Cai Haoyuan, Wang Mengwei, Wu Zhuohui, Wang Xiaoping, Liu Jing
Opt Express. 2022 Sep 26;30(20):35219-35231. doi: 10.1364/OE.469855.
In this work, a near-perfect broadband absorber, consisting of Fe, MgF, Fe, TiO and MgF planar film, is proposed and investigated through simulations and experiments. The Fe material is first applied in the multilayer film structure, and it is proved to be more favorable for achieving broadband absorption. MgF and TiO are chosen as anti-reflection coatings to decrease unwanted reflections. The proposed absorber is optimized by employing a hybrid numerical method combining the transfer matrix method (TMM) and the genetic algorithm (GA). Under normal incidence conditions, the average absorption of the absorber is 97.6% in the range of 400 to 1400 nm. The finite difference time domain (FDTD) method and phase analysis reveal that the anti-reflection property and the Fabry-Perot resonance result in broadband absorption performance. Furthermore, when an additional Fe-MgF layer is inserted on the bottom Fe layer, an average absorption of 97.9% in the range of 400 to 2000 nm can be achieved. Our approach could be of vital significance for numerous applications involving solar energy.
在这项工作中，提出了一种由铁（Fe）、氟化镁（MgF）、铁（Fe）、二氧化钛（TiO）和氟化镁（MgF）平面薄膜组成的近乎完美的宽带吸收器，并通过模拟和实验进行了研究。铁材料首次应用于多层薄膜结构中，事实证明它更有利于实现宽带吸收。选择氟化镁和二氧化钛作为减反射涂层以减少不必要的反射。通过采用结合传输矩阵法（TMM）和遗传算法（GA）的混合数值方法对所提出的吸收器进行了优化。在垂直入射条件下，该吸收器在400至1400纳米范围内的平均吸收率为97.6%。时域有限差分（FDTD）方法和相位分析表明，减反射特性和法布里-珀罗共振导致了宽带吸收性能。此外，当在底部铁层上插入一个额外的铁-氟化镁层时，在400至2000纳米范围内可实现97.9%的平均吸收率。我们的方法对于众多涉及太阳能的应用可能具有至关重要的意义。
