title: The electronic structures of group-V-group-IV hetero-bilayer structures: a first-principles study.
abstract: Recent findings of group-V nanosheets provide new building units for van der Waals hetero-nanostructures. Based on first-principles calculation, we investigate the structural and electronic properties of bilayer hetero-sheets composed of group-V (arsenene/antimonene) and group-IV (graphene/silicene) layers. These hetero-sheets exhibit typical van der Waals features with small binding energies and soft interlayer elastic constants. In the hetero-sheets, the Dirac characteristics of the group-IV layer and the semiconducting feature of the group-V one are well preserved, which causes a Schottky contact at the metal-semiconductor interface. The Schottky barriers are always p-type in the Si-based hetero-sheets, whereas in the C-based ones, the interfacial feature is sensitive to the interlayer distance. A tensile strain would induce a p-type-to-n-type Schottky barrier transition for the As-C hetero-sheet, while a compressive strain can cause a Schottky-to-ohmic contact transition in the Sb-C one. Moreover, due to the inhomogeneous charge redistribution, a sizeable band gap is opened at the Dirac point of the Sb-Si hetero-sheet, which could be linearly modulated by perpendicular strains around the equilibrium site. The versatile electronic structures and tunable interfacial properties enable the group-V-group-IV hetero-bilayer structures to have many potential applications in nano-devices and nano-electronics.
authors.affiliation: Department of Physics, Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Xiasha College Park, Hangzhou, Zhejiang 310018, People's Republic of China. wangyanli-04@tsinghua.org.cn.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Ding