title: Templated Self-Assembly of Ultrathin Gold Nanowires by Nanoimprinting for Transparent Flexible Electronics.
abstract: We fabricated flexible, transparent, and conductive metal grids as transparent conductive materials (TCM) with adjustable properties by direct nanoimprinting of self-assembling colloidal metal nanowires. Ultrathin gold nanowires (diameter below 2 nm) with high mechanical flexibility were confined in a stamp and readily adapted to its features. During drying, the wires self-assembled into dense bundles that percolated throughout the stamp. The high aspect ratio and the bundling yielded continuous, hierarchical superstructures that connected the entire mesh even at low gold contents. A soft sintering step removed the ligand barriers but retained the imprinted structure. The material exhibited high conductivities (sheet resistances down to 29 Ω/sq) and transparencies that could be tuned by changing wire concentration and stamp geometry. We obtained TCMs that are suitable for applications such as touch screens. Mechanical bending tests showed a much higher bending resistance than commercial ITO: conductivity dropped by only 5.6% after 450 bending cycles at a bending radius of 5 mm.
authors.affiliation: INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
authors.forename: Johannes H M
authors.initials: JH
authors.lastname: Maurer
authors.affiliation: INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
authors.forename: Lola
authors.initials: L
authors.lastname: González-García
authors.affiliation: INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Reiser
authors.affiliation: INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kanelidis
authors.affiliation: INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kraus
keywords: Metal grids; flexible electronics; nanoimprint; transparent conductive electrodes; ultrathin gold nanowires