TY - JOUR
T1 - Van der Waals trilayers and superlattices
T2 - Modification of electronic structures of MoS2 by intercalation
AU - Lu, Ning
AU - Guo, Hongyan
AU - Wang, Lu
AU - Wu, Xiaojun
AU - Zeng, Xiao Cheng
PY - 2014/5/7
Y1 - 2014/5/7
N2 - We perform a comprehensive first-principles study of the electronic properties of van der Waals (vdW) trilayers via intercalating a two-dimensional (2D) monolayer (ML = BN, MoSe2, WS2, or WSe2) between a MoS2 bilayer to form various MoS2/ML/MoS 2 sandwich trilayers. We find that the BN monolayer is the most effective sheet to decouple the interlayer vdW coupling of the MoS2 bilayer, and the resulting sandwich trilayer can recover the electronic structures of the MoS2 monolayer, particularly the direct-gap character. Further study of the MoS2/BN superlattices confirms the effectiveness of the BN monolayer for the decoupling of the MoS 2-MoS2 interaction. In addition, the intercalation of a transition-metal dichalcogenide (TMDC) MoSe2 or WSe2 sheet makes the sandwich trilayer undergo an indirect-gap to direct-gap transition due to the newly formed heterogeneous S/Se interfaces. In contrast, the MoS 2/WS2/MoS2 sandwich trilayer still retains the indirect-gap character of the MoS2 bilayer due to the lack of the heterogeneous S/Se interfaces. Moreover, the 3D superlattice of the MoS 2/TMDC heterostructures also exhibits similar electronic band characters to the MoS2/TMDC/MoS2 trilayer heterostructures, albeit a slight decrease of the bandgap compared to the trilayers. Compared to the bulk MoS2, the 3D MoS2/TMDC superlattice can give rise to new and distinctive properties. Our study offers not only new insights into electronic properties of the vdW multilayer heterostructures but also guidance in designing new heterostructures to modify electronic structures of 2D TMDC crystals.
AB - We perform a comprehensive first-principles study of the electronic properties of van der Waals (vdW) trilayers via intercalating a two-dimensional (2D) monolayer (ML = BN, MoSe2, WS2, or WSe2) between a MoS2 bilayer to form various MoS2/ML/MoS 2 sandwich trilayers. We find that the BN monolayer is the most effective sheet to decouple the interlayer vdW coupling of the MoS2 bilayer, and the resulting sandwich trilayer can recover the electronic structures of the MoS2 monolayer, particularly the direct-gap character. Further study of the MoS2/BN superlattices confirms the effectiveness of the BN monolayer for the decoupling of the MoS 2-MoS2 interaction. In addition, the intercalation of a transition-metal dichalcogenide (TMDC) MoSe2 or WSe2 sheet makes the sandwich trilayer undergo an indirect-gap to direct-gap transition due to the newly formed heterogeneous S/Se interfaces. In contrast, the MoS 2/WS2/MoS2 sandwich trilayer still retains the indirect-gap character of the MoS2 bilayer due to the lack of the heterogeneous S/Se interfaces. Moreover, the 3D superlattice of the MoS 2/TMDC heterostructures also exhibits similar electronic band characters to the MoS2/TMDC/MoS2 trilayer heterostructures, albeit a slight decrease of the bandgap compared to the trilayers. Compared to the bulk MoS2, the 3D MoS2/TMDC superlattice can give rise to new and distinctive properties. Our study offers not only new insights into electronic properties of the vdW multilayer heterostructures but also guidance in designing new heterostructures to modify electronic structures of 2D TMDC crystals.
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U2 - 10.1039/c4nr00783b
DO - 10.1039/c4nr00783b
M3 - Article
C2 - 24676364
AN - SCOPUS:84898074403
SN - 2040-3364
VL - 6
SP - 4566
EP - 4571
JO - Nanoscale
JF - Nanoscale
IS - 9
ER -