摘要
GeSe作为二维材料的新成员,近年来引起了人们的广泛关注。文章采用第一性原理方法,选取PBE泛函和HSE06杂化泛函,研究了二维GeSe材料的电子结构和光学性质。结果表明:二维GeSe是带隙为1.56 eV的间接带隙半导体,价带顶和导带底分别位于Γ-Y方向和Γ-X方向,价带主要由Ge-4p和Se-4p杂化而成,且价带顶边缘附近出现Ge-4s态,这对二维GeSe的电子结构有重要影响;从能带结构和态密度出发,系统研究了二维GeSe的折射、消光和吸收等光学性质;介电函数虚部的第一个峰值出现在2.15 eV,对应电子从第一个价带到第一个导带的跃迁,主要是电子从Ge-s、Se-pz态到Ge-px、py、pz态的跃迁。沿zigzag方向和armchair方向的静态介电常数分别为7.56和7.00。二维GeSe的吸收边缘在1200 nm左右,对可见光波有很强的吸收且具有较强的光偏振敏感性。研究结果表明GeSe在光学和光电子等领域极具应用潜力。
GeSe,as a new member of two-dimensional materials,has attracted extensive attention in recent years.The electronic structure and optical properties of two-dimensional GeSe were systematically studied by using the PBE as well as the HSE06 hybrid functional.The results show that two-dimensional GeSe is an indirect band gap semiconductor with a band gap of 1.56 eV.The valence band maximum and the conduction band minimum are located in theΓ-Y andΓ-X directions,respectively.The valence band is mainly composed with Ge-4p and Se-4p states,and the Ge-4s state appears near the edge of the valence band,which has an important influence on the electronic structure of two-dimensional GeSe.Based on the band structure and density of states,the optical properties of two-dimensional GeSe,including its optical refraction,extinction and absorption,were systematically studied.The first peak of the imaginary part of the dielectric function appears at 2.15 eV,which corresponds to the transition of electrons from the first valence band to the first conduction band,mainly from Ge-s,Se-pz to Ge-px,py,pz.The static dielectric constant along zigzag and armchair direction is 7.56 and 7.00,respectively.The absorption edge of two-dimensional GeSe is about 1200 nm.The strong absorption in visible light range,and optical anisotropy of two-dimensional GeSe greatly stimulate its widely applications in optical and optoelectronic field.
作者
范强
青海银
曹进
杨建会
FAN Qiang;QING Haiyin;CAO Jin;YANG Jianhui(School of Electronic and Material Engineering,Leshan Normal University,Leshan Sichuan 614000 China;School of Mathematics and Physics,Leshan Normal University,Leshan Sichuan 614000 China)
出处
《乐山师范学院学报》
2021年第8期1-6,19,共7页
Journal of Leshan Normal University
基金
四川省教育厅科研项目“高效SnSe基热电材料的多晶制备、性能及应用研究”(18CZ0030)
乐山市科技局科技计划项目“新型热电材料SnSe的多晶制备与性能研究”(19GZD006)和“掺杂提高n型GeSe热电性能”(20GZD033)
乐山师范学院科研项目“硒化锗的掺杂调控及热电性能研究”(LZD022)和“硫族热电材料的可控制备与性能研究”(LZDP014)
关键词
二维GeSe
电子结构
光学性质
第一性原理
Two-dimensional GeSe
Electronic Structure
Optical Properties
First Principle
