BN链掺杂的石墨烯纳米带的电学及磁学特性

基于密度泛函理论第一性原理系统研究了BN链掺杂石墨烯纳米带(GNRs)的电学及磁学特性, 对锯齿型石墨烯纳米带(ZGNRs)分非磁态(NM)、反铁磁态(AFM)及铁磁性(FM)三种情况分别进行考虑. 重点研究了单个BN链掺杂的位置效应. 计算发现: BN链掺杂扶手椅型石墨烯纳米带(AGNRs) 能使带隙增加, 不同位置的掺杂, 能使其成为带隙丰富的半导体. BN链掺杂非磁态ZGNR的不同位置, 其金属性均降低, 并能出现准金属的情况; BN链掺杂反铁磁态ZGNR, 能使其从半导体变为金属或半金属(half-metal), 这取决于掺杂的位置; BN链掺杂铁磁态ZGNR, 其金属性保持不变, 与掺杂位置无关. 这些结果表明: BN链掺杂能有效调控石墨烯纳米带的电子结构, 并形成丰富的电学及磁学特性, 这对于发展各种类型的石墨烯基纳米电子器件有重要意义.关键词：石墨烯纳米带BN链掺杂输运性质自旋极化

Electrical and magnetic properties of graphene nanoribbons with BN-chain doping

By using the first-principles method based on the density-functional theory, electrical and magnetic properties of graphene nanoribbons (GNRs) with the BN-chain doping are systematically studied. For the zigzag-edge graphene nanoribbon (ZGNR), its multispin-state properties: spin-unpolarized non-magnetism (NM) state, spin-polarized ferromagnetic (FM), and anti-ferromagnetic (AFM) states, are considered. The emphasis on our investigations is the effect of doping position for a single BN-chain. It is found that the BN-chain doping armchair-edge graphene nanoribbon (AGNR) has an increase in bandgap and becomes semiconductors with various different bandgaps upon the doping positions. When the ZGNR at the NM state is doped by the BN-chain, its metallic property is weakened, and the quasi-metallic property can also occur. The BN-chain doping ZGNR at the AFM state makes it change from a semiconductor to a metal or half-metal, depending on doping positions. And the BN-chain doping ZGNR at the FM state always keeps its metallic property unchanged regardless of the doping positions. These results indicate that the BN-chain doping can effectively modulate the electronic structure to form abundant electrical and magnetic properties for GNRs. It is of important significance for developing various kinds of nanodevices based on GNRs.
Keywords：graphene nanoribbonBN-chain dopingelectronic transportspin polarization