| 引用本文格式: Cheng Jun. Theoretical investigation of the mechanical properties, electronic structure and phonon transport characteristics of 2D X2UO4 (X = K, Rb, Cs) [J]. J. At. Mol. Phys., 2025, 42(2): 026003 (in Chinese) 程钧. 理论探索二维X2UO4 (X = K, Rb, Cs)的力学特征、电子结构和声子输运特征 [J]. 原子与分子物理学报, 2025, 42(2): 026003] |
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| 理论探索二维X2UO4 (X = K, Rb, Cs)的力学特征、电子结构和声子输运特征 |
| Theoretical investigation of the mechanical properties, electronic structure and phonon transport characteristics of 2D X2UO4 (X = K, Rb, Cs) |
| 摘要点击 202 全文点击 257 投稿时间：2023-08-01 修订日期：2023-08-09 |
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| DOI编号
10.19855/j.1000-0364.2025.026003 |
| 中文关键词
二维材料，能带，迁移率，声子，热导率 |
| 英文关键词
two-dimensional material, band structure, mobility, phonon, thermal conductivity. |
| 基金项目
湖北省教育厅科学研究计划项目（B2021159）；十堰社科思想库课题项目（sysk202330） |
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| 中文摘要
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| 本文用基于密度泛函理论的第一性原理计算方法，研究了三种建议的二维材料X2UO4 (X = K, Rb, Cs)的稳定性、弹性、电子结构和声子振动特性。计算结果显示，三种材料同时具备较好的热力学、动力学和机械稳定性。电子结构表明，三种材料属于宽禁带间接半导体，其计算能隙分别是3.90、3.79和3.42 eV，并且有着71.31 − 174.23 cm2/Vs的电子迁移率。声子输运特性表明，三种材料的声子色散均没有虚频出现，声学模和低频光学模呈现强烈耦合，且有着低频率low-lying声子，这使得材料具备很强的声子非谐效应、低声子群速度和强声子散射率，从而表现出很低晶格热导率，在300 K温度下时仅为 0.16 − 0.19 W/mK。这些特性表明，二维X2UO4 (X = K, Rb, Cs)在纳米电子和热电器件领域具备应用潜力。 |
| 英文摘要
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| Based on the first principles of density functional theory, we proposed three novel two-dimensional materials, KU2O4, RbU2O4 and CsU2O4, and further investigated their stability, elastic, electronic structure and phonon vibration characteristics. The calculation results show that the three 2D materials are wide-gap indirect semiconductors, with band-gaps of 3.90, 3.79, and 3.42 eV, respectively, and deliver electron mobilities of 71.31 − 174.23 cm2/Vs at 300 K. The phonon transport results show that all phonon dispersions have no virtual frequency, in which acoustic and low-frequency optical modes are strongly coupled, as well as low-frequencies for low-lying phonons, resulting in strong phonon-phonon anharmonic effect, low phonon group velocities and strong phonon scattering rates. As a result, they exhibit low lattice thermal conductivities of 0.16 − 0.19 W/mK at 300 K. All these properties indicate that 2D X2UO4 (X = K, Rb, Cs) have high potential applications in the field of nanoelectronics and thermoelectric devices. |
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