Two-dimensional phonon transport in graphene

Abstract

Properties of phonons -quanta of the crystal lattice vibrations -in graphene have attracted strong attention of the physics and engineering communities. Acoustic phonons are the main heat carriers in graphene near room temperature while optical phonons are used for counting the number of atomic planes in Raman experiments with few-layer graphene. It was shown both theoretically and experimentally that transport properties of phonons, i.e. energy dispersion and scattering rates, are substantially different in the quasi two-dimensional system such as graphene compared to basal planes in graphite or three-dimensional bulk crystals. The unique nature of two-dimensional phonon transport translates to unusual heat conduction in graphene and related materials. In this review we outline different theoretical approaches developed for phonon transport in graphene, discuss contributions of the in-plane and cross-plane phonon modes and provide comparison with available experimental thermal conductivity data. Particular attention is given to analysis of recent theoretical results for the phonon thermal conductivity of graphene and few-layer graphene, and the effects of the strain, defects and isotopes on the phonon transport in these systems.

Generalized Two-Temperature Model for Coupled Phonons in Nanosized Graphene

“…Recent studies 9,23,[48][49][50] showed that the thermal conductivity of graphene increases logarithmically (~logL) with the size of sample, which is taken to fit MD results shown in Fig. 3.…”

Phonon and thermal properties of exfoliated TaSe2 thin films

“…The successful exfoliation of graphene [1] and discoveries of its unique electrical [2,3] and thermal [4][5][6][7] properties have motivated searches for other quasi two-dimensional materials with interesting properties, as well as techniques for their synthesis and characterization [8][9][10][11][12]. As a group, layered van der Waals materials [8] can be cleaved mechanically or exfoliated chemically by breaking the relatively weak bonding between the layers.…”

Specific heat of twisted bilayer graphene: Engineering phonons by atomic plane rotations

“…Theoretical investigations employed different models of the lattice vibrations, molecular dynamics simulations, density functional method and Boltzmann transport equation approach [13][14][19][20][21][22][23]. Recently the attention has been shifted to twisted few-layer graphene (T-FLG), which demonstrates intriguing electron [24][25][26][27] and phonon properties [28][29][30][31][32][33][34][35][36].…”

“…Here  is the phonon frequency, [19,32,39]. Therefore, a proper choice of the force constant matrices  is crucial for obtaining the correct phonon frequencies and for accurate calculation of phonon specific heat.…”