Upper limits to near-field radiative heat transfer: Generalizing the blackbody concept

Owen D. Miller, Alejandro W. Rodriguez, Steven G. Johnson

Research output: Chapter in Book/Report/Conference proceedingConference contribution


For 75 years it has been known that radiative heat transfer can exceed far-field blackbody rates when two bodies are separated by less than a thermal wavelength. Yet an open question has remained: what is the maximum achievable radiative transfer rate? Here we describe basic energy-conservation principles that answer this question, yielding upper bounds that depend on the temperatures, material susceptibilities, and separation distance, but which encompass all geometries. The simple structures studied to date fall far short of the bounds, offering the possibility for significant future enhancement, with ramifications for experimental studies as well as thermophotovoltaic applications.

Original languageEnglish (US)
Title of host publicationActive Photonic Materials VIII
EditorsGanapathi S. Subramania, Stavroula Foteinopoulou
ISBN (Electronic)9781510602311
StatePublished - 2016
EventActive Photonic Materials VIII - San Diego, United States
Duration: Aug 28 2016Sep 1 2016

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherActive Photonic Materials VIII
Country/TerritoryUnited States
CitySan Diego

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


  • Blackbody
  • Radiative heat transfer
  • Thermophotovoltaics


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