Structural & electronic properties of zigzag silicene nanoribbons with symmetric/asymmetric edge passivations via fluorine and hydrogen

The intriguing properties of silicene nanoribbons indicate potential applications in nanoelectronic devices. The first-principles calculation based on density functional theory has been performed to investigate the structural, electronic and magnetic properties of asymmetric (sp³-sp²) and symmetric (sp³-sp³) edge functionalized zigzag silicene nanoribbons (ZSiNR). The structural analysis reveals that fully fluorinated ZSiNR for both asymmetric and symmetric edge functionalized ZSiNRs are energetically more stable irrespective of ribbon width. For selective structures, the magnetic ground state is found to be robust against thermal excitations at room temperature (25 meV) indicating their potential for practical applications. Moreover, bipolar magnetic semiconductor and half-metallic behavior have been observed in spin-based band structure calculations. Further, the spin-dependent transport properties of ZSiNR have been performed using the two-terminal device model which produces negative differential resistance (NDR) behavior due to spin-down current. This investigation reveals the immense capabilities of fluorine symmetric and asymmetric termination to modulate the electronic and spintronic properties of ZSiNR. Thus, the present work can pave the way for futuristic electronics and spintronics nanodevices.