具有可调谐电子性能的AlAs/CdS异质结的第一性原理计算  

First-principles calculations of AlAs/CdS heterostructure with tunable electronic properties

作　　者：赵佳恒 栾丽君[1] 陈晶亮 张研[1] 杨云[2] 魏星 樊继斌[1] 刘剑[3] 田野[4] 段理[1] ZHAO JiaHeng;LUAN LiJun;CHEN JingLiang;ZHANG Yan;YANG Yun;WEI Xing;FAN JiBin;LIU Jian;TIAN Ye;DUAN Li(School of Materials Science and Engineering,Chang’an University,Xi’an 710061,China;School of Information Engineering,Chang’an University,Xi’an 710061,China;School of Physics,Shandong University,Jinan 250100,China;Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]长安大学材料科学与工程学院,西安710061 [2]长安大学信息工程学院,西安710061 [3]山东大学物理学院,济南250100 [4]中国科学院物理研究所,北京100190

出　　处：《中国科学：物理学、力学、天文学》2022年第9期32-42,共11页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家重点研发计划(编号:2018YFB1600200);国家自然科学基金(编号:51802025);陕西省科技计划项目(编号:2019JQ-676,2020KWZ-008)资助。

摘　　要：本文采用基于密度泛函理论(Density Functional Theory, DFT)的第一性原理计算了AlAs/CdS异质结的几何结构、电子和光学性质.结果显示, AlAs/CdS异质结是具有0.688 eV直接带隙的Ⅱ型范德华(vdW)异质结,这有利于促进光生电子-空穴对的有效分离.当给异质结施加电场和应变时,异质结的带隙均可以调控为零,成功实现半导体到金属的转变,同时还伴随直接带隙-间接带隙的改变.更有趣的是,与两个单层相比, AlAs/CdS异质结的光吸收系数更高,吸收范围更加宽泛.上述特性表明AlAs/CdS异质结在光电探测器等光电子器件领域具有极大潜力.In this study, the first-principles based on density functional theory(DFT) are exploited to calculate the geometric structure, electronic and optical properties of the AlAs/CdS van der Waals heterostructure. According to our results, the AlAs/CdS heterostructure possesses type-Ⅱ band alignment and a direct band gap of 0.688 eV, which is beneficial to the spatical effective separation of photogenerated electron-hole pairs. When the external electric field and strain are applied,a transition from the semiconductor to the metal is successfully accomplished. Additionally, the band structure of the heterostructure can be changed to an indirect band gap by the external electric field as well as strain. More interestingly,compared with the monolayers, the light absorption coefficient of the AlAs/CdS heterostructure is higher and the absorption range is wider. The above-mentioned characteristics indicate that the novel two-dimensional(2D) AlAs/CdS heterostructure can be potentially used in the fields of optoelectronic devices such as photodetectors.

关 键 词：第一性原理 AlAs/CdS异质结 外加电场 应变 能带对准 

分 类 号：O469[理学—凝聚态物理]