In this paper, the design and analysis of an ultra-broadband solar absorber based on the combination of two TiN metasurface resonators are presented. The absorber comprises a periodic array of combined TiN disk-square ring resonators located on a stack of TiO₂/TiN films. The proposed absorber shows a high average absorption of 94% in the wavelength range of 250–3000 nm and provides a continuous bandwidth of 2200 nm (i.e., 250 nm to 2450 nm) for the absorption above 90%. The effects of geometrical parameters and the oblique incidences for both TE- and TM-polarized incident light on the absorption are discussed. Also, the impact of using other plasmonic metals instead of TiN is investigated. Simulation results obtained by the finite-difference time-domain (FDTD) method indicate a high absorption of about 80%, even for an oblique incidence up to 50° for both polarizations. Having outstanding properties like high absorption, ultra-wide bandwidth, independence to irradiance polarization, and insensitivity to radiation angle make the presented solar absorber a promising choice for various high-temperature applications like energy harvesting and emitting.

在本文中，提出了基于两个 TiN 超表面谐振器组合的超宽带太阳能吸收器的设计和分析。吸收器包括位于 TiO ₂堆栈上的组合 TiN 圆盘方形环形谐振器的周期性阵列/TiN 薄膜。所提出的吸收剂在 250-3000 nm 的波长范围内显示出 94% 的高平均吸收率，并为 90% 以上的吸收率提供 2200 nm（即 250 nm 至 2450 nm）的连续带宽。讨论了几何参数和 TE 和 TM 偏振入射光的斜入射对吸收的影响。此外，还研究了使用其他等离子体金属代替 TiN 的影响。通过有限差分时域 (FDTD) 方法获得的模拟结果表明，即使对于两种偏振的斜入射角高达 50°，也有大约 80% 的高吸收率。具有高吸收、超宽带宽、不受辐照偏振影响等突出特性，