Author(s)

Zichun Li, Jinhua Li, Ye Zhang, Yingjiao Zhai, Xueying Chu, Yu Zhang

Corresponding Author

Jinhua Li

ABSTRACT

We propose a design of a broadband absorber based on a multi-layer metamaterial nanostructure composed of a periodic array of silver-silica-silver (Ag-SiO2-Ag) cubes and a silver (Ag) bottom film. The proposed structure can achieve nearly perfect absorption with an average absorbance of 97% spanning a broad range from visible to near-infrared (i.e.,from 600 nm to 1300 nm), showing a 90% absorption bandwidth over 412 nm, and the peak absorption is up to 99.8%. The excitation of superior surface plasmon resonance combined with the resonance induced by the metal-insulator-metal Fabry-Perot (FP) cavity leads to this broadband perfect absorption. The polarization and angle insensitivity is demonstrated by analyzing the absorption performance with oblique incidences for both TE- and TM-polarized waves. In addition, we discuss the impact of various metal materials and geometry structure on absorption performance in detail. The proposed broadband metamaterial absorber shows a promising prospect in applications such as solar cell, infrared detection, and imaging. Moreover, the use of a thin titanium cap and an aluminum film instead of noble metals has the potential to reduce production cost in applications.

KEYWORDS

broadband absorber, multi-layer metamaterials, near-infrared