Surface potential studies using Kelvin force spectroscopy

A home-built Kelvin force microscope combined with a spectroscopic method is dedicated to local measurements of topography and contact potential differences (CPD). This technique is based on a simple modification of a noncontact atomic force microscopy (nc-AFM), where a bias voltage is applied between the sample and tip during the CPD measurement. The changes in CPD between the tip and various sample materials have been measured. Kelvin force spectra of Pd/Si and of self-assembling monolayer films (SAMs) are presented. © 1998 Springer-Verlag.