title: Quasi-freestanding epitaxial silicene on Ag(111) by oxygen intercalation.
abstract: Silicene is a monolayer allotrope of silicon atoms arranged in a honeycomb structure with massless Dirac fermion characteristics similar to graphene. It merits development of silicon-based multifunctional nanoelectronic and spintronic devices operated at room temperature because of strong spin-orbit coupling. Nevertheless, until now, silicene could only be epitaxially grown on conductive substrates. The strong silicene-substrate interaction may depress its superior electronic properties. We report a quasi-freestanding silicene layer that has been successfully obtained through oxidization of bilayer silicene on the Ag(111) surface. The oxygen atoms intercalate into the underlayer of silicene, resulting in isolation of the top layer of silicene from the substrate. In consequence, the top layer of silicene exhibits the signature of a 1 × 1 honeycomb lattice and hosts massless Dirac fermions because of much less interaction with the substrate. Furthermore, the oxidized silicon buffer layer is expected to serve as an ideal dielectric layer for electric gating in electronic devices. These findings are relevant for the future design and application of silicene-based nanoelectronic and spintronic devices.
authors.affiliation: Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2525, Australia.
authors.forename: Yi
authors.initials: Y
authors.lastname: Du
authors.affiliation: Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2525, Australia.
authors.forename: Jincheng
authors.initials: J
authors.lastname: Zhuang
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, P. R. China.
authors.forename: Jiaou
authors.identifier: 0000-0002-4686-1821
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2525, Australia.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China.
authors.forename: Hongsheng
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China.
authors.forename: Jijun
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2525, Australia.
authors.forename: Xun
authors.initials: X
authors.lastname: Xu
authors.affiliation: Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2525, Australia.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Feng
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Haidian District, Beijing 100080, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Chen
authors.affiliation: Institute of Physics, Chinese Academy of Sciences, Haidian District, Beijing 100080, China.
authors.forename: Kehui
authors.identifier: 0000-0002-7698-5673
authors.initials: K
authors.lastname: Wu
authors.affiliation: Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2525, Australia.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2525, Australia.
authors.forename: Shi Xue
authors.identifier: 0000-0003-3824-7693
authors.initials: SX
authors.lastname: Dou
mesh_terms: D004581:Electronics; D018625:Microscopy, Atomic Force; D016252:Microscopy, Scanning Tunneling; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D012834:Silver; D010100:Oxygen; D012825:Silicon
keywords: DFT; Silicene; angle-resolved photoemission spectroscopy; intercalation; quasi-free-standing; scanning tunneling microscopy