Electrical-field tuned thermoelectric performance of graphene nanoribbon with sawtooth edges

By using first-principle calculations combined with the non-equilibrium Green's function approach, we report that a vertical electrical field can modulate the thermoelectric performance of a graphene nanoribbon with sawtooth edges. The results show that the sawtooth graphene nanoribbon exhibits the spin-dependent Seebeck effect under the temperature gradients, and is strengthened by increasing the width of the sawtooth graphene nanoribbon. When the vertical electrical field is applied to the device, the spin-dependent Seebeck effect can also be enhanced. The vertical electrical field can modulate the device transferring from hole-conducting to electron-conducting. This opens up the possibility of tuning the thermal transport properties of the device by the electrical field.