SURFACE POTENTIAL MEASUREMENT BY ATOMIC FORCE MICROSCOPY USING A QUARTZ RESONATOR

Scanning Kelvin probe microscopy is demonstrated by using a noncontact atomic force microscope with a 1 MHz quartz length-extensional resonator as a force sensor. A tungsten probe tip glued onto the end of the quartz rod is electrically connected to the electrode of the resonator. To detect Coulomb force, frequency shift signal is used instead of oscillation amplitude of the resonator. A surface potential on a Au(111) single crystal with nanoscale carbon dots is measured. The potential difference is observed between the Au surface and the carbon dots.