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HL: Fachverband Halbleiterphysik
HL 24: Graphene: Electronic properties and transport (O, jointly with HL, TT)
HL 24.11: Vortrag
Montag, 11. März 2013, 18:30–18:45, H17
Graphene on boron nitride microwave transistors driven by graphene nanoribbon back-gates — Christian Benz1,2, •Maximilian Thürmer1, Fan Wu1, Zeineb Ben Aziza1, Jens Mohrmann1, Hilbert von Löhneysen1,2,3,4, Kenji Watanabe5, Takashi Taniguchi5, and Romain Danneau1,2 — 1Institute of Nanotechnology, Karlsruhe Institute of Technology, Germany — 2Institute of Physics, Karlsruhe Institute of Technology, Germany — 3DFG Center for Functional Nanostructures, Karlsruhe Institute of Technology, Germany — 4Institute for Solid-State Physics, Karlsruhe Institute of Technology, Germany — 5Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
We have designed ultra-thin graphene microwave transistors by using pre-patterned metal or graphene nanoribbon back-gates and hexagonal boron nitride (h-BN) as a dielectric substrate. Despite the inhomogeneities induced by the graphene transfer process, we show that it is possible to operate these types of devices across a broad range of microwave frequencies. For the graphene nanoribbon gates, we observe a deviation of the current gain from the usual 1/f trend that can be attributed to the large gate resistance of these systems as we demonstrate with our small-signal model. The scattering parameter analysis shows a very limited back-action from the channel onto the graphene nanoribbon gates. Our work thus proves that graphene microwave transistors could be driven by graphene nanoribbon gates.