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.
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The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.
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.
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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.
The authors declare no competing interests.
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 Fig. 1–9; Supplementary Sections 1–3