Edge‐disorder effects on electric transport in metallic graphene nanoribbons at finite temperature

Abstract

We theoretically study electric transport in edge-disordered armchair graphene nanoribbons (ED-AGNRs) using an extended Hückel model combined with the non-equilibrium Green's function formulation. We find that ED-AGNRs exhibit the Anderson localization even at the Fermi energy (i.e., charge neutral point) originating from broken chiral symmetry of the system. Moreover, the localization length increases with temperature at low-density edge disorder, whereas it is almost independent of temperature at high-density one.

Variation in characteristics of graphene nanoribbon field-effect transistors caused by edge disorder: Computational simulation of atomistic device

“…The effects of ED on graphene materials have been studied experimentally and theoretically. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Theoretical investigations showed that the electrical conductance of GNRs with ED decreases exponentially with their length. [19][20][21][22] Furthermore, Xu et al showed experimentally that the conductance decays exponentially even at room temperature.…”

“…[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Theoretical investigations showed that the electrical conductance of GNRs with ED decreases exponentially with their length. [19][20][21][22] Furthermore, Xu et al showed experimentally that the conductance decays exponentially even at room temperature. 23) Previously, we clarified theoretically that this non-ohmic behavior originates in Anderson localization caused by the ED.…”

Theoretical Design of Edge-Disordered Graphene Nanorribbon FETs

“…Here, g is the dimensionless conductance, which is defined by g＝G=G 0 , where G 0 is the conductance quantum. 15) (Fig. 4 Here, the origin of the energy (¥＝0 eV) is chosen to be the Fermi energy.…”

“…( 6 ), which is applicable for the energy regimes near the bottom of the conduction band and the top of the valence band. 15) ると，バンドエッジ付近(導電体のバンドボトムより…”

“…The central region is connected to semi-infinite pristine GNR leads without disorder. The hydrogen atoms for passivation are eliminated from the figure for simplicity 15).…”