Electronic, magnetic, and spin‐polarized transport properties of hybrid graphene/boron‐nitride nanoribbons having 5‐8‐5 line defects at the heterojunction

Abstract

Using the spin‐polarized density functional theory, we have investigated electronic, magnetic, and spin‐polarized transport properties of hybrid boron‐nitrde/graphene (BNC) nanoribbons having the BB and NN line defect at the heterojunction. Our results show that the defective systems behave as robust spin‐selective half‐semiconductor in the whole range of the graphene nanoribbon width considered in this work. Application of an electric field gives rise to antiferromagnetic half‐metallic behavior in both systems. The range of electric field maintaining the half‐metallicity is much larger for the BB line defect system than for the NN line defect system. Beyond a threshold of field intensity, the NN line defect system becomes nonmagnetic semiconductor, while the BB line defect system behaves as ferromagnetic metal with spin density located at the heterojunction. Finally, the spin‐polarized transport calculation reveals that both systems can be efficient spin filters.

Interface effects in hybrid hBN-graphene nanoribbons

“…Induced half-metallic responses due to spin polarization through defective interfaces of h-BN/graphene was reported in the work of Lan et al . 25 . Also, laterally repeating h-BN/graphene systems present a variety of electronic properties according to the geometry of the h-BN/layers, and can be potentially used in optical devices 26 .…”

Recent advances in hybrid graphene‐BN planar structures

“…By using ab initio molecular dynamics and spin-polarized density functional theory, Lan line defects at all nanoribbon widths, the hybrids acted as spin selected half-semiconductor. 45 In contrast, for C-C 5-8-5 defects, the nanoribbons were metallic. 23 Zhao et al performed first-principles calculation on the band structure of graphene domain embedded BN sheets before and after single H adsorption on different sites.…”

“…Finally, the effects of structural defects and adsorbate modifications on the electronic structure of BNC hybrid planar structures are also worth of mention. By using ab initio molecular dynamics and spin‐polarized density functional theory, Lan et al and Ghosh et al studied the formation of 5‐8‐5 B‐B/N‐N and C‐C line defects on the BNC hybrid nanoribbons, respectively. For B‐B and N‐N 5‐8‐5 line defects at all nanoribbon widths, the hybrids acted as spin selected half‐semiconductor .…”

“…By using ab initio molecular dynamics and spin‐polarized density functional theory, Lan et al and Ghosh et al studied the formation of 5‐8‐5 B‐B/N‐N and C‐C line defects on the BNC hybrid nanoribbons, respectively. For B‐B and N‐N 5‐8‐5 line defects at all nanoribbon widths, the hybrids acted as spin selected half‐semiconductor . In contrast, for C‐C 5‐8‐5 defects, the nanoribbons were metallic .…”

“…Nonequilibrium Green's functions in combination with density functional theory can also be applied in the calculation of spin‐polarized transmission spectra, therefore leading to the theoretical estimation of the spin filtering efficiency. Based on these calculations, three nanoribbon structures have been identified as superior spin filter: two BN stripes embedded graphene nanoribbons with Cr‐benzene adsorbed on the graphene stripes, half BN‐stripe embedded graphene nanoribbons with H saturated at the ribbon edge, and graphene‐BN nanoribbon possessing B‐B and N‐N line defects in the heterojunction . The former two nanoribbons are armchair while the latter one is zigzag.…”