Cr、Sn、Co掺杂对层状二维材料MoSi2N4的电子和光学性能的影响

基于新合成的二维材料MoSi₂N₄（MSN），我们建立了一系列MSN的掺杂模型进行了第一原理计算。首先，我们计算了本征MSN的电子特性，包括其能带结构和态密度。然后我们研究了Cr、Sn和Co掺杂对MSN的电子和光学性质的影响。结果表明，在3种掺杂体系中，Co掺杂体系表现出最低的形成能，这表明Co掺杂体系是最稳定的。通过带隙计算表明，尽管3种掺杂模型都降低了MSN的固有带隙，但却表现出3种不同的电子特性。态密度图也显示，Cr和Co掺杂体系都在导带底（CBM）和价带顶（VBM）附近产生局部尖峰。此外，光学性质的计算中表明，掺杂后体系的光学性质也得到了改善。

Effects of Cr, Sn, Co Doping on Electronic and Optical Properties of Layered Two-Dimensional Material MoSi2N4

Based on the newly synthesized two-dimensional material MoSi₂N₄ (MSN), we developed a series of doped models of MSN for first-principles calculations. Firstly, we calculated the electronic properties of intrinsic MSN, including its band structure and density of states. Then we investigated the effects of Cr, Sn, and Co-doping on the electronic and optical properties of MSN. Our work demonstrates that the Co-doped system exhibits the lowest formation energy among the three doped systems, which indicates that the Co-doped system is the most stable one. The calculations of band gaps show that although all three doped models decrease the band gap of intrinsic MSN, three doped systems exhibit three different electronic properties. The densities of state diagrams also show that the Cr-doped system and the Co-doped system both produce local spikes near conduction band minimum (CBM) and valence band maximum (VBM). Furthermore, the optical properties of the MSN have also been improved a lot after doping.