表面修饰对硅锗合金纳米线的内部键长分布及能带影响的机理研究  

Influence of various surface passivations on bond length and band structure for Si-Ge alloy nanowires

作　　者：徐祥福[1] 雷露军 李天乐[1] 朱伟玲[1] 陈星源[1] XU Xiang-Fu;LEI Lu-Jun;LI Tian-Le;ZHU Wei-Ling;CHEN Xing-Yuan(Guangdong University of Petrochemial Technology,Maoming 525000,China)

机构地区：[1]广东石油化工学院应用物理系

出　　处：《原子与分子物理学报》2019年第6期946-952,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(61475195,11547201);广东省自然科学基金(2015A030313873,2017A030307008)

摘　　要：采用密度泛函第一性原理方法,研究了三种不同官能团修饰对硅锗<111>方向纳米线内部键长分布的不均匀性及能带影响,计算结果表明CH 3修饰加剧了键长分布不均性,与其它两个官能团相比,键长峰值弱化,键长范围扩大,也就是键长发生了再分布,F修饰对键长表现出了拉力效应,但并没有引起键长的再分布.同时,通过计算电子性质,以H修饰纳米线为参考,因不同官能团修饰对键长不均匀性的影响不同,使能带Z点位置下移幅度不同,CH 3修饰纳米线下移幅度最大,F次之,H修饰的下移幅度最小,这为利用不均匀性调控电子结构提供了理论依据.The effect of three various surface passivations on the<111>orientation Si-Ge alloy nanowires`structural inhomogeneity was studied by the first principle.The calculated results show that CH 3 surface passivation aggravates the structure inhomogeneity and leads to the bond length redistributed.The F modification shows the tensile stress response to the bond length,without causing the redistribution of the bond length.Moreover,the effects of different functional group modifications on the intrinsic inhomogeneity are different by calculating the electron density and using H modified nanowires as reference,which lead the Z point position of the energy band to move down differently.CH 3 surface passivation makes the maximum Z point down.These conclusions could provide a theoretical reference for the use of inhomogeneity to regulate the electronic structure of Si-Ge alloy nanowires.

关 键 词：第一性原理 硅锗合金纳米线 表面修饰官能团 键长再分布 

分 类 号：O562[理学—原子与分子物理]