From lone-pair electrons to dual phonon channels: unraveling Te-dominated transport in monolayer Sb2Te3
发布时间：2026-05-21点击次数：
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影响因子：2.8
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DOI码：10.1088/1367-2630/ae6bb0
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所属单位：中国矿业大学
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发表刊物：New Journal of Physics
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刊物所在地：Institute of Physics (IOP)
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项目来源：国家自然科学基金面上项目(No. 12374079)
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关键字：lone-pair electrons, phonon coherence, anharmonicity
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摘要：Conventional Peierls theory is inadequate for describing thermal transport in strongly anharmonic compounds, such as two-dimensional layered chalcogenides containing lone-pair electrons;
the underlying physics of their ultralow thermal conductivity remains to be explored. Here, using monolayer Sb2Te3 as a model system, we elucidate the mechanism behind its ultralow lattice
thermal conductivity by evaluating the competing contributions of particle-like propagation and wave-like tunneling. The particle-like transport channel is suppressed by the dominant quartic anharmonicity induced by the stereochemically active lone-pair electrons of the tetrahedrally coordinated Te(1)-5pz orbital, primarily via enhancement of four-phonon scattering. In contrast, the wave-like transport channel is enhanced by the flattening of the Te(2)-derived phonon branches, a result of the relatively weak covalent bonding in the octahedral coordination, thereby promoting phonon coherence. Consequently, the combined model of the Te(1)-dominated particle-like and Te(2)-dominated wave-like channels accurately accounts for the total thermal
conductivity, achieving excellent agreement with experimental measurements in both magnitude and temperature dependence. For example, the calculated T−0.73 scaling exponent for the temperature dependence closely matches the experimental value of T−0.76. Our work identifies the interplay of lone-pair electrons and covalent bonding configuration as a key governing mechanism for thermal transport in two-dimensional layered chalcogenides, providing a novel perspective on their thermal properties.
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第一作者：吴凯
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合写作者：周冉,时洪亮
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论文类型：期刊论文
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通讯作者：段益峰*
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论文编号：053504
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学科门类：理学
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一级学科：物理学
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文献类型：J
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卷号：28
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页面范围：053504
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ISSN号：1367-2630
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是否译文：否
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发表时间：2026-05-21
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收录刊物：SCI
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发布期刊链接：https://iopscience.iop.org/article/10.1088/1367-2630/ae6bb0
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