Theoretical Predictions of Size-Dependent Carrier Mobility and Polarity in Graphene

Abstract

First-principles density functional theory coupled with deformation potential calculations indicate a strong width-dependent carrier mobility: for an armchair graphene ribbon whose width (i.e., number of carbons along the edge) is N = 3k, the room-temperature electron mobility is calculated to be approximately 10(6) cm(2) V(-1) s(-1) and the hole mobility approximately 10(4) cm(2) V(-1) s(-1), while for N = 3k + 1 or 3k + 2, the hole mobility is calculated to be 4-8 x 10(5) cm(2) V(-1) s(-1) and the electron mobility approximately 10(4) cm(2) V(-1) s(-1). Such alternating behavior is absent in zigzag-type graphene.

Intrinsic Charge Transport in Stanene: Roles of Bucklings and Electron–Phonon Couplings

“…D LA can also be obtained by simulating lattice dilation of the unit cell and by measuring the change of Fermi level with respect to strains ( Figure S2, Supporting Information). [21,22] along zigzag and armchair directions exhibit almost the same values (5.14 and 5.0 eV, respectively), which is also in agreement with previous theoretical results. [24] Stanene also shows nearly the same D LA values along zigzag and armchair directions, but about one order of magnitude smaller compared to graphene.…”

“…The intrinsic room-temperature mobility of stanene (2-3 × 10 3 cm 2 V −1 s −1 ) is two orders of magnitude lower that of graphene (2 × 10 5 cm 2 V −1 s −1 ). [21,24,25] It is noted that the intrinsic mobility of stanene is smaller compared to graphene, although the weaker el-ph couplings in stanene favor high carrier mobility. However, this is not obscure because the phonon frequency of stanene is one order of magnitude lower than that of graphene.…”

Theoretical investigation of the electronic structures and carrier transport of hybrid graphene and boron nitride nanostructure

“…In this work, we present an investigation on the electronic structures and carrier transport properties of one dimensional hybrid graphene and h-BN nanostructure by using first-principles calculations and an analytic expression of charge carrier mobility formulated by Bardeen and Shockley based on the deformation potential theory. [16][17][18][19][20] The electronic properties of hybrid C-BN nanostructures are compared with individual component of pristine armchair graphene nanoribbon (a-GNR) and armchair Boron Nitride nanoribbon (a-BNNR). In the presence of the hybridization bond formed at the interface with a-BNNR, the electronic structures of hybridized graphene nanoribbon, like band gap, work function, electron and hole mobility show typical family behaviors, but with minor difference from pristine armchair graphene nanoribbon due to the quantum confinement effect.…”

“…Under the effective mass approximation and the longitudinal acoustic phonon scattering mechanism considered here, the charge carrier mobility in deformation potential theory for one dimensional system read as an analytical expression [16][17][18] …”

“…This method has been applied to other one-dimensional materials. [16][17][18][19] The required parameters, E 1 , m* and C, in Eq. (1) are completely parameterized by firstprinciples calculations.…”