Wu Dong, Liu Chang, Liu Yumin, Yu Li, Yu Zhongyuan, Chen Lei, Ma Rui, Ye Han
Opt Lett. 2017 Feb 1;42(3):450-453. doi: 10.1364/OL.42.000450.
We propose and numerically investigate a novel ultra-broadband solar absorber by applying iron in a 2D simple metamaterial structure. The proposed structure can achieve the perfect absorption above 95% covering the wavelength range from 400 to 1500 nm. The average absorption reaches 97.8% over this wavelength range. The broadband perfect absorption is caused by the excitation of localized surface plasmon resonance and propagating surface plasmon resonance. We first propose and demonstrate that the iron is obviously beneficial to achieve impedance matching between the metamaterial structure and the free space over an ultra-broad frequency band in the visible and near-infrared region, which play an extremely important role to generate an ultra-broadband perfect absorption. In order to further broaden the absorption band, we also demonstrate the perfect absorption exceeding 92% for the 400-2000 nm range by adding the number of metal-dielectric pairs and using both gold and iron simultaneously in the proposed structure. The average absorption of the improved absorber reaches 96.4% over the range of 400-2000 nm. The metamaterial absorbers using iron are very promising for many applications, which can greatly broaden the perfect absorption band in the solar spectrum and, meanwhile, can enormously reduce the cost in the actual production.
我们提出并通过在二维简单超材料结构中应用铁来对一种新型超宽带太阳能吸收器进行数值研究。所提出的结构能够在400至1500纳米的波长范围内实现高于95%的完美吸收。在此波长范围内平均吸收率达到97.8%。宽带完美吸收是由局域表面等离子体共振和传播表面等离子体共振的激发引起的。我们首先提出并证明，铁对于在可见光和近红外区域的超宽频带上实现超材料结构与自由空间之间的阻抗匹配明显有益，这对于产生超宽带完美吸收起着极其重要的作用。为了进一步拓宽吸收带，我们还通过在所提出的结构中增加金属 - 电介质对的数量并同时使用金和铁，证明了在400 - 2000纳米范围内完美吸收超过92%。改进后的吸收器在400 - 2000纳米范围内的平均吸收率达到96.4%。使用铁的超材料吸收器在许多应用中非常有前景，它可以极大地拓宽太阳光谱中的完美吸收带，同时在实际生产中可以大幅降低成本。
