Intrinsic Thermal conductivities of monolayer transition metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te)
Intrinsic Thermal conductivities of monolayer transition metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te)
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DOI：
10.1038/s41598-019-40882-2
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发表时间：
2019-03
影响因子：
4.6
通讯作者：
M. Zulfiqar;Yinchang Zhao;Geng Li;Zhengcao Li;J. Ni
中科院分区：
文献类型：
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作者：
M. Zulfiqar;Yinchang Zhao;Geng Li;Zhengcao Li;J. Ni
单层到多层过渡金属二硫族化合物的成功合成，开启了纳米电子学的新纪元。为了在电子器件中有效地实现它们，同时照顾到它们的过热问题，它们的热输运特性的表征是极其重要的。因此，我们采用第一性原理计算和玻尔兹曼输运方程相结合的方法系统地研究了单层过渡金属二硫化物MX2（M = Mo， W; X = S, Se, Te）的热输运性质。我们发现，在这六种半导体材料中，单层wte2具有最低的晶格热导率κ l (33:66 Wm−1K−1at 300 K)，而其中ws2具有最高的晶格热导率（113:97 Wm−1K−1at 300 K）。进一步分析表明，高（低）非调和散射和同位素散射以及低（高）声子群速度导致了κ lin WTe2（WS2）单层的最低（最高）值。此外，我们还计算了累积热导率与平均自由程的函数关系，表明长度在400 nm左右的纳米结构会大幅降低热导率。这些结果为设计二维过渡金属二硫族化合物MX2（M = Mo， W; X = S, Se, Te）电子学提供了从导热角度的重要理解。
The successful synthesis of the single to few layer transition metal dichalcogenides has opened a new era in the nanoelectronics. For their efficient implementations in the electronic devices while taking care of their overheating issues, the characterization of their thermal transport properties is extremely vital. So, we have systematically investigated the thermal transport properties of monolayer transition metal dichalcogenides MX2(M = Mo, W; X = S, Se, Te) by combining the first-principles calculations with Boltzmann transport equation. We find that monolayer WTe2possesses the lowest lattice thermal conductivityκL(33:66 Wm−1K−1at 300 K) among these six semiconducting materials, in contrast to the highestκL(113:97 Wm−1K−1at 300 K) of WS2among them. Further analyses reveal that the higher (lower) anharmonic and isotopic scatterings together with the lower (higher) phonon group velocities lead to the lowest (highest) value ofκLin WTe2(WS2) monolayer. In addition, we have also calculated the cumulative thermal conductivityκCas a function of mean free path, which indicates that the nanostructures with the length of about 400 nm would reduceκLdrastically. These results offer important understanding from thermal conductivity point of view to design the 2D transition metal dichalcogenides MX2(M = Mo, W; X = S, Se, Te) electronics.