Resonant thermal transport in semiconductor barrier structures

TL;DR

This paper investigates how semiconductor barrier structures like TSB and TDB can suppress phonon transport and exhibit resonant thermal effects, including phonon tunneling and Fabry-Perot resonances, affecting thermal conductance.

Contribution

It demonstrates the presence of resonant thermal transport phenomena in semiconductor barrier structures, combining phonon tunneling and Fabry-Perot resonances.

Findings

High-frequency phonons undergo resonant tunneling in TDB structures.

Fabry-Perot resonances cause oscillations in thermal conductance.

Thermal conductance can be modulated by barrier structures.

Abstract

I report that thermal single-barrier (TSB) and thermal double-barrier (TDB) structures (formed, for example, by inserting one or two regions of a few Ge monolayers in Si) provide both a suppression of the phonon transport as well as a resonant-thermal-transport effect. I show that high-frequency phonons can experience a traditional double-barrier resonant tunneling in the TDB structures while the formation of Fabry-Perot resonances (at lower frequencies) causes quantum oscillations in the temperature variation of both the TSB and TDB thermal conductances $\sigma_{\text{TSB}}$ and $\sigma_{\text{TDB}}$.