论文标题
通过热切换磁性偏振子使用可扩展的微结构VO2元信息的激发来增强红外发射
Enhanced Infrared Emission by Thermally Switching the Excitation of Magnetic Polariton with Scalable Microstructured VO2 Metasurfaces
论文作者
论文摘要
动态辐射冷却吸引了快速增长的兴趣，因为它适应不断变化的环境，并承诺比静态对应物更能节省能源。在这里，我们通过用微结构二氧化钒（VO2）的元素进行热切换磁极的激发来展示增强的红外发射。温度依赖性红外光谱清楚地表明，当加热超过其相变温度时，在波长在2到6 UM处制造的可调式元面的光谱会显着增强。可调的发射光谱也证明对发射率和极化角度不敏感，因此可以将VO2元表面视为弥漫性红外发射极。相变时，数值光学模拟和分析电感电感模型模型阐明了用绝缘或金属VO2对磁极的抑制或激发。通过热真空测试，通过可调VO2跨表面增强的热发射的效果得到了实验证明。对于相同的0.2 W的加热功率，发现相变时可调Vo2元脉冲发射极的稳态温度比参考V2O5发射器的静态光谱发射量低于20级，其静态光谱发射量与相变前的vo2元时间的静态光谱相同。在较高温度下，在较高温度下，在较高温度下，具有金属vo2的辐射式跨表发射器的辐射热电导率为3.96 W/m2k，在较低温度下进行绝缘VO2，显然表明辐射热消散的近六倍。
Dynamic radiative cooling attracts fast-increasing interest due to its adaptability to changing environment and promises for more energy-savings than the static counterpart. Here we demonstrate enhanced infrared emission by thermally switching the excitation of magnetic polariton with microstructured vanadium dioxide (VO2) metasurfaces fabricated via scalable and etch-free processes. Temperature-dependent infrared spectroscopy clearly shows that the spectral emittance of fabricated tunable metasurfaces at wavelengths from 2 to 6 um is significantly enhanced when heated beyond its phase transition temperature, where the magnetic polariton is excited with metallic VO2. The tunable emittance spectra are also demonstrated to be insensitive to incidence and polarization angles such that the VO2 metasurface can be treated as a diffuse infrared emitter. Numerical optical simulation and analytical inductance-capacitance model elucidate the suppression or excitation of magnetic polariton with insulating or metallic VO2 upon phase transition. The effect of enhanced thermal emission with the tunable VO2 metasurface is experimentally demonstrated with a thermal vacuum test. For the same heating power of 0.2 W, the steady-state temperature of the tunable VO2 metasurface emitter after phase transition is found to be 20degC lower than that of a reference V2O5 emitter whose static spectral emittance is almost the same as that of the VO2 metasurface before phase transition. The radiative thermal conductance for the tunable metasurface emitter is found to be 3.96 W/m2K with metallic VO2 at higher temperatures and 0.68 W/m2K with insulating VO2 at lower temperatures, clearly demonstrating almost six-fold enhancement in radiative heat dissipation.
