掺杂单层MoS_2电子结构的第一性原理计算

First Principles Calculation of Electronic Structure of Doped Monolayer MoS_2

采用第一性原理研究Cu,Ag,Au掺杂单层MoS_2的键长畸变、能带结构和态密度。探讨Cu,Ag,Au掺杂对单层MoS_2电子结构的影响。结果表明:Cu,Ag,Au在S位掺杂的杂质能都低于在Mo位掺杂的杂质能,其在S位掺杂的体系的稳定性强于在Mo位掺杂的体系。在S位掺杂时,杂质与最近邻的Mo,S原子的键长都发生了畸变,畸变率最大的是dAu-Mo,达23.8%。与单层MoS_2的超胞相比,掺杂体系的禁带中出现了4条新能级,导带和价带的能量向低能区移动。杂质原子周围存在着电荷聚集,同时也存在电荷损失。

Based on the first principle,the bond length,band structures and density of states of Cu,Ag and Au doped monolayer MoS2 were studied.The effects of Cu,Ag and Au doped on the monolayer MoS2 electronic structure were discussed.The results show that the impurity energy of Cu,Ag,Au doping at the S position always lower than that doping at the Mo position,so that there is the more stably of Cu,Ag,Au doping at the S position.When the Cu,Ag,Au dope at the S position,the bond length of impurity atom and nearest neighbor S,Mo atom are distorted,the maximum of aberration rate dAu-Mois up to 23.8%.Comparing with the monolayer MoS2,the doped system appears four new energy levels in forbidden band.The energy of the conduction band and valence band turns to the low energy region.Charge gathers around impurity atoms,at the same time,a charge loss exits.