Hu Yue, Xu Jiaxuan, Ruan Xiulin, Bao Hua
University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, 200240, PR China.
CTG Wuhan Science and Technology Innovation Park, China Three Gorges Corporation, Wuhan, 430010, PR China.
Nat Commun. 2024 Apr 17;15(1):3304. doi: 10.1038/s41467-024-47716-4.
Defect scattering is well known to suppress thermal transport. In this study, however, we perform both molecular dynamics and Boltzmann transport equation calculations, to demonstrate that introducing defect scattering in nanoscale heating zone could surprisingly enhance thermal conductance of the system by up to 75%. We further reveal that the heating zone without defects yields directional nonequilibrium with overpopulated oblique-propagating phonons which suppress thermal transport, while introducing defects redirect phonons randomly to restore directional equilibrium, thereby enhancing thermal conductance. We demonstrate that defect scattering can enable such thermal transport enhancement in a wide range of temperatures, materials, and sizes, and offer an unconventional strategy for enhancing thermal transport via the manipulation of phonon directional nonequilibrium.
众所周知,缺陷散射会抑制热传输。然而,在本研究中,我们进行了分子动力学和玻尔兹曼输运方程计算,以证明在纳米级加热区域引入缺陷散射会出人意料地将系统的热导率提高多达75%。我们进一步揭示,无缺陷的加热区域会产生定向非平衡,其中斜向传播的声子数量过多,从而抑制热传输,而引入缺陷会使声子随机重新定向以恢复定向平衡,从而提高热导率。我们证明,缺陷散射能够在很宽的温度、材料和尺寸范围内实现这种热传输增强,并提供了一种通过操纵声子定向非平衡来增强热传输的非常规策略。