The operation of chemical vapor-deposited (CVD) graphene field-effect transistors (GFETs) is highly sensitive to environmental factors such as the substrate, polymer residues, ambient condition, and other species adsorbed on the graphene surface due to their high defect density. As a result, CVD GFETs often exhibit a large hysteresis and time-dependent instability. These problems become a major roadblock in the systematic study of graphene devices. We report a facile process to alleviate these problems, which can be used to fabricate stable high performance CVD GFETs with symmetrical current-voltage (I-V) characteristics and an effective carrier mobility over 6000 cm(2) V(-1) s(-1). This process combined a few steps of processes in sequence including pre-annealing in a vacuum, depositing a passivation layer, and the final annealing in a vacuum, and eliminated ∼50% of charging sources primarily originating from water reduction reactions.
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