Super-Planckian radiative heat transfer between macroscale metallic surfaces due to near-field and thin-film effects
Abstract
In this study, we demonstrate that the radiative heat transfer between metallic planar surfaces exceeds the blackbody limit by employing the near-field and thin-film effects over macroscale surfaces. Nanosized polystyrene particles were used to create a nanometer gap between aluminum thin films of different thicknesses from 80 nm to 13 nm coated on 5 × 5 mm2 silicon chips, while the vacuum gap spacing is fitted from the near-field measurement with bare silicon samples. The near-field radiative heat flux between 13-nm-thick Al thin films at 215 nm gap distance is measured to be 6.4 times over the blackbody limit and 420 times to the far-field radiative heat transfer between metallic surfaces under a temperature difference of 65 K with the receiver at room temperature. The experimental results are validated by theoretical calculation based on fluctuational electrodynamics, and the heat enhancement is explained by non-resonant electromagnetic coupling within the subwavelength vacuum gap and resonant coupling inside the nanometric Al thin film with s polarized waves. This work will facilitate the applications of near-field radiation in thermal power conversion, radiative refrigeration, and noncontact heat control where metallic materials are involved.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 14, 2020
- Source ID
- 10.1063/5.0008259
Entities
People
- Christian Messner
- Lee Lambert
- Linshuang Long
- Liping Wang
- Payam Sabbaghi
- Sydney Taylor
- Xiaoyan Ying
Organizations
- Air Force Office of Scientific Research
- Arizona State University
- National Science Foundation