title: Self-assembled and intercalated film of reduced graphene oxide for a novel vacuum pressure sensor.
abstract: We report a new method for measuring vacuum pressures using Van der Waals (VDW) interactions between reduced graphene oxide (RGO) sheets. For this purpose, we utilized a reaction-based self-assembly process to fabricate various intercalated RGO (i-RGO) films, and monitored their electrical behavior with changing pressure and temperature. Pumping to remove gas from a vacuum chamber produced a decrease in the sheet resistance of i-RGO. With further pumping, distinctly different sheet resistance behaivors were observed depending on the measurement temperature. With increasing vacuum pressure, the resistance increased at 100 °C, whereas it decreased at 30 °C. Two types of VDW interactions are proposed to explain these features: a local VDW interaction between RGO sheets that resulted in V-shaped curves of sheet resistance with pressure changes and broad VDW interactions that occur between RGO sheets when the elastic force required to bend carbon clusters on an RGO sheet exceeds their vibrational energy at low temperatures. On the basis of the results, we propose that the resistance behavior of i-RGO as a function of vacuum pressure can be interpreted as the sum of the two different VDW interactions.
authors.affiliation: Department of Engineering in Energy and Applied Chemistry Silla University, Busan 617-736, Republic of Korea.
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Ahn
authors.affiliation: Department of Engineering in Energy and Applied Chemistry Silla University, Busan 617-736, Republic of Korea.
authors.forename: Jura
authors.initials: J
authors.lastname: Jung
authors.affiliation: Department of Engineering in Energy and Applied Chemistry Silla University, Busan 617-736, Republic of Korea.
authors.forename: Yongwoo
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Engineering in Energy and Applied Chemistry Silla University, Busan 617-736, Republic of Korea.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Electrical Engineering Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Kukjoo
authors.initials: K
authors.lastname: Kim
authors.affiliation: Advanced Materials Engineering Korea Polytechnic University, Jungwang dong Shihung 429-793, Republic of Korea.
authors.forename: Seong Eui
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Institute of NT.IT fusion technology, Ajou university, Worldcup ro 260, Youngtong gu Suwon 16499, Republic of Korea.
authors.forename: Sungyun
authors.initials: S
authors.lastname: Kim
authors.affiliation: National Institute for Nanomaterials Technology (NINT) San 31, Hyoja-Dong, Nam-Gu, Pohang 790-784, Republic of Korea.
authors.forename: Kyeong-Keun
authors.initials: KK
authors.lastname: Choi