title: Modulation of the Dirac point voltage of graphene by ion-gel dielectrics and its application to soft electronic devices.
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 (V(DD) = 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.
authors.affiliation: Nano Electronics Laboratory, Samsung Advanced Institute of Technology , Suwon, Gyeonggi-do 443-803, South Korea.
authors.forename: Un Jeong
authors.initials: UJ
authors.lastname: Kim
authors.forename: Tae Geun
authors.initials: TG
authors.lastname: Kim
authors.forename: Youngseon
authors.initials: Y
authors.lastname: Shim
authors.forename: Yeonsang
authors.initials: Y
authors.lastname: Park
authors.forename: Chang-Won
authors.initials: CW
authors.lastname: Lee
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Kim
authors.forename: Hyo Sug
authors.initials: HS
authors.lastname: Lee
authors.forename: Dae-Young
authors.initials: DY
authors.lastname: Chung
authors.forename: Jineun
authors.initials: J
authors.lastname: Kihm
authors.forename: Young-Geun
authors.initials: YG
authors.lastname: Roh
authors.forename: Jaesoong
authors.initials: J
authors.lastname: Lee
authors.forename: Hyungbin
authors.initials: H
authors.lastname: Son
authors.forename: Sangsig
authors.initials: S
authors.lastname: Kim
authors.forename: Jaehyun
authors.initials: J
authors.lastname: Hur
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Hwang
keywords: flexible devices; graphene transistor; ion-gel dielectric