γ-Graphyne-1 band structure modeling and simulation

Abstract

γ-graphyne-1 as a two-Dimensional (2D) carbon allotrope possesses sp and sp2 hybridized carbon atoms and has intrinsic semiconducting properties. Nonmetallic and tunable bandgap properties of γ-graphyne-1 nanomaterial creates perfect opportunities for designing novel electronic devices so is entitled to an accurate investigation. In this research the geometrical and electronic properties of γ-graphyne-1 is investigated via Tight Binding (TB) approach. Furthermore, the detailed TB description of band gap and band structure of γ-graphyne-1 fitted to Density Functional Tight Binding (DFTB) results is provided. It is found that 1.34eV band gap of γ-graphyne-1 in TB calculations supports DFTB results by using hopping energy and bond length of graphene as references which is being reported by theoretical results. Theoretically hopping energy and bond length for a pair of carbon atoms in the graphene structure around −2.86eV and 1.421 Å have been reported respectively. Additionally, two linear and quadratic formulas are proposed to predict the hopping energy of bonds of γ-graphyne-1 which can be used in the future TB based research on graphyne family nanomaterials and 2D carbon allotropes.