Current Saturation and Voltage Gain in Bilayer Graphene Field Effect Transistors
- 22 February 2012
- journal article
- research article
- Published by American Chemical Society (ACS) in Nano Letters
- Vol. 12 (3), 1324-1328
- https://doi.org/10.1021/nl2038634
Abstract
The emergence of graphene with its unique electrical properties has triggered hopes in the electronic devices community regarding its exploitation as a channel material in field effect transistors. Graphene is especially promising for devices working at frequencies in the 100 GHz range. So far, graphene field effect transistors (GFETs) have shown cutoff frequencies up to 300 GHz, while exhibiting poor voltage gains, another important figure of merit for analog high frequency applications. In the present work, we show that the voltage gain of GFETs can be improved significantly by using bilayer graphene, where a band gap is introduced through a vertical electric displacement field. At a displacement field of-1.7 V/nm the bilayer GFETs exhibit an intrinsic voltage gain up to 35, a factor of 6 higher than the voltage gain in corresponding monolayer GFETs. The transconductance, which limits the cutoff frequency of a transistor, is not degraded by the displacement field and is similar in both monolayer and bilayer GFETs. Using numerical simulations based on an atomistic p(z), tight-binding Hamiltonian we demonstrate that this approach can be extended to sub-100 nm gate lengths.Keywords
This publication has 28 references indexed in Scilit:
- High-Frequency Graphene Voltage AmplifierNano Letters, 2011
- High-frequency, scaled graphene transistors on diamond-like carbonNature, 2011
- On the Importance of Bandgap Formation in Graphene for Analog Device ApplicationsIEEE Transactions on Nanotechnology, 2011
- Channel Length Scaling in Graphene Field-Effect Transistors Studied with Pulsed Current−Voltage MeasurementsNano Letters, 2011
- High-speed graphene transistors with a self-aligned nanowire gateNature, 2010
- Graphene transistorsNature Nanotechnology, 2010
- 100-GHz Transistors from Wafer-Scale Epitaxial GrapheneScience, 2010
- Two-dimensional gas of massless Dirac fermions in grapheneNature, 2005
- Experimental observation of the quantum Hall effect and Berry's phase in grapheneNature, 2005
- Electric Field Effect in Atomically Thin Carbon FilmsScience, 2004