General Raman-based method for evaluating the carrier mobilities of chemical vapor deposited graphene

We report a method to evaluate the electrical properties of chemical-vapor-deposited (CVD) graphene samples from their Raman characteristics, regardless of the synthesis method or catalyst type. We synthesized five types of graphene on Cu and CuNi alloy catalysts by thermal CVD and inductively coupled plasma (ICP) CVD, respectively, and measured the Raman properties and carrier mobilities of hundreds of field effect transistors (FETs) fabricated with each CVD graphene. The Raman characteristics of the five CVD graphene types were plotted as a function of carrier mobility. The full width at half maximum (FWHM) of the 2D peak of CVD graphene, Γ_2D, was found to decrease in proportion to carrier mobility, but the intensity ratio of the Raman D and G bands (I_D/I_G) was not related. In particular, the mobility due to long range scattering, μ_l, obtained by fitting the transport curves of the FET devices, showed a linear relationship with the logarithm of the carrier mobility and could be expressed by logμ_l=α+β⋅Γ_2D, where α and β are 12.157 and −0.116, respectively, regardless of the CVD graphene type. We proposed a general method to evaluate the electrical properties of all CVD graphenes without directly measuring the carrier mobility by analyzing the 2D FWHM of the CVD graphene.