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arXiv · 1005.2258

Probing top-gated field effect transistor of reduced graphene oxide monolayer made by dielectrophoresis

K. S. Vasu·Biswanath Chakraborty·S. Sampath·A. K. Sood
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Abstract

We demonstrate top-gated field effect transistor made of reduced graphene oxide (RGO) monolayer (graphene) by dielectrophoresis. Raman spectrum of RGO flakes of typical size of 5μm x 5μm show a single 2D band at 2687 cm-1, characteristic of a single layer graphene. The two probe current - voltage measurements of RGO flakes, deposited in between the patterned electrodes with a gap of 2.5 μm using a.c. dielectrophoresis show ohmic behavior with a resistance of ~ 37kΩ. The temperature dependence of the resistance (R) of RGO measured between temperatures 305 K to 393 K yields temperature coefficient of resistance [dR/dT]/R ~ -9.5x10-4 K-1, same as mechanically exfoliated single layer graphene. The field effect transistor action was obtained by electrochemical top-gating using solid polymer electrolyte (PEO + LiClO4) and Pt wire. Ambipolar nature of graphene flakes is observed upto a doping level of ~ 6x1012/cm2 and carrier mobility of ~ 50 cm2V-1sec-1. The source - drain current characteristics shows a tendency of current saturation at high source - drain voltage which is analyzed quantitatively by a diffusive transport model.

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K. S. Vasu, Biswanath Chakraborty, S. Sampath, A. K. Sood. 2010-05-13. Probing top-gated field effect transistor of reduced graphene oxide monolayer made by dielectrophoresis. https://doi.org/10.1016/j.ssc.2010.05.018

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