Spin thermoelectric properties in fluorinated asymmetric zigzag SiC nanoribbons with boron and nitrogen impurities

We investigated the spin caloritronic properties of zigzag silicon carbide nanoribbons with asymmetric fluorine edges (2F-8ZSiCNR-1F) doped with boron (B) or nitrogen (N) using density functional theory. Doping 2F-8ZSiCNRs-F with group III/V elements changes band structure states near the Fermi surface and modifies the systems magnetic moment. The doped structures exhibit magnetic metallic, half-metallic, and spin-semiconducting properties, with the dopant type and position significantly influencing spin-dependent thermoelectric properties. Pure thermal spin current reach 50-90 nA, while B and N doping induce perfect spin-filtering with negative differential thermal resistance. At zero chemical potential, the spin Seebeck coefficient (S_S) ranges from 0.01 mV K^-1 to 1.5 mV K^-1. These results highlight the potential of impurity engineering to enhance thermoelectric performance in spin caloritronic applications.