He Gui-Cang, Shi Li-Na, Hua Yi-Lei, Zhu Xiao-Li
Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, P. R. China.
Phys Chem Chem Phys. 2022 Feb 2;24(5):3059-3065. doi: 10.1039/d1cp04914c.
In this work, the electron-phonon, phonon-phonon, and phonon structure scattering mechanisms and their effect on the thermal and thermoelectric properties of a silver nanowire (AgNW) is investigated in the temperature range of 10 to 300 K. The electron-phonon scattering rate decreases with the increase of temperature. The phonon-phonon scattering rate increases with temperature and becomes greater than the electron-phonon scattering rate when the temperature is higher than the Debye temperature (223 K). The rate of phonon structure scattering is constant. The total phonon scattering rate decreases with temperature when the temperature is lower than about 150 K, and increases when the temperature is higher than 150 K. Correspondingly, the temperature dependent variation trend of the lattice thermal conductivity is opposite diametrically to that of the total phonon scattering rate. The thermoelectric properties of the AgNW are strongly coupled with the thermal conductivity the phonon and electron transition. The thermoelectric properties of the material are quantified by the figure of merit (). The value of the AgNW is greater than that of bulk silver in the corresponding temperature range, and this difference increases with temperature. The order of the of the AgNW is about 13 times greater than that of bulk silver at room temperature. The large increase of the value of the AgNW is mainly due to the enhanced electron scattering and phonon scattering mechanisms in the AgNW.
在这项工作中，研究了电子 - 声子、声子 - 声子和声子结构散射机制及其在10至300 K温度范围内对银纳米线（AgNW）热学和热电性能的影响。电子 - 声子散射率随温度升高而降低。声子 - 声子散射率随温度升高而增加，并且当温度高于德拜温度（223 K）时变得大于电子 - 声子散射率。声子结构散射率是恒定的。当温度低于约150 K时，总声子散射率随温度降低，而当温度高于150 K时增加。相应地，晶格热导率随温度变化的趋势与总声子散射率的趋势完全相反。AgNW的热电性能与热导率、声子和电子跃迁密切相关。材料的热电性能通过品质因数（）来量化。在相应温度范围内，AgNW的 值大于块状银，并且这种差异随温度增加。在室温下，AgNW的 顺序大约比块状银大13倍。AgNW的 值大幅增加主要是由于AgNW中增强的电子散射和声子散射机制。
