title: New quantum spin Hall insulator in two-dimensional MoS2 with periodically distributed pores.
abstract: MoS2, one of the transition metal dichalcogenides (TMDs), has gained a lot of attention due to its excellent semiconductor characteristics and potential applications. Here, based on density functional theory methods, we predict a novel 2D QSH insulator in the porous allotrope of monolayer MoS2 (g-MoS2), consisting of MoS2 squares and hexagons. g-MoS2 has a nontrivial gap as large as 109 meV, comparable with previously reported 1T'-MoS2 (80 meV) and so-MoS2 (25 meV). We demonstrate that the origin of the 2D QSH effect in g-MoS2 originates from the pure d-d band inversion, different from the conventional band inversion between s-p, p-p or d-p orbitals. The new polymorph greatly enriches the TMD family and its stabilities are confirmed using phonon spectrum analysis. In particular, its porous structure endows it with the potential for efficient gas separation and energy storage applications.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China. liming_wu@fjirsm.ac.cn and University of Chinese Academy of Sciences, Beijing 100039, People's Republic of China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Liu
authors.affiliation: Bremen Center for Computational Materials Science, University of Bremen, Am Falturm 1, 28359 Bremen, Germany. liujiang86@gmail.com and Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, 01187 Dresden, Germany.
authors.forename: Liujiang
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Bremen Center for Computational Materials Science, University of Bremen, Am Falturm 1, 28359 Bremen, Germany. liujiang86@gmail.com.
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenheim
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China. liming_wu@fjirsm.ac.cn.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Wu