Metamaterial perfect absorbers have been the subject of many studies in recent years. Near-unity light harvesting in an ultra-broadband frequency range is the prime goal in many applications such as photoconversion systems. While the most common designs for achieving this goal are periodic plasmonic architectures, this work reveals the unprecedented potential of random designs for ultra-broadband light absorption. A metal-insulator-metal (MIM) structure with a periodically patterned top layer has discrete translational symmetry. The proposed theory, supported by numerical simulations, unveils the fact that breaking this symmetry in the top layer introduces multiple resonant units with separate spectra, and the superposition of these separate resonances broaden the overall response. The random absorber is realized using the oblique angle deposition-induced atomic scale shadowing effect. Based on the experimental results and numerical calculations, the proposed disorder plasmonic design can propose unity absorption (> 90%) over the spectral range from 520 to 1270 nm.

近年来，超材料完美吸收体已成为许多研究的主题。在许多应用（例如光电转换系统）中，超宽带频率范围内的近统一光收集是主要目标。尽管实现此目标的最常见设计是周期性等离子体结构，但这项工作揭示了随机设计在超宽带光吸收方面的空前潜力。具有周期性图案化的顶层的金属-绝缘体-金属（MIM）结构具有离散的平移对称性。所提出的理论在数值模拟的支持下揭示了以下事实：打破顶层的这种对称性会引入具有独立光谱的多个共振单元，并且这些独立共振的叠加扩大了整体响应。利用倾斜角沉积引起的原子尺度阴影效应来实现无规吸收体。根据实验结果和数值计算，所提出的无序等离子体设计可以在520至1270 nm的光谱范围内提出统一的吸收（> 90％）。