新型二维SiO_(2)结构及面内应变对其光电性质影响的第一性原理研究  

A Novel Two-dimensional SiO_(2) Structure and Influence of In-plane Strain on Its Photoelectric Properties:First-principles Study

作　　者：刘雪婷 刘禹成 赵子昂 王丹丹[1,2] 张勇[1,2] 冯明[1,2] LIU Xueting;LIU Yucheng;ZHAO Ziang;WANG Dandan;ZHANG Yong;FENG Ming(College of Physics,Jilin Normal University,Siping 136000,China;Key Laboratory of Functional Materials Physics and Chemistry of Ministry of Education,Jilin Normal University,Changchun 130022,China)

机构地区：[1]吉林师范大学物理学院,吉林四平136000 [2]吉林师范大学功能材料物理与化学教育部重点实验室,吉林长春130022

出　　处：《发光学报》2023年第8期1496-1504,共9页Chinese Journal of Luminescence

基　　金：吉林省自然科学基金(YDZJ202201ZYTS307,20210101409JC)。

摘　　要：SiO_(2)通常以三维晶体或无定形结构存在,限制了其在新技术如新一代集成电路中的应用,因此二维SiO_(2)的研究引起了越来越多的关注。本文通过删除三维层状CaAl_(2)Si_(2)O_(8)结构中的Ca和Al原子,直接构建出新的二维SiO_(2)构型。采用基于密度泛函理论的第一性原理计算,结构优化获得的新型2D SiO_(2)具有P⁃62m对称性,群号189。通过结合能、弹性系数、分子动力学模拟和声子谱计算,发现新型2D SiO2具有高机械稳定性、热力学稳定性和动力学稳定性。电子性质和光学性质计算发现,2D SiO_(2)是带隙为6.08 eV绝缘体,且具有良好的光透射率和光导率。此外,通过研究面内双轴应变对2D SiO_(2)电子和光学性质的影响,发现2D SiO_(2)的带隙和介电函数受面内拉伸应变的影响较压缩应变略大,不过其整体光学性质受应变影响不大,保证了其在实际应用中电子性质和光学性质的稳定性。SiO_(2) usually exists in three-dimensional crystal or amorphous structure,which limits its application in new technologies such as new integrated circuits,so the research on two-dimensional SiO_(2) has attracted more and more attention.In this paper,a new two-dimensional SiO_(2) configuration is constructed directly by removing Ca and Al atoms from the three-dimensional layered CaAl_(2)Si_(2)O_(8) structure.Using the first principles calculation based on density functional theory,the structure optimization results in the new 2D SiO2 with P⁃62m symmetry and group number 189.Through calculating binding energy,elastic coefficient,molecular dynamics simulation and phonon spectrum,it is found that the new 2D SiO_(2) has high mechanical,thermodynamic and dynamic stability.Further calculations of electronic and optical properties show that 2D SiO2 is an insulator with band gap of 6.08 eV,and has good optical transmittance and optical conductivity.In addition,by studying the effect of in-plane biaxial strain on the electronic and optical properties of 2D SiO_(2),it is shown that the band gap and dielectric function of 2D SiO_(2) are slightly more affected by the in-plane tensile strain than by the compression strain,but the strain impact on the overall optical properties of 2D SiO_(2) is modest,which ensures the stability of the electronic and optical properties in practical applications.

关 键 词：二维SiO_(2) 电子性质 光学性质 第一性原理计算 

分 类 号：O482.31[理学—固体物理]