Fig. 1. The real parts（a）and imaginary parts（b）of conductivity of BDS under different Fermi energy varying from 0.11 eV to 0.15 eV. The parameters of BDS are：g=40，εc=3，vF=106m/sT=300K，μ=3×104cm2V-1s-1（τ=4.5×10-13s）

Fig. 2. Schematic designs of dual-tunable triple-band MA model，（a）three-dimensional view，（b）two-dimensional top view，（c）two-dimensional side view

Fig. 3. Equivalent circuit model of proposed triple-band absorber

Fig. 4. Calculated (a) reflectance, transmittance, and absorptance spectra of proposed dual-tunable triple-band absorber, (b)the absorption spectra of the numerical simulation and LC circuit model

Fig. 5. The absorptance for different lengths of the (a) rod A, (b) rod B, and (c) rod C

Fig. 6. The distributions of electric field intensity at frequencies of（a）peak I，（b）peak II and（c）peak III in the X-Y plane. The distributions of electric field intensity at frequencies of（d）peak I，（e）peak II and（f）peak III in the Y-Z plane

Fig. 7. The change laws of absorption spectra under different Fermi energies for the VO₂ conductivity of 100 000 S/m

Fig. 8. Calculated (a) transmission, (b) reflection, (c) absorption spectra of the proposed triple-band MA at various VO₂ conductivities when the Fermi energy of BDS is 0.13 eV

Fig. 9. The variations of the absorption spectra of the three-band absorber with the thickness of BDS、SiO₂ and VO₂ layers