Experimental evidence for the significance of optical phonons in thermal transport of tin monosulfide
Experimental evidence for the significance of optical phonons in thermal transport of tin monosulfide
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DOI：
10.1088/1367-2630/acb3ed
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发表时间：
2023-01
影响因子：
3.3
通讯作者：
P. Wu;N. Murai;Tongrui Li;R. Kajimoto;M. Nakamura;M. Kofu;K. Nakajima;K. Xia;Kunling Peng-Kunling-Pen
中科院分区：
文献类型：
--
作者：
P. Wu;N. Murai;Tongrui Li;R. Kajimoto;M. Nakamura;M. Kofu;K. Nakajima;K. Xia;Kunling Peng-Kunling-Pen
晶格动力学的理解对于量子材料中的热输运性质的工程设计是必不可少的。基于规范的观点，声学声子被认为是热流中的主要热载体。在本文中，通过使用最先进的非弹性中子散射技术结合第一性原理计算，阐明了光学声子在确定热电材料SnS的晶格热导率方面发挥着关键作用。此外，与声学声子相反，观察到光学声子随温度表现出明显的软化和加宽。我们的观察不仅揭示了光学声子在热输运中的重要性，而且还提供了抑制光学声子传播以优化SnS热电性能的重要线索。
The understanding of the lattice dynamics is essential for engineering the thermal transport properties in quantum materials. Based on the canonical point of view, acoustic phonons are believed to be the principal thermal carriers in heat flow. Here, in this work, optical phonons are elucidated to play a pivotal role in determining the lattice thermal conductivity in thermoelectric material SnS by using the state-of-the-art inelastic neutron scattering technique combined with first-principles calculations. Additionally, in contrast to acoustic phonons, optical phonons are observed to exhibit pronounced softening and broadening with temperature. Our observations not only shed light on the significance of the optical phonons in thermal transport but also provide a vital clue to suppress the propagation of optical phonons to optimize the thermoelectric performance of SnS.