Spin effects in thermoelectric properties of Al- and P-doped zigzag silicene nanoribbons

Electric and thermoelectric properties of silicene nanoribbons doped with Al and P impurity atoms are investigated theoretically for both antiparallel and parallel orientations of the edge magnetic moments. In the former case, appropriately arranged impurities can lead to a net magnetic moment, and thus also to spin dependent transport and spin thermoelectric phenomena. In the latter case, in turn, spin thermoelectric effects also occur in the absence of impurities. To calculate spin density distribution and transport parameters we use ab initio numerical methods based on the density functional theory. The obtained results clearly show that the spin thermopower can be considerably enhanced by the impurities. This enhancement appears in certain regions of chemical potential.