Screening model for nanowire surface-charge sensors in liquid

Martin Hedegård Sørensen, Asger Mortensen, Mads Brandbyge

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    The conductance change of nanowire field-effect transistors is considered a highly sensitive probe for surface charge. However, Debye screening of relevant physiological liquid environments challenge device performance due to competing screening from the ionic liquid and nanowire charge carriers. The authors discuss this effect within Thomas-Fermi and Debye-Hückel theory and derive analytical results for cylindrical wires which can be used to estimate the sensitivity of nanowire surface-charge sensors. They study the interplay between the nanowire radius, the Thomas-Fermi and Debye screening lengths, and the length of the functionalization molecules. The analytical results are compared to finite-element calculations on a realistic geometry. ©2007 American Institute of Physics.
    Original languageEnglish
    JournalApplied Physics Letters
    Issue number10
    Pages (from-to)102105
    Publication statusPublished - 2007

    Bibliographical note

    Copyright (2007) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.




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