title: Theoretical two-atom thick semiconducting carbon sheet.
abstract: A two-dimensional carbon allotrope, H-net, is proposed using first principle calculations. H-net incorporates C4 distorted squares, C6 hexagons, and C8 octagons. Unlike previously reported planar graphene and other theoretical carbon sheets, H-net is a two-atom thick polymorph with identical C6 + C4 + C6 components cross-facing and covalently buckled to feature a handshake-like model. The feasibility of H-net is evident from its dynamic stability as confirmed by phonon-mode analysis and its lower total energy. H-net is energetically more favorable than synthesized graphdiyne and theoretical graphyne, BPC, S-graphene, polycyclic net, α-squarographite, and lithographite. We explored a possible route for the synthesis of H-net from graphene nanoribbons. Electronic band structure calculations indicated that H-net is a semiconductor with an indirect band gap of 2.11 eV, whereas graphene and many other two-dimensional carbon sheets are metallic. We also explored the electronic structure of one-dimensional nanoribbons derived from H-net. The narrowest H-net nanoribbon showed metallic behavior, whereas the other nanoribbons are semiconductors with band gaps that increase as the nanoribbons widen. H-net and its tailored nanoribbons are expected to possess more electronic properties than graphene because of their exceptional crystal structure and different energy band gaps.
authors: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China. hjl@ysu.edu.cn.
authors: Meng
authors: M
authors: Hu
authors: Yu
authors: Y
authors: Shu
authors: Lin
authors: L
authors: Cui
authors: Bo
authors: B
authors: Xu
authors: Dongli
authors: D
authors: Yu
authors: Julong
authors: J
authors: He