掺杂对锯齿形(Zigzag)石墨烯纳米带输运性质的影响

Doping Effects on the Transport Properties of Zigzag Graphene Nanoribbons

基于第一性原理计算,研究了掺杂对锯齿形石墨烯纳米带电子输运性质的影响。研究发现,掺杂原子种类、掺杂位置的不同将对电子输运产生极大的影响。当中间散射区域的中心C原子被B杂质原子代替时,在电子输运谱的费米能级以下会出现一个零透射的波谷,而另一侧则不变;当带中心杂质为N原子时情况正好相反。零透射波谷的出现意味着有带隙产生,即发生了从金属到半导体的转变。当杂质原子从中心位置移到带边缘时,波谷将移到费米能级的另一侧,从而引起从受主到施主特征的转变,这是杂质原子的束缚态与边缘态相互作用的结果。

The doping effects on the transport properties of zigzag graphene nanoribbons（ZGNR） are investigated using first-principles calculations. It is found that the transport properties of ZGNR are strongly dependent on the doped materials,as well as the position of the dopants. When the impurity B or N is placed at the center of the nanorib bons, there is a zero-transmission Lorentzian dip appearing at the opposite side of the Fermi level, and eventually induces a transition of the zigzag GNR from metallic to semiconducting. When the impurity approaches the edge, the dip moves to another side of the Fermi level. That is, an unusual acceptor-donor transition is observed in zigzag nanorib bons, which is due to the interaction between the bound state of impurity and the edge states.