▎ 摘　　要

We report using chemical functionalization to control local carrier type and density in graphene. Low frequency transport measurements demonstrate independent carrier types and densities within adjacent graphene and hydrogenated graphene regions. Measurements of the Hall coefficient confirm that the charge carriers change sign about the charge neutrality point, that the graphene carrier density retains its linear dependence on a back gate voltage, and that the hydrogenated graphene carrier density deviates from a linear relationship. Transport measurements across the bipolar interface reveal an increasing interface resistance for higher hydrogen concentrations and a source of constant resistance for lower hydrogen concentrations. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4794990]