title: Reduced Water Vapor Transmission Rate of Graphene Gas Barrier Films for Flexible Organic Field-Effect Transistors.
abstract: Preventing reactive gas species such as oxygen or water is important to ensure the stability and durability of organic electronics. Although inorganic materials have been predominantly employed as the protective layers, their poor mechanical property has hindered the practical application to flexible electronics. The densely packed hexagonal lattice of carbon atoms in graphene does not allow the transmission of small gas molecules. In addition, its outstanding mechanical flexibility and optical transmittance are expected to be useful to overcome the current mechanical limit of the inorganic materials. In this paper, we reported the measurement of the water vapor transmission rate (WVTR) through the 6-layer 10 × 10 cm(2) large-area graphene films synthesized by chemical vapor deposition (CVD). The WVTR was measured to be as low as 10(-4) g/m(2)·day initially, and stabilized at ∼0.48 g/m(2)·day, which corresponds to 7 times reduction in WVTR compared to bare polymer substrates. We also showed that the graphene-passivated organic field-effect transistors (OFETs) exhibited excellent environmental stability as well as a prolonged lifetime even after 500 bending cycles with strain of 2.3%. We expect that our results would be a good reference showing the graphene's potential as gas barriers for organic electronics.
authors.affiliation: †Department of Chemistry, College of Natural Sciences Seoul National University, Gwanakro-1, Seoul 151-747, Republic of Korea.
authors.forename: Kyoungjun
authors.initials: K
authors.lastname: Choi
authors.affiliation: ‡Polymer Research Institute, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.|§Smart I/O Control Device Research Section, Electronics and Telecommunications Research Institute, 218 Gajeong-ro, Yuseong-gu, Daejeon 305-700, South Korea.
authors.forename: Sooji
authors.initials: S
authors.lastname: Nam
authors.affiliation: ⊥SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Youngbin
authors.initials: Y
authors.lastname: Lee
authors.forename: Mijin
authors.initials: M
authors.lastname: Lee
authors.affiliation: ‡Polymer Research Institute, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.|#Department of Energy Engineering, Hanyang University, Seoul 133-791, Republic of Korea.
authors.forename: Jaeyoung
authors.initials: J
authors.lastname: Jang
authors.affiliation: †Department of Chemistry, College of Natural Sciences Seoul National University, Gwanakro-1, Seoul 151-747, Republic of Korea.
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: ‡Polymer Research Institute, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Jeong
authors.forename: Hyeongkeun
authors.initials: H
authors.lastname: Kim
authors.affiliation: ⊗Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Eunha-ri san 101, Bongdong-eup, Wanju-gun, Jeollabukdo (or Jeonbuk) 565-905, Republic of Korea.
authors.forename: Sukang
authors.initials: S
authors.lastname: Bae
authors.affiliation: ⊥SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Ji-Beom
authors.initials: JB
authors.lastname: Yoo
authors.affiliation: ⊥SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Sung M
authors.initials: SM
authors.lastname: Cho
authors.affiliation: ⊥SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Jae-Boong
authors.initials: JB
authors.lastname: Choi
authors.affiliation: ⊥SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Ho Kyoon
authors.initials: HK
authors.lastname: Chung
authors.affiliation: ▰School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: ‡Polymer Research Institute, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.
authors.forename: Chan Eon
authors.initials: CE
authors.lastname: Park
authors.affiliation: †Department of Chemistry, College of Natural Sciences Seoul National University, Gwanakro-1, Seoul 151-747, Republic of Korea.
authors.forename: Byung Hee
authors.initials: BH
authors.lastname: Hong
keywords: OFETs; bending cycles; graphene barrier; water vapor transmittance rate