Absorptivity Control Over the Visible to Mid-Infrared Range Using a Multilayered Film Consisting of Thermochromic Vanadium Dioxide
Absorptivity Control Over the Visible to Mid-Infrared Range Using a Multilayered Film Consisting of Thermochromic Vanadium Dioxide
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DOI：
10.1007/s10765-021-02944-4
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发表时间：
2022-03-01
影响因子：
2.2
通讯作者：
Horibe, Akihiko
中科院分区：
文献类型：
--
作者：
Isobe, Kazuma;Tomioka, Minoru;Horibe, Akihiko
二氧化钒（VO 2）是一种相变材料，根据其温度表现出金属或绝缘特性。在这项研究中，提出了一种由VO 2，二氧化硅（SiO2）和金组成的多层膜作为超材料，该超材料根据环境温度在宽波长范围内切换其吸收率，作为建筑颜料的基本元素。在高温下，多层膜在中红外波长处表现出高吸收率，促进辐射冷却。同时，该多层膜在可见光和近红外波段表现出较低的吸收率，增强了对太阳光的吸收。与比辐射率为0.8的灰体相比，夏季日平均热通量有可能被抑制。相反，在较低的温度下，多层显示相反的吸收在中红外和可见光范围内，其日平均热通量增加，在冬季。VO 2的金属-绝缘体相变引起了与表面声子和表面等离子体激元相关的共振波长在红外波长处的剧烈偏移，以及在可见光波长处的光学干涉，起源于SiO2层的界面处。因此，太阳光吸收和辐射冷却的辐射热通量同时控制取决于VO 2的温度。
Vanadium dioxide (VO2) is a phase transition material that exhibits metallic or insulating characteristics depending upon its temperature. In this study, a multilayered film consisting of VO2, silicon dioxide (SiO2) and gold was proposed as a metamaterial that switches its absorptivity over a broad wavelength range depending on the ambient temperature as a fundamental element of a building pigment. At high temperatures, the multilayer showed a high absorptivity at mid-infrared wavelengths, promoting radiative cooling. Simultaneously, the multilayer presented a low absorptivity in the visible and near-infrared wavelengths, enhancing sunlight absorption. The daily average heat flux can possibly be suppressed in summer in comparison with a gray body whose emissivity was 0.8. Conversely, at a lower temperatures, the multilayer showed opposite absorptivity in both the mid-infrared and visible ranges, and its daily average heat flux increased in winter. The metal-insulator phase transition of VO2 caused a drastic shift of the resonant wavelength related to surface phonons and surface plasmons at an infrared wavelength, and optical interference at a visible wavelength, originating at the interface of the SiO2 layer. Thus, the radiative heat flux for both sunlight absorption and radiative cooling was simultaneously controlled depending on the temperature of VO2.