Ag掺杂对单层MoS_2的电子结构和光学性质影响

Effects of Ag-doped on Electron Structure and Optical Properties of Monolayer MoS_2

基于密度泛函理论框架下的平面波超软赝势方法,计算了Ag掺杂单层MoS_2中的能带结构、态密度和光学性质.计算结果显示单层MoS_2具有直接带隙结构,禁带宽度为1.63 eV;Ag掺杂后,Ag 4d与S 3p,Mo 4d发生轨道杂化,在费米能级处产生了多条杂化能级,表现为半金属特性,其中吸收峰、反射峰和能量损失峰峰值均有不同程度减小并向低能方向发生偏移,计算结果为Ag掺杂单层MoS_2的光电子器件制备提供了理论依据.

Based on the first principles method of density functional theory,the band structure and optical absorption properties of monolayer MoS_2 doped with Ag were calculated. The calculations showed that the intrinsic monolayer MoS_2 had a direct band gap structure with a value of 1.63 eV. When Ag-doped,there were some hybrid energy level at the Fermi level because of S 3p and Mo 4d which produced the orbital hybridization with Ag 4d. Peaks included the absorption peak,the reflection peak and the energy loss peak had decreased to varying degrees and shifted to the low energy direction. The calculated results provided a theoretical basis for the fabrication of optoelectronic devices with Ag-doped of monolayer MoS_2.