Will molecules ever sit at the thermoelectric table?

TL;DR

This paper reviews the potential of molecular junctions for thermoelectric energy conversion, highlighting the gap between theoretical predictions and experimental demonstrations, and discusses necessary steps for technological viability.

Contribution

It provides a comprehensive review of the current state, challenges, and future steps needed to develop molecular junctions into practical thermoelectric devices.

Findings

Molecular junctions can act as sharp energy filters for electrons.

There is a significant gap between theoretical predictions and experimental results.

Key steps are identified to transition from fundamental research to practical applications.

Abstract

Molecular junctions comprise small molecules on the order of one or a few nanometers in length, chemically attached to two electrodes of metal or semiconductors. They have recently been identified as promising candidates for materials/devices for thermoelectric energy conversion. Molecules have the potential to act as sharp energy filters for electrical currents and could outperform other materials considered for thermoelectric energy conversion so far, thereby providing a wide-spread technological relevance thermoelectrics could not achieve to date. However, there is a clear gap between predictions and demonstrations in the literature studying thermoelectric molecular junctions. This opinionated review seeks to highlight necessary steps needed for this approach to transition from fundamental research into a viable technology. Some important conjectures, on which the study of molecular junctions is based, are reviewed.