Impeded thermal transport in Si multiscale hierarchical architectures with phononic crystal nanostructures
Impeded thermal transport in Si multiscale hierarchical architectures with phononic crystal nanostructures
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DOI：
10.1103/physrevb.91.205422
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发表时间：
2015-05-15
影响因子：
3.7
通讯作者：
Paul, O.
中科院分区：
文献类型：
--
作者：
Nomura, M.;Kage, Y.;Paul, O.
在室温下，对单晶硅和多晶硅二维声子晶体（PnC）纳米结构中的面内热传导和声子输运进行了研究。声子图案化对热导率的影响在多晶硅PnC中比在单晶硅PnC中更大。这种影响的差异归因于两种材料中由晶界散射引起的热声子平均自由程（MFP）分布的差异。晶粒尺寸分析和使用蒙特卡罗技术的数值模拟表明，晶界和声子图案化是针对不同MFP长度尺度的有效声子散射机制。这种多尺度声子散射结构覆盖了热声子MFP广泛分布的很大一部分，从而有效地降低了热传导。
In-plane thermal conduction and phonon transport in both single-crystalline and polycrystalline Si two-dimensional phononic crystal (PnC) nanostructures were investigated at room temperature. The impact of phononic patterning on thermal conductivity was larger in polycrystalline Si PnCs than in single-crystalline Si PnCs. The difference in the impact is attributed to the difference in the thermal phonon mean free path (MFP) distribution induced by grain boundary scattering in the two materials. Grain size analysis and numerical simulation using the Monte Carlo technique indicate that grain boundaries and phononic patterning are efficient phonon scattering mechanisms for different MFP length scales. This multiscale phonon scattering structure covers a large part of the broad distribution of thermal phonon MFPs and thus efficiently reduces thermal conduction.