title: Selective metal deposition at graphene line defects by atomic layer deposition.
abstract: One-dimensional defects in graphene have a strong influence on its physical properties, such as electrical charge transport and mechanical strength. With enhanced chemical reactivity, such defects may also allow us to selectively functionalize the material and systematically tune the properties of graphene. Here we demonstrate the selective deposition of metal at chemical vapour deposited graphene's line defects, notably grain boundaries, by atomic layer deposition. Atomic layer deposition allows us to deposit Pt predominantly on graphene's grain boundaries, folds and cracks due to the enhanced chemical reactivity of these line defects, which is directly confirmed by transmission electron microscopy imaging. The selective functionalization of graphene defect sites, together with the nanowire morphology of deposited Pt, yields a superior platform for sensing applications. Using Pt-graphene hybrid structures, we demonstrate high-performance hydrogen gas sensors at room temperature and show its advantages over other evaporative Pt deposition methods, in which Pt decorates the graphene surface non-selectively.
authors.affiliation: 1] Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA [2] Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea [3].
authors.forename: Kwanpyo
authors.initials: K
authors.lastname: Kim
authors.affiliation: 1] Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA [2] Department of Materials Science and Engineering, Incheon National University, Incheon 406-772, Korea [3].
authors.forename: Han-Bo-Ram
authors.initials: HB
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Johnson
authors.affiliation: 1] Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA [2] Department of Chemistry, University of Eastern Finland, Joensuu, Finland.
authors.forename: Jukka T
authors.initials: JT
authors.lastname: Tanskanen
authors.affiliation: Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Nan
authors.initials: N
authors.lastname: Liu
authors.affiliation: 1] Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA [2] Department of Chemistry, Chung-Ang University, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756, Korea.
authors.forename: Myung-Gil
authors.initials: MG
authors.lastname: Kim
authors.affiliation: 1] Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA [2] School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 440-746, Korea.
authors.forename: Changhyun
authors.initials: C
authors.lastname: Pang
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Chiyui
authors.initials: C
authors.lastname: Ahn
authors.affiliation: Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Stacey F
authors.initials: SF
authors.lastname: Bent
authors.affiliation: Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Zhenan
authors.initials: Z
authors.lastname: Bao