发射率
光辉
材料科学
钨
红外线的
热辐射
远红外
辐射传输
热的
热传导
制作
热导率
光电子学
凝聚态物理
光学
热力学
复合材料
物理
病理
冶金
医学
替代医学
作者
Kechao Tang,Wang Xi,Kaichen Dong,Ying Liu,Jiachen Li,Bo Sun,Xiang Zhang,Chris Dames,Cheng‐Wei Qiu,Jie Yao,Junqiao Wu
标识
DOI:10.1002/adma.201907071
摘要
Abstract Thermal radiation from a black body increases with the fourth power of absolute temperature ( T 4 ), an effect known as the Stefan–Boltzmann law. Typical materials radiate heat at a portion of this limit, where the portion, called integrated emissivity (ε int ), is insensitive to temperature (|dε int /d T | ≈ 10 −4 °C –1 ). The resultant radiance bound by the T 4 law limits the ability to regulate radiative heat. Here, an unusual material platform is shown in which ε int can be engineered to decrease in an arbitrary manner near room temperature (|dε int /d T | ≈ 8 × 10 −3 °C –1 ), enabling unprecedented manipulation of infrared radiation. As an example, ε int is programmed to vary with temperature as the inverse of T 4 , precisely counteracting the T 4 dependence; hence, thermal radiance from the surface becomes temperature‐independent, allowing the fabrication of flexible and power‐free infrared camouflage with unique advantage in performance stability. The structure is based on thin films of tungsten‐doped vanadium dioxide where the tungsten fraction is judiciously graded across a thickness less than the skin depth of electromagnetic screening.
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