Thermal radiative properties of a photonic crystal structure sandwiched by SiC gratings

Spectral and directional control of thermal emission holds substantial importance in applications where heat transfer is predominantly by thermal radiation. In this work, we investigate the spectral and directional properties of thermal emission from a novel structure, which is constituted with a photonic crystal (PC) sandwiched by SiC gratings. Numerical results based on the RCWA algorithm reveal that greatly enhanced emissivity can be achieved in a broad frequency band and in a wide range of angle of emission. This promising emission feature is found to be caused by excitation of surface phonon polaritons (SPhPs), PC mode, magnetic polaritons (MPs) and Fabry-Pérot resonance from high order diffracted waves, as well as the coupling between different resonant modes. We show that the broad enhanced emissivity band can be manipulated by adjusting the dimensional parameters of the structure properly.

► We propose a novel structure made of a photonic crystal sandwiched by SiC gratings. ► High emissivity can be achieved in a broad spectral band and angle range. ► We explain the result by excitation of multiple excited modes and their coupling.