title: Topological transitions in carbon nanotube networks via nanoscale confinement.
abstract: Efforts aimed at large-scale integration of nanoelectronic devices that exploit the superior electronic and mechanical properties of single-walled carbon nanotubes (SWCNTs) remain limited by the difficulties associated with manipulation and packaging of individual SWNTs. Alternative approaches based on ultrathin carbon nanotube networks (CNNs) have enjoyed success of late with the realization of several scalable device applications. However, precise control over the network electronic transport is challenging due to (i) an often uncontrollable interplay between network coverage and its detailed topology and (ii) the inherent electrical heterogeneity of the constituent SWNTs. In this article, we use template-assisted fluidic assembly of SWCNT networks to explore the effect of geometric confinement on the network topology. Heterogeneous SWCNT networks dip-coated onto submicrometer wide ultrathin polymer channels become increasingly aligned with decreasing channel width and thickness. Experimental-scale coarse-grained computations of interacting SWCNTs show that the effect is a reflection of a topology that is no longer dependent on the network density, which in turn emerges as a robust knob that can induce semiconductor-to-metallic transitions in the network response. Our study demonstrates the effectiveness of directed assembly on channels with varying degrees of confinement as a simple tool to tailor the conductance of the otherwise heterogeneous network, opening up the possibility of robust large-scale CNN-based devices.
authors.affiliation: NSF Nanoscale Science and Engineering Center for High-Rate Nanomanufacturing, Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115, USA.
authors.forename: Sivasubramanian
authors.initials: S
authors.lastname: Somu
authors.forename: Hailong
authors.initials: H
authors.lastname: Wang
authors.forename: Younglae
authors.initials: Y
authors.lastname: Kim
authors.forename: Laila
authors.initials: L
authors.lastname: Jaberansari
authors.forename: Myung Gwan
authors.initials: MG
authors.lastname: Hahm
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Taehoon
authors.initials: T
authors.lastname: Kim
authors.forename: Xugang
authors.initials: X
authors.lastname: Xiong
authors.forename: Yung Joon
authors.initials: YJ
authors.lastname: Jung
authors.forename: Moneesh
authors.initials: M
authors.lastname: Upmanyu
authors.forename: Ahmed
authors.initials: A
authors.lastname: Busnaina