Mn-O共掺单层MoS2磁性和光学性质的第一性原理研究

First-principles study on properties of magnetic and optical of Mn-O co-doped MoS2 monolayer

摘要:

基于第一性原理自旋极化密度泛函计算了O，Mn单掺杂和Mn-O共掺杂MoS2单层系统的电子结构、磁性和光学性质. 在Mn和Mn-O掺杂后，由于自旋向上通道中杂质带的出现，导致MoS2单层系统从自旋向上和自旋向下态密度完全对称的非磁性半导体转变为磁矩1〖 μ〗_B和1.08〖 μ〗_B的铁磁半导体，磁矩主要集中在掺杂的Mn原子上，而自旋向下通道仍保持半导体特征，其自旋间隙分别为1.613和0.396 eV. 同时发现Mn-O共掺杂后，在低能量区域(0~2.5 eV)，其介电常数、折射系数和吸收系数相比未掺杂和O单掺杂的MoS2系统增强显著，并出现了红移现象.

Abstract:

The electronic structure, magnetic properties and optical properties of the O, Mn single doped and Mn-O co-doped MoS2 monolayer systems are calculated based on the first-principles spin-polarization density functional theory. For Mn and Mn-O doped, the MoS2 monolayer system evolve from a completely symmetric band structures in spin-up and spin-down channels to a half-metal (HM) ferromagnet with completely (100%) spin polarization. their magnetic moments are 1 μB and 1.08 μB, mainly concentrated on the doped Mn atoms. while the spin-down channel remains semiconducting character but with a smaller spin-down gap of 1.613 and 0.396 eV due to appearance of the impurity bands. Meanwhile, in the low energy region (0~2.5 eV), it’s dielectric constant, refractive index and absorption coefficient are significantly enhanced compared with the undoped and O-doped MoS2 system, red shift phenomenon appear after Mn-O co-doped.