Design of ultra-wideband high-absorptivity solar absorber based on MIM resonant structure

The invention discloses an ultra-wideband high-absorptivity solar absorber based on an MIM resonant structure, the absorber structure takes metal tungsten (W) as a substrate, a plurality of layers of stacked discs on the substrate are respectively composed of metal titanium (Ti), amorphous Ge2Sb2Te5 (A-GST) or gallium arsenide (GaAs), and a three-layer MIM continuous layer gap plasma strong resonator is formed. In the wavelength range of 0.3-2.5 [mu] m, the average absorption rate is 97.48%, and the solar spectrum weighted absorption efficiency is 98.02%; in the whole working wave band of 0.3-4 microns, the average absorption rate is 96.95%, and the solar spectrum weighted absorption efficiency is 97.54%. The bandwidth of which the absorption rate is greater than 95% is 2.37 [mu] m, and the bandwidth of which the absorption rate is greater than 90% is 3.57 [mu] m. Therefore, ultra-wide-band and efficient solar energy absorption is realized. Due to the symmetry of the structure, the structure has an excellent