采用基于第一性原理的贋势平面波方法，对比研究未掺杂和分别掺杂非金属P、半导体Si 及金属Al 的单层MoS2的电子结构和光学性质。计算结果表明：掺杂均转变为p 型半导体且导带向低能方向显著偏移，带隙减小，掺P和Si 由K 点转变为Γ 点直接带隙、掺Al 形成K -Γ 间接带隙半导体；通过态密度和布局分析得出：掺杂改变载流子的浓度及杂质原子与S-3p、Mo-4d 形成的杂化轨道，对光学性质产生相应影响，其中掺Al 对MoS2 的光学性质影响最为显著，可增大MoS2的静态介电常数、折射率n0，降低能量损失。

The electric structure and optical properties of monolayer MoS1.89X0.11 have been calculated by the first-principle pseudo-potential method based on density functional theory (DFT). The results show that monolayer MoS1.89X0.11 (X=P, Si, Al) turn to a p-type semiconductor and the conduction band bottom is moved to the direction of low energy. The band gap of monolayer MoS2 of P-doped and Si-doped is turned from K-point to Γ point in the BZ. The band gap of monolayer MoS2 of Al-doped turned to an indirect semiconductor at K -Γ point. Through analyzing the density of states and decentralization of grid, the optical properties of monolayer MoS2 is changed for the variation of carrier concentration and the hybrid orbitals of impurity atoms with S-3p and Mo-4d, especially Al-doped is the most effect that the static dielectric constant and refractive index is increased and the energy loss function is reduced.