title: Variation in the c-axis conductivity of multi-layer graphene due to H2 exposure.
abstract: The variation of the c-axis conductivity of a multilayer graphene (MLG) as a function of H2 pressure from vacuum to 20 bar has been investigated. MLG was connected to the electrodes vertically using a wet transfer process. After exposure to H2 gas pressure up to 20 bar, the chemisorption of dissociated atomic hydrogen on MLG affects its electrical and structural properties. The formation of C-H bonds causes a decoupling of graphene layers, and then interferes with charge transfer through the out of plane. As a result, the c-axis conductivity decreases. Furthermore, the electron doping effect and the decoupling of the layers were confirmed using Raman spectroscopy. Hydrogenated carbons induce a defect structure of MLG which results in the expansion of layers. We observed a 43.54% increase in the thickness of the MLG after H2 exposure using atomic force microscopy.
authors.affiliation: Department of physics, Incheon National University, Incheon, 406-772, Republic of Korea. kbh37@inu.ac.kr.
authors.forename: Jaekyung
authors.initials: J
authors.lastname: Kim
authors.forename: Cheol Hwan
authors.initials: CH
authors.lastname: Kwak
authors.forename: Woochan
authors.initials: W
authors.lastname: Jung
authors.forename: Yun Suk
authors.initials: YS
authors.lastname: Huh
authors.forename: Byung Hoon
authors.initials: BH
authors.lastname: Kim