Atomic resolution scanning tunneling microscope study of single-wailed carbon nanotubes on GaAs(110)

摘要

We have studied single-walled carbon nanotubes (SWNTs) on the cleaved GaAs(110) surface using an ultrahigh vacuum (UHV) scanning tunneling microscope (STM). SWNTs were deposited via an in situ UHV dry contact transfer (DCT) procedure and subsequent STM images provide simultaneous resolution of the nanotube chirality and substrate lattice. Room temperature scanning tunneling spectroscopy measurements reveal semiconducting nanotube features within the substrate band gap indicative of a transport mechanism other than direct tip to substrate tunneling. Nanotube gaps scale appropriately and are found to be in reasonable agreement with theoretical, values. SWNTs were transfer-red to the GaAs surface with minimal additional contamination and no indication of damage to either nanotube or substrate, recommending the DCT technique as a general deposition procedure for a variety of systems incompatible with ambient processing. (C) 2004 American Vacuum Society.