Near-field thermal radiation transfer between semiconductors based on thickness control and introduction of photonic crystals

Abstract

We numerically investigate the spectral control of near-field thermal radiation transfer using interband absorption in semiconductors and the band-folding effect in photonic crystals (PCs) for highly efficient thermophotovoltaics. We reveal that the near-field coupling between two semiconductors (Si and GaSb) realizes frequency-selective thermal radiation transfer concentrated above their bandgap energy when their thicknesses are optimized considering their absorption coefficient spectra. Moreover, we elucidate the role of PC structures in the near-field thermal radiation transfer and demonstrate that the band-folding effect in PCs can further increase both the radiation power and frequency selectivity of the near-field thermal radiation transfer.