1. Modulation of the Dirac point voltage of graphene by ion-gel dielectrics and its application to soft electronic devices
- Author
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Youngseon Shim, Hyungbin Son, Tae-Ho Kim, Dae Young Chung, Un Jeong Kim, Jaesoong Lee, Sangsig Kim, Sungwoo Hwang, Jineun Kihm, Young Geun Roh, Jaehyun Hur, Yeonsang Park, Chang-Won Lee, Hyo Sug Lee, and Tae Geun Kim
- Subjects
Materials science ,business.industry ,Graphene ,Gate dielectric ,General Engineering ,Analytical chemistry ,General Physics and Astronomy ,Dielectric ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,law.invention ,Ion ,chemistry.chemical_compound ,chemistry ,CMOS ,law ,Ionic liquid ,Physics::Atomic and Molecular Clusters ,Optoelectronics ,General Materials Science ,Voltage source ,Physics::Chemical Physics ,business ,Voltage - 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.
- Published
- 2015