Computational Studies of two-dimensional graphene-like materials
Chih-Piao Chuu1*, Yongmao Cai1, Kuan-Hung Liu2, C. M. Wei1, M. Y. Chou1,2,3
1IAMS, Academia Sinica, Taipei, Taiwan
2Department of Physics, National Taiwan University, Taipei, Taiwan
3School of Physics, Georgia Institute of Technology, Atlanta, Georgia, United States of America
* presenting author:Chih-Piao Chuu,
Two-dimensional atomic thin layers are intriguing materials and building blocks for the development of micro-electronic devices. Due to the improved techniques in crystal growth, materials with few layers or a single layer showing quite different electronic properties compared to the bulk can be realized nowadays in laboratory. We discuss two systems in this talk, which are isostructural derivatives of graphene: hybrid h-BNC monolayer and the monolayer of silicene and germanene on graphene [1].

We have performed first-principles calculations for these two systems. In the former, we examine the phase stability, formation energy, band gap opening, and the modification in the electronic structure and Fermi velocity upon the introduction of h-BN segments into the graphene lattice. The electronic properties are also evaluated by considering the electron self-energy within the many-body perturbation theory in order to provide an accurate description of the quasiparticle spectra. The pattern of B-N domains in the dilute limit will be discussed in detail based on the geometric size and shape, symmetry consideration, co-doping concentration, formation energy, and interface effects. For the latter, we study the effect of substrate interaction on the physical properties of these systems. Of particular interest is the induced change in the electronic structure, the modification of the Fermi velocity, the gap opening, the charge doping from the substrate, and the stability of the combined system. The energetics of forming the 2D silicone structure on a substrate is carefully evaluated in comparison with possible three-dimensional cluster structures.

[1] Y. Cai, C.-P. Chuu, C. M. Wei, and M. Y. Chou, Phys. Rev. B 88, 245408 (2013).

Keywords: graphene, silicene, first-principles calculations