论文标题
单层中的高内在晶格导热率$ _2 $ n $ _4 $
High intrinsic lattice thermal conductivity in monolayer MoSi$_2$N$_4$
论文作者
论文摘要
最近，一种新颖的二维（2D）MXENE，MOSI $ _2 $ n $ _4 $，成功合成了出色的环境稳定性，高载体移动性和中等频段隙（Science 369，670，2020）。在这项工作中，单层MOSI的固有晶格导热率$ _2 $ n $ _4 $可以通过基于第一原理计算来求解声子Boltzmann传输方程来预测。尽管MO和复杂的晶体结构的原子量很重，但单层MOSI $ _2 $ n $ _4 $出乎意料地在300至800 K之间表现出很高的晶格导热率。在300 k之间，它的平面晶格导热率为224 wm $^{ - 1} $^{ - 1} $ K $ K $^$^{-1} $^{-1}。详细的分析表明，较大的组速度和较小的非谐度是其高晶格导热率的主要原因。我们还计算了单层WSI $ _2 $ n $ _4 $的晶格导热率，这仅比Mosi $ _2 $ n $ _4 $的晶格导热率。我们的发现表明，单层Mosi $ _2 $ n $ _4 $和WSI $ _2 $ n $ _4 $是未来纳米电子设备中热运输的潜在2D材料。
Very recently, a novel two-dimension (2D) MXene, MoSi$_2$N$_4$, was successfully synthesized with excellent ambient stability, high carrier mobility, and moderate band gap (Science 369, 670, 2020). In this work, the intrinsic lattice thermal conductivity of monolayer MoSi$_2$N$_4$ is predicted by solving the phonon Boltzmann transport equation based on the first-principles calculations. Despite the heavy atomic mass of Mo and complex crystal structure, the monolayer MoSi$_2$N$_4$ unexpectedly exhibits a quite high lattice thermal conductivity over a wide temperature range between 300 to 800 K. At 300 K, its in-plane lattice thermal conductivity is 224 Wm$^{-1}$K$^{-1}$. The detailed analysis indicates that the large group velocities and small anharmonicity are the main reasons for its high lattice thermal conductivity. We also calculate the lattice thermal conductivity of monolayer WSi$_2$N$_4$, which is only a little smaller than that of MoSi$_2$N$_4$. Our findings suggest that monolayer MoSi$_2$N$_4$ and WSi$_2$N$_4$ are potential 2D materials for thermal transport in future nano-electronic devices.
