Nanogap near-field thermophotovoltaics

Anthony Fiorino, Linxiao Zhu, Dakotah Thompson, Rohith Mittapally, Pramod Reddy, Edgar Meyhofer

Research output: Contribution to journalLetterpeer-review

250 Scopus citations


Conversion of heat to electricity via solid-state devices is of great interest and has led to intense research of thermoelectric materials1,2. Alternative approaches for solid-state heat-to-electricity conversion include thermophotovoltaic (TPV) systems where photons from a hot emitter traverse a vacuum gap and are absorbed by a photovoltaic (PV) cell to generate electrical power. In principle, such systems may also achieve higher efficiencies and offer more versatility in use. However, the typical temperature of the hot emitter remains too low (<1,000 K) to achieve a sufficient photon flux to the PV cell, limiting practical applications. Theoretical proposals3–12 suggest that near-field (NF) effects13–18 that arise in nanoscale gaps may be leveraged to increase the photon flux to the PV cell and significantly enhance the power output. Here, we describe functional NFTPV devices consisting of a microfabricated system and a custom-built nanopositioner and demonstrate an ~40-fold enhancement in the power output at nominally 60 nm gaps relative to the far field. We systematically characterize this enhancement over a range of gap sizes and emitter temperatures, and for PV cells with two different bandgap energies. We anticipate that this technology, once optimized, will be viable for waste heat recovery applications.

Original languageEnglish (US)
Pages (from-to)806-811
Number of pages6
JournalNature nanotechnology
Issue number9
StatePublished - Sep 1 2018

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • General Materials Science
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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