Phonon transport in periodic silicon nanoporous films with feature sizes greater than 100 nm
Phonon transport in periodic silicon nanoporous films with feature sizes greater than 100 nm
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DOI：
10.1103/physrevb.87.195301
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发表时间：
2013-05-03
影响因子：
3.7
通讯作者：
McGaughey, Alan J. H.
中科院分区：
文献类型：
--
作者：
Jain, Ankit;Yu, Ying-Ju;McGaughey, Alan J. H.
固体硅薄膜和硅薄膜与周期性孔阵列的热导率预测使用Monte Carlo技术，包括声子边界散射和玻尔兹曼输运方程。作为输入所需的体声子性质从谐波和非谐波晶格动力学计算。晶格动力学计算所需的力常数是从使用密度泛函理论计算的力获得的。对于固体和多孔膜，面内热导率的预测捕捉到以前的实验测量的幅度和趋势。由于预测方法将声子视为具有本体性质的颗粒，结果表明，与孔隙的二次周期性相关的相干声子模式对特征尺寸大于100 nm的多孔膜中的热传输没有贡献。
The thermal conductivities of solid silicon thin films and silicon thin films with periodic pore arrays are predicted using a Monte Carlo technique to include phonon-boundary scattering and the Boltzmann transport equation. The bulk phonon properties required as input are obtained from harmonic and anharmonic lattice dynamics calculations. The force constants required for the lattice dynamics calculations are obtained from forces calculated using density functional theory. For both solid and porous films, the in-plane thermal conductivity predictions capture the magnitudes and trends of previous experimental measurements. Because the prediction methodology treats the phonons as particles with bulk properties, the results indicate that coherent phonon modes associated with the secondary periodicity of the pores do not contribute to thermal transport in porous films with feature sizes greater than 100 nm.