title: Hybrid graphene and graphitic carbon nitride nanocomposite: gap opening, electron-hole puddle, interfacial charge transfer, and enhanced visible light response.
abstract: Opening up a band gap and finding a suitable substrate material are two big challenges for building graphene-based nanodevices. Using state-of-the-art hybrid density functional theory incorporating long-range dispersion corrections, we investigate the interface between optically active graphitic carbon nitride (g-C(3)N(4)) and electronically active graphene. We find an inhomogeneous planar substrate (g-C(3)N(4)) promotes electron-rich and hole-rich regions, i.e., forming a well-defined electron-hole puddle, on the supported graphene layer. The composite displays significant charge transfer from graphene to the g-C(3)N(4) substrate, which alters the electronic properties of both components. In particular, the strong electronic coupling at the graphene/g-C(3)N(4) interface opens a 70 meV gap in g-C(3)N(4)-supported graphene, a feature that can potentially allow overcoming the graphene's band gap hurdle in constructing field effect transistors. Additionally, the 2-D planar structure of g-C(3)N(4) is free of dangling bonds, providing an ideal substrate for graphene to sit on. Furthermore, when compared to a pure g-C(3)N(4) monolayer, the hybrid graphene/g-C(3)N(4) complex displays an enhanced optical absorption in the visible region, a promising feature for novel photovoltaic and photocatalytic applications.
authors.affiliation: Centre for Computational Molecular Science, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Queensland 4072, Brisbane, Australia. a.du@uq.edu.au
authors.forename: Aijun
authors.initials: A
authors.lastname: Du
authors.forename: Stefano
authors.initials: S
authors.lastname: Sanvito
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Dawei
authors.initials: D
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiao
authors.forename: Ting
authors.initials: T
authors.lastname: Liao
authors.forename: Qiao
authors.initials: Q
authors.lastname: Sun
authors.forename: Yun Hau
authors.initials: YH
authors.lastname: Ng
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Zhu
authors.forename: Rose
authors.initials: R
authors.lastname: Amal
authors.forename: Sean C
authors.initials: SC
authors.lastname: Smith
mesh_terms: D004583:Electrons; D006108:Graphite / Q000737:chemistry*; D008027:Light; D053761:Nanocomposites / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*
chemical_list: D009570:Nitriles; C011206:cyanogen; D006108:Graphite