非金属元素掺杂二硒化钨/石墨烯异质结对其肖特基调控的理论研究  

Theoretical study on Schottky regulation of WSe2/graphene heterostructure doped with nonmetallic elements

作　　者：马浩浩 张显斌[1] 魏旭艳 曹佳萌 Ma Hao-Hao;Zhang Xian-Bin;Wei Xu-Yan;Cao Jia-Meng(School of Science,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]西安理工大学理学院,西安710048

出　　处：《物理学报》2020年第11期215-225,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60771053,60971015);陕西省创新能力支撑计划(批准号:2018PT-27)资助的课题.

摘　　要：采用平面波超软赝势方法研究了非金属元素掺杂对二硒化钨/石墨烯肖特基电子特性的影响.研究表明二硒化钨与石墨烯层间以范德瓦耳斯力结合形成稳定的结构.能带结果表明二硒化钨与石墨烯在稳定层间距下形成n型肖特基势垒.三维电子密度差分图表明石墨烯中的电子向二硒化钨移动,使二硒化钨表面带负电,石墨烯表面带正电,界面形成内建电场.分析表明,将非金属原子掺杂二硒化钨可以有效地调控二硒化钨/石墨烯肖特基势垒的类型和高度. C, O原子掺杂二硒化钨时,肖特基类型由p型转化为n型,并有效降低了肖特基势垒的高度;N, B原子掺杂二硒化钨时,掺杂二硒化钨体系表现出金属性,与石墨烯接触表现为欧姆接触.本文结果可为二维场效应晶体管的设计与制作提供相关指导.In order to effectively control the type and height of Schottky barrier,it is crucial to appropriately select the material and method of controlling the type and height of the Schottky barrier effectively.Two-dimensional materials exhibit massive potential in research and development due to their unique electrical,optical,thermal and mechanical properties.Graphene is a two-dimensional material found earliest,which has many excellent properties,such as high carrier mobility and large surface area.However,single-layered graphene has a zero band gap,which limits its response in electronic devices.Unlike the graphene,the transition metal sulfides have various band structures and chemical compositions,which greatly compensate for the defect of zero gap in graphene.From among many two-dimensional transition metal sulfides,we choose WSe2.The reason is that the single-layered WSe2 possesses the photoelectric excellent performance,band gap that can meet the majority of requirements in electronic and photoelectric devices,and transport properties that can be adjusted to p-type or bipolar which is first found in semiconductor materials.And compared with metal,the graphene at room temperature has superior properties such as high electron mobility,resistivity of 10-6 W·m lower than copper and silver,coefficient of thermal conductivity 5300 W/(m·K)large than 10 times that of copper,aluminum and other metal,and hardness exceeding the diamond,fracture strength up to 100 times more than that of iron and steel.The Two-dimensional semiconductors along with semimetallic graphene are seen as the basic building blocks for a new generation of nanoelectronic devices,in this sense,the artificially designed transition metal sulfide heterostructure is a promising option for ultrathin photodetectors.At present,most researchers focus on the control of the type and height of Schottky via heterojunction doped metallic element.However,there are few Schottky that are doped by nonmentallic element.Therefore,our work provides the interaction bet

关 键 词：异质结 二硒化钨 能带调控 第一性原理 

分 类 号：TB33[一般工业技术—材料科学与工程]