title: Selective growth of graphene in layer-by-layer via chemical vapor deposition.
abstract: Selective and precise control of the layer number of graphene remains a critical issue for the practical applications of graphene. First, it is highly challenging to grow a continuous and uniform few-layer graphene since once the monolayer graphene fully covers a copper (Cu) surface, the growth of the second layer stops, resulting in mostly nonhomogeneous films. Second, from the selective adlayer growth point of view, there is no clear pathway for achieving this. We have developed the selective growth of a graphene adlayer in layer-by-layer via chemical vapor deposition (CVD) which makes it possible to stack graphene on a specific position. The key idea is to deposit a thin Cu layer (∼40 nm thick) on pre-grown monolayer graphene and to apply additional growth. The thin Cu atop the graphene/Cu substrate acts as a catalyst to decompose methane (CH4) gas during the additional growth. The adlayer is grown selectively on the pre-grown graphene, and the thin Cu is removed through evaporation during CVD, eventually forming large-area and uniform double layer graphene. With this technology, highly uniform graphene films with precise thicknesses of 1 to 5 layers and graphene check patterns with 1 to 3 layers were successfully demonstrated. This method provides precise LBL growth for a uniform graphene film and a technique for the design of new graphene devices.
authors.affiliation: Graphene Research Institute, Sejong University, Seoul 143-747, Korea. jwjung@sejong.ac.kr.
authors.forename: Jaehyun
authors.initials: J
authors.lastname: Park
authors.forename: Hyosub
authors.initials: H
authors.lastname: An
authors.forename: Dong-Chul
authors.initials: DC
authors.lastname: Choi
authors.forename: Sajjad
authors.initials: S
authors.lastname: Hussain
authors.forename: Wooseok
authors.initials: W
authors.lastname: Song
authors.forename: Ki-Seok
authors.initials: KS
authors.lastname: An
authors.forename: Won-Jun
authors.initials: WJ
authors.lastname: Lee
authors.forename: Naesung
authors.initials: N
authors.lastname: Lee
authors.forename: Wan-Gyu
authors.initials: WG
authors.lastname: Lee
authors.forename: Jongwan
authors.initials: J
authors.lastname: Jung