Journal: Nature Communications

Article Title: Radiative heat transfer exceeding the blackbody limit between macroscale planar surfaces separated by a nanosize vacuum gap

doi: 10.1038/ncomms12900

Figure Lengend Snippet: ( a ) Heat rate, Q , as a function of the temperature difference between the emitter and receiver, Δ T , for various separation gaps, d . In all cases, the temperature of the receiver, T r , 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 T r 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 Q back .

Article Snippet: It can also be seen that the bottom Si substrate has a nearly uniform temperature of 300 K. Validation of the coupled fluctuational electrodynamics-COMSOL Multiphysics model was performed by comparing numerical predictions against unprocessed experimental data measured when the device was in the open ( d =3,500±22 nm) and closed ( d =150±5 nm) positions.

Techniques:

Journal: Nature Communications

Article Title: Radiative heat transfer exceeding the blackbody limit between macroscale planar surfaces separated by a nanosize vacuum gap

doi: 10.1038/ncomms12900

Figure Lengend Snippet: ( a ) Heat rate, Q , as a function of the temperature difference between the emitter and receiver, Δ T , for various separation gaps, d . In all cases, the temperature of the receiver, T r , 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 T r 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 Q back .

Article Snippet: Theoretical curves of heat rate Q as a function of the temperature difference Δ T between the emitter and receiver for a specific separation gap d were calculated using a coupled fluctuational electrodynamics-COMSOL Multiphysics comprehensive model to account for radiation transfer in the emitter–receiver region Q e–r as well as the background heat transfer Q back .

Techniques: