Near-field thermodynamics and nanoscale energy harvesting

TL;DR

This paper investigates the thermodynamics of near-field thermal radiation between polar media, demonstrating significantly higher work flux potential at the nanoscale compared to blackbody radiation, with explicit formulas for materials supporting surface phonon polaritons.

Contribution

It provides a theoretical analysis of maximum work flux and efficiency bounds for near-field thermal radiation energy harvesting, including explicit expressions for polar materials.

Findings

Near-field radiation yields higher work flux than blackbody radiation.

Explicit formulas for work flux and efficiency bounds are derived for surface phonon polariton materials.

Nanoscale energy harvesting can be optimized using near-field effects.

Abstract

We study the thermodynamics of near-field thermal radiation between two identical polar media at different temperatures. As an application, we consider an idealized energy harvesting process from sources at near room temperature at the nanoscale. We compute the maximum work flux that can be extracted from the radiation in the near-field regime and compare it with the corresponding maximum work flux in the blackbody regime. This work flux is considerably higher in the near-field regime. For materials that support surface phonon polaritons, explicit expressions for the work flux and an upper bound for the efficiency as functions of the surface wave frequency are obtained.