Fig. 1. Equivalent model of one-dimensional photonic crystal

Fig. 2. Energy band structures for photonic crystals with three different multilayer films. (a) n_a=n_b; (b) n_a>n_b; (c) n_a≫n_b

Fig. 3. Refractive indexes and extinction coefficients of Si, SiO₂ and ZnO thin films. (a) Refractive index; (b) extinction coefficient

Fig. 4. Energy band curve of Si/ZnO photonic crystal. (a) HL1 structure; (b) HL2 structure

Fig. 5. Simulated reflectance spectra of photonic crystals with different layers

Fig. 6. Simulated reflectance spectra for HL1 and HL2. (a) HL1; (b) HL2

Fig. 7. Structural diagram of 13-layer photonic crystal and reflection spectra of different photonic crystals. (a) Structural diagram of 13-layer photonic crystal; (b) reflection spectra of Si/SiO₂ and Si/ZnO photonic crystals

Fig. 8. Simulated reflectance spectrum of photonic crystal at incidence angle range of 0°-60°

Fig. 9. Electric field intensity distribution of incident electromagnetic wave. (a) Center wavelength of 3.8 μm; (b) center wavelength of 10.4 μm; (c) center wavelength of 6.5 μm

Fig. 10. Comparison of measured and calculated infrared reflectances