Research Article

Nano Research

, Volume 1, Issue 4, pp 321-332

Open Access This content is freely available online to anyone, anywhere at any time.

Imaging electronic structure of carbon nanotubes by voltage-contrast scanning electron microscopy

  • Aravind VijayaraghavanAffiliated withInstitut für Nanotechnologie, Forschungszentrum Karlsruhe Email author 
  • , Sabine BlattAffiliated withInstitut für Nanotechnologie, Forschungszentrum KarlsruhePhysikalisches Institut, Universität Karlsruhe
  • , Christoph MarquardtAffiliated withInstitut für Nanotechnologie, Forschungszentrum KarlsruhePhysikalisches Institut, Universität Karlsruhe
  • , Simone DehmAffiliated withInstitut für Nanotechnologie, Forschungszentrum Karlsruhe
  • , Raghav WahiAffiliated withInstitut für Nanotechnologie, Forschungszentrum Karlsruhe
  • , Frank HennrichAffiliated withInstitut für Nanotechnologie, Forschungszentrum Karlsruhe
  • , Ralph KrupkeAffiliated withInstitut für Nanotechnologie, Forschungszentrum Karlsruhe Email author 

Abstract

We introduce voltage-contrast scanning electron microscopy (VC-SEM) for visual characterization of the electronic properties of single-walled carbon nanotubes. VC-SEM involves tuning the electronic band structure and imaging the potential profi le along the length of the nanotube. The resultant secondary electron contrast allows to distinguish between metallic and semiconducting carbon nanotubes and to follow the switching of semiconducting nanotube devices, as confi rmed by in situ electrical transport measurements. We demonstrate that high-density arrays of individual nanotube devices can be rapidly and simultaneously characterized. A leakage current model in combination with fi nite element simulations of the device electrostatics is presented in order to explain the observed contrast evolution of the nanotube and surface electrodes. This work serves to fill a void in electronic characterization of molecular device architectures.

http://static-content.springer.com/image/art%3A10.1007%2Fs12274-008-8034-3/MediaObjects/12274_2008_8034_Fig1_HTML.jpg

Keywords

Carbon nanotubes electronic properties voltage-contrast scanning electron microscopy electrostatics