Thermal conductivity of semiconductor superlattices: Experimental study of interface scattering

TL;DR

This study measures the thermal conductivity of GaAs/AlAs superlattices with varying interface roughness, revealing smaller-than-expected variations consistent with theoretical models, using experimental differential 3w method.

Contribution

First experimental investigation of how interface roughness affects thermal conductivity in GaAs/AlAs superlattices at room temperature.

Findings

Thermal conductivity varies with interface roughness.

Measured values are smaller than theoretical predictions.

Results support existing models but suggest refinements are needed.

Abstract

We present thermal conductivity measurements performed in three short-period (GaAs)_9(AlAs)_5 superlattices. The samples were grown at different temperatures, leading to different small scale roughness and broadening of the interfaces. The cross-plane conductivity is measured with a differential 3w method, at room temperature. The order of magnitude of the overall thermal conductivity variation is consistent with existing theoretical models, although the actual variation is smaller than expected.