Surface decorated silicon nanowires: a route to high-ZT thermoelectrics

TL;DR

This paper proposes using surface decorated silicon nanowires, such as nanotrees and alkyl functionalization, to significantly enhance thermoelectric efficiency by reducing phonon conductance while maintaining electronic conductance.

Contribution

It introduces a novel approach of surface decoration on silicon nanowires to improve thermoelectric performance, supported by atomistic calculations.

Findings

Phonon conductance is significantly reduced in decorated SiNWs.

Surface decoration outperforms surface disorder in ultra-thin wires.

High thermoelectric figure of merit (ZT) achieved in proposed structures.

Abstract

Based on atomistic calculations of electron and phonon transport, we propose to use surface decorated Silicon nanowires (SiNWs) for thermoelectric applications. Two examples of surface decorations are studied to illustrate the underlying deas: Nanotrees and alkyl functionalized SiNWs. For both systems we find, (i) that the phonon conductance is significantly reduced compared to the electronic conductance leading to high thermoelectric figure of merit, $ZT$, and (ii) for ultra-thin wires surface decoration leads to significantly better performance than surface disorder.