Ambipolar Graphene Field Effect Transistors by Local Metal Side Gates

TL;DR

This paper demonstrates ambipolar graphene transistors controlled by local metal side gates, showing comparable on/off ratios to global gates and tunability via back and side gates, with enhanced effects when the back gate is floating.

Contribution

It introduces a method for controlling graphene transistors with local metal side gates, providing tunability and improved performance over traditional global gating.

Findings

Side gated field effect has high on/off ratio.

Floating back gate enhances the side gated field effect.

Electrostatic simulations support experimental observations.

Abstract

We demonstrate ambipolar graphene field effect transistors individually controlled by local metal side gates. The side gated field effect can have on/off ratio comparable with that of the global back gate, and can be tuned in a large range by the back gate and/or a second side gate. We also find that the side gated field effect is significantly stronger by electrically floating the back gate compared to grounding the back gate, consistent with the finding from electrostatic simulation.