Surface transfer hole doping of epitaxial graphene using MoO3 thin film

Synchrotron-based in situ photoelectron spectroscopy investigations demonstrate effective surface transfer p-type doping of epitaxial graphene (EG) thermally grown on 4H-SiC(0001) via the deposition of MoO3 thin film on top. The large work function difference between EG and MoO3 facilitates electron transfer from EG to the MoO3 thin film. This leads to hole accumulation in the EG layer with an areal hole density of about 1.0x10(13) cm(-2), and places the Fermi level 0.38 eV below the graphene Dirac point. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3441263]