缺陷对石墨烯电子结构的影响

摘要

First-principles calculations within the generalized gradient approximation（GGA） and density functional theory（DFT） are carried out on the electrical structure of eigen and defective Graphene supercell.Several defects,including Stone-Wales defects,single vacancy defects and double vacancy defects,and their effects on the electrical properties of Graphene are studied.It is found that the existence of the several defects are all accompanied with new energy states in the gap,and magnify the Graphene＇s band gap to a corresponding degree,and the density of state changes accordingly.Stones-wales defects add the Graphene＇s band gap up from 0e V to 0.637 eV,and single vacancy defects to 1.591 eV,and double vacancy defects to 1.207 eV.%基于第一性原理计算方法,通过密度泛函理论（DFT）和广义梯度近似（GGA）对本征及含有缺陷的石墨烯超晶胞进行了电子结构的计算,研究了多种缺陷对石墨烯电子结构的影响。研究发现,多种缺陷均使石墨烯能带在费米能级附近出现缺陷态对应的能带,并导致其能隙有不同程度的增大,而且与之对应的态密度也随之发生相应的变化。其中,Stone-Wales缺陷使石墨烯带隙由0 eV增至0.637 eV,单空位缺陷使带隙由0 eV增至1.591 eV,双空位缺陷使带隙由0 eV增至1.207 eV。