Prospects of asymmetrically H-terminated zigzag germanene nanoribbons for spintronic application

摘要

First-principles investigations have been performed to explore the spin based electronic and transport properties of asymmetrically H-terminated zigzag germanene nanoribbons (2H-H ZGeNR). Investigations reveal a significant formation energy difference (Delta E-F = EF(2H-H) - EF(H-H) similar to -0.49 eV), highlighting more energetic stability for asymmetric edge termination compared to symmetric edge termination, irrespective of the ribbon width. Further, magnetic moment analysis and total energy calculations were performed to unveil that these structures have a magnetic ground state with preferred ferromagnetic (FM) coupling. The calculated E-k structures project a unique bipolar semiconducting behaviour for 2H-H ZGeNR which is contrast to H-terminated ZGeNR. Half-metallic transformation has also been revealed via suitable p-type or n-type doping for these structures. Finally, transport calculations were performed to highlight the selective contributions of spin-down (spin-up) electrons in the I-V characteristics of the doped 2H-H ZGeNR, suggesting their vitality for spintronic device applications. (C) 2016 Published by Elsevier B.V.