采用格林函数方法研究了堆叠石墨片对锯齿型石墨纳米带电子输运性质的影响,计算了两种不同堆叠方式下锯齿型石墨纳米带的电导.研究发现,由于堆叠石墨片与石墨纳米带的耦合作用,锯齿型石墨纳米带的电导谱出现了电导谷.在远离费米能处,两种堆叠方式下的电导谷位置相近甚至重合;而在费米能附近,两种堆叠方式下的电导谷存在差异.此外,讨论了堆叠石墨片的几何尺寸对锯齿型石墨纳米带电子输运的影响.结果显示,随石墨片几何尺寸的增大,锯齿型石墨纳米带在两种堆叠方式下远离费米能处的电导谷逐渐向费米能方向移动,同时其费米能附近的电导谷在两种堆叠方式下的差异随石墨片尺寸的增大变得更为明显.研究结果表明,堆叠石墨片能够有效地调制锯齿型石墨纳米带的电子输运性质.
The effect of stacked graphene flakes (GFs) on the electronic transport property of zigzag-edged graphene nanoribbon (ZGNR) is investigated.By using the Green's function method,we calculate the conductances of ZGNRs with two different stacked-type GFs.It is found that the coupling effect between ZGNRs and GFs can induce dips at the conductance profiles in two different stacked-types.For both stacked-types,the dips far away from the Fermi level are nearly overlapped.However,the position of conductance dip near the Fermi level depends on the stacked-type.In addition,we discuss the effect of geometric size of GF on the electronic transport property.The results show that with the increase of the size of GF,the dips far away the Fermi level in two stacked-types gradually move toward the Fermi level,while the discrepancy of the dips near the Fermi level is much evident.Our results indicate that the stacked GFs can effectively tune the electronic transport of ZGNR.