Ultrahigh Density Alignment of Carbon Nanotube Arrays by Dielectrophoresis

    Authors

    S. Shekhar; P. Stokes;S. I. Khondaker

    Comments

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    Abbreviated Journal Title

    ACS Nano

    Keywords

    carbon nanotube; directed assembly; solution processed; array; THIN-FILM TRANSISTORS; ALIGNED ARRAYS; LARGE-SCALE; ELECTRONICS; PERFORMANCE; DEVICES; Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience &; Nanotechnology; Materials Science, Multidisciplinary

    Abstract

    We report ultrahigh density assembly of aligned single-walled carbon nanotube (SWNT) two-dimensional arrays via AC dielectrophoresis using high-quality surfactant-free and stable SWNT solutions. After optimization of frequency and trapping time, we can reproducibly control the linear density of the SWNT between prefabricated electrodes from 0.5 SWNT/mu m to more than 30 SWNT/mu m by tuning the concentration of the nanotubes in the solution. Our Maximum density of 30 SWNT/mu m Is the highest for aligned arrays via any solution processing technique reported so far. Further increase of SWNT concentration results in a dense array with multiple layers. We discuss how the orientation and density of the nanotubes vary with concentrations and channel lengths. Electrical measurement data show that the densely packed aligned arrays have low sheet resistances. Selective removal of metallic SWNTs via controlled electrical breakdown produced field-effect transistors with high current on-off ratio. Ultrahigh density alignment reported here will have important implications in fabricating high quality devices for digital and analog electronics.

    Journal Title

    Acs Nano

    Volume

    5

    Issue/Number

    3

    Publication Date

    1-1-2011

    Document Type

    Article

    Language

    English

    First Page

    1739

    Last Page

    1746

    WOS Identifier

    WOS:000288570600023

    ISSN

    1936-0851

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