Thermodynamics and energy conversion of near-field thermal radiation: maximum work and efficiency bounds

TL;DR

This paper investigates the theoretical limits of converting near-field thermal radiation into work, focusing on surface phonon-polaritons, and derives bounds on maximum work and efficiency.

Contribution

It provides a new analysis of the maximum extractable work and efficiency bounds for near-field thermal radiation involving surface phonon-polaritons.

Findings

Maximum work flux is determined considering dominant surface modes.

An upper bound for the first law efficiency is established.

Surface phonon-polaritons play a key role in energy conversion limits.

Abstract

We analyse the process of conversion of near-field thermal radiation into usable work by considering the radiation emitted between two planar sources supporting surface phonon-polaritons. The maximum work flux that can be extracted from the radiation is obtained taking into account that the spectral flux of modes is mainly dominated by these surface modes. The thermodynamic efficiencies are discussed and an upper bound for the first law efficiency is obtained for this process.