Fig. 1. Schematic diagram of single-layer BP structure.

Fig. 2. Conductivity dispersion curve for two-dimensional BP: (a) The real part of the conductivity; (b) the imaginary part of the conductivity.

Fig. 3. Schematic diagram of 2D BP-SiO₂ sandwich structure

Fig. 4. Absorptivity of a 2D BP-SiO₂ sandwich periodic structure with different thicknesses of the underlying SiO₂.

Fig. 5. Absorption rate difference of 2D BP-SiO₂ sandwich periodic structure in two directions of X and Y under different thicknesses of SiO₂.