Abstract Based on the density functional theory and first-principles calculations we conducted a comprehensive study of the thermal transport properties of dynamical stable 2D IV-VI semiconductors MX (M = Ge, Sn; X = S, Se). The calculated lattice thermal conductivity is anisotropic, and the larger value of a a x i s can be attributed to the higher phonon group velocity, besides, the optical modes of SnSe made a great contribution to the lattice thermal conductivity as a result of the most optical modes are located in the low frequency range. In addition, the lattice thermal conductivity of GeX is generally larger than that of SnX, which can be also attributed to the larger phonon group velocity. Our research reveals the thermal transport characteristics of 2D MX and points out the difference in lattice thermal conductivity of GeX and SnX.

中文翻译：

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对二维 IV-VI 半导体 MX (M = Ge, Sn; X = S, Se) 中声子热传输的综合研究

摘要 基于密度泛函理论和第一性原理计算，我们对动态稳定的二维 IV-VI 半导体 MX (M = Ge, Sn; X = S, Se) 的热传输特性进行了全面研究。计算的晶格热导率是各向异性的，aaxis 值越大，声子群速度越大，此外，SnSe 的光模对晶格热导率的贡献很大，因为大多数光模位于在低频范围内。此外，GeX 的晶格热导率一般比 SnX 大，这也可以归因于较大的声子群速度。我们的研究揭示了 2D MX 的热传输特性，并指出了 GeX 和 SnX 晶格热导率的差异。