La,Ce,Nd掺杂对单层MoS_2电子结构的影响

为了研究稀土掺杂对单层MoS2电子结构的影响,文章基于密度泛函理论框架下的第一性原理,采用平面波赝势方法分别计算了本征及La,Ce,Nd掺杂单层MoS2的晶格参数、能带结构、态密度和差分电荷密度.计算发现,稀土掺杂所引起的晶格畸变与杂质原子的共价半径大小有关,La杂质附近的键长变化最大,Nd杂质附近的键长变化最小.能带结构分析表明,La掺杂可以在MoS2的禁带中引入3个能级,Ce掺杂可以形成6个新能级,Nd掺杂可以形成4个能级,并对杂质能级属性进行了初步分析.差分电荷密度分布显示,稀土掺杂可以使单层MoS2中的电子分布发生改变,尤其是f电子的存在会使差分电荷密度呈现出反差极大的物理图象.

Effects of La,Ce and Nd doping on the electronic structure of monolayer MoS2

To study the effect of rare earth element doping on the electronic structure of monolayer MoS₂, the lattice parameters, band structures, density of states, and electron density differences of La, Ce and Nd doped and intrinsic monolayer MoS₂ are calculated, respectively, using first-principles density functional theory based on the plane wave pseudopotential method in this paper. Calculations indicate that variations of bond length near La impurity are maximum, but they are the minimum near Nd impurity. Analysis points out that lattice distortion in doped monolayer of MoS₂ is relative to the magnitude of the covalent radius of doping atom. Analysis of band structure shows that La, Ce and Nd doping can induce three, six and four energy levels, respectively, in the forbidden band of MoS₂, and that the properties of impurity levels are analyzed. Rare earth doped monolayer MoS₂ make change in electron distribution through the analysis of electron density difference, and especially, the existence of f electrons can induce the electron density difference to exhibit a physical image with a great contrast.
Keywords： first principles 2')" href="#">MoS₂ rare earth doping electronic structure