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Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
Graphene field effect transistors with niobium contacts and asymmetric transfer characteristics
Antonio Di Bartolomeo1, Filippo Giubileo, Francesco Romeo
1Dipartimento di Fisica 'E.R. Caianiello' and Centro Interdipartimentale NanoMates, Università degli Studi di Salerno, Fisciano, Salerno, Italy. CNR-SPIN, Fisciano, Salerno, Italy.
Abstract:
We fabricate back-gated field effect transistors using niobium electrodes on mechanically exfoliated monolayer graphene and perform electrical characterization in the pressure range from atmospheric down to 10(-4) mbar. We study the effect of room temperature vacuum degassing and report asymmetric transfer characteristics with a resistance plateau in the n-branch. We show that weakly chemisorbed Nb acts as p-dopant on graphene and explain the transistor characteristics by Nb/graphene interaction with unpinned Fermi level at the interface.
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