单层MoS_2吸附X_3(X=Cu,Ag,Au)团簇电子结构的第一性原理计算

First-principles study on electronic properties of monolayer MoS_2 with X_3(X = Cu,Ag,Au) cluster adsorbing

本文基于第一性原理方法采用密度泛函理论研究了单层MoS_2吸附Cu_3,Ag_3,Au_3团簇的稳定性、能带结构和态密度.通过研究发现单层MoS_2在S位吸附Cu_3,Ag_3,Au_3团簇稳定性强于在Mo位吸附;Cu_3,Ag_3,Au_3团簇在单层MoS_2表面吸附产生3条杂质能级,分别是Cu、Ag、Au原子与S形成共价键下的形成了施主能级与受主能级;Cu,Ag、Au拥有良好的金属性致使单层MoS_2向导体转变.吸附体系的态密度在低能区主要来源于S的3s、Mo的5s以及Cu、Ag、Au的3d、4d、5d轨道的贡献;能量值在-7.5eV^-1eV范围内Cu、Ag、Au的d轨道与S的p发生杂化,形成了较高的态密度峰值.费米能附近的电荷分布主要于Mo-S、Cu-S、Ag-S、Au-S的成键方向.

In this work,the structural stabilities,band structures and densities of states of monolayer MoS 2 adsorbed with X 3(X=Cu,Ag,Au)clusters are studied by first principles method.It is found that the stability of monolayer MoS 2 adsorbed with Cu 3,Ag 3 or Au 3 cluster in the S position is stronger than that in the Mo position;3 impurity levels related to the donor and acceptor levels formed by covalent bonds between X 3 and S atoms are emerged in the adsorption systems.The metallic properties of Cu,Ag,and Au lead to the transition of monolayer MoS 2 to conductors.The densities of states of the adsorption systems are mainly derived from Mo 3s,S 5s and 3d,4d and 5d orbitals of,respectively,Cu,Ag and Au in the low energy region.The d orbitals of Cu,Ag and Au are hybridized with the p orbitals of S,and a higher peak of density of states is formed in the range from-7.5 eV to-1 eV.At the same time,the charge distribution is mainly in the directions of Mo-S,Cu-S,Ag-S and Au-S bonds near the Fermi energy.