基于一维周期性金属-介质薄膜多波段高效吸收体的制备及其光学特性研究

通过热蒸发和磁控溅射方法在厚金属Ag反射层上制备了由一维周期性Ag金属薄层和MoO3/SiO2介质层组成的多波段吸收体。实验结果表明:随着周期数（N）的增加，吸收峰的个数也相应增加，且精确等于周期数。对于Ag薄层厚度为14 nm、MoO3层和SiO2层厚度分别为2 nm及135 nm的吸收体，实验测得在400~900 nm波长范围内的积分吸收效率从N=1时的29.4%增加到N=6时的57.2%，趋势与理论计算结果一致。此外，测量结果表明:吸收峰对入射角度及偏振不敏感。笔者还在柔性聚对苯二甲酸乙二醇酯衬底上制备了多层吸收体，弯曲1 000次后仍基本保持原有的吸波性能。该吸收体在光伏和热辐射调控等领域具有潜在应用价值。

Fabrication and optical properties of efficient multiband absorbers based on one-dimensional periodic metal-dielectric multilayers

Multiband absorbers comprised of one dimensional periodic Ag metallic thin layer and MoO3/SiO2 dielectric layer on a reflective Ag thick layer were fabricated by thermal evaporation and magnetron sputtering methods. Experimental results show that with the number of unit cell (N) increasing, the number of the absorption peaks increases accordingly and precisely equals N. For our fabricated devices with 14 nm thick Ag layer, 2 nm thick MoO3 layer, and 135 nm thick SiO2 layer, the integrated absorption efficiency over the wavelength range from 400 nm to 900 nm increases from 29.4%when N=1 to 57.2% when N=6, the trend of which is consistent with the calculation results. Moreover, measurements show that the absorption peaks are insensitive to the incident angles and polarizations. The multilayer absorbers were also fabricated on flexible polyethylene terephthalate substrates, which maintained their original absorption performances after bending for 1 000 times. The fabricated absorbers may have potential applications in areas like photovoltaics and thermal emission tailoring.