Ultra-broadband metamaterial perfect solar absorber with polarization-independent and large incident angle-insensitive

Broadband metamaterial perfect absorbers have attracted a great attention to the people who study its use in solar energy harvesting. However, it is an extremely challenge to integrate such properties as ultra-broadband, perfect absorption, polarization-independent, angle-insensitive to a large incident angle and so on into a simple absorber structure. In this paper, we use FDTD to design a simple ultra-broadband metamaterial perfect absorber, consisting of x-cavity titanium nano-disk array based on a Silicon nitride-Titanium-Silicon nitride-Titanium four -layer structure. The optimized results indicate that the absorber broadband absorption spectra range from 400 nm to 2500 nm with 97.6% average absorption at normal incidence. The interactions among SPR, MR and CR lead to a high absorption. Moreover, the absorber is both polarization-independent and large incident angle -insensitive for both TE and TM-polarized waves. In addition, the absorber has an extremely high tolerance to fabrication errors, which is of great significance for practical production and application.

Automated summary

This paper presents the design and study of a broadband metamaterial perfect absorber, which exhibits high absorption efficiency over a wide wavelength range. The absorber is polarization-independent and angle-insensitive, making it suitable for solar energy harvesting applications.