In this work, a novel solar absorber with wide angle tolerance and insensitivity to polarization is proposed. The upper layer of the absorber comprises two polygonal structures, which can achieve an absorption rate of 94.2% across a broad wavelength range of 2218 nm (584 nm - 2802 nm). The performance of the absorber is simulated and verified using the finite difference time domain (FDTD) method combined with impedance matching theory. Through examining the electromagnetic field distribution at absorption peaks, the physical mechanism is elucidated. Moreover, incorporating refractory metals and nonmetallic materials in its design enhances the stability of the absorber, making it suitable for various extreme environments. This indicates its potential applications in solar energy storage and solar thermal photovoltaic systems.

中文翻译：

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基于双多边形超材料结构的超宽带太阳能吸收器

在这项工作中，提出了一种具有宽角度公差和对偏振不敏感的新型太阳能吸收器。吸收体的上层由两个多边形结构组成，在2218 nm（584 nm - 2802 nm）的宽波长范围内可以实现94.2%的吸收率。采用时域有限差分(FDTD)方法结合阻抗匹配理论对吸波体的性能进行了仿真和验证。通过检查吸收峰处的电磁场分布，阐明了其物理机制。此外，在设计中加入难熔金属和非金属材料，增强了吸收器的稳定性，使其适用于各种极端环境。这表明其在太阳能存储和太阳能热光伏系统中的潜在应用。