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Estimating Schottky barrier heights using the current characteristics of sparse CNT networks

POSTER

Abstract

Carbon nanotube (CNT) thin film networks are a promising platform used for field effect transistor devices with bio-sensitivity. There is compelling evidence that this sensitivity occurs due to changes in the transport across metallic (m) and semiconducting (s) tube junctions in the network due to electrostatic gating. Transport across individual m-s junctions is asymmetric and nonlinear due to the Schottky barriers formed at the m-s CNT junctions. In large dense CNT network devices the nonlinear signature of individual m-s junctions is washed out in the overall current characteristics. However, we have observed the nonlinear signature of the m-s junctions in the current characteristics of sparse CNT network devices. To understand the interaction between the individual junctions and the overall network morphology we studied the current characteristics of sparse CNT network devices from room temperature down to 20 K. By varying the temperature of these devices we were able to probe the energetic dependence of the CNT Schottky barriers. We used two distinct models to extract the height of the Schottky barriers from the set of temperature data. While the models differ significantly, both models suggest a transition in the dominant transport mechanism at low temperatures.

Authors

  • Alejandro Jimenez

    California Polytechnic State University

  • Antara Bhattacharya

    SLAC National Accelerator Laboratory, Department of Physics, University of Nevada, Reno, 89557, USA, School of Mathematics and Physics, the University of Queensland, Brisbane, QLD 4072, Australia, University of California, Berkeley, National Institute for Materials Science, Lawrence Berkeley National Lab, Chemical Engineering, Stanford University, Santa Clara University, Lawrence Livermore National Laboratory, University of California San Diego, University of Nevada, Reno, Nihon University, Osaka U., LLNL, SLAC, U. of Nevada, Reno, California State University, Chico, Lawrence Livermore National Laboratory; UC, Irvine, Chemical Engineering and Materials Science, University of Minnesota Twin Cities, Physics, California Polytechnic State University, San Luis Obispo, Oak Ridge National Lab, Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407, USA, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand, California Polytechnic State University, University of California, Santa Barbara, Department of Physics, California Polytechnic State University, Victoria University of Wellington, Palo Alto High School, Palo Alto, CA, Navy Children School, Mumbai, Maharashtra, India

  • Antara Bhattacharya

    SLAC National Accelerator Laboratory, Department of Physics, University of Nevada, Reno, 89557, USA, School of Mathematics and Physics, the University of Queensland, Brisbane, QLD 4072, Australia, University of California, Berkeley, National Institute for Materials Science, Lawrence Berkeley National Lab, Chemical Engineering, Stanford University, Santa Clara University, Lawrence Livermore National Laboratory, University of California San Diego, University of Nevada, Reno, Nihon University, Osaka U., LLNL, SLAC, U. of Nevada, Reno, California State University, Chico, Lawrence Livermore National Laboratory; UC, Irvine, Chemical Engineering and Materials Science, University of Minnesota Twin Cities, Physics, California Polytechnic State University, San Luis Obispo, Oak Ridge National Lab, Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407, USA, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand, California Polytechnic State University, University of California, Santa Barbara, Department of Physics, California Polytechnic State University, Victoria University of Wellington, Palo Alto High School, Palo Alto, CA, Navy Children School, Mumbai, Maharashtra, India

  • Colleen A. Marlow

    California Polytechnic State University