Nanoscale Multilayer Transition-Metal Dichalcogenide Heterostructures: Band Gap Modulation by Interfacial Strain and Spontaneous Polarization
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- 作者：Liangzhi Kou ; Thomas Frauenheim ; Changfeng Chen
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2013
- 出版时间：May 16, 2013
- 年：2013
- 卷：4
- 期：10
- 页码：1730-1736
- 全文大小：418K
- 年卷期：v.4,no.10(May 16, 2013)
- ISSN：1948-7185
文摘
Using density functional theory calculations, we unveil intriguing electronic properties of nanoscale multilayer transition-metal dichalcogenide (TMDC) heterostructures, (MoX2)n(MoY2)m (X, Y = S, Se or Te). Our results show that the structural stability and electronic band structure of the TMDC heterostructures depend sensitively on the choice of constituent components and their relative thickness. In particular, the electronic band gap can be tuned over a wide range by the intrinsic mismatch strain and spontaneous electrical polarization at the interface of the heterostructures, which suggests desirable design strategies for TMDC-based devices with an easily adjustable band gap. These interfacial effects also make the electronic properties more susceptible to the influence of a bias electric field, which can induce sensitive and considerable changes in the band gap and even produce a semiconductor鈥搈etal transition at relatively low electric fields. Such effective electronic band gap engineering via a combination of internal (i.e., the composition and layer thickness) and external (i.e., a bias field) control makes the TMDC-based heterostructures promising candidates for applications in a variety of nanodevices.