Thermal conductivity of InAs/GaSb superlattice

TL;DR

This study measures the cross-plane thermal conductivity of InAs/GaSb superlattices across a wide temperature range, revealing significant reductions compared to bulk material, with implications for thermoelectric and optoelectronic devices.

Contribution

It provides the first detailed measurement of thermal conductivity in InAs/GaSb superlattices from 13 K to 300 K and introduces a power-law model for non-linear thermal behavior.

Findings

Thermal conductivity is reduced by up to 2 orders of magnitude compared to bulk GaSb.

Low thermal conductivity (~1-8 W/m·K) suitable for thermoelectric applications.

A power-law model captures non-linear thermal conductivity behavior.

Abstract

The cross-plane thermal conductivity of a type II InAs/GaSb superlattice (T2SL) is measured from 13 K to 300 K using the 3{\omega} method. Thermal conductivity is reduced by up to 2 orders of magnitude relative to the GaSb bulk substrate. The low thermal conductivity of around 1-8 W/m\cdotK may serve as an advantage for thermoelectric applications at low temperatures, while presenting a challenge for T2SL quantum cascade lasers and high power light emitting diodes. We introduce a power-law approximation to model non-linearities in the thermal conductivity, resulting in increased or decreased peak temperature for negative or positive exponents, respectively.