In this paper, we propose an ultra-broadband multi-slot cross bowtie (MSCB) nanoantenna for light absorption, whose elements compose of dual rectangles and cross bowtie and rectangular slots. The optical characteristics are analysis numerically by the three-dimensional finite-difference time-domain (FDTD) method. The results show that the average absorptivity of the nanostructure is over 90% in 400–1800-nm waveband, which covered the visible and near-infrared region. We attribute the better absorption property of the nanoantenna to the combining of plasmon coupling effects between slots, high-order modes, and surface plasmon resonance. Our work provides a promising method for the future developments of more advanced absorber for energy harvesting, thermoelectrics, and imaging.

中文翻译：

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MSCB纳米天线作为超宽带吸收器的数值研究

在本文中，我们提出了一种用于光吸收的超宽带多槽十字领结（MSCB）纳米天线，其元件由双矩形和十字领结和矩形缝隙组成。通过三维有限差分时域（FDTD）方法对光学特性进行数值分析。结果表明，在覆盖可见光和近红外区域的400-1800 nm波段中，纳米结构的平均吸收率超过90％。我们将纳米天线的更好吸收特性归因于缝隙，高阶模和表面等离子体共振之间的等离子体耦合效应的结合。我们的工作为未来用于能量收集，热电和成像的更先进吸收器的发展提供了一种有前途的方法。