Characterization of graphene Drude conductivity by terahertz and infrared spectroscopy methods

Extreme sensitivity of graphene films to a technological transfer and the device fabrication steps requires the development of non-destructive contactless characterization methods. Here we have employed the methods of terahertz time-domain spectroscopy and Fourier-transform infrared spectroscopy to investigate the graphene electrical conductivity, described in terms of the high-frequency Drude model. Commercial CVD graphene samples were wet-transferred to different substrates in order to demonstrate advantages of remote characterization methods over contact-based approaches for determination of carrier density and mobility values in two-dimensional materials.