Gate-induced half-metallicity in semihydrogenated silicene

The first-principles calculations indicate that the semihydrogenated silicene (H@Silicene) is a ferromagnetic semiconductor. By the ab initio quantum transport theory, we study for the first time the transport properties of H@Silicene with pristine silicene as electrodes. A high on/off current ratio of 106 is obtained in the single-gated H@Silicene device. More importantly, a spin-polarized current can be generated. The spin-filter efficiency increases with the gate voltage and reaches 100% at a voltage of 1.9 V. Our results suggest that a gate voltage can induce half-metallicity in H@Silicene. Therefore, a new avenue is opened for H@Silicene in application of spintronics.