Thermal Radiative Heat Transfer Between Closely Spaced Nanostructures

Thermal emission control with nanostructures has attracted considerable attention because of its potential applications in thermophotovoltaic (TPV) devices [1–3]. The optical-to-electrical conversion in a TPV system is driven by photons with energy higher than the electronic bandgap of the photovoltaic cell. A narrow-band emitter with emission spectrum slightly above the bandgap is ideal, which maximizes the conversion efficiency as well as minimizes the waste heat that deteriorates the performance of the cell. Specially designed nanostructures alters the band structure of photons in much the same way as the crystal lattice does on electrons inside semiconductors, thus changing the thermal emission spectrum. By employing nanostructure-enabled emission control, Lin, et al, projected an efficiency of 34% for TPV systems [2].