B(N)掺杂单壁碳纳米管的Al原子吸附性能的第一性原理研究  

First-principle study of the effect of boron (nitrogen)-doping on adsorbing characteristics of aluminum on single-walled carbon nanotubes

作　　者：王昆鹏[1] 师春生 赵乃勤[1] 杜希文[1] 

机构地区：[1]天津大学材料科学与工程学院,天津市材料复合与功能化重点实验室,天津300072

出　　处：《物理学报》2008年第12期7833-7840,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50771071)资助的课题~~

摘　　要：采用基于密度泛函理论的平面波赝势方法和广义梯度近似,对未掺杂、掺B、掺N的碳纳米管(CNT)不同位置上Al原子的吸附进行了几何优化,计算了吸附Al、掺杂前后CNT的能带结构、态密度、差分电荷密度、电荷布居数和吸附能.计算结果表明,掺B使CNT形成缺电子状态,利于具有自由电子的Al原子的吸附结合,可显著提高Al在金属性的(5,5)CNT和半导性的(8,0)CNT外壁的吸附能;掺杂N形成多电子状态,在费米能级附近半满的施主能级也利于填充Al的价电子,改善Al在(5,5)CNT和(8,0)CNT外壁的吸附结合性.掺B提高了Al与CNT的离子性键结合,掺N提高了Al与CNT的共价性键结合,均改善了CNT外壁Al原子的吸附,此种方法有望改善Al基体和CNT之间的界面结合.The geometrical structures of adsorbed aluminum atoms on different sites of undoped and boron （ nitrogen）-doped single- walled carbon nanotubes （SWCNTs） were optimized using plane wave pseudopotential method with generalized gradient approximation based upon the density functional theory. The band structures, density of states, electron density difference, Mulliken population, adsorption energies of both undoped and boron （nitrogen）-doped SWCNTs were calculated theoretically. The results revealed that boron-doping enhances the adsorption energy Ea of Al on metallic （5,5） CNTs and semiconducting （8, 0） CNTs by forming an electron-deficient structure filled with the electrons offered by Al atom. Meanwhile the results also suggest that nitrogen-doping increases Ea of Al on SWCNTs by forming electron-rich half-filled donor structure around Fermi level filled with the electrons of Al atom. Boron- and nitrogen-doping enhance the adsorption energy Ea by forming ionic-bond-type and covalent-bond-type bonds, respectively. The doping effect may also be beneficial to strengthening contact of interfaces between Al matrix and CNTs.

关 键 词：密度泛函理论 单壁碳纳米管 B(N)掺杂 Al原子吸附 

分 类 号：O472[理学—半导体物理]