Transport-map analysis of ionic liquid-gated ambipolar WSe2 field-effect transistors

So Jeong Park, Deukhyeon Nam, Dae Young Jeon, Gyu Tae Kim

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


We present the electrical characteristics of ionic liquid-gated ambipolar WSe2 field-effect transistors (FET) and analyze them graphically using a transport map. With the transport map, the ambipolar I-V characteristics, which have either electrons or holes as the majority charge carriers depending on the bias conditions, were easily divided into the electron and hole conduction regimes. The effect of the drain bias (V d) on trapped charges is inferred from the decreased offset voltage, which indicates the downward deflection of the channel energy band with the V d. We confirmed the change of the majority carrier types shown in the transport map by analyzing the output curves, which show a transition from rectifying to saturated behavior. The existence of a relatively thin Schottky barrier for hole conduction is supported by the degradation in the transconductance curves and the variation in V th with the V d. These results provide important information for understanding the operating mechanism of ambipolar WSe2 FETs gated by ionic liquids and can be extended to FETs based on other two-dimensional semiconducting materials.

Original languageEnglish
Article number075022
JournalSemiconductor Science and Technology
Issue number7
Publication statusPublished - 2019 Jun 21

Bibliographical note

Funding Information:
This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2016R1A6A3A11933511, NRF-2017M3A7B4049167), the Future Semiconductor Device Technology Development Program (10067739) funded by Ministry of Trade, Industry &Energy (MOTIE), Korea Semiconductor Research Consortium (KSRC), the Korea Institute of Science and Technology (KIST) Institutional Program and a Korea University Grant.

Publisher Copyright:
© 2019 IOP Publishing Ltd.


  • Schottky barrier transistor
  • WSe field-effect transistor
  • ionic liquid gating
  • transport map, graphical analysis

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry


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