Significant reduction of graphene thermal conductivity by phononic crystal structure

Abstract

We studied the thermal conductivity of graphene phononic crystal (GPnC), also named as graphene nanomesh, by molecular dynamics simulations. The dependences of thermal conductivity of GPnCs (κ GPnC ) on both length and temperature are investigated. It is found that the thermal conductivity of GPnCs is significantly lower than that of graphene (κ G ) and can be efficiently tuned by changing the porosity and period length.For example, the ratio κ GPnC / κ G can be changed from 0.1 to 0.01 when the porosity is changed from about 21% to 65%. The phonon participation ratio spectra reveal that more phonon modes are localized in GPnCs with larger porosity. Our results suggest that creating GPnCs is a valuable method to efficiently manipulate the thermal conductivity of graphene.

Generalized Two-Temperature Model for Coupled Phonons in Nanosized Graphene

“…In our simulations, the width of simulation cell is set as 5. is consistent with previous studies 35,36 .…”

Ultra-low thermal conductivity of two-dimensional phononic crystals in the incoherent regime

“…Based on phonon BTE, the in-plane thermal conductivity (κ = κ LA + 2κ TA ) of 2D Si PnCs can be derived as an integral, which is given by Eq. (10). The determination of all parameters, such as phonon dispersions and B U , Θ in Eq.…”

“…[1][2][3][4][5][6][7][8][9][10][11] Since different length scales are associated with phonons and electrons, thermal and electrical conductivity can be independently optimized in a periodic nanomesh of holey structure. Reproducible low-thermal conductivity, sufficient electrical properties and good mechanical strength make 2D Si PnCs as a promising candidate for thermoelectric applications, such as electrical power generation and onchip thermal management for solid state devices.…”

Atomistic simulations of phonon behaviors in isotopically doped graphene with Sierpinski carpet fractal structure

“…For the past few years, the major methods to tune the thermal conductivity (k) of graphene are introducing the defects or isotopic doping atoms [11], conducting superlattice structures [12], adding different strains [13] and building some specific structures [14][15][16]. Hu et al investigate the effects of the defects and isotopic doping atoms on the thermal conductivity of graphene using the molecular dynamics (MD) simulation [11].…”

“…The maximum reduction ratios of the thermal conductivity in zigzag GNR and armchair GNR are ∼60% and ∼40% by applying different strains, respectively. Moreover, conducting some specific structures is an effective approach to manipulate the thermal conductivity of the graphene monolayer [14][15][16][17]. Cui et al investigate the k of a novel graphene wrinkle structure using the MD method, which is dropped by 36% and 52% in the parallel and perpendicular directions at 300 K [14].…”