Journal article
Terahertz wafer-scale mobility mapping of graphene on insulating substrates without a gate
Department of Micro- and Nanotechnology, Technical University of Denmark1
Nanocarbon, Department of Micro- and Nanotechnology, Technical University of Denmark2
Center for Nanostructured Graphene, Centers, Technical University of Denmark3
Graphenea4
Teraherts Technologies and Biophotonics, Department of Photonics Engineering, Technical University of Denmark5
Department of Photonics Engineering, Technical University of Denmark6
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
Language: | English |
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Year: | 2015 |
Pages: | 30721-30729 |
ISSN: | 10944087 |
Types: | Journal article |
DOI: | 10.1364/oe.23.030721 |
ORCIDs: | Petersen, Dirch Hjorth , Bøggild, Peter and Jepsen, Peter Uhd |