Terahertz wafer-scale mobility mapping of graphene on insulating substrates without a gate

Jonas Due Buron, David M. A. Mackenzie, Dirch Hjorth Petersen, Amaia Pesquera, Alba Centeno, Peter Bøggild, Amaia Zurutuza, Peter Uhd Jepsen

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Abstract

We demonstrate wafer-scale, non-contact mapping of essential carrier transport parameters, carrier mobility (mu(drift)), carrier density (N-S), DC sheet conductance (sigma(dc)), and carrier scattering time (tau(SC)) in CVD graphene, using spatially resolved terahertz time-domain conductance spectroscopy. sigma(dc) and tau(SC) are directly extracted from Drude model fits to terahertz conductance spectra obtained in each pixel of 10 x 10 cm(2) maps with a 400 mu m step size. sigma(dc)- and tau(SC)-maps are translated into mu(drift) and N-S maps through Boltzmann transport theory for graphene charge carriers and these parameters are directly compared to van der Pauw device measurements on the same wafer. The technique is compatible with all substrate materials that exhibit a reasonably low absorption coefficient for terahertz radiation. This includes many materials used for transferring CVD graphene in production facilities as well as in envisioned products, such as polymer films, glass substrates, cloth, or paper substrates. (c) 2015 Optical Society of America
Original languageEnglish
JournalOptics Express
Volume23
Issue number24
Pages (from-to)30721-30729
ISSN1094-4087
DOIs
Publication statusPublished - 2015

Keywords

  • Nondestructive testing
  • Nanomaterials
  • Spectroscopy, condensed matter
  • Spectroscopy, terahertz
  • Materials and process characterization
  • Thin films, other properties

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