扶手椅型单壁碳纳米管中的B/N对共掺杂  

Boron/nitrogen pairs doping in armchair single-walled carbon nanotubes

作　　者：徐慧[1] 肖金[1] 欧阳方平[1] 

机构地区：[1]中南大学物理科学与技术学院,长沙410083

出　　处：《物理学报》2010年第6期4186-4193,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50504017);湖南省自然科学基金(批准号:07JJ3102);中南大学理科发展基金(批准号:08SDF02;09SDF09)资助的课题~~

摘　　要：利用第一性原理电子结构计算方法,研究了扶手椅型单壁碳纳米管(SWCNT)的B/N对掺杂效应.研究发现,对于扶手椅型SWCNT两个不同的掺杂位点,B/N对更容易发生在与管轴线成30°角的P1位点上.B/N对的掺杂使得金属性SWCNT能隙打开,且能隙随着B/N对轴向掺杂浓度的升高而逐渐增大.同时,还发现两B/N对掺杂后SWCNT的电子结构敏感地依赖于B/N对在圆周上的相对位置,能隙随着B/N对相对距离的增大而增大.这归结于B/N对的掺入影响了原有的电荷分布,这种影响是局域的,B/N对相对距离的增大使得B/N对总的影响区域也增大.这些研究结果有助于获得纯净的半导体,并能对其电子结构进行有效的控制.By performing first principles electronic structure calculations,we have revealed the effect of boron/nitrogen pairs doping in armchair single-walled carbon nanotubes （ SWCNT）. It is shown that for two kinds of sites in the armchair SWCNT,the doping of B/N pairs can more easily happen on the P1 site which is at 30° angle to the tube axis. An energy gap is opened in metallic SWCNT by doping B/N pairs,and the energy gap increases with raising the axial concentration of the B/N pairs. Moreover,when two couples of B/N pairs are doped in SWCNT,the electronic structure is sensitive to the relative positions of B/N pairs in the couple along the circumference of tubes. It’s due to that the original charge distribution is changed by B/N pairs doping,and the effect of B/N pairs is localized. When the distance between B/N pairs increases,the extent of the effect is increased. This result may contribute to preparing pure semiconductor and effectively controlling the electronic structure.

关 键 词：单壁碳纳米管 B/N对掺杂 电子结构 第一性原理 

分 类 号：O483[理学—固体物理]