Energy Transport by Radiation in Hyperbolic Material Comparable to Conduction
Energy Transport by Radiation in Hyperbolic Material Comparable to Conduction
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DOI：
10.1002/adfm.201905830
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发表时间：
2019-12
影响因子：
19
通讯作者：
H. Salihoglu;V. Iyer;T. Taniguchi;Kenji Watanabe;P. Ye;Xianfan Xu
中科院分区：
文献类型：
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作者：
H. Salihoglu;V. Iyer;T. Taniguchi;Kenji Watanabe;P. Ye;Xianfan Xu
与传导相比，辐射作为散装材料内部的传热模式通常可以忽略不计。在这里，研究了辐射对双曲材料六方氮化硼 (hBN) 内部能量传输的贡献。利用双曲色散，即介电成分沿主方向具有相反的符号，声子极化子对能量传输有显着贡献，因为与普通材料相比，声子极化子具有更多数量的传播模式。开发了多体模型来解释温度分布不均匀的材料中的辐射传热。研究发现，通过六方氮化硼的总辐射传热很大程度上是由 Reststrahlen 能带内的高 κ 模式贡献的，并且与声子传导相当。与温度相关的热传输的实验测量还表明，辐射对热传输的贡献与声子的贡献相同。因此，这项工作首次表明，材料内部的辐射传热可以与声子传导传热相媲美。
Radiation as a heat transfer mode inside a bulk material is usually negligible in comparison to conduction. Here, the contribution of radiation to energy transport inside a hyperbolic material, hexagonal boron nitride (hBN), is investigated. With hyperbolic dispersion, i.e., opposite signs of dielectric components along principal directions, phonon polaritons contribute significantly to energy transport due to a much greater number of propagating modes compared to that in a normal material. A many‐body model is developed to account for radiative heat transfer in a material with a nonuniform temperature distribution. The total radiative heat transfer through hBN is found to be largely contributed by the high‐κ modes within the Reststrahlen bands, and is comparable to phonon conduction. Experimental measurements of temperature‐dependent thermal transport also show that radiative contribution to thermal transport is of the same order as that from phonons. Therefore, this work shows, for the first time, radiative heat transfer inside a material can be comparable to phonon conductive heat transfer.