Abstract The structural, magnetic, electronic and optical properties of the pure and Mn-X (X = O, S, Se or Te) codoped monolayer WSe2 systems are quantitatively examined through first-principles calculations. The lower formation energy under Se-rich condition shows that the codoped systems under Se-rich condition is more stable than W-rich condition, especially the Mn-O codoping is the most stable with the minimum formation energy -2.08 eV. Although the pure monolayer WSe2 is a nonmagnetic semiconductor, the codoped systems are all magnetic with total magnetic moments of 1.00 µB due to the introduced one unpaired electron. It is worth mentioning that the Mn-Se and Mn-Te codoping make the monolayer WSe2 display magnetic half-metallic properties. Finally, the optical properties of the pure and codoped monolayer WSe2 are studied in x (parallel to the WSe2 plane) and z (perpendicular to the WSe2 plane) directions. An interesting red-shift phenomenon has been observed in the curves of imaginary part of the dielectric function and absorption spectra for the Mn-X codoping, suggesting their quite promising applications in optoelectronic devices.

中文翻译：

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通过 Mn-X（X=O、S、Se 或 Te）共掺杂改善单层 WSe2 的磁、电子和光学性能

摘要 通过第一性原理计算定量研究了纯和 Mn-X（X = O、S、Se 或 Te）共掺杂单层 WSe2 系统的结构、磁性、电子和光学性质。富硒条件下较低的形成能表明富硒条件下的共掺杂体系比富W条件下更稳定，尤其是Mn-O共掺杂最稳定，最小形成能-2.08 eV。虽然纯单层 WSe2 是一种非磁性半导体，但由于引入了一个不成对电子，共掺杂系统都是磁性的，总磁矩为 1.00 µB。值得一提的是，Mn-Se 和 Mn-Te 共掺杂使单层 WSe2 显示出磁性半金属特性。最后，在 x（平行于 WSe2 平面）和 z（垂直于 WSe2 平面）方向上研究纯和共掺杂单层 WSe2 的光学特性。在Mn-X共掺杂的介电函数虚部曲线和吸收光谱中观察到了一个有趣的红移现象，表明它们在光电器件中的应用前景广阔。