Letter | Published:

A near-field radiative heat transfer device


Recently, several reports have experimentally shown near-field radiative heat transfer (NFRHT) exceeding the far-field blackbody limit between planar surfaces1,2,3,4,5. However, owing to the difficulties associated with maintaining the nanosized gap required for measuring a near-field enhancement, these demonstrations have been limited to experiments that cannot be implemented in large-scale devices. This poses a bottleneck to the deployment of NFRHT concepts in practical applications. Here, we describe a device bridging laboratory-scale measurements and potential NFRHT engineering applications in energy conversion6,7 and thermal management8,9,10. We report a maximum NFRHT enhancement of approximately 28.5 over the blackbody limit with devices made of millimetre-sized doped Si surfaces separated by vacuum gap spacings down to approximately 110 nm. The devices use micropillars, separating the high-temperature emitter and low-temperature receiver, manufactured within micrometre-deep pits. These micropillars, which are about 4.5 to 45 times longer than the nanosize vacuum spacing at which radiation transfer takes place, minimize parasitic heat conduction without sacrificing the structural integrity of the device. The robustness of our devices enables gap spacing visualization by scanning electron microscopy (SEM) before performing NFRHT measurements.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

Code availability

The computer codes that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.


  1. 1.

    Song, B. et al. Radiative heat conductances between dielectric and metallic parallel plates with nanoscale gaps. Nat. Nanotechnol. 11, 509–514 (2016).

  2. 2.

    Watjen, J. I., Zhao, B. & Zhang, Z. M. Near-field radiative heat transfer between doped-Si parallel plates separated by a spacing down to 200 nm. Appl. Phys. Lett. 109, 203112 (2016).

  3. 3.

    Fiorino, A. et al. Giant enhancement in radiative heat transfer in sub-30 nm gaps of plane parallel surfaces. Nano Lett. 18, 3711–3715 (2018).

  4. 4.

    Ghashami, M. et al. Precision measurement of phonon-polaritonic near-field energy transfer between macroscale planar structures under large thermal gradients. Phys. Rev. Lett. 120, 175901 (2018).

  5. 5.

    Lim, M., Song, J., Lee, S. S. & Lee, B. J. Tailoring near-field thermal radiation between metallo-dielectric multilayers using coupled surface plasmon polaritons. Nat. Commun. 9, 4302 (2018).

  6. 6.

    DiMatteo, R. S. et al. Enhanced photogeneration of carriers in a semiconductor via coupling across a nonisothermal nanoscale vacuum gap. Appl. Phys. Lett. 79, 1894–1896 (2001).

  7. 7.

    Fiorino, A. et al. Nanogap near-field thermophotovoltaics. Nat. Nanotechnol. 13, 806–811 (2018).

  8. 8.

    Ito, K., Nishikawa, K., Miura, A., Toshiyoshi, H. & Iizuka, H. Dynamic modulation of radiative heat transfer beyond the blackbody limit. Nano Lett. 17, 4347–4353 (2017).

  9. 9.

    Elzouka, M. & Ndao, S. High temperature near-field nanothermomechanical rectification. Sci. Rep. 7, 44901 (2017).

  10. 10.

    Fiorino, A. et al. A thermal diode based on nanoscale thermal radiation. ACS Nano 12, 5774–5779 (2018).

  11. 11.

    Polder, D. & Van Hove, M. Theory of radiative heat transfer between closely spaced bodies. Phys. Rev. B 4, 3303–3314 (1971).

  12. 12.

    Ottens, R. S. et al. Near-field radiative heat transfer between macroscopic planar surfaces. Phys. Rev. Lett. 107, 014301 (2011).

  13. 13.

    Ijiro, T. & Yamada, N. Near-field radiative heat transfer between two parallel SiO2 plates with and without microcavities. Appl. Phys. Lett. 106, 23103 (2015).

  14. 14.

    Hu, L., Narayanaswamy, A., Chen, X. & Chen, G. Near-field thermal radiation between two closely spaced glass plates exceeding Planck’s blackbody radiation law. Appl. Phys. Lett. 92, 133106 (2008).

  15. 15.

    Lang, S. et al. Dynamic measurement of near-field radiative heat transfer. Sci. Rep. 7, 13916 (2017).

  16. 16.

    Ito, K., Miura, A., Iizuka, H. & Toshiyoshi, H. Parallel-plate submicron gap formed by micromachined low-density pillars for near-field radiative heat transfer. Appl. Phys. Lett. 106, 083504 (2015).

  17. 17.

    Yang, J. et al. Observing of the super-Planckian near-field thermal radiation between graphene sheets. Nat. Commun. 9, 4033 (2018).

  18. 18.

    Bernardi, M. P., Milovich, D. & Francoeur, M. Radiative heat transfer exceeding the blackbody limit between macroscale planar surfaces separated by a nanosize vacuum gap. Nat. Commun. 7, 12900 (2016).

  19. 19.

    St-Gelais, R., Guha, B., Zhu, L., Fan, S. & Lipson, M. Demonstration of strong near-field radiative heat transfer between integrated nanostructures. Nano Lett. 14, 6971–6975 (2014).

  20. 20.

    St-Gelais, R., Zhu, L., Fan, S. & Lipson, M. Near-field radiative heat transfer between parallel structures in the deep subwavelength regime. Nat. Nanotechnol. 11, 515–519 (2016).

  21. 21.

    Lim, M., Lee, S. S. & Lee, B. J. Near-field thermal radiation between doped silicon plates at nanoscale gaps. Phys. Rev. B 91, 195136 (2015).

  22. 22.

    Voicu, R. C., Al Zandi, M., Müller, R. & Wang, C. Nonlinear numerical analysis and experimental testing for an electrothermal SU-8 microgripper with reduced out-of-plane displacement. J. Phys. Conf. Ser. 922, 12006 (2017).

  23. 23.

    DiMatteo, R. et al. Micron-gap thermophotovoltaics (MTPV). AIP Conf. Proc. 738, 42–51 (2004).

  24. 24.

    Francoeur, M., Vaillon, R. & Mengüç, M. P. Thermal impacts on the performance of nanoscale-gap thermophotovoltaic power generators. IEEE Trans. Energy Convers. 26, 686–698 (2011).

  25. 25.

    Thompson, D. et al. Hundred-fold enhancement in far-field radiative heat transfer over the blackbody limit. Nature 561, 216–221 (2018).

  26. 26.

    Greffet, J. J., Bouchon, P., Brucoli, G. & Marquier, F. Light emission by nonequilibrium bodies: local Kirchhoff law. Phys. Rev. X 8, 021008 (2018).

  27. 27.

    Chung, S. & Park, S. Effects of temperature on mechanical properties of SU-8 photoresist material. J. Mech. Sci. Technol. 27, 2701–2707 (2013).

  28. 28.

    Rousseau, E., Laroche, M. & Greffet, J.-J. Radiative heat transfer at nanoscale: closed-form expression for silicon at different doping level. J. Quant. Spectrosc. Ra. 111, 1005–1014 (2010).

  29. 29.

    Basu, S., Lee, B. J. & Zhang, Z. M. Infrared radiative properties of heavily doped silicon at room temperature. J. Heat. Transf. 132, 23301 (2010).

  30. 30.

    Maier, S. A. Plasmonics: Fundamentals and Applications (Springer, 2007).

Download references


The authors acknowledge financial support from the National Science Foundation (grant no. CBET-1253577). This work was performed in part at the Utah Nanofab sponsored by the College of Engineering, Office of the Vice President for Research and the Utah Science Technology and Research (USTAR) initiative of the State of Utah. The authors appreciate the support of the staff and facilities that made this work possible. This work also made use of University of Utah shared facilities of the Micron Technology Foundation Inc. Microscopy Suite sponsored by the College of Engineering, Health Sciences Center, Office of Vice President for Research and the Utah Science Technology and Research (USTAR) initiative of the State of Utah.

Author information

This work was conceived by J.D. and M.F. Design, fabrication and testing of the device, as well as the associated numerical simulations, were performed by J.D. under the supervision of M.F. Calibration of the experimental system was done by J.D. and L.T. under the supervision of M.F. The manuscript was written by J.D. and M.F with comments provided by L.T.

Correspondence to Mathieu Francoeur.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information: Nature Nanotechnology thanks Raphael St-Gelais and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Fig. 1–9; Supplementary Sections 1–3

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark
Fig. 1: NFRHT device and measurement set-up.
Fig. 2: Gap- and temperature-dependent radiative heat flux and heat transfer coefficient.
Fig. 3: Analysis of NFRHT enhancement.