene on the MoS2 substrate are metallic, while those of LB silicene on the MoS2 substrate are semiconductors with small band gaps due to the interface effects. The band gap is dependent on the rotation angle and stacking pattern, whereas the formation energy is not. High carrier mobility of LB silicene is preserved in these heterostructures. More interestingly, the band gap can be further tuned by applying a vertical external electric field. These features are helpful for the fabrication of nanoscaled electronic devices using silicene.