We systematically investigated the modulation of heat transport of experimentally accessible two-dimensional (2D) group-III chalcogenides by first-principles calculations. It was found that intrinsic thermal conductivity (κ) of chalcogenides MX (M = Ga, In; X = S, Se) were desirable for efficient heat dissipation. Meanwhile, we showed that the long-ranged harmonic and anharmonic interactions played an important role in heat transport of the chalcogenides. The difference of κ among the 2D group-III chalcogenides can be well described by the Slack model and can be mainly attributed to phonon group velocity. Based on that, we proposed three methods including strain engineering, size effect and making Janus structures to effectively modulate the κ of 2D group-III chalcogenides, with different underlying mechanisms. We found that tensile strain and rough boundary scattering could continuously decrease the κ while compressive strain could increase the κ of 2D group-III chalcogenides. On the other side, the change of κ by producing Janus structures is permanent and dependent on the structural details. These results provide guilds to modulate heat transport properties of 2D group-III chalcogenides for devices application.

我们通过第一性原理计算系统地研究了实验可访问的二维 (2D) III 族硫属化物的热传输调制。发现硫属化物MX（M = Ga，In；X = S，Se）的固有热导率（κ）对于有效散热是理想的。同时，我们发现长程谐波和非谐波相互作用在硫属化物的热传输中起着重要作用。Slack 模型可以很好地描述二维 III 族硫属化物之间κ的差异，并且主要归因于声子群速度。在此基础上，我们提出了三种方法，包括应变工程、尺寸效应和制造 Janus 结构来有效调节κ二维 III 族硫属化物，具有不同的潜在机制。我们发现拉伸应变和粗糙边界散射可以不断降低κ，而压缩应变可以增加2D III 族硫属化物的κ 。另一方面，通过产生 Janus 结构来改变κ是永久性的，并且取决于结构细节。这些结果为调节用于器件应用的二维 III 族硫属化物的热传输特性提供了依据。