Ultra-broadband metamaterial absorber based on all-metal nanostructures

Abstract

Abstract In this paper, we propose an ultra-broadband metamaterial absorber based on the connected cylindrical holes (CCHs). The designed structure can achieve more than 90% absorptivity under normal incidence, ranging from ultraviolet to near-infrared (i.e. from 300 nm to 1260 nm), and the peak absorption is up to 99.73%. The excitation of surface plasmon resonance combined with air-slots modes leads to this broadband absorption. For both the TE and TM polarizations, the polarization insensitivity and angle insensitivity are discussed. In order to clearly figure out the physical absorption mechanism, the distribution of electric and magnetic fields is analyzed. In addition, we also demonstrate that the nanostructures absorption performance can be turned by structural parameters. This ultra-broadband metamaterial absorber has application prospects in solar cells, infrared detection and conversion of photovolatics.