Fundamentals and applications of near-field radiative energy transfer

Abstract

This article reviews the recent advances in near-field radiative energy transfer, particularly in its fundamentals and applications. When the geometrical features of radiating objects or their separating distances fall into the sub-wavelength range, near-field phenomena such as photon tunneling and surface polaritons begin to play a key role in energy transfer. The resulting heat transfer rate can greatly exceed the blackbody radiation limit by several orders magnitude. This astonishing feature cannot be conveyed by the conventional theory of thermal radiation, generating strong demands in fundamental research that can address thermal radiation in the near field. Important breakthroughs of near-field thermal radiation are presented here, covering from the essential physics that will help better understand the basics of near-field thermal radiation to the most recent theoretical as well as experimental findings that will further promote the fundamental understanding. Applications of near-field thermal radiation in various fields are also discussed, including the radiative property manipulation, near-field thermophotovoltaics, nanoinstrumentation and nanomanufacturing, and thermal rectification.