Enhancement of thermospin effect in ZGNRs via p-n co-doping on edge

Electronic and thermoelectric properties are studied for ferromagnetic zigzag graphene nanoribbons (ZGNRs) co-doped by a pair of boron and nitrogen atoms on one edge. In case of the 1st nearest neighbor co-doping, the two dopants are partly neutralized by each other and the corresponding impurity states approach to the Fermi energy symmetrically from high and low energies. As a result, the electronic properties are effectively manipulated and the conductances of different spin show opposite behaviours. Over a large range from zero temperature to higher-than-room temperature, the system shows a strong spin thermopower with a spin Seebeck coefficient much bigger than the charge one. These findings suggest that doped ZGNRs can be promising materials for spintronic and thermospintronic devices.