中国物理B ›› 2014, Vol. 23 ›› Issue (10): 106801-106801.doi: 10.1088/1674-1056/23/10/106801

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Stacking stability of MoS2 bilayer： An ab initio study

陶鹏, 郭怀红, 杨腾, 张志东   

  1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • 收稿日期:2014-03-25 修回日期:2014-04-28 出版日期:2014-10-15 发布日期:2014-10-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11004201 and 50831006) and the National Basic Research Program of China (Grant No. 2012CB933103). Yang Teng acknowledges the IMR SYNL-Young Merit Scholars and T.S. Kê Research Grant for support.

Stacking stability of MoS2 bilayer： An ab initio study

Tao Peng (陶鹏), Guo Huai-Hong (郭怀红), Yang Teng (杨腾), Zhang Zhi-Dong (张志东)   

  1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2014-03-25 Revised:2014-04-28 Online:2014-10-15 Published:2014-10-15
  • Contact: Yang Teng E-mail:yangteng@imr.ac.cn
  • About author:68.35.-p; 61.30.Hn; 68.65.Ac; 62.50.-p
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11004201 and 50831006) and the National Basic Research Program of China (Grant No. 2012CB933103). Yang Teng acknowledges the IMR SYNL-Young Merit Scholars and T.S. Kê Research Grant for support.

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摘要： The study of the stacking stability of bilayer MoS2 is essential since a bilayer has exhibited advantages over single layer MoS2 in many aspects for nanoelectronic applications. We explored the relative stability, optimal sliding path between different stacking orders of bilayer MoS2, and (especially) the effect of inter-layer stress, by combining first-principles density functional total energy calculations and the climbing-image nudge-elastic-band (CI-NEB) method. Among five typical stacking orders, which can be categorized into two kinds (Ⅰ: AA, AB and Ⅱ: AA', AB', A'B), we found that stacking orders with Mo and S superposing from both layers, such as AA' and AB, is more stable than the others. With smaller computational efforts than potential energy profile searching, we can study the effect of inter-layer stress on the stacking stability. Under isobaric condition, the sliding barrier increases by a few eV/(uc·GPa) from AA' to AB', compared to 0.1 eV/(uc·GPa) from AB to [AB]. Moreover, we found that interlayer compressive stress can help enhance the transport properties of AA'. This study can help understand why inter-layer stress by dielectric gating materials can be an effective means to improving MoS2 on nanoelectronic applications.

关键词: MoS2, stacking order, climbing-image nudge-elastic band, isobaric sliding

Abstract: The study of the stacking stability of bilayer MoS2 is essential since a bilayer has exhibited advantages over single layer MoS2 in many aspects for nanoelectronic applications. We explored the relative stability, optimal sliding path between different stacking orders of bilayer MoS2, and (especially) the effect of inter-layer stress, by combining first-principles density functional total energy calculations and the climbing-image nudge-elastic-band (CI-NEB) method. Among five typical stacking orders, which can be categorized into two kinds (Ⅰ: AA, AB and Ⅱ: AA', AB', A'B), we found that stacking orders with Mo and S superposing from both layers, such as AA' and AB, is more stable than the others. With smaller computational efforts than potential energy profile searching, we can study the effect of inter-layer stress on the stacking stability. Under isobaric condition, the sliding barrier increases by a few eV/(uc·GPa) from AA' to AB', compared to 0.1 eV/(uc·GPa) from AB to [AB]. Moreover, we found that interlayer compressive stress can help enhance the transport properties of AA'. This study can help understand why inter-layer stress by dielectric gating materials can be an effective means to improving MoS2 on nanoelectronic applications.

Key words: MoS2, stacking order, climbing-image nudge-elastic band, isobaric sliding

中图分类号:  (Solid surfaces and solid-solid interfaces: structure and energetics)

  • 68.35.-p
61.30.Hn (Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions) 68.65.Ac (Multilayers) 62.50.-p (High-pressure effects in solids and liquids)