Significantly enhanced thermoelectric performance of interstitial N-doped graphene: A density functional theory study

The thermoelectric characteristics of interstitial nitrogen (N)-doped graphene have been studied using the first principles calculations combined with the semi-classical Boltzmann theory. We found that the Seebeck coefficient of N-doped graphene is 3 and 5.5 times higher compared to pristine graphene, along with ZT values. At room temperature, for pristine graphene, the ZT value stands at 0.81, whereas it rises to 0.98 and 1.00 for N-doped graphene with 6.25 % and 50 % nitrogen doping, respectively. The increase in the Seebeck coefficient of N-doped graphene is due to the increase in the effective mass band as the chemical potential rises above the conduction band minimum. We observed that N-doped graphene exhibits the highest ZT value in the positive energy range, indicating a p-type character. Our findings suggest that N-doped graphene has promising potential for thermoelectric applications and provides insights into the underlying physics governing the thermoelectric properties of doped graphene materials.