Design and analysis of a planar and multilayer metamaterial with the dual-functions of an ultra-broadband and high absorptivity absorber and a multi-wavelength resonator

This absorber exhibits a hierarchical structure, featuring layers of ZnO, Zr, yttria-stabilized zirconia (YSZ), Zr, YSZ, Al, YSZ and Al from top to bottom. Simulation analyses were conducted using COMSOL Multiphysics (R) simulation software (version 6.1). The primary innovation of this multilayer metamaterial lies in its entirely planar configuration, enabling switchable functionality: one ultra-broadband with high absorptivity (facilitated by the ZnO layer) and three narrowband absorption peaks (achieved through the Al layer). The simulation results clearly demonstrate that when light was incident from the ZnO direction onto this designed structure, the investigated planar and multi-functional absorber exhibited excellent absorber characteristics. Over an ultra-wide broadband range from 395 to 2070nm, the average absorptivity reached an impressive 95.03%. When light was incident from the Al direction onto the investigated planar and dual-functional absorber, three narrowband absorption peaks were observed at wavelengths 355, 550 and 1200nm. The second innovation highlights the effectiveness of ZnO as an anti-reflection layer, elevating the absorptivity of the ultra-broadband absorber. The third innovation establishes that Al is the optimal metal choice. It is worth noting that while using no Al layer or substituting Al with other metals did not diminish the absorptivity of the ultra-broadband absorber, alternative metals might adversely affect the absorptivity of the multi-wavelength absorber.