空位缺陷对单层MoS_2电子结构的影响  

Effects of Vacancy Defects on Electronic Structure of Monolayer MoS_2

作　　者：雷天民[1] 吴胜宝[1] 张玉明[1] 刘佳佳[1] 姜海青[1] 张志勇[2] 

机构地区：[1]西安电子科技大学,陕西西安710071 [2]西北大学,陕西西安710069

出　　处：《稀有金属材料与工程》2015年第3期608-611,共4页Rare Metal Materials and Engineering

基　　金：国家重大科技专项(2011ZX02707)

摘　　要：为了研究单层Mo S2中的空位缺陷形成及其对电子结构的影响,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单层Mo S2中Mo空位和S空位的形成能、空位附近的晶格畸变、Mo S2层中的电子分布以及态密度(DOS)和能带结构。计算结果显示,2种空位缺陷都具有点缺陷特征,其附近的电子分布呈现出明显的局域化特点,且S空位比Mo空位更容易形成。通过与本征态Mo S2电子结构的对比分析,发现2种空位缺陷的存在对单层Mo S2的电子结构、尤其是对导带高能量区域的能态密度会产生十分明显的影响,这些影响可能与空位缺陷引入的缺陷能级有关。In order to study the formation of vacancy defects and its impact on the electronic structure of monolayer Mo S2, Mo and S vacancy formation energy, the lattice distortion near the vacancy defects, and electron distribution, as well as density of states（DOS） and band structures in the monolayer Mo S2 were calculated in the plane wave pseudo-potential method, using the first-principle calculation based on the density function theory. The calculation results show that both vacancy defects have the point defect characteristics, their nearby electronic distribution shows clear localization features, and S vacancies are more easily formed than Mo vacancies. Comparing with the electronic structure of the intrinsic Mo S2, the existence of two kinds of vacancy defects has an effect on the electronic structure of monolayer Mo S2, especially density of states in high energy region of the conduction band, which may be related to defect levels introduced by vacancy defects.

关 键 词：第一性原理 MOS2 空位 电子结构 

分 类 号：O572.322[理学—粒子物理与原子核物理]