Enhanced energy transport owing to nonlinear interface interaction

Abstract

It is generally expected that the interface coupling leads to the suppression of thermal transport through coupled nanostructures due to the additional interface phonon-phonon scattering. However, recent experiments demonstrated that the interface van der Waals interactions can significantly enhance the thermal transfer of bonding boron nanoribbons compared to a single freestanding nanoribbon. To obtain a more in-depth understanding on the important role of the nonlinear interface coupling in the heat transports, in the present paper, we explore the effect of nonlinearity in the interface interaction on the phonon transport by studying the coupled one-dimensional (1D) Frenkel-Kontorova lattices. It is found that the thermal conductivity increases with increasing interface nonlinear intensity for weak inter-chain nonlinearity. By developing the effective phonon theory of coupled systems, we calculate the dependence of heat conductivity on interfacial nonlinearity in weak inter-chain couplings regime which is qualitatively in good agreement with the result obtained from molecular dynamics simulations. Moreover, we demonstrate that, with increasing interface nonlinear intensity, the system dimensionless nonlinearity strength is reduced, which in turn gives rise to the enhancement of thermal conductivity. Our results pave the way for manipulating the energy transport through coupled nanostructures for future emerging applications.

Nanomechanical probing of the layer/substrate interface of an exfoliated InSe sheet on sapphire

“…Most of the studies performed on van der Waals heterostructures to date have been directed towards the measurement of the electron transport through the heterostructure or of the charge transfer at an interface 5 . However, the phonon transport through an interface plays an equally important role 6 7 as it defines the cooling rate and so governs the thermal properties of a multi-layer structure. Specifically, the balance of electron and phonon transport between nanolayers quantifies the efficiency, ZT , in thermoelectric devices 8 9 10 .…”

Anomalous interfacial temperature profile induced by phonon localization

“…Particularly, as characteristic lengths of materials approach the energy carriers mean free paths, the transport processes are no longer dominated by scattering inside the bulk materials, but are dominated instead by scattering at heterojunction interfaces. Recently, there have been extensive studies on interfacial thermal conduction through systems of atomic structures via analytical calculations [6][7][8][9][10] and non-equilibrium molecular dynamics (NEMD) simulations [11][12][13]. Meanwhile, experimental studies have shown that interfacial structures and bonding can have a marked effect on thermal transport [14][15][16][17][18].…”

Overcoming nanoscale friction barriers in transition metal dichalcogenides

“…[29][30][31][32] Finally, the method can be exploited to guide the deconvolution of vibrational spectra and to study the phonon-phonon coupling in a broad variety of applications. [33][34][35][36][37]…”