Rb吸附石墨烯纳米带电子性质和光学性质的研究  

The electronic and optical properties of rubidium adsorbed on graphene nanoribbons

作　　者：王伟华[1] 罗杰 周嘉旭 WANG Wei-Hua;LUO Jie;ZHOU Jia-Xu(Extreme Conditions Physics Research Team,College of Mathematics and Physics,Inner Mongolia Minzu University,Tongliao 028000,China)

机构地区：[1]内蒙古民族大学数理学院极端条件物理科研团队,通辽028000

出　　处：《原子与分子物理学报》2024年第2期80-86,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11964026);内蒙古自治区自然科学基金(2016BS0107,2019MS01010,2019MS06017);内蒙古自治区高等学校科学技术研究项目(NJZZ22470,NJZZ19145);内蒙古民族大学科学研究基金(NMDYB20040)。

摘　　要：本文基于密度泛函理论的第一性原理方法了计算了Rb、O和H吸附石墨烯纳米带的差分电荷密度、能带结构、分波态密度和介电函数,调制了石墨烯纳米带的电子性质和光学性质,给出了不同杂质影响材料光学特性的规律.结果表明本征石墨烯纳米带为n型直接带隙半导体且带隙值为0.639 eV;Rb原子吸附石墨烯纳米带之后变为n型简并直接带隙半导体,带隙值为0.494 eV;Rb和O吸附石墨烯纳米带变为p型简并直接带隙半导体,带隙值增加为0.996 eV;增加H吸附石墨烯纳米带后,半导体类型变为n型直接带隙半导体,且带隙变为0.299 eV,带隙值相对减小,更有利于半导体发光器件制备.吸附Rb、O和H原子后,石墨烯纳米带中电荷密度发生转移,导致C、Rb、O和H之间成键作用显著.吸附Rb之后,在费米能级附近由C-2p、Rb-5s贡献;增加O原子吸附之后,O-2p在费米能级附近贡献非常活跃,C-2p、Rb-5s和O-2p电子态之间强烈的杂化效应,促使费米能级附近的杂质能级分裂成能带;再增加H原子吸附之后,Rb-4p贡献发生蓝移,O-2p在费米能级附近贡献非常强,费米能级分裂出两条能带.Rb、O和H的吸附后,明显调制了石墨烯纳米带的光学性质.Based on the first principles of density functional theory,in this paper,we calculate the differential charge densities,energy band structures,partial state densities and dielectric functions of Rb,O and H adsorbed graphene nanoscales,modulate the electronic and optical properties of graphene nanostrips,and study the laws of different impurities affecting the optical properties of materials.The results show that the intrinsic graphene nanostrip is an n-type direct bandgap semiconductor with a bandgap value of 0.639 eV.After the Rb atom adsorbed on graphene nanostrip,it becomes an n-type degenerate direct bandgap semiconductor with a bandgap value of 0.494 eV;Rb and O adsorbed graphene nanostrips become the p-type degenerate direct bandgap semi⁃conductors,and the bandgap value increases to 0.996 eV;after increasing the H adsorption on graphene nanostrip,its semiconductor type becomes n-type direct bandgap semiconductor with the smaller bandgap of 0.299 eV,which is more conducive to the preparation of semiconductor luminescent devices.After adsorptions of Rb,O and H atoms,the charge density in the graphene nanoribbon shifts,resulting in significant bonding between C,Rb,O and H.After adsorption of Rb,C-2p and Rb-5s contribute near the Fermi energy level.After in⁃creasing the adsorption of O atoms,O-2p contributes very actively near the Fermi energy level,and the hybridization of C-2p,Rb-5s and O-2p electronic states promotes the impurity levels near the Fermi level to split into energy bands.After adding H atom adsorption,the Rb-4p contribution is blue-shifted,and the O-2p contribution is very strong near the Fermi energy level,and the Fermi energy level splits into two energy bands.After the adsorption of Rb,O and H,the optical properties of graphene nanostrips are clearly modulated.

关 键 词：石墨烯纳米带 能带结构 光学性质 分波态密度 第一性原理 

分 类 号：O474[理学—半导体物理]