Three-terminal semiconductor junction thermoelectric devices: improving performance

TL;DR

This paper proposes a three-terminal semiconductor thermoelectric device leveraging bosonic thermal terminals, demonstrating potential for higher efficiency through tailored boson distributions and strong electron-boson coupling, with a Bi2Te3/Si superlattice setup.

Contribution

It introduces a novel three-terminal thermoelectric device design where bosonic energy distributions influence performance, surpassing traditional two-terminal devices.

Findings

Enhanced figure of merit possible with narrow boson energy distribution.

Strong electron-boson coupling, such as with optical phonons, improves efficiency.

Proposed Bi2Te3/Si superlattice setup achieves high figure of merit.

Abstract

A three-terminal thermoelectric device based on a $p$-$i$-$n$ semiconductor junction is proposed, where the intrinsic region is mounted onto a, typically bosonic, thermal terminal. Remarkably, the figure of merit of the device is governed also by the energy distribution of the {\em bosons} participating in the transport processes, in addition to the electronic one. An enhanced figure of merit can be obtained when the relevant distribution is narrow and the electron-boson coupling is strong (such as for optical phonons). We study the conditions for which the figure of merit of the three-terminal junction can be greater than those of the usual thermoelectric devices made of the same material. A possible setup with a high figure of merit, based on Bi$_2$Te$_3$/Si superlattices, is proposed.