Loading...

Manipulation of structural, electronic and transport properties of hydrogen-passivated graphene atomic sheet through vacancy defects: First-principles numerical simulations based on density-functional-theory along with tight-binding approximation

Sattar, A ; Sharif University of Technology | 2019

545 Viewed
  1. Type of Document: Article
  2. DOI: 10.1088/2053-1591/ab2426
  3. Publisher: Institute of Physics Publishing , 2019
  4. Abstract:
  5. Using the first-principles procedure of density-functional-theory within tight-binding approximation and nonequilibrium Green's function formalism, this paper reports on the impact of vacancy defects on the structural, electronic and transport properties of hydrogen-passivated graphene atomic sheet. After the introduction of vacancy defects in graphene atomic sheet passivated with hydrogen atoms, apart from increase in band gap, a suppression is noted in the intensity of transmission channels and density of states arising from the long array deformations of the graphene sheet and a corresponding shift of the Fermi level. This in turn decreases the conductance of the defected graphene atomic sheet. In case of slow-ion bombardment method, the conductance of the sheet decreases slowly and its value of the order 10-6 S before vanishing the percolation drops to the order 10-10 as the percolation of the sheet is destroyed. But in case of fast bombardment the conductance of the sheet shows a linear drop before vanishing of the percolation of the sheet, and its value of the order 10-6 S before vanishing the percolation drops to the order 10-10 as the percolation of the sheet is destroyed. Furthermore, it is found that the atomic vacancy defects effectively terminate the original smooth sp2-hybrid network of 2D graphene atomic sheet that leads to modify its electronic and transport properties, especially a decrease in its electrical conductance. Interestingly, transmission spectrum of graphene atomic wire with large vacancy defects of 143 attains identical shape to that of a molecular benzene ring. © 2019 IOP Publishing Ltd
  6. Keywords:
  7. Density-functional-theory ; Nonequilibrium green function ; Percolation threshold ; Tight-binding ; Transmission coefficient ; Atoms ; Defects ; Drops ; Energy gap ; Graphene ; Hydrogen ; Ion bombardment ; Passivation ; Solvents ; Transport properties ; First-principles simulations ; Non-equilibrium green functions ; Percolation thresholds ; Tight binding ; Transmission coefficients ; Vacancy Defects ; Density functional theory
  8. Source: Materials Research Express ; Volume 6, Issue 8 , 2019 ; 20531591 (ISSN)
  9. URL: https://iopscience.iop.org/article/10.1088/2053-1591/ab2426