Mode-Wise Thermal Conductivity of Bismuth Telluride
Mode-Wise Thermal Conductivity of Bismuth Telluride
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DOI：
10.1115/1.4024356
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发表时间：
2013-09
影响因子：
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通讯作者：
Yaguo Wang;Bo Qiu;A. McGaughey;X. Ruan;Xianfan Xu
中科院分区：
文献类型：
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作者：
Yaguo Wang;Bo Qiu;A. McGaughey;X. Ruan;Xianfan Xu
热性能和传输控制对于许多应用都很重要，例如，热电材料需要低导热率。了解模态声子特性对于识别热传输的主要声子模式和设计用于热传输控制的有效声子势垒至关重要。在本文中，我们采用时域（TD）和频域（FD）简正模分析来研究模态声子特性并计算碲化铋中的声子色散关系和声子弛豫时间。我们的模拟结果与之前报道的从超快时间分辨测量获得的数据一致。通过结合频率相关的非简声声子群速度和寿命，预测模式热导率可以揭示不同波长和偏振的热载流子的贡献。 [DOI：10.1115/1.4024356]
Thermal properties and transport control are important for many applications, for example, low thermal conductivity is desirable for thermoelectrics. Knowledge of modewise phonon properties is crucial to identify dominant phonon modes for thermal transport and to design effective phonon barriers for thermal transport control. In this paper, we adopt time-domain (TD) and frequency-domain (FD) normal-mode analyses to investigate mode-wise phonon properties and to calculate phonon dispersion relations and phonon relaxation times in bismuth telluride. Our simulation results agree with the previously reported data obtained from ultrafast time-resolved measurements. By combining frequency-dependent anharmonic phonon group velocities and lifetimes, mode-wise thermal conductivities are predicted to reveal the contributions of heat carriers with different wavelengths and polarizations. [DOI: 10.1115/1.4024356]