Defect Generation in Single-Walled Carbon Nanotubes Induced by Electronic Excitation

Abstract

Probing metallic single walled carbon nanotubes (SWNTs) with a tip of scanning tunneling microscope (STM) was found to induce defects in the tubes. Scanning tunneling spectroscopic measurements of local density of states revealed that the defects imaged by STM are characterized by a localized HOMO-LUMO gap of 0.8 eV, which well accounts for the reported metal-semiconductor conversion in SWNT-based field-effect transistor that is induced by low-energy electron irradiation These phenomena, presumably induced by electronic excitations, should be crucial in fabrication processes of SWNT-based electronic devices.