We report an ultrabroadband perfect metamaterial absorber, comprising a two-dimensional array of a hemi-ellipsoid shaped metallo-dielectric multilayered structure. What we believe, to the best of our knowledge, is an unprecedented average absorbance of ${\sim}99\%$ is theoretically demonstrated in the 300 to 4500 nm spectral range at normal incidence. We use 20 pairs of molybdenum–germanium metallo-dielectric layers with tungsten as the ground metal placed on a silicon substrate. Our design is polarization-independent as well as angle-insensitive (up to 60°), making it a perfect “superabsorber.” Theoretical modeling based on effective medium theory validates our full-wave simulation results. The figure-of-merit calculations suggest that our superabsorber can outperform recently reported broadband absorbers. The proposed design has potential application in thermophotovoltaics for solar energy harvesting.

中文翻译：

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偏振和角度不敏感的超宽带完美超材料吸收器，用于热光电

我们报告了一个超宽带完美的超材料吸收体，包括一个半椭圆形的金属介电多层结构的二维阵列。据我们所知，平均吸光度为$ {\ sim} 99 \％$理论上在法向入射时在300至4500 nm光谱范围内得到证明。我们使用20对钼-锗金属介电层，其中钨作为放置在硅基板上的底金属。我们的设计与偏振无关，并且对角度不敏感（最大60°），使其成为完美的“超级吸收体”。基于有效介质理论的理论建模验证了我们的全波仿真结果。品质因数计算表明，我们的超级吸收剂可以胜过最近报道的宽带吸收剂。拟议的设计在太阳能光伏热光伏领域有潜在的应用。