Photoemission electron microscopy of individual single-walled carbon nanotubes

Individual suspended single-walled carbon nanotubes were observed by means of C 1s and secondary electron photoemission electron microscopy. No band bending was observed in the images, suggesting that the depletion width near the catalytic Fe/nanotube or substrate Si/nanotube contact is comparable to the spatial resolution of 40 nm or less. Work function differences between the nanotubes were clearly observed in secondary electron images. The work functions of 93 SWNTs were found to range within 0.6 eV, but most distributed in a much narrower energy range of 0.2 eV.