Spin-resolved transport properties in zigzag α-graphyne nanoribbons with symmetric and asymmetric edge fluorinations

Using the non-equilibrium Green's function method and the spin-polarized density functional theory, we investigate the stability and spin-resolved electronic transport properties of zigzag α-graphyne nanoribbons (ZαGYNRs) with symmetric (F-ZαGYNRs-F) and asymmetric (F₂-ZαGYNRs-F) edge fluorinations. Our results show edge fluorination can enhance the stability of ZαGYNRs. The spin-resolved transport calculations reveal that the devices of F-ZαGYNRs-F with odd ribbon widths behave as a conductor with a linear current-voltage relationship, while the semiconductor property and perfect bipolar spin-filtering effect can be observed in those devices with even ribbon widths. In contrast, the spin-resolved transport properties of the asymmetric edge fluorinated F₂-ZαGYNRs-F systems are independent of the ribbon width. Moreover, the F₂-ZαGYNRs-F device is a perfect spin device with nearly 100% bipolar spin-filtering and spin negative differential resistance effects in a wide bias voltage region. And the magnetoresistance effect with the order of 10⁶ and the spin rectification ratio as high as 10⁸ have also been predicted. These phenomena suggest ZαGYNRs with asymmetric edge fluorination can be considered as a promising candidate material for nano-electronics and spintronics.