Thermal Interface Conductance Between Aluminum and Silicon by Molecular Dynamics Simulations

Abstract

The thermal interface conductance between Al and Si was simulated by a non-equilibrium molecular dynamics method. In the simulations, the coupling between electrons and phonons in Al are considered by using a stochastic force. The results show the size dependence of the interface thermal conductance and the effect of electron-phonon coupling on the interface thermal conductance. To understand the mechanism of interface resistance, the vibration power spectra are calculated. We find that the atomic level disorder near the interface is an important aspect of interfacial phonon transport, which leads to a modification of the phonon states near the interface.There, the vibrational spectrum near the interface greatly differs from the bulk. This change in the vibrational spectrum affects the results predicted by AMM and DMM theories and indicates new physics is involved with phonon transport across interfaces.

Phonon transmission at crystalline-amorphous interfaces studied using mode-resolved atomistic Green's functions

“…The most widely used simplified models for phonon transmission at an interface, the acoustic mismatch model (AMM) in the long wavelength limit [5] and the diffuse mismatch model (DMM) in the short wavelength limit [3], fail to explain many experimental observations and cannot account for the atomic structure of the interface [5]. Molecular dynamics (MD) simulations allow the overall value of the TBR to be computed [6][7][8][9][10][11], and recent works also provide frequency and mode-resolved information on interfacial heat flux [12][13][14][15][16]. The phonon wave-packet method, which is a moderesolved technique based on MD, can predict interface thermal conductance by tracking the transmitted and reflected energy including full anharmonicity of the interaction potentials, but * Corresponding author: aminnich@caltech.edu it is computationally expensive and difficult to apply to oblique angles [17,18].…”

Generalized Two-Temperature Model for Coupled Phonons in Nanosized Graphene

“…Liao et al have generalized TTM for the coupled phonon-magnon diffusion and predicted a magnon cooling effect 16 . Besides, some reports show TTM is implemented with molecular dynamics which is used to study electron-phonon coupled in metal/semiconductor systems 19,21,22 .…”

Phonon transmission across an interface between two crystals

“…Oscillations of this kind were predicted in the model of a one-dimensional chain in paper [11]. Probably, it is such oscillations that were found in numerical simulations in work [16].…”

“…We expand it and K αβ into the Fourier series and substitute the result in Eq. (16). The first, largest term of the series turns out to be:…”

“…In the most recent study [16], it has been found that atoms at the interface oscillate with a frequency exceeding the maximum possible frequency in a given crystal.…”