Fig. 3.

Temperature dependence of the Seebeck coefficient and PFT at fixed carrier density. (A) Measured Seebeck coefficient in G/hBN ($n=-0.2\times {10}^{12}\hspace{0.5em}\mathrm{c}{\mathrm{m}}^{-2}$, solid squares) and G/SiO₂ ($n=-0.3\times {10}^{12}\hspace{0.5em}\mathrm{c}{\mathrm{m}}^{-2}$, open squares) devices are plotted together with the theoretical values (solid lines) calculated by using the screened Coulomb-scattering model discussed in the text. Dashed lines serve as guides to emphasize the nonlinear behavior. (B) Measured PFT (same density as in A; solid and open squares) from both devices are compared with theoretical values (solid lines).