双轴应变对二维IV-VI硫族化合物电子特性的影响  

Effect of biaxial strain on the monolayer binaryⅣ-Ⅵchalcogenides

作　　者：郭颖 赵高扬[1] GUO Ying;ZHAO Gaoyang(School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, China;School of Physics and Telecommunication Engineering, Shaanxi Key Laboratory of Catalysis,Shaanxi University of Technology, Hanzhong 723001, China)

机构地区：[1]西安理工大学材料科学与工程学院,西安710048 [2]陕西理工大学物理与电信工程学院,陕西汉中723001

出　　处：《功能材料》2022年第1期1104-1111,共8页Journal of Functional Materials

基　　金：陕西省科技厅青年项目(2021JQ-749);陕西省教育厅2019年度重点科学研究计划项目(19JS009)。

摘　　要：利用密度泛函理论(density function theory,DFT)模拟计算了二维Ⅳ-Ⅵ硫族化合物(MXs:SnS、SnSe、SnTe、GeS、GeSe和GeTe)的本征结构和电子特性,重点研究了双轴应变对MXs的能带结构特点、带隙大小和费米能级的影响。发现应变对单层MXs的色散关系影响不大,但是对带隙大小的影响较大,而且压缩应变对带隙的影响大于拉伸应变。同时应变还可以调节GeSe、GeTe、SnSe和SnTe的直接带隙与间接带隙之间的转换。在应变的作用下单层MXs的费米能级随应变系数ε值的增加而降低,且压缩应变的影响大于拉伸应变的影响。采用应变工程研究二维MXs电子特性的变化趋势能为下一步实验上设计出高性能的二维半导体器件提供理论依据。The structural and electronic properties of the binaryⅣ-Ⅵchalcogenides MXs(GeS,GeSe,GeTe,SnS,SnSe,and SnTe)are researched by using density functional theory.The energy band structures,bandgaps,and Fermi level of monolayer MXs are investigated under the external in-plane biaxial strains in a range of-5%-5%.The band structure of monolayer MXs with strains is similar to those without strains,while the bandgaps change so sharply.The bandgap variation of monolayer MXs induced by compressive strain is larger than the corresponding tensile strain.The indirect-to-direct-bandgap-transformation of GeSe,GeTe,SnSe,and SnTe can be obtained while the strain is enforced.The Fermi level of monolayer MXs monotonically decreases with increasing the values of strainε,and it can be seen that compressive strain is more effective than the corresponding tensile strain.We hope the convertibility electronic properties of monolayer MXs by the strain is helpful to the experimentally on the electronic and optical devices.

关 键 词：密度泛函理论 双轴应变 单层MXs 带隙 

分 类 号：O472.4[理学—半导体物理] TB34[理学—物理]