title: Penetration and lateral diffusion characteristics of polycrystalline graphene barriers.
abstract: We report penetration and lateral diffusion behavior of environmental molecules on synthesized polycrystalline graphene. Penetration occurs through graphene grain boundaries resulting in local oxidation. However, when the penetrated molecules diffuse laterally, the oxidation region will expand. Therefore, we measured the lateral diffusion rate along the graphene-copper interface for the first time by the environment-assisted crack growth test. It is clearly shown that the lateral diffusion is suppressed due to the high van der Waals interaction. Finally, we employed bilayer graphene for a perfect diffusion barrier facilitated by decreased defect density and increased lateral diffusion path.
authors.affiliation: Department of Mechanical Engineering, KAIST, Daejeon 305-701, Korea. tskim1@kaist.ac.kr.
authors.forename: Taeshik
authors.initials: T
authors.lastname: Yoon
authors.forename: Jeong Hun
authors.initials: JH
authors.lastname: Mun
authors.forename: Byung Jin
authors.initials: BJ
authors.lastname: Cho
authors.forename: Taek-Soo
authors.initials: TS
authors.lastname: Kim
mesh_terms: D003300:Copper / Q000737:chemistry; D003460:Crystallization; D004058:Diffusion; D006108:Graphite / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry
chemical_list: D008670:Metals; D010087:Oxides; D006108:Graphite; D003300:Copper