Figure 2: Gap- and temperature-dependent heat rate.
(a) Heat rate, Q, as a function of the temperature difference between the emitter and receiver, ΔT, for various separation gaps, d. In all cases, the temperature of the receiver, Tr, is fixed at 300 K. The symbols show unprocessed experimental data, while the coloured bands are numerical simulations obtained from the coupled fluctuational electrodynamics-COMSOL Multiphysics comprehensive model. The gap sizes d in the open and closed positions are known, with some small uncertainty, from the manufacturing of the device and the associated measured heat rates are in good agreement with numerical predictions. It was not possible to measure directly the intermediate gap sizes, such that they were estimated from the comprehensive heat transfer model. (b) Simulated temperature distribution in the device via the comprehensive model for an input heat rate Q of 0.92 W, a separation gap d of 150 nm and a fixed receiver temperature Tr of 300 K resulting in an emitter temperature of 420 K. Heat spreading outside the emitter portion of the device results in background heat transfer Qback.
