Mechanism of bright selective imaging of single-walled carbon nanotubes on insulators by scanning electron microscopy

Individual single-walled carbon nanotubes (SWNTs) produce highly bright images of the insulator surface around them when observed by scanning electron microscopy at low primary-electron voltage. We found that the insulator surface near SWNTs emits more secondary electrons due to electrons supplied through SWNTs connecting to the outside area of the primary-electron beam scanning. SWNTs are thus highlighted as bright lines corresponding to the electron-beam-induced current range around them. This technique provides a useful and effective way to investigate lateral growth morphology of SWNTs on the substrate. (C) 2004 American Institute of Physics.