2021 年 19 巻 p. 125-130
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 (PFmax) at an optimal μ [or optimal carrier concentration (nopt)]. In addition, we clarified the T dependence of nopt and PFmax and explained the existence of nopt in terms of the thermal excitation of electrons between the valence and conduction bands, which cannot be predicted by the conventional Mott formula.