论文标题
2D硒的异常低导热系数：一项从头算研究
Abnormally low thermal conductivity of 2D selenene: An ab initio study
论文作者
论文摘要
根据第一原理计算，研究了2 $α$ selenene的晶格导热率和2 $α$ selenene的热传输性能。各向同性的平面导热系数低至3.04 w m $^{ - 1} $ k $^{ - 1} $在室温下，甚至异常低于$α$ - tellurene，该tellurece处理类似构型和降低debye温度。我们发现这种异常现象是源于声音子分支的较大非谐声。此外，还展示了声子光谱，弹性特性和相关的热性能。声音子主要有助于总热导率。此外，进一步研究了尺寸效应，边界效应，三个子过程过程的总相空间，声子群速度和放松时间，最后一个揭示了最后一个空间，是2D硒中热运输的关键成分。
The lattice thermal conductivity and thermal transport properties of 2D $α$-selenene are investigated based on the first-principles calculations. The isotropic in-plane thermal conductivity is as low as 3.04 W m$^{-1}$ K$^{-1}$ at room temperature, even abnormally lower than $α$-tellurene which processes analogous configuration and lower Debye temperature. We find this abnormal phenomenon reasonably stems from the larger anharmonicity of the acoustic phonon branch. Moreover, the phonon spectra, elastic properties, and related thermal properties are also exhibited. Acoustic phonons contribute mainly to the total thermal conductivity. Furthermore, size effect, boundary effect, the total phase space for three-phonon processes, phonon group velocity and relaxation time are further investigated, and the last one is unveiled to be the key ingredient of thermal transport in 2D selenene.
