MoS2, one of transition metal dichalcogenides (TMDs), has caused a lot of attentions for its excellent semiconductor characteristics and potential applications. Here, based on the density functional theory methods, we predict a novel 2D quantum spin hall (QSH) insulator in the porous allotrope of monolayer MoS2 (g-MoS2), consisting of MoS2 square and hexagon. The g-MoS2 has a nontrivial gap as large as 109 meV, comparable with previous reported 1T'-MoS2 (80 meV), so-MoS2 (25 meV). We demonstrate that the origin of 2D QSH effect in g-MoS2 originates from the pure d-d band interaction, different from conventional band inversion between s−p, p−p or d−p orbitals. Such new polymorph greatly enriches the TMDs family and its stabilities are confirmed by phonon spectrum analysis. In particular, porous structure also endows it potential application in efficient gas separation and energy storage.
@article{arxiv.1512.02854,
title = {New Quantum Spin Hall Insulator in Two-dimensional MoS$_2$ with Periodically Distributed Pores},
author = {Peng-Fei Liu and Liujiang Zhou and Thomas Frauenheim and Li-Ming Wu},
journal= {arXiv preprint arXiv:1512.02854},
year = {2016}
}