Probing induced defects in individual carbon nanotubes using electrostatic force microscopy

Structural defects greatly affect the electronic properties of single wall carbon nanotubes (CNT’s), for instance by increasing the sensitivity to their environment; an effect which can be utilized for better performance of CNT based chemical sensors. Here we show that electrostatic force microscopy (EFM) can be used as a non-invasive technique for probing defects in individual CNT’s supported on insulating substrates. The technique is demonstrated by monitoring the change in EFM signal upon intentionally inducing defect by an oxygen plasma etch, and is applied to assess the quality of as-grown CNT samples and to study the effect of exposing CNT’s to the low energy electron irradiation of a scanning electron microscope (SEM). PACS 68.37.-d; 68.37.Ps; 61.46.Fg; 68.35.Dv