Liu Ying-Guang, Li Heng-Xuan, Qiu Yu-Jun, Li Xin, Huang Chun-Pu
Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology, North China Electric Power University, Baoding 071003, Hebei, China.
Phys Chem Chem Phys. 2023 Nov 1;25(42):29080-29087. doi: 10.1039/d3cp03994c.
The improvement of interfacial thermal conductance (ITC) is a crucial aspect of the thermal management of nanodevices. In this paper, the effect of embedding Sn nanoparticles at the Si/Ge interface on ITC was investigated using non-equilibrium molecular dynamics (NEMD) simulations. It was found that although Sn has a higher atomic weight than both silicon and germanium, the ITC can be enhanced by 1.95 times when the nanoparticles reach a suitable number and diameter. The phonon transmission functions and density of states clearly indicate that an increased ITC can be attributed to the enhanced inelastic phonon scattering facilitated by Sn nanoparticles. This enhancement opens up novel channels for interfacial phonon transport. However, when the number of nanoparticles surpasses a suitable value, elastic phonons begin to dominate heat transport, leading to a subsequent decrease in the ITC. Sensitivity analysis further underscores that the ITC exhibits greater responsiveness to changes in diameter. In addition, it is also shown that with increasing temperature, a higher frequency phonon excitation occurs, increasing phonon inelastic scattering and interface transmission. These findings offer a novel strategy for enhancing ITC and deepening our comprehension of both elastic and inelastic phonon processes in interfacial phonon transport.
界面热导率(ITC)的提高是纳米器件热管理的一个关键方面。在本文中,使用非平衡分子动力学(NEMD)模拟研究了在Si/Ge界面嵌入Sn纳米颗粒对ITC的影响。研究发现,尽管Sn的原子量高于硅和锗,但当纳米颗粒达到合适的数量和直径时,ITC可提高1.95倍。声子传输函数和态密度清楚地表明,ITC的增加可归因于Sn纳米颗粒促进的非弹性声子散射增强。这种增强为界面声子传输开辟了新的通道。然而,当纳米颗粒的数量超过合适的值时,弹性声子开始主导热传输,导致ITC随后下降。敏感性分析进一步强调,ITC对直径变化表现出更大的响应性。此外,研究还表明,随着温度升高,会发生更高频率的声子激发,增加声子非弹性散射和界面传输。这些发现为提高ITC以及深化我们对界面声子传输中弹性和非弹性声子过程的理解提供了一种新策略。