Maximum Thermoelectric Power Factor and Optimal Carrier Concentration of Bilayer Graphene at Various Temperatures

Abstract

The thermoelectric response of bilayer graphene over a wide temperature range (0 < T ≤ 400 K) was theoretically investigated using linear response theory combined with a Green's function technique. We found that the power factor PF for a fixed chemical potential μ exhibits a maximum at a certain T. On the other hand, we found that the PF for a fixed T exhibits a maximum (PF_max) at an optimal μ [or optimal carrier concentration (n_opt)]. In addition, we clarified the T dependence of n_opt and PF_max and explained the existence of n_opt in terms of the thermal excitation of electrons between the valence and conduction bands, which cannot be predicted by the conventional Mott formula.