The giant Stark effect(GSE) in a set of van der Waals(vdW) heterostructures is studied using first-principles methods. A straightforward model based on quasi-Fermi levels is proposed to describe the influence of an ex...The giant Stark effect(GSE) in a set of van der Waals(vdW) heterostructures is studied using first-principles methods. A straightforward model based on quasi-Fermi levels is proposed to describe the influence of an external perpendicular electric field on both band gap and band edges. Although a general linear GSE is observed, which is induced by the almost linear variation of the band edges of each layer in the heterostructures, when vdW heterostructures is subjected to small electric fields the variation becomes nonlinear. This can be attributed to the band offsets-induced interlayer charge transfer and resulted intraand inter-layer Coulomb interactions. Our work, thus offers new insight into the mechanism of the nonlinear GSE in vdW heterostructures, which is important for the applications of vdW heterostructures on nanoelectronic devices.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2016YFB0700700)the National Natural Science Foundation of China(Grant Nos.61622406,11674310,61571415,61427901,51502283,and U1530401)
文摘The giant Stark effect(GSE) in a set of van der Waals(vdW) heterostructures is studied using first-principles methods. A straightforward model based on quasi-Fermi levels is proposed to describe the influence of an external perpendicular electric field on both band gap and band edges. Although a general linear GSE is observed, which is induced by the almost linear variation of the band edges of each layer in the heterostructures, when vdW heterostructures is subjected to small electric fields the variation becomes nonlinear. This can be attributed to the band offsets-induced interlayer charge transfer and resulted intraand inter-layer Coulomb interactions. Our work, thus offers new insight into the mechanism of the nonlinear GSE in vdW heterostructures, which is important for the applications of vdW heterostructures on nanoelectronic devices.
