Modulation of the Dirac point voltage of graphene by ion-gel dielectrics and its application to soft electronic devices

Un Jeong Kim, Tae Geun Kim, Youngseon Shim, Yeonsang Park, Chang Won Lee, Tae Ho Kim, Hyo Sug Lee, Dae Young Chung, Jineun Kihm, Young Geun Roh, Jaesoong Lee, Hyungbin Son, Sangsig Kim, Jaehyun Hur, Sung Woo Hwang

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23 Citations (Scopus)

Abstract

We investigated systematic modulation of the Dirac point voltage of graphene transistors by changing the type of ionic liquid used as a main gate dielectric component. Ion gels were formed from ionic liquids and a non-triblock-copolymer-based binder involving UV irradiation. With a fixed cation (anion), the Dirac point voltage shifted to a higher voltage as the size of anion (cation) increased. Mechanisms for modulation of the Dirac point voltage of graphene transistors by designing ionic liquids were fully understood using molecular dynamics simulations, which excellently matched our experimental results. It was found that the ion sizes and molecular structures play an essential role in the modulation of the Dirac point voltage of the graphene. Through control of the position of their Dirac point voltages on the basis of our findings, complementary metal-oxide-semiconductor (CMOS)-like graphene-based inverters using two different ionic liquids worked perfectly even at a very low source voltage (VDD = 1 mV), which was not possible for previous works. These results can be broadly applied in the development of low-power-consumption, flexible/stretchable, CMOS-like graphene-based electronic devices in the future.

Original languageEnglish
Pages (from-to)602-611
Number of pages10
JournalACS Nano
Volume9
Issue number1
DOIs
Publication statusPublished - 2015 Jan 1

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Keywords

  • flexible devices
  • graphene transistor
  • ion-gel dielectric

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

Cite this

Kim, U. J., Kim, T. G., Shim, Y., Park, Y., Lee, C. W., Kim, T. H., Lee, H. S., Chung, D. Y., Kihm, J., Roh, Y. G., Lee, J., Son, H., Kim, S., Hur, J., & Hwang, S. W. (2015). Modulation of the Dirac point voltage of graphene by ion-gel dielectrics and its application to soft electronic devices. ACS Nano, 9(1), 602-611. https://doi.org/10.1021/nn505925u