In this paper, a novel broadband plasmonic absorber based on cross-shaped titanium nitride (TiN) resonators in the ultraviolet, visible, and near-infrared regions is presented. The proposed perfect solar absorber consists of periodic arrays of cross-shaped TiN resonators located on a stack of ${{\rm SiO}_2}/{\rm TiN}$SiO2/TiN layers. By using the finite-difference time-domain method, the effects of variations of the thickness and radius of the elliptical metasurface resonators on the absorption are comprehensively investigated. The cross-shaped metamaterial absorber exhibits an averaged absorption of 90%, ranging from 200 to 3000 nm, and shows over 90% absorption from 200 to 2500 nm. Furthermore, the proposed absorber indicates absorption efficiency over 80% for an oblique incidence up to 50 deg for both TE- and TM-polarized light. These features make the proposed solar absorber usable in many solar-based applications, imaging, and thermal emitting.

中文翻译：

---

基于十字形TiN谐振器的超宽带超材料吸收器。

在本文中，提出了一种新型的宽带等离子体吸收器，该吸收器基于紫外，可见光和近红外区域中的十字形氮化钛（TiN）谐振器。提出的理想太阳能吸收器由位于$ {{\ rm SiO} _2} / {\ rm TiN} $ SiO2 / TiN层堆叠上的十字形TiN谐振器的周期性阵列组成。通过使用时域有限差分法，全面研究了椭圆形超表面谐振器的厚度和半径变化对吸收的影响。十字形超材料吸收体在200至3000 nm范围内显示90％的平均吸收率，在200至2500 nm处显示90％以上的吸收率。此外，对于TE和TM偏振光，倾斜入射角高达50度时，所提出的吸收体均显示超过80％的吸收效率。