How good can CVD-grown monolayer graphene be?

Chemical vapor deposition (CVD) is considered the most promising method for pushing graphene into commercial products. However, CVD grown graphene is usually of low quality. In this work we explore how good can CVD-derived monolayer graphene be. Through the combinational optimization of the main processes of growth, transfer, device fabrication and measurements, we show that the optimized CVD graphene can present performance comparable to mechanical exfoliated ones: in particular, high carrier mobility at room temperature on the Si/SiO2 substrate, perfect electron-hole symmetry and excellent uniformity (the mobility ranged from 5000 to 12,000 cm(2) V(-1) s(-1) with an average mobility of ∼ 8800 cm(2) V(-1) s(-1) and 50% were higher than 10,000 cm(2) V(-1) s(-1)). In addition we found that the adsorbed oxygen and water molecules on graphene lead to p-type doping in graphene, and transferred charges bring charged impurity scattering to the transporting carriers in the graphene channel. It is therefore necessary to carry out electrical measurements under vacuum to obtain high intrinsic carrier mobility CVD grown graphene.