Fig. 2
From: Thermal radiation from subwavelength objects and the violation of Planck’s law
Super-Planckian far-field radiative heat transfer in SiN suspended pads. a SiN pads with lateral dimensions of 50 μm × 50 μm and thickness t separated by a gap d larger than the thermal wavelength λTh. b Computed ratio between the exact radiative heat conductance and the blackbody result for the system in panel a as a function of the pad thickness and at room temperature6. The different curves corresponding to the different values of the gap in the far-field regime (see legend). The inset shows the absolute value of the thermal conductance for a 20 μm gap. Panel a and b were adapted with permission from ref. 6. Copyright (2018) by the American Physical Society. c Nanofabricated experimental platform used to probe radiative heat transfer7. The receiver and emitter devices are SiN pads suspended by support beams from a substrate and feature embedded Pt resistance thermometers-heaters. The pads have lateral dimensions of 60 μm × 80 μm and varying thickness. d Measured radiative conductance in the setup of panel c at room temperature (black circles; left axis) for a 20 μm gap as a function of the pad thickness from about 11 μm to 270 nm. The black triangles (left axis) correspond to the computed blackbody result and the red circles (right axis) are the ratio of the measured to the simulated radiative conductance. Notice that the back-body limit is overcome by more than two orders of magnitude for the thinnest devices. Panel c and d were reprinted from ref. 7 with permission. Copyright (2019) from Springer Nature
