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论文类型： 期刊论文

发表时间： 2016-07-01

发表刊物： SCIENCE ADVANCES

收录刊物： SCIE、EI、PubMed、Scopus

卷号： 2

期号： 7

页面范围： e1600067

ISSN号： 2375-2548

关键字： DFT,Silicene,angle-resolved photoemission spectroscopy,intercalation,quasi-free-standing,scanning tunneling microscopy

摘要： 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 spin-tronic 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 x 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