Super-Planckian Thermophotovoltaics Without Vacuum Gaps

Thermophotovoltaic (TPV) systems could be very attractive for energy efficiency, as they allow the harvesting of radiative waste heat as electricity. The authors describe an efficient TPV generator whose spectrum of radiative thermal power is frequency-selective and exceeds the Planckian limit. Their device does not require a vacuum gap between the hot and cold parts of the system, and can be handily realized with existing nanofabrication methods. Thus this work shows the way to efficient TPV generators that are quite practical for application.