Study of quantum capacitance in N doped few layer graphene

The intrinsically small density of states at the Fermi level in graphene results in a small serial quantum capacitance $C_{Q}$, which diminishes the total device capacitance value ($C_{tot})$ in supercapacitors. In this work, we studied $C_{Q}$ of N doped graphene in pyrrolic(N1), graphitic (N2) and pyridinic (N3) configurations. The observed $C_{Q}$ value for sample N1 was significantly different from samples N2 and N3, as predicted by DFT calculations, thus implying that precisely engineered dopant configurations, rather than concentration, can enhance $C_{Q}$. Such approaches are pivotal for alleviating the existing bottlenecks in both graphene-based device scaling and supercapacitor electrode limitations.