ABSTRACT
Carbon atoms could form 3D diamond, 3D graphites, two-dimensional layered graphenes, one-dimensional (1D) graphene nanoribbons, 1D carbon nanotubes, 0D carbon toroids, 0D C60-related fullerenes, and 0D carbon onions. The rich geometric structures and electronic properties of the Si-adsorbed and Si-doped graphene systems are thoroughly explored using the density functional theory implemented by the Vienna ab initio simulation package. A theoretical framework, which is developed within the first-principles calculations, is utilized to fully explore the essential properties of the Si-adsorbed and Si-substituted graphene systems. Monolayer graphene has a planar geometry with a honeycomb lattice, being different from the buckled structures in layered silicene, germanene, and tinene. Transmission electron microscopy is one of the most powerful pieces of equipment in characterizing the nanoscaled geometric structures, especially for the side-view properties. A high-energy electron beam, with a very narrow distribution width, can penetrate an ultrathin sample to generate a diffraction spectrum by the interactions of charge carriers and condensed-matter systems.
