Wednesday, December 30, 2015

Abstract-Terahertz imaging and spectroscopy of large-area single-layer graphene

J. L. Tomaino, A. D. Jameson, J. W. Kevek, M. J. Paul, A. M. van der Zande, R. A. Barton, P. L. McEuen, E. D. Minot, and Yun-Shik Lee

We demonstrate terahertz (THz) imaging and spectroscopy of a 15 × 15-mm2single-layer graphene film on Si using broadband THz pulses. The THz images clearly map out the THz carrier dynamics of the graphene-on-Si sample, allowing us to measure sheet conductivity with sub-mm resolution without fabricating electrodes. The THz carrier dynamics are dominated by intraband transitions and the THz-induced electron motion is characterized by a flat spectral response. A theoretical analysis based on the Fresnel coefficients for a metallic thin film shows that the local sheet conductivity varies across the sample from σs = 1.7 × 10−3 to 2.4 × 10−3 Ω−1 (sheet resistance, ρs = 420 - 590 Ω/sq).
© 2011 OSA
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