Li吸附对石墨烯、BC_7、C_7N电学性质影响的第一性原理研究  

First Principle Study on the Effect of Li Adsorption on Electrical Properties of Graphene,BC_7,C_7N

作　　者：刘学杰[1] 贾颖[1] 姜远涛 李沛艾 任元[1] 

机构地区：[1]内蒙古科技大学机械工程学院,包头014010

出　　处：《人工晶体学报》2015年第3期823-829,851,共8页Journal of Synthetic Crystals

基　　金：国家自然科学基金(50845065);内蒙古自治区自然科学基金(2014MS0516)

摘　　要：基于密度泛函理论(DFT)的第一性原理方法,对Li在本征石墨烯、BC7和C7N表面最稳定位置的吸附进行了结构优化,计算了本征石墨烯、BC7和C7N吸附Li前后的能带结构,态密度,电荷转移,差分电荷密度和结合能。结果表明,B掺杂浓度为12.5%(原子分数)时可显著提高石墨烯的Li吸附能,N掺杂浓度为12.5%(原子分数)时减弱了石墨烯的Li吸附能。吸附Li后的graphene-Li、BC7-Li和C7N-Li体系均显示出金属性,且Li与石墨烯、BC7和C7N体系间存在离子键和共价键的混合。The geometrical structures of Li atom adsorption on the most stable sites of pristine graphene and BC7,C7 N surface were optimized by first principle method based on density functional theory（ DFT）. The band structures,density of states（ DOS）,electron transferring,electron density differences and binding energies of both pristine graphene and BC7,C7 N were calculated theoretically. The calculated results reveal that,the adsorbing energy of Li atom on graphene remarkably increases when Bdoping concentration is 12. 5%; however, it decreases when N-doping concentration is 12. 5%.Graphene-Li,BC7-Li and C7N-Li all have metal properties. There is mixed ionic and covalent bonds between Li and graphene,BC7 and C7N.

关 键 词：第一性原理 石墨烯 Li吸附 电子结构 

分 类 号：O469[理学—凝聚态物理]