Janus silicene nanoribbons with zigzag edges

Abstract

In this study, the spin-dependent electronic and thermoelectric transport properties of zigzagedge Janus silicene nanoribbons (ZJSiNs) are systematically investigated using density functional theory combined with coherent quantum transport formalism. Our results demonstrate that pristine ZJSiNs exhibit an intrinsic spin-semiconducting phase with strong spin polarization over a wide range of ribbon widths and a tunable band gap. Upon both hole and electron doping, the system undergoes a transition to a robust half-metallic state that remains stable against width variations, analogous to the undoped spin-semiconducting phase. The application of temperature gradients and external bias voltages induces spin-dependent thermal and charge currents with distinct threshold temperatures and current magnitudes for different spin channels, even in the halfmetallic regime, due to compensation effects between spin-up and spin-down carriers. Fully spinpolarized transport can be achieved through appropriate charge doping under combined bias voltage and thermal gradient. Overall, ZJSiNs, combining semiconducting and half-metallic behaviors with tunable thermoelectric features such as the spin Seebeck coefficient and figure of merit, emerge as promising candidates for spin-dependent silicene-based devices.