Ma Yuanchen, Hu Junhao, Li Wenfeng, Yang Zhengmei
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China.
School of Artificial Intelligence, Beijing University of Posts and Telecommunications, Beijing 100876, China.
Nanomaterials (Basel). 2023 Oct 8;13(19):2726. doi: 10.3390/nano13192726.
Ultrathin broadband absorbers with high efficiency, wide angular tolerance, and low fabrication cost are in demand for various applications. Here, we present an angle-insensitive ultrathin (<150 nm) broadband absorber with an average 96.88% (experiment) absorptivity in the whole visible range by utilizing a simple dielectric-semiconductor-lossy metal triple-layer film structure. The excellent broadband absorption performance of the device results from the combined action of the enhanced absorptions in the semiconductor and lossy metal layers exploiting strong interference effects and can be maintained over a wide viewing angle up to ±60°. Benefiting from the lossy metal providing additional absorption, our design reduces the requirement for the semiconductor's material dispersion and has great flexibility in the material selection of the metal layer. Additionally, the lithography-free nature of the proposed broadband visible absorber provides a high-throughput fabrication convenience, thus holding great potential for its large-area applications in various fields.
具有高效率、宽角度容忍度和低制造成本的超薄宽带吸收器在各种应用中都有需求。在此，我们通过利用一种简单的电介质-半导体-有损金属三层薄膜结构，展示了一种角度不敏感的超薄（<150 nm）宽带吸收器，其在整个可见光范围内的平均吸收率为96.88%（实验值）。该器件优异的宽带吸收性能源于利用强干涉效应在半导体和有损金属层中增强吸收的联合作用，并且可以在高达±60°的宽视角范围内保持。得益于有损金属提供额外的吸收，我们的设计降低了对半导体材料色散的要求，并且在金属层的材料选择上具有很大的灵活性。此外，所提出的宽带可见光吸收器的无光刻特性提供了高通量制造的便利性，因此在各个领域的大面积应用中具有巨大潜力。
