de Vries Insa F, Osthues Helena, Doltsinis Nikos L
Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster and Center for Multiscale Theory & Computation, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany.
iScience. 2023 Mar 18;26(4):106447. doi: 10.1016/j.isci.2023.106447. eCollection 2023 Apr 21.
Cross-plane thermal conductivities of transition metal dichalcogenide (M = Mo, W; X = S, Se) bilayers are determined by homogeneous nonequilibrium molecular dynamics. The best insulator is found to be : , closely followed by : and : . Thermal conductivities of heterobilayers are close to the average of the two corresponding homobilayer values, despite the mass and lattice mismatch. To disentangle the effects of atomic mass, lattice constant, and interaction potential, these three parameters are systematically varied. Phonon spectral analysis provides further insight into their roles and reveals the weak influence of spectral overlap between the two layers and the dominance of boundary scattering. The observed trends can be rationalized using Slack's formula in terms of the average atomic mass and the Debye temperature. Accurate interlayer interaction potentials are developed based on experimental elastic constants. Their effect on the bilayer cross-plane thermal conductivities is found to be minor.
通过均匀非平衡分子动力学确定了过渡金属二硫属化物（M = Mo、W；X = S、Se）双层的面内热导率。发现最佳绝缘体是：，紧随其后的是：和：。尽管存在质量和晶格失配，但异质双层的热导率接近两个相应同质双层值的平均值。为了厘清原子质量、晶格常数和相互作用势的影响，系统地改变了这三个参数。声子光谱分析进一步深入了解了它们的作用，并揭示了两层之间光谱重叠的微弱影响以及边界散射的主导地位。利用斯莱克公式，根据平均原子质量和德拜温度，可以解释观察到的趋势。基于实验弹性常数开发了精确的层间相互作用势。发现它们对双层面内热导率的影响较小。
