Fig. 1. Structure of 4H-SiC-based metasurface resonator. (a) Schematic of working model; (b) schematic of numerical simulation parameters, default array (or grating) height h₁=1 μm, perimeter (or width) D=1.35 μm, and substrate height h₂=0.5 μm

Fig. 2. 4H-SiC dielectric function measured by ellipsometric experiments. (a) Anisotropic dielectric function and comparison with Ref. [27]; (b) temperature-dependent real part of normal dielectric function ε_x; (c) temperature-dependent imaginary part of normal dielectric function ε_x

Fig. 3. Numerical calculation results on the period dependence of the emissivity. (a) Numerical simulation results of emissivity against experiment results^[18] and the simulated transmissivity; (b) emissivity of grating structure with period P=6.6 μm at different angles; (c) emissivity of array structure with period P=3.0 μm at different angles; (d) emissivity-incidence angle dispersion relation for the grating structure with period P=6.6 μm; (e) emissivity-incidence angle dispersion relation for the array structure with period P=3.0 μm

Fig. 4. Period-dependent calculation results of emissivity of the resonant structure. (a) Emissivity of period in the range of 3 μm and 4.9 μm; (b) emissivity of period in the range of 5.1 μm and 7.5 μm

Fig. 5. Normalized absorption energy distribution of the resonant structures. (a) LSPhPs emission mode at period P=3.5 μm; (b) LSPhPs emission mode at period P=5.3 μm; (c) LSPhPs emission mode at period P=6.5 μm; (d) ZFLO emission mode at period P=3.5 μm; (e) ZFLO emission mode at period P=5.3 μm; (f) ZFLO emission mode at period P=6.5 μm

Fig. 6. Emissivity-periodic dispersion relations at θ=40°. (a) Period dependence of spectral selectivity of emissivity; period dependence of spatial coherence of emissivity for (b) ZFLO mode, (c) LSPhPs mode, and (d) SPhPs mode

Fig. 7. Emissivity-incidence angle dispersion relations for resonant structures at P=6.6 μm and T=300 K. (a) Incidence angle dependence of spectral selectivity of emissivity^[28]; (b) spatial coherence of emissivity at different temperatures for the region B ; (c) spatial coherence of emissivity at different temperatures for the region C

Fig. 8. Emissivity performance of the resonant structure. (a) Period dependence of Q-factor at θ=40° and T=300 K; (b) incidence angle dependence of Q-factor at different temperatures with period P=6.6 μm