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arXiv · 1302.1360

Quantitative Determination of the Band-Gap of WS2 with Ambipolar Ionic Liquid-Gated Transistors

Daniele Braga·Ignacio Gutiérrez Lezama·Helmuth Berger·Alberto F. Morpurgo
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Abstract

We realized ambipolar Field-Effect Transistors by coupling exfoliated thin flakes of tungsten disulphide (WS2) with an ionic liquid-dielectric. The devices show ideal electrical characteristics, including very steep sub-threshold slopes for both electrons and holes and extremely low OFF-state currents. Thanks to these ideal characteristics, we determine with high precision the size of the band-gap of WS2 directly from the gate-voltage dependence of the source-drain current. Our results demonstrate how a careful use of ionic liquid dielectrics offers a powerful strategy to study quantitatively the electronic properties of nano-scale materials.

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Daniele Braga, Ignacio Gutiérrez Lezama, Helmuth Berger, Alberto F. Morpurgo. 2013-02-06. Quantitative Determination of the Band-Gap of WS2 with Ambipolar Ionic Liquid-Gated Transistors. https://doi.org/10.1021/nl302389d

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