Electronic structures of zigzag silicene nanoribbons with asymmetric sp2-sp3 edges

The nanomaterials with peculiar spintronic characteristics, such as half-metals, spin gapless semiconductors [X. L. Wang, Phys. Rev. Lett. 100, 156404 (2008)], and bipolar magnetic semiconductors [Li et al., Nanoscale 4, 5680 (2012)], play the crucial role in nano-electronics and spintronics. Here, we report the zigzag silicene nanoribbons (ZSiNRs) with asymmetric sp(2)-sp(3) edges are bipolar magnetic semiconductors due to the incorporation of Klein and zigzag edge states. With the bipolar feature, these asymmetric ZSiNRs can be altered to half-metals with opposite conductive spin channels by p-type and n-type dopings. Moreover, the semiconducting properties can also be tailored by the strain, which makes the nanoribbons into spin gapless semiconductors or ferromagnetic metals. (C) 2013 AIP Publishing LLC.