Design of an ultrabroadband infrared metamaterial absorber in the atmospheric transparent window

Abstract

In order to meet the demand for broadband absorbers in the infrared transparent window of the atmosphere, we designed an ultrabroadband metamaterial absorber (MA), which is composed of a germanium-zinc sulfide-chromium-zinc sulfide (Ge-ZnS-Cr-ZnS) disk periodic array and a chromium (Cr) bottom layer. In the infrared transparent window of the atmosphere, the average absorption of the MA is as high as 99.1%, and ultrabroadband near-perfect absorption is realized. Moreover, the absorber is polarization independent and insensitive to the angle of incidence. The ultrabroadband and high-absorption metamaterial absorber has broad application prospects in solar cells, photodetectors, thermophotovoltaics, and thermal emitters.