B - N Chain Doped Graphene Nanobelts And Electronic Structure Of The Study Of First Principles

Due to the unique geometry structure, electronic properties and potential applications in the future electron devices, graphene nanoribbons (GNRs) have have attracted a widespread consensus. Using first-principle calculation based on the density function theory(DFT), the electronic structure of graphene nanoribbons doped with Boron-Nitrogen(B-N) chain have been studied in this paper. The main results are shown as follows.Introducing a single B-N chain doping in different positions for zigzag graphene nanoribbons(ZGNRs)/armchair graphene nanoribbons(AGNRs), and the electronic structure properties have been investigated. The direction of B-N chain is parallelized to the edges of GNRs. The effects of symmetry and width of GNRs have also been considered.We find the total energy of the dopped systems are higher that of the pectect systems. Moreover, for the same dopped systems, it is also can be found the GNRs with B-N chains doped at the edge have the lowest total energy, which means that B-N chain is apt to move to the edge.Then, the electronic structure properties of B-N chain dopped GNRs have been studied. For the ZGNRs, when B-N chain is dopped in the middle or sub-middle, the band have little change than the pure ZGNRs. But, when B-N chain is dopped at the edge of ZGNRs, the band is changed evidently. The edge states are clearly observed in the band structures of the systems. And the spin nondegenerate phenomenon can be found. And also, the band gaps have been opened. Theory analyses indicate that all of the phenomena are attributed to the redistribution of the electronics in edge states.For AGNRs, the electronic structures are sensitive to the doping positions and the band width. When B-N chain is dopped at the edge of AGNRs, the change of band is much larger than that of other positions. Especially, for the AGNRs with width7, we can find the change of band gap can reach to1.1eV for defferent B-N chain dopping postions.These results indicate that B-N doping is an effective approach for modulating the spin electronic structure band gap of GNRs, maybe useful to the design of nano-devices in the future.