▎ 摘　　要

We investigate the magneto-transport properties of epitaxial graphene single-layer on 4H-SiC( 0001), grown by atmospheric pressure graphitization in Ar, followed by H-2 intercalation. We directly demonstrate the importance of saturating the Si dangling bonds at the graphene/SiC(0001) interface to achieve high carrier mobility. Upon successful Si dangling bonds elimination, carrier mobility increases from 3 000 cm(2)V(-1)s(-1) to > 11 000 cm(2)V-(1)s(-1) at 0.3 K. Additionally, graphene electron concentration tends to decrease from a few 10(12) cm(-2) to less than 10(12) cm(-2). For a typical large (30 x 280 mu m(2)) Hall bar, we report the observation of the integer quantum Hall states at 0.3 K with well developed transversal resistance plateaus at Landau level filling factors of v = 2, 6, 10, 14... 42 and Shubnikov de Haas oscillation of the longitudinal resistivity observed from about 1 T. In such a device, the Hall state quantization at v = 2, at 19 T and 0.3 K, can be very robust: the dissipation in electronic transport can stay very low, with the longitudinal resistivity lower than 5 m Omega, for measurement currents as high as 250 mu A. This is very promising in the view of an application in metrology.