Ilyasov V V, Meshi B C, Nguyen V C, Ershov I V, Nguyen D C
Department of Physics, Don State Technical University, 1 Gagarin Sq, 344000 Rostov on Don, Russia.
Department of Electronic Materials, School of Engineering Physics, Hanoi University of Science and Technology, 1 Dai Co Viet Rd, 10000 Hanoi, Vietnam.
J Chem Phys. 2014 Jul 7;141(1):014708. doi: 10.1063/1.4885857.
The paper presents the results of ab initio study of the opportunities for tuning the band structure, magnetic and transport properties of zigzag graphene nanoribbon (8-ZGNR) on hexagonal boron nitride (h-BN(0001)) semiconductor heterostructure by transverse electric field (E(ext)). This study was performed within the framework of the density functional theory (DFT) using Grimme's (DFT-D2) scheme. We established the critical values of E(ext) for the 8-ZGNR/h-BN(0001) heterostructure, thereby providing for semiconductor-halfmetal transition in one of electron spin configurations. This study also showed that the degeneration in energy of the localized edge states is removed when E(ext) is applied. In ZGNR/h-BN (0001) heterostructure, value of the splitting energy was higher than one in ZGNRs without substrate. We determined the effect of low E(ext) applied to the 8-ZGNR/h-BN (0001) semiconductor heterostructure on the preserved local magnetic moment (LMM) (0.3μ(B)) of edge carbon atoms. The transport properties of the 8-ZGNR/h-BN(0001) semiconductor heterostructure can be controlled using E(ext). In particular, at a critical value of the positive potential, the electron mobility can increase to 7× 10(5) cm(2)/V s or remain at zero in the spin-up and spin-down electron subsystems, respectively. We established that magnetic moments (MMs), band gaps, and carrier mobility can be altered using E(ext). These abilities enable the use of 8-ZGNR/h-BN(0001) semiconductor heterostructure in spintronics.
本文展示了通过横向电场（E(ext)）对锯齿形石墨烯纳米带（8-ZGNR）/六方氮化硼（h-BN(0001)）半导体异质结构的能带结构、磁性和输运性质进行从头算研究的结果。本研究是在密度泛函理论（DFT）框架内使用格林姆（DFT-D2）方案进行的。我们确定了8-ZGNR/h-BN(0001)异质结构的E(ext)临界值，从而在一种电子自旋构型中实现半导体-半金属转变。该研究还表明，施加E(ext)时，局域边缘态的能量简并被消除。在ZGNR/h-BN(0001)异质结构中，分裂能的值高于无衬底的ZGNR中的值。我们确定了施加于8-ZGNR/h-BN(0001)半导体异质结构的低E(ext)对边缘碳原子保留的局域磁矩（LMM）（0.3μ(B)）的影响。8-ZGNR/h-BN(0001)半导体异质结构的输运性质可以通过E(ext)来控制。特别是，在正电势的临界值下，电子迁移率可分别在自旋向上和自旋向下的电子子系统中增加到7×10(5) cm(2)/V s或保持为零。我们确定可以使用E(ext)改变磁矩（MMs）、带隙和载流子迁移率。这些特性使得8-ZGNR/h-BN(0001)半导体异质结构能够用于自旋电子学。
