B/N掺杂对双层石墨烯电子特性影响的第一性原理研究

利用平面波超软赝势方法研究了B/N原子单掺杂和共掺杂对双层石墨烯电子特性的影响.对掺杂双层石墨烯进行结构优化,并计算了能带结构、态密度、分波态密度等.分析表明,层间范德瓦尔斯相互作用对双层石墨烯的电子特性有比较明显的影响;B/N原子单掺杂分别对应p型和n型掺杂,会使掺杂片层的能带平移,使得体系能带结构产生较大分裂;双层掺杂的石墨烯能带结构与掺杂原子的相对位置和距离有关,对电子特性有明显的调控作用.其中特别有意义的是,B/N双层共掺杂在不同位置情况下会得到金属性或禁带宽度约为0.3 eV的半导体能带.

First-principles calculations of electronic structure for B/N doped bilayer graphene

The effect of B/N doping on bilayer graphene is investigated using the density functional theory. After relaxing the structures of doped bilayer graphene, the band structures, density of states and partial density of states are calculated. The computed results show that the interlayer van der Waals interaction obviously affects the electronic character. B or N mono-doping method results in the p-type or n-type trait respectively, which moves the corresponding Fermi level and then splits the band structure distinctly. The band characters of B/N bilayer doping are related with the doping sites and reciprocal distance. Interestingly, either conductive or semi-conductive band (with a gap about 0.3eV) can be obtained by using different B/N bilayer co-doping sites.