Electric field modulation of the band structure in MoS₂/WS₂ van der waals heterostructure

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• 作者：Wei Li^a ; ^c ; Tianxing Wang^a ; Xianqi Dai^a ; ^b ; ^xqdai@htu.cn ; Xiaolong Wang^a ; Caiyun Zhai^a ; Yaqiang Ma^a ; Shanshan Chang^a ; Yanan Tang^b
• 关键词：C. MoS2/WS2 heterostructure ; D. band structure ; B. external electric field
• 刊名：Solid State Communications
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：250
• 期：Complete
• 页码：9-13
• 全文大小：1221 K
• 卷排序：250

文摘

Using density functional theory calculations, we investigate the bandstructure of MoS2/WS2 van der waals heterostructure by applying external electric field perpendicular to the layers. It is demonstrated that the MoS2/WS2 is a type-II heterostructure, and therefore the electrons and holes are spatially separated. The band gap of MoS2/WS2 heterostructure continuously decreases with increasing external electric field, eventually a transition from semiconductor to metal is observed. Applying external electric field along +z direction and −z directions has different effects on the band gap due to the intrinsic spontaneous polarization in MoS2/WS2 heterostructure. The calculated result indicates that the band inversion in MoS2/WS2 heterostructure can be induced by changing the strength of the external electric field. The external electric field can significantly tune the band offsets almost linearly and modify the band alignment between MoS2 and WS2. The present study would open a new avenue for application of such transition-metal dichalcogenides heterostructures in future nano- and optoelectronics.