Modified series model for cross-plane thermal conductivity of short-period Si/Ge superlattices

Abstract

Superlattices have great application potentials in thermo-electric materials and solid laser techniques. Their complicated heat transport mechanisms due to size effects, multi-interfaces and mini-band are very important issues for the prediction of thermal conductivity. In this paper, the short-period Si/Ge superlattices are investigated by a modified series model based on the Debye-Callaway description. The Lambert Law is used to describe the phonon emission within hemisphere space. In addition, the phonon interface transmission coefficients obtained from the phonon wave packet simulation are incorporated into boundary condition of the model, which removes the fitting parameters in the model. Better agreement with experiment is obtained. The effects of temperature, wavelength-dependent phonon transmission, superlattice periods, as well as the thickness of Ge layer are considered in this paper. superlattices, thermal conductivity, Debye-Callaway model, LambertLaw PACS number(s): 63.20.Kr, 63.22.+m, 65.80.+n, 68.65.Cd Citation:Feng Y, Liang X G. Modified series model for cross-plane thermal conductivity of short-period Si/Ge superlattices.

Anisotropic thermal conductivity of AlGaN/GaN superlattices

“…In order to get over those lacks, one can model thermal conductivity of superlattices using molecular dynamics [42,43], Green's function [44] or Boltzmann transport equation [32,45,46]. But despite mentioned disadvantages, Callaway model still can provide a rather good estimation of thermal conductivity [25,47,48].…”

Cross-plane thermal conductivity of GaN/AlN superlattices

“…Due to a) Authors to whom correspondence should be addressed: anna.spindlberger@jku.at and alberta.bonanni@jku.at the anisotropy of the thermal conductivity tensor, the inplane component κ of the thermal conductivity is expected to exhibit a different heat conduction than the cross-plane one 37 . The interface resistance affects the interface crossing of phonons and leads to a quenching of the thermal conductivity, as reported for Ge/Si superlattices [38][39][40] and for up to eight pairs of AlN/GaN multilayers 41 .…”

Calculation of Thermal Conductivity of AlGaN/GaN Superlattices

“…Such a small difference shows that even though calculation of thermal conductivity with Callaway model involves the use of number of fitting parameters, although the TBC may be rather approximated than calculated and though there can be some differences in the calculated values of thermal conductivity, it still can be used for preliminary or qualitative analysis, as it was done, for example, not only in our previous work, but also in refs. [17,23,44].…”