Band structure engineering in a MoS2/PbI2 van der Waals heterostructure via an external electric field
Band structure engineering in a MoS2/PbI2 van der Waals heterostructure via an external electric field
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通过外部电场对 MoS2/PbI2 范德华异质结构进行能带结构工程
DOI：
10.1039/c6cp06046c
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发表时间：
2016-11-07
影响因子：
3.3
通讯作者：
Dai, Xianqi
中科院分区：
文献类型：
--
作者：
Ma, Yaqiang;Zhao, Xu;Dai, Xianqi
使用密度泛函理论 (DFT) 研究外部电场 (E 场) 下 MoS2/PbI2 范德华 (vdW) 异质结构的能带结构工程。结果表明，MoS2/PbI2 vdW 异质结具有直接带隙的 II 型异质结，因此最低能量的电子-空穴对在空间上分离。同时，能带结构在电场下可以得到有效调制，带隙随电场呈线性变化，表明存在巨大的斯塔克效应。这得到了异质结构中 MoS2 和 PbI2 能带边缘的进一步支持。此外，MoS2/PbI2 vdW异质结构在各种电场下经历了从II型到I型再到II型的转变。我们的计算结果为实验研究铺平了道路，并为vdW异质结构在电子和光电器件中的应用提供了新的视角。
Band structure engineering in a MoS2/PbI2 van der Waals (vdW) heterostructure under an external electric field (E-field) is investigated using density functional theory (DFT). It is demonstrated that the MoS2/PbI2 vdW heterostructure has a type-II heterojunction with a direct bandgap, and thus the lowest energy electron-hole pairs are spatially separated. Meanwhile, the band structure could be effectively modulated under an E-field and the bandgap shows linear variations with the E-field, indicating a giant Stark effect. This gets further support from the band edges of MoS2 and PbI2 in the heterostructure. Moreover, the MoS2/PbI2 vdW heterostructure experiences transitions from type-II to type-I and then to type-II under various E-fields. Our calculated results pave the way for experimental research and provide a new perspective for the application of the vdW heterostructure in electronic and optoelectronic devices.