近年来二维过渡金属硫族化合物(transition metal dichalcogenides, TMDs)展现了优异的电输运性质。为了理解其结 构与性能的关系，本文利用第一性原理计算，深入研究了Se元素替换及双层堆垛对单层TMDs材料PtS₂电子结构及迁移率的影响，同时阐明了其背后的机理。研究发现，Se元素替换和双层堆垛均对价带顶附近的电子结构影响较大。电子结构的变化，使得单层结构的空穴迁移率随着元素替换数量的增加而减小，而双层堆垛能够较大幅度提升空穴迁移率。例如，在300 K下，由于等效电声耦合强度的减弱，在单层PtS₂上堆垛一层PtS₂或PtSe₂均可将空穴迁移率提升一个数量级。因此，堆垛是一种提升TMDs电输运性质的有效策略。我们的工作为进一步优化二维TMDs材料的电输运性质提供了理论指导。

 The excellent electrical transport properties of transition metal dichalcogenides (TMDs) materials have been demonstrated in recent years. To understand the relationship between structure and properties, first-principles calculations are carried out to study the electronic structure and mobility in two-dimensional PtS₂-like systems. The effects of Se substitution and double-layer stacking on the effective mass, electron-acoustic phonon coupling, and mobility are analyzed, revealing the influences on electrical transport properties. It is found that Se substitution and layer-stacking both have more influences on the valance band maximum than the conduction band minimum. Furthermore, the hole mobility in monolayer Pt(S_1-xSe_x)₂ decreases with the increase of Se concentration x. While mobility in bilayer systems such as PtS₂-PtS₂ , PtS₂-PtSe₂ are one-order larger than that in monolayer PtS₂ because of the so small electron-acoustic phonon coupling. Therefore, our work provides the theoretical guidance that the layer stacking is an effective way to optimize and improve the electrical transport in two-dimensional TMDs materials.