Electronic properties of CVD graphene grown on copper

We report the electronic properties of graphene grown by chemical vapor deposition (CVD) on copper foils at ambient pressure. Large size graphene films (4 inch*4 inch) are synthesized and transferred to SiO2/Si substrate. Raman mapping demonstrates that the films consist primarily of monolayer graphene (up to $\sim $90{\%} area coverage). Low temperature transport measurements are performed on devices made from such CVD graphene. The ``half-integer'' quantum Hall effect, which is the hall-mark of mono-layer graphene, has been observed in these devices. We also observe the ambipolar field effect and weak localization, which allow us to extract carrier mobility $\sim $3000cm$^2$/Vs and phase coherence length $\sim $300nm at 1.5K.