title: Tunable and sizable band gap in silicene by surface adsorption.
abstract: Opening a sizable band gap without degrading its high carrier mobility is as vital for silicene as for graphene to its application as a high-performance field effect transistor (FET). Our density functional theory calculations predict that a band gap is opened in silicene by single-side adsorption of alkali atom as a result of sublattice or bond symmetry breaking. The band gap size is controllable by changing the adsorption coverage, with an impressive maximum band gap up to 0.50 eV. The ab initio quantum transport simulation of a bottom-gated FET based on a sodium-covered silicene reveals a transport gap, which is consistent with the band gap, and the resulting on/off current ratio is up to 10(8). Therefore, a way is paved for silicene as the channel of a high-performance FET.
authors.affiliation: State Key Laboratory of Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, P R China.
authors.forename: Ruge
authors.initials: R
authors.lastname: Quhe
authors.forename: Ruixiang
authors.initials: R
authors.lastname: Fei
authors.forename: Qihang
authors.initials: Q
authors.lastname: Liu
authors.forename: Jiaxin
authors.initials: J
authors.lastname: Zheng
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Chengyong
authors.initials: C
authors.lastname: Xu
authors.forename: Zeyuan
authors.initials: Z
authors.lastname: Ni
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Wang
authors.forename: Dapeng
authors.initials: D
authors.lastname: Yu
authors.forename: Zhengxiang
authors.initials: Z
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Lu