Hall effect mobility of epitaxial graphene grown on silicon carbide

Epitaxial graphene (EG) films were grown in vacuo by silicon sublimation from the (0001) and (000 (1) over bar) faces of 4H-SiC and 6H-SiC. Hall effect mobilities and sheet carrier densities of the films were measured at 300 and 77 K and the data depended on the growth face. About 40% of the samples exhibited holes as the dominant carrier, independent of face. Generally, mobilities increased with decreasing carrier density, independent of carrier type and substrate polytype. The contributions of scattering mechanisms to the conductivities of the films are discussed. The results suggest that for near-intrinsic carrier densities at 300 K epitaxial graphene mobilities will be similar to 150 000 cm(2) V(-1) s(-1) on the (000 (1) over bar) face and similar to 5800 cm(2) V(-1) s(-1) on the (0001) face. (C) 2009 American Institute of Physics. [doi:10.1063/1.3224887]