Radiative heat transfer between objects separated by nanometer-sized gaps is of considerable interest due to its promise for both non-contact modulation of heat transfer and for thermophotovoltaic energy conversion. Although radiative heat transfer at macroscopic distances is well understood, radiative heat transfer at the nanoscale remains largely unexplored. In this talk, I will describe ongoing efforts in our group to experimentally elucidate nanoscale heat radiation. Specifically, I will present our recent experimental work where we have addressed the following questions: 1) Can existing theories accurately describe radiative heat transfer in single nanometer sized gaps1? 2) What is the role of film thickness on nanoscale radiation2? and 3) Can radiative thermal conductances that are orders of magnitude larger than those between blackbodies be achieved3? In order to address these questions we have developed a variety of instrumentation including novel nanopositioning platforms and microdevices, which will also be described. Finally, I will briefly outline how these advances can be leveraged for future investigations of both nanoscale radiative heat transport and thermophotovoltaic energy conversion.

References:

[1] K. Kim, B. Song, V. Fernández-Hurtado, W. Lee, W. Jeong, L. Cui, D. Thompson, J. Feist, M. T. H. Reid, F. J. García-Vidal, J. C. Cuevas, E. Meyhofer and P. Reddy, “Radiative heat transfer in the extreme near-field”, Nature 528, 387-391 (2015).

[2] B. Song, Y. Ganjeh, S. Sadat, D. Thompson, A. Fiorino, V. Fernández-Hurtado, J. Feist, F. J. García-Vidal, J. C. Cuevas, P. Reddy and E. Meyhofer, “Enhancement of near-field radiative heat transfer using polar dielectric thin films“, Nature Nanotechnology 10, 253-258 (2015).

[3] B. Song, D. Thompson, A. Fiorino, Y. Ganjeh, P. Reddy and E. Meyhofer, “Radiative heat conductance between dielectric and metallic parallel plates at nanoscale gaps”, Nature Nanotechnology 11, 509-514 (2016).