title: Improved optical sintering efficiency at the contacts of silver nanowires encapsulated by a graphene layer.
abstract: Graphene/silver nanowire (AgNWs) stacked electrodes, i.e., graphene/AgNWs, are fabricated on a glass substrate by air-spray coating of AgNWs followed by subsequent encapsulation via a wet transfer of single-layer graphene (SLG) and multilayer graphene (MLG, reference specimen) sheets. Here, graphene is introduced to improve the optical sintering efficiency of a xenon flash lamp by controlling optical transparency and light absorbing yield in stacked graphene/AgNW electrodes, facilitating the fusion at contacts of AgNWs. Intense pulsed light (IPL) sintering induced ultrafast (<20 ms) welding of AgNW junctions encapsulated by graphene, resulting in approximately a four-fold reduction in the sheet resistance of IPL-treated graphene/AgNWs compared to that of IPL-treated AgNWs. The role of graphene in IPL-treated graphene/AgNWs is further investigated as a passivation layer against thermal oxidation and sulfurization. This work demonstrates that optical sintering is an efficient way to provide fast welding of Ag wire-to-wire junctions in stacked electrodes of graphene/AgNWs, leading to enhanced conductivity as well as superior long-term stability under oxygen and sulfur atmospheres.
authors.affiliation: Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Korea.
authors.forename: Seung-Bok
authors.initials: SB
authors.lastname: Yang
authors.forename: HongKyw
authors.initials: H
authors.lastname: Choi
authors.forename: Da Som
authors.initials: DS
authors.lastname: Lee
authors.forename: Choon-Gi
authors.initials: CG
authors.lastname: Choi
authors.forename: Sung-Yool
authors.initials: SY
authors.lastname: Choi
authors.forename: Il-Doo
authors.initials: ID
authors.lastname: Kim
keywords: contact resistance; graphene; intense pulsed light; junction welding; optical sintering; silver nanowires