▎ 摘　　要

The linear dispersion relation in graphene(1,2) gives rise to a surprising prediction: the resistivity due to isotropic scatterers, such as white-noise disorder(3) or phonons(4-8), is independent of carrier density, n. Here we show that electron-acoustic phonon scattering(4-6) is indeed independent of n, and contributes only 30 V to graphene's room-temperature resistivity. At a technologically relevant carrier density of 1 x10(12) cm(-2), we infer a mean free path for electron-acoustic phonon scattering of > 2 mm and an intrinsic mobility limit of 2 x 10(5) cm(2) V-1 s(-1). If realized, this mobility would exceed that of InSb, the inorganic semiconductor with the highest known mobility ( similar to 7.7 x 10(4) cm(2) V-1 s(-1); ref. 9) and that of semiconducting carbon nanotubes ( similar to 1 x 10(5) cm(2) V-1 s(-1); ref. 10). A strongly temperature-dependent resistivity contribution is observed above similar to 200 K ( ref. 8); its magnitude, temperature dependence and carrier-density dependence are consistent with extrinsic scattering by surface phonons at the SiO2 substrate11,12 and limit the room-temperature mobility to similar to 4 x 10(4) cm(2) V-1 s(-1), indicating the importance of substrate choice for graphene devices13.