Liu Xianghui, Chang Qi, Yan Max, Wang Xin, Zhang Haiwen, Zhou Han, Fan Tongxiang
State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Phys Chem Chem Phys. 2020 Jul 7;22(25):13965-13974. doi: 10.1039/d0cp01943g. Epub 2020 Jun 17.
Metamaterials with spectrally selective absorptance operating in the mid-infrared range have attracted much interest in numerous applications. However, it remains a challenge to economically fabricate scalable meta-absorbers with tailorable absorptance bands. This work demonstrates a conceptually simple and low-cost yet effective design strategy to achieve spectrally selective absorption with tailorable band positions at MIR by colloidal lithography. The strategy ingeniously uses residual diameter fluctuations of circular resonators etched through monodisperse colloidal particles for achieving superposition of multiple magnetic resonances and thereby a more than doubled absorption band, which is neglected in previous works. The proposed meta-absorber features densely packed thick aluminum resonators with a rather narrow diameter distribution and enhanced capacitive coupling among them. Moreover, the tailorability of the absorption band can be achieved by a parameterized variation in the fabrication process. As a proof of concept, infrared stealth and radiative cooling are demonstrated based on our meta-absorbers. The design and fabrication strategy create versatile metamaterials for advanced radiative thermal engineering.
在中红外波段具有光谱选择性吸收率的超材料在众多应用中引起了广泛关注。然而，经济地制造具有可定制吸收带的可扩展超吸收器仍然是一个挑战。这项工作展示了一种概念上简单、低成本但有效的设计策略，通过胶体光刻技术在中红外波段实现具有可定制带位置的光谱选择性吸收。该策略巧妙地利用通过单分散胶体颗粒蚀刻的圆形谐振器的残余直径波动来实现多个磁共振的叠加，从而获得一个比以前工作中忽略的吸收带宽增加一倍以上的吸收带。所提出的超吸收器具有密集排列的厚铝谐振器，其直径分布相当窄，并且它们之间的电容耦合增强。此外，吸收带的可定制性可以通过制造过程中的参数化变化来实现。作为概念验证，基于我们的超吸收器展示了红外隐身和辐射冷却。该设计和制造策略为先进的辐射热工程创造了多功能超材料。
