论文标题
半导体纳米系统中高度限制的热流的普遍行为：从纳米节到金属
Universal behavior of highly-confined heat flow in semiconductor nanosystems: from nanomeshes to metalattices
论文作者
论文摘要
对应于声子平均自由路径的长度尺度上的纳米结构可以控制半导体中的热流，并可以设计其热性能。但是，边界的影响限制了批量模型的有效性，而第一原理计算在计算上太昂贵，无法对真实设备进行建模。在这里，我们使用极端的紫外线来研究具有深纳米级特征大小的3D纳米结构硅金属含量中的声子传输动力学，并观察到相对于散装而大大降低了导热率。为了解释这种行为，我们发展了一种预测理论，其中热传导分离为几何渗透性成分和固有的粘性贡献，这是由于纳米级限制对声子流的新的普遍效应而产生的。使用实验和原子模拟，我们表明我们的理论适用于从Metalattices，NanoMeshes，多孔纳米线到纳米网络的一般一般固定的硅纳米系统，这些网络具有下一代能量效率设备的极大兴趣。
Nanostructuring on length scales corresponding to phonon mean free paths provides control over heat flow in semiconductors and makes it possible to engineer their thermal properties. However, the influence of boundaries limits the validity of bulk models, while first principles calculations are too computationally expensive to model real devices. Here we use extreme ultraviolet beams to study phonon transport dynamics in a 3D nanostructured silicon metalattice with deep nanoscale feature size, and observe dramatically reduced thermal conductivity relative to bulk. To explain this behavior, we develop a predictive theory wherein thermal conduction separates into a geometric permeability component and an intrinsic viscous contribution, arising from a new and universal effect of nanoscale confinement on phonon flow. Using experiments and atomistic simulations, we show that our theory applies to a general set of highly-confined silicon nanosystems, from metalattices, nanomeshes, porous nanowires to nanowire networks, of great interest for next-generation energy-efficient devices.
