Atomistic Band-Structure Computation for Investigating Coulomb Dephasing and Impurity Scattering Rates of Electrons in Graphene

Abstract

In this paper, by introducing a generalized quantum-kinetic model which is coupled self-consistently with Maxwell and Boltzmann transport equations, we elucidate the significance of using input from first-principles band-structure computations for an accurate description of ultra-fast dephasing and scattering dynamics of electrons in graphene. In particular, we start with the tight-binding model (TBM) for calculating band structures of solid covalent crystals based on localized Wannier orbital functions, where the employed hopping integrals in TBM have been parameterized for various covalent bonds. After that, the general TBM formalism has been applied to graphene to obtain both band structures and wave functions of electrons beyond the regime of effective low-energy theory. As a specific example, these calculated eigenvalues and eigen vectors have been further utilized to compute the Bloch-function form factors and intrinsic Coulomb diagonal-dephasing rates for induced optical coherence of electron-hole pairs in spectral and polarization functions, as well as the energy-relaxation time from extrinsic impurity scattering of electrons for non-equilibrium occupation in band transport.

Electronic, transport, magnetic, and optical properties of graphene nanoribbons and their optical sensing applications: A comprehensive review

“…The overlapping of nearest neighbor out-of-plane orbitals (π orbitals) gives rise to bonding and anti-bonding electronic states, which are formed below and above the Fermi level, respectively. [2,64,165] In spite of having high electron mobility and electrical conductivity, graphene cannot be used in typical electronic applications due to the lack of bandgap. It limits the application of graphene in electronic devices.…”

“…(b) The corresponding 3D plot of π band. Adopted from [64] band cross each other at the K and K 0 -points lying in the first BZ. The position of the Fermi level (at E ¼ 0) is shown by the dotted line in Figure 3a.…”

“…The overlapping of nearest neighbor out‐of‐plane orbitals ( orbitals) gives rise to bonding and anti‐bonding electronic states, which are formed below and above the Fermi level, respectively. [ 2,64,165 ]…”

“…It is observed that, in comparison to pristine AGNRs, the unusual optical selection rules result due to the unusual transition channels associated with the nearly flat edge bands. [64] Moreover, the edge and surface functionalization of graphene nanoribbons can also modify the optical behavior of graphene nanoribbons. [65][66][67] Recently, it has been reported that the ZGNRs with the same size and functional groups have a narrower bandgap and absorption edge than the AGNR.…”

Impedance Spectroscopy of Encapsulated Single Graphene Layers

“…Single-layer graphene (SLG) is not only a promising candidate as an electrode material in electrochemical applications [ 12 ], but also exhibits transparency, superior combined mechanical stability and flexibility and gives rise to several fascinating charge transport phenomena. In zero-band gap graphene, metallic or ballistic charge transport has been reported [ 13 , 14 , 15 , 16 , 17 , 18 ], whereas variable-range hopping has been observed in semi-conducting graphene [ 19 ]. In its pure form, SLG is predicted to be a zero-band gap semiconductor, where the valence and conduction bands touch at the Dirac points in the dispersion relation of electron energy E vs. propagation wave vector k [ 20 , 21 ].…”