Surface potential investigation on single wall carbon nanotubes by Kelvin probe force microscopy and atomic force microscope potentiometry.

Surface potentials of single wall carbon nanotubes (SWNTs) connecting two metallic electrodes have been investigated by both Kelvin probe force microscopy (KFM) and atomic force microscope potentiometry (AFMP). By comparing the surface potential measurements obtained by both methods, we also studied the major factors affecting the potential measurements of the SWNTs, such as the surroundings, stray electric fields, and the effect of the AFM tip size, which can be larger than the SWNT diameter. In this study, we used KFM based on non-contact AFM and AFMP using the point-by-point contact mode in which the AFM tip worked as a voltage probe. [ABSTRACT FROM AUTHOR]